Vendor Update Go Libs (#13166)

* update github.com/alecthomas/chroma v0.8.0 -> v0.8.1

* github.com/blevesearch/bleve v1.0.10 -> v1.0.12

* editorconfig-core-go v2.1.1 -> v2.3.7

* github.com/gliderlabs/ssh v0.2.2 -> v0.3.1

* migrate editorconfig.ParseBytes to Parse

* github.com/shurcooL/vfsgen to 0d455de96546

* github.com/go-git/go-git/v5 v5.1.0 -> v5.2.0

* github.com/google/uuid v1.1.1 -> v1.1.2

* github.com/huandu/xstrings v1.3.0 -> v1.3.2

* github.com/klauspost/compress v1.10.11 -> v1.11.1

* github.com/markbates/goth v1.61.2 -> v1.65.0

* github.com/mattn/go-sqlite3 v1.14.0 -> v1.14.4

* github.com/mholt/archiver v3.3.0 -> v3.3.2

* github.com/microcosm-cc/bluemonday 4f7140c49acb -> v1.0.4

* github.com/minio/minio-go v7.0.4 -> v7.0.5

* github.com/olivere/elastic v7.0.9 -> v7.0.20

* github.com/urfave/cli v1.20.0 -> v1.22.4

* github.com/prometheus/client_golang v1.1.0 -> v1.8.0

* github.com/xanzy/go-gitlab v0.37.0 -> v0.38.1

* mvdan.cc/xurls v2.1.0 -> v2.2.0

Co-authored-by: Lauris BH <lauris@nix.lv>

go.mod

@@ -18,27 +18,30 @@ require (
 	gitea.com/macaron/session v0.0.0-20200902202411-e3a87877db6e
 	gitea.com/macaron/toolbox v0.0.0-20190822013122-05ff0fc766b7
 	github.com/PuerkitoBio/goquery v1.5.1
-	github.com/alecthomas/chroma v0.8.0
+	github.com/RoaringBitmap/roaring v0.5.1 // indirect
-	github.com/blevesearch/bleve v1.0.10
+	github.com/alecthomas/chroma v0.8.1
+	github.com/andybalholm/brotli v1.0.1 // indirect
+	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
+	github.com/blevesearch/bleve v1.0.12
 	github.com/couchbase/gomemcached v0.0.0-20191004160342-7b5da2ec40b2 // indirect
 	github.com/cznic/b v0.0.0-20181122101859-a26611c4d92d // indirect
 	github.com/cznic/mathutil v0.0.0-20181122101859-297441e03548 // indirect
 	github.com/cznic/strutil v0.0.0-20181122101858-275e90344537 // indirect
 	github.com/denisenkom/go-mssqldb v0.0.0-20200428022330-06a60b6afbbc
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible
-	github.com/dlclark/regexp2 v1.2.1 // indirect
+	github.com/dlclark/regexp2 v1.4.0 // indirect
 	github.com/dustin/go-humanize v1.0.0
-	github.com/editorconfig/editorconfig-core-go/v2 v2.1.1
+	github.com/editorconfig/editorconfig-core-go/v2 v2.3.7
 	github.com/emirpasic/gods v1.12.0
 	github.com/ethantkoenig/rupture v0.0.0-20180203182544-0a76f03a811a
 	github.com/facebookgo/ensure v0.0.0-20160127193407-b4ab57deab51 // indirect
 	github.com/facebookgo/stack v0.0.0-20160209184415-751773369052 // indirect
 	github.com/facebookgo/subset v0.0.0-20150612182917-8dac2c3c4870 // indirect
-	github.com/gliderlabs/ssh v0.2.2
+	github.com/gliderlabs/ssh v0.3.1
 	github.com/glycerine/go-unsnap-stream v0.0.0-20190901134440-81cf024a9e0a // indirect
 	github.com/go-enry/go-enry/v2 v2.5.2
 	github.com/go-git/go-billy/v5 v5.0.0
-	github.com/go-git/go-git/v5 v5.1.0
+	github.com/go-git/go-git/v5 v5.2.0
 	github.com/go-ldap/ldap/v3 v3.2.4
 	github.com/go-redis/redis/v7 v7.4.0
 	github.com/go-sql-driver/mysql v1.5.0
@@ -47,76 +50,80 @@ require (
 	github.com/gobwas/glob v0.2.3
 	github.com/gogs/chardet v0.0.0-20191104214054-4b6791f73a28
 	github.com/gogs/cron v0.0.0-20171120032916-9f6c956d3e14
+	github.com/golang/snappy v0.0.2 // indirect
 	github.com/google/go-github/v32 v32.1.0
-	github.com/google/uuid v1.1.1
+	github.com/google/uuid v1.1.2
 	github.com/gorilla/context v1.1.1
 	github.com/hashicorp/go-retryablehttp v0.6.7 // indirect
 	github.com/hashicorp/go-version v1.2.1
-	github.com/huandu/xstrings v1.3.0
+	github.com/huandu/xstrings v1.3.2
+	github.com/imdario/mergo v0.3.11 // indirect
 	github.com/issue9/assert v1.3.2 // indirect
 	github.com/issue9/identicon v1.0.1
 	github.com/jaytaylor/html2text v0.0.0-20160923191438-8fb95d837f7d
 	github.com/jmhodges/levigo v1.0.0 // indirect
 	github.com/kballard/go-shellquote v0.0.0-20170619183022-cd60e84ee657
 	github.com/keybase/go-crypto v0.0.0-20200123153347-de78d2cb44f4
-	github.com/klauspost/compress v1.10.11
+	github.com/klauspost/compress v1.11.1
+	github.com/klauspost/pgzip v1.2.5 // indirect
 	github.com/lafriks/xormstore v1.3.2
 	github.com/lib/pq v1.8.1-0.20200908161135-083382b7e6fc
 	github.com/lunny/dingtalk_webhook v0.0.0-20171025031554-e3534c89ef96
-	github.com/markbates/goth v1.61.2
+	github.com/markbates/goth v1.65.0
-	github.com/mattn/go-colorable v0.1.7 // indirect
 	github.com/mattn/go-isatty v0.0.12
 	github.com/mattn/go-runewidth v0.0.9 // indirect
-	github.com/mattn/go-sqlite3 v1.14.0
+	github.com/mattn/go-sqlite3 v1.14.4
 	github.com/mgechev/dots v0.0.0-20190921121421-c36f7dcfbb81
 	github.com/mgechev/revive v1.0.3-0.20200921231451-246eac737dc7
-	github.com/mholt/archiver/v3 v3.3.0
+	github.com/mholt/archiver/v3 v3.3.2
-	github.com/microcosm-cc/bluemonday v1.0.3-0.20191119130333-0a75d7616912
+	github.com/microcosm-cc/bluemonday v1.0.4
-	github.com/minio/minio-go/v7 v7.0.4
+	github.com/minio/minio-go/v7 v7.0.5
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/msteinert/pam v0.0.0-20151204160544-02ccfbfaf0cc
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
 	github.com/niklasfasching/go-org v1.3.2
 	github.com/oliamb/cutter v0.2.2
-	github.com/olivere/elastic/v7 v7.0.9
+	github.com/olivere/elastic/v7 v7.0.20
 	github.com/pelletier/go-toml v1.8.1
 	github.com/pkg/errors v0.9.1
 	github.com/pquerna/otp v1.2.0
-	github.com/prometheus/client_golang v1.1.0
+	github.com/prometheus/client_golang v1.8.0
-	github.com/prometheus/procfs v0.0.4 // indirect
 	github.com/quasoft/websspi v1.0.0
 	github.com/remyoudompheng/bigfft v0.0.0-20190321074620-2f0d2b0e0001 // indirect
 	github.com/sergi/go-diff v1.1.0
-	github.com/shurcooL/httpfs v0.0.0-20190527155220-6a4d4a70508b // indirect
+	github.com/shurcooL/httpfs v0.0.0-20190707220628-8d4bc4ba7749 // indirect
-	github.com/shurcooL/vfsgen v0.0.0-20181202132449-6a9ea43bcacd
+	github.com/shurcooL/vfsgen v0.0.0-20200824052919-0d455de96546
 	github.com/stretchr/testify v1.6.1
 	github.com/syndtr/goleveldb v1.0.0
 	github.com/tecbot/gorocksdb v0.0.0-20181010114359-8752a9433481 // indirect
 	github.com/tinylib/msgp v1.1.2 // indirect
 	github.com/tstranex/u2f v1.0.0
+	github.com/ulikunitz/xz v0.5.8 // indirect
 	github.com/unknwon/com v1.0.1
 	github.com/unknwon/i18n v0.0.0-20200823051745-09abd91c7f2c
 	github.com/unknwon/paginater v0.0.0-20151104151617-7748a72e0141
-	github.com/urfave/cli v1.20.0
+	github.com/urfave/cli v1.22.4
-	github.com/xanzy/go-gitlab v0.37.0
+	github.com/willf/bitset v1.1.11 // indirect
+	github.com/xanzy/go-gitlab v0.38.1
 	github.com/yohcop/openid-go v1.0.0
 	github.com/yuin/goldmark v1.2.1
 	github.com/yuin/goldmark-highlighting v0.0.0-20200307114337-60d527fdb691
 	github.com/yuin/goldmark-meta v0.0.0-20191126180153-f0638e958b60
 	go.jolheiser.com/hcaptcha v0.0.4
 	go.jolheiser.com/pwn v0.0.3
-	golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a
+	golang.org/x/crypto v0.0.0-20201012173705-84dcc777aaee
-	golang.org/x/net v0.0.0-20200904194848-62affa334b73
+	golang.org/x/net v0.0.0-20201010224723-4f7140c49acb
-	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
+	golang.org/x/oauth2 v0.0.0-20200902213428-5d25da1a8d43
-	golang.org/x/sys v0.0.0-20200918174421-af09f7315aff
+	golang.org/x/sys v0.0.0-20201015000850-e3ed0017c211
 	golang.org/x/text v0.3.3
 	golang.org/x/time v0.0.0-20200630173020-3af7569d3a1e // indirect
-	golang.org/x/tools v0.0.0-20200921210052-fa0125251cc4
+	golang.org/x/tools v0.0.0-20200929161345-d7fc70abf50f
+	google.golang.org/appengine v1.6.7 // indirect
 	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
 	gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df
-	gopkg.in/ini.v1 v1.61.0
+	gopkg.in/ini.v1 v1.62.0
 	gopkg.in/yaml.v2 v2.3.0
-	mvdan.cc/xurls/v2 v2.1.0
+	mvdan.cc/xurls/v2 v2.2.0
 	strk.kbt.io/projects/go/libravatar v0.0.0-20191008002943-06d1c002b251
 	xorm.io/builder v0.3.7
 	xorm.io/xorm v1.0.5

modules/context/repo.go

@@ -222,11 +222,7 @@ func (r *Repository) GetEditorconfig() (*editorconfig.Editorconfig, error) {
 		return nil, err
 	}
 	defer reader.Close()
-	data, err := ioutil.ReadAll(reader)
+	return editorconfig.Parse(reader)
-	if err != nil {
-		return nil, err
-	}
-	return editorconfig.ParseBytes(data)
 }
 
 // RetrieveBaseRepo retrieves base repository

vendor/cloud.google.com/go/compute/metadata/.repo-metadata.json

@@ -1,12 +0,0 @@
-{
-  "name": "metadata",
-  "name_pretty": "Google Compute Engine Metadata API",
-  "product_documentation": "https://cloud.google.com/compute/docs/storing-retrieving-metadata",
-  "client_documentation": "https://godoc.org/cloud.google.com/go/compute/metadata",
-  "release_level": "ga",
-  "language": "go",
-  "repo": "googleapis/google-cloud-go",
-  "distribution_name": "cloud.google.com/go/compute/metadata",
-  "api_id": "compute:metadata",
-  "requires_billing": false
-}

vendor/cloud.google.com/go/compute/metadata/metadata.go

@@ -61,25 +61,14 @@ var (
 	instID  = &cachedValue{k: "instance/id", trim: true}
 )
 
-var (
+var defaultClient = &Client{hc: &http.Client{
-	defaultClient = &Client{hc: &http.Client{
+	Transport: &http.Transport{
-		Transport: &http.Transport{
+		Dial: (&net.Dialer{
-			Dial: (&net.Dialer{
+			Timeout:   2 * time.Second,
-				Timeout:   2 * time.Second,
+			KeepAlive: 30 * time.Second,
-				KeepAlive: 30 * time.Second,
+		}).Dial,
-			}).Dial,
+	},
-			ResponseHeaderTimeout: 2 * time.Second,
+}}
-		},
-	}}
-	subscribeClient = &Client{hc: &http.Client{
-		Transport: &http.Transport{
-			Dial: (&net.Dialer{
-				Timeout:   2 * time.Second,
-				KeepAlive: 30 * time.Second,
-			}).Dial,
-		},
-	}}
-)
 
 // NotDefinedError is returned when requested metadata is not defined.
 //
@@ -151,7 +140,7 @@ func testOnGCE() bool {
 	}()
 
 	go func() {
-		addrs, err := net.LookupHost("metadata.google.internal")
+		addrs, err := net.DefaultResolver.LookupHost(ctx, "metadata.google.internal")
 		if err != nil || len(addrs) == 0 {
 			resc <- false
 			return
@@ -206,10 +195,9 @@ func systemInfoSuggestsGCE() bool {
 	return name == "Google" || name == "Google Compute Engine"
 }
 
-// Subscribe calls Client.Subscribe on a client designed for subscribing (one with no
+// Subscribe calls Client.Subscribe on the default client.
-// ResponseHeaderTimeout).
 func Subscribe(suffix string, fn func(v string, ok bool) error) error {
-	return subscribeClient.Subscribe(suffix, fn)
+	return defaultClient.Subscribe(suffix, fn)
 }
 
 // Get calls Client.Get on the default client.
@@ -280,9 +268,14 @@ type Client struct {
 	hc *http.Client
 }
 
-// NewClient returns a Client that can be used to fetch metadata. All HTTP requests
+// NewClient returns a Client that can be used to fetch metadata.
-// will use the given http.Client instead of the default client.
+// Returns the client that uses the specified http.Client for HTTP requests.
+// If nil is specified, returns the default client.
 func NewClient(c *http.Client) *Client {
+	if c == nil {
+		return defaultClient
+	}
+
 	return &Client{hc: c}
 }
 
@@ -303,8 +296,12 @@ func (c *Client) getETag(suffix string) (value, etag string, err error) {
 		// being stable anyway.
 		host = metadataIP
 	}
+	suffix = strings.TrimLeft(suffix, "/")
 	u := "http://" + host + "/computeMetadata/v1/" + suffix
-	req, _ := http.NewRequest("GET", u, nil)
+	req, err := http.NewRequest("GET", u, nil)
+	if err != nil {
+		return "", "", err
+	}
 	req.Header.Set("Metadata-Flavor", "Google")
 	req.Header.Set("User-Agent", userAgent)
 	res, err := c.hc.Do(req)
@@ -407,11 +404,7 @@ func (c *Client) InstanceTags() ([]string, error) {
 
 // InstanceName returns the current VM's instance ID string.
 func (c *Client) InstanceName() (string, error) {
-	host, err := c.Hostname()
+	return c.getTrimmed("instance/name")
-	if err != nil {
-		return "", err
-	}
-	return strings.Split(host, ".")[0], nil
 }
 
 // Zone returns the current VM's zone, such as "us-central1-b".

vendor/github.com/RoaringBitmap/roaring/.travis.yml

@@ -8,13 +8,9 @@ install:
 notifications:
   email: false
 go:
-- "1.7.x"
-- "1.8.x"
-- "1.9.x"
-- "1.10.x"
-- "1.11.x"
 - "1.12.x"
 - "1.13.x"
+- "1.14.x"
 - tip
 
 # whitelist

vendor/github.com/RoaringBitmap/roaring/README.md

@@ -1,5 +1,9 @@
-roaring [![Build Status](https://travis-ci.org/RoaringBitmap/roaring.png)](https://travis-ci.org/RoaringBitmap/roaring) [![Coverage Status](https://coveralls.io/repos/github/RoaringBitmap/roaring/badge.svg?branch=master)](https://coveralls.io/github/RoaringBitmap/roaring?branch=master) [![GoDoc](https://godoc.org/github.com/RoaringBitmap/roaring?status.svg)](https://godoc.org/github.com/RoaringBitmap/roaring) [![Go Report Card](https://goreportcard.com/badge/RoaringBitmap/roaring)](https://goreportcard.com/report/github.com/RoaringBitmap/roaring)
+roaring [![Build Status](https://travis-ci.org/RoaringBitmap/roaring.png)](https://travis-ci.org/RoaringBitmap/roaring) [![GoDoc](https://godoc.org/github.com/RoaringBitmap/roaring?status.svg)](https://godoc.org/github.com/RoaringBitmap/roaring) [![GoDoc](https://godoc.org/github.com/RoaringBitmap/roaring/roaring64?status.svg)](https://godoc.org/github.com/RoaringBitmap/roaring/roaring64) [![Go Report Card](https://goreportcard.com/badge/RoaringBitmap/roaring)](https://goreportcard.com/report/github.com/RoaringBitmap/roaring)
 [![Build Status](https://cloud.drone.io/api/badges/RoaringBitmap/roaring/status.svg)](https://cloud.drone.io/RoaringBitmap/roaring)
+![Go-CI](https://github.com/RoaringBitmap/roaring/workflows/Go-CI/badge.svg)
+![Go-ARM-CI](https://github.com/RoaringBitmap/roaring/workflows/Go-ARM-CI/badge.svg)
+![Go-Windows-CI](https://github.com/RoaringBitmap/roaring/workflows/Go-Windows-CI/badge.svg)
+![Go-macos-CI](https://github.com/RoaringBitmap/roaring/workflows/Go-macos-CI/badge.svg)
 =============
 
 This is a go version of the Roaring bitmap data structure. 
@@ -7,7 +11,7 @@ This is a go version of the Roaring bitmap data structure.
 
 
 Roaring bitmaps are used by several major systems such as [Apache Lucene][lucene] and derivative systems such as [Solr][solr] and
-[Elasticsearch][elasticsearch], [Apache Druid (Incubating)][druid], [LinkedIn Pinot][pinot], [Netflix Atlas][atlas],  [Apache Spark][spark], [OpenSearchServer][opensearchserver], [Cloud Torrent][cloudtorrent], [Whoosh][whoosh],  [Pilosa][pilosa],  [Microsoft Visual Studio Team Services (VSTS)][vsts], and eBay's [Apache Kylin][kylin].
+[Elasticsearch][elasticsearch], [Apache Druid (Incubating)][druid], [LinkedIn Pinot][pinot], [Netflix Atlas][atlas],  [Apache Spark][spark], [OpenSearchServer][opensearchserver], [Cloud Torrent][cloudtorrent], [Whoosh][whoosh],  [Pilosa][pilosa],  [Microsoft Visual Studio Team Services (VSTS)][vsts], and eBay's [Apache Kylin][kylin]. The YouTube SQL Engine, [Google Procella](https://research.google/pubs/pub48388/), uses Roaring bitmaps for indexing.
 
 [lucene]: https://lucene.apache.org/
 [solr]: https://lucene.apache.org/solr/
@@ -172,10 +176,70 @@ That is, given a fixed overhead for the universe size (x), Roaring
 bitmaps never use more than 2 bytes per integer. You can call
 ``BoundSerializedSizeInBytes`` for a more precise estimate.
 
+### 64-bit Roaring
+
+By default, roaring is used to stored unsigned 32-bit integers. However, we also offer
+an extension dedicated to 64-bit integers. It supports roughly the same functions:
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/RoaringBitmap/roaring/roaring64"
+    "bytes"
+)
+
+
+func main() {
+    // example inspired by https://github.com/fzandona/goroar
+    fmt.Println("==roaring64==")
+    rb1 := roaring64.BitmapOf(1, 2, 3, 4, 5, 100, 1000)
+    fmt.Println(rb1.String())
+
+    rb2 := roaring64.BitmapOf(3, 4, 1000)
+    fmt.Println(rb2.String())
+
+    rb3 := roaring64.New()
+    fmt.Println(rb3.String())
+
+    fmt.Println("Cardinality: ", rb1.GetCardinality())
+
+    fmt.Println("Contains 3? ", rb1.Contains(3))
+
+    rb1.And(rb2)
+
+    rb3.Add(1)
+    rb3.Add(5)
+
+    rb3.Or(rb1)
+
+
+
+    // prints 1, 3, 4, 5, 1000
+    i := rb3.Iterator()
+    for i.HasNext() {
+        fmt.Println(i.Next())
+    }
+    fmt.Println()
+
+    // next we include an example of serialization
+    buf := new(bytes.Buffer)
+    rb1.WriteTo(buf) // we omit error handling
+    newrb:= roaring64.New()
+    newrb.ReadFrom(buf)
+    if rb1.Equals(newrb) {
+    	fmt.Println("I wrote the content to a byte stream and read it back.")
+    }
+    // you can iterate over bitmaps using ReverseIterator(), Iterator, ManyIterator()
+}
+```
+
+Only the 32-bit roaring format is standard and cross-operable between Java, C++, C and Go. There is no guarantee that the 64-bit versions are compatible.
 
 ### Documentation
 
-Current documentation is available at http://godoc.org/github.com/RoaringBitmap/roaring
+Current documentation is available at http://godoc.org/github.com/RoaringBitmap/roaring and http://godoc.org/github.com/RoaringBitmap/roaring64
 
 ### Goroutine safety
 

vendor/github.com/RoaringBitmap/roaring/arraycontainer.go

@@ -876,6 +876,41 @@ func (ac *arrayContainer) loadData(bitmapContainer *bitmapContainer) {
 	ac.content = make([]uint16, bitmapContainer.cardinality, bitmapContainer.cardinality)
 	bitmapContainer.fillArray(ac.content)
 }
+
+func (ac *arrayContainer) resetTo(a container) {
+	switch x := a.(type) {
+	case *arrayContainer:
+		ac.realloc(len(x.content))
+		copy(ac.content, x.content)
+
+	case *bitmapContainer:
+		ac.realloc(x.cardinality)
+		x.fillArray(ac.content)
+
+	case *runContainer16:
+		card := int(x.cardinality())
+		ac.realloc(card)
+		cur := 0
+		for _, r := range x.iv {
+			for val := r.start; val <= r.last(); val++ {
+				ac.content[cur] = val
+				cur++
+			}
+		}
+
+	default:
+		panic("unsupported container type")
+	}
+}
+
+func (ac *arrayContainer) realloc(size int) {
+	if cap(ac.content) < size {
+		ac.content = make([]uint16, size)
+	} else {
+		ac.content = ac.content[:size]
+	}
+}
+
 func newArrayContainer() *arrayContainer {
 	p := new(arrayContainer)
 	return p

vendor/github.com/RoaringBitmap/roaring/bitmapcontainer.go

@@ -203,6 +203,33 @@ func (bcmi *bitmapContainerManyIterator) nextMany(hs uint32, buf []uint32) int {
 	return n
 }
 
+func (bcmi *bitmapContainerManyIterator) nextMany64(hs uint64, buf []uint64) int {
+	n := 0
+	base := bcmi.base
+	bitset := bcmi.bitset
+
+	for n < len(buf) {
+		if bitset == 0 {
+			base++
+			if base >= len(bcmi.ptr.bitmap) {
+				bcmi.base = base
+				bcmi.bitset = bitset
+				return n
+			}
+			bitset = bcmi.ptr.bitmap[base]
+			continue
+		}
+		t := bitset & -bitset
+		buf[n] = uint64(((base * 64) + int(popcount(t-1)))) | hs
+		n = n + 1
+		bitset ^= t
+	}
+
+	bcmi.base = base
+	bcmi.bitset = bitset
+	return n
+}
+
 func newBitmapContainerManyIterator(a *bitmapContainer) *bitmapContainerManyIterator {
 	return &bitmapContainerManyIterator{a, -1, 0}
 }
@@ -934,6 +961,32 @@ func (bc *bitmapContainer) loadData(arrayContainer *arrayContainer) {
 	}
 }
 
+func (bc *bitmapContainer) resetTo(a container) {
+	switch x := a.(type) {
+	case *arrayContainer:
+		fill(bc.bitmap, 0)
+		bc.loadData(x)
+
+	case *bitmapContainer:
+		bc.cardinality = x.cardinality
+		copy(bc.bitmap, x.bitmap)
+
+	case *runContainer16:
+		bc.cardinality = len(x.iv)
+		lastEnd := 0
+		for _, r := range x.iv {
+			bc.cardinality += int(r.length)
+			resetBitmapRange(bc.bitmap, lastEnd, int(r.start))
+			lastEnd = int(r.start+r.length) + 1
+			setBitmapRange(bc.bitmap, int(r.start), lastEnd)
+		}
+		resetBitmapRange(bc.bitmap, lastEnd, maxCapacity)
+
+	default:
+		panic("unsupported container type")
+	}
+}
+
 func (bc *bitmapContainer) toArrayContainer() *arrayContainer {
 	ac := &arrayContainer{}
 	ac.loadData(bc)

vendor/github.com/RoaringBitmap/roaring/fastaggregation.go

@@ -213,3 +213,120 @@ func HeapXor(bitmaps ...*Bitmap) *Bitmap {
 	}
 	return heap.Pop(&pq).(*item).value
 }
+
+// AndAny provides a result equivalent to x1.And(FastOr(bitmaps)).
+// It's optimized to minimize allocations. It also might be faster than separate calls.
+func (x1 *Bitmap) AndAny(bitmaps ...*Bitmap) {
+	if len(bitmaps) == 0 {
+		return
+	} else if len(bitmaps) == 1 {
+		x1.And(bitmaps[0])
+		return
+	}
+
+	type withPos struct {
+		bitmap *roaringArray
+		pos    int
+		key    uint16
+	}
+	filters := make([]withPos, 0, len(bitmaps))
+
+	for _, b := range bitmaps {
+		if b.highlowcontainer.size() > 0 {
+			filters = append(filters, withPos{
+				bitmap: &b.highlowcontainer,
+				pos:    0,
+				key:    b.highlowcontainer.getKeyAtIndex(0),
+			})
+		}
+	}
+
+	basePos := 0
+	intersections := 0
+	keyContainers := make([]container, 0, len(filters))
+	var (
+		tmpArray   *arrayContainer
+		tmpBitmap  *bitmapContainer
+		minNextKey uint16
+	)
+
+	for basePos < x1.highlowcontainer.size() && len(filters) > 0 {
+		baseKey := x1.highlowcontainer.getKeyAtIndex(basePos)
+
+		// accumulate containers for current key, find next minimal key in filters
+		// and exclude filters that do not have related values anymore
+		i := 0
+		maxPossibleOr := 0
+		minNextKey = MaxUint16
+		for _, f := range filters {
+			if f.key < baseKey {
+				f.pos = f.bitmap.advanceUntil(baseKey, f.pos)
+				if f.pos == f.bitmap.size() {
+					continue
+				}
+				f.key = f.bitmap.getKeyAtIndex(f.pos)
+			}
+
+			if f.key == baseKey {
+				cont := f.bitmap.getContainerAtIndex(f.pos)
+				keyContainers = append(keyContainers, cont)
+				maxPossibleOr += cont.getCardinality()
+
+				f.pos++
+				if f.pos == f.bitmap.size() {
+					continue
+				}
+				f.key = f.bitmap.getKeyAtIndex(f.pos)
+			}
+
+			minNextKey = minOfUint16(minNextKey, f.key)
+			filters[i] = f
+			i++
+		}
+		filters = filters[:i]
+
+		if len(keyContainers) == 0 {
+			basePos = x1.highlowcontainer.advanceUntil(minNextKey, basePos)
+			continue
+		}
+
+		var ored container
+
+		if len(keyContainers) == 1 {
+			ored = keyContainers[0]
+		} else {
+			//TODO: special case for run containers?
+			if maxPossibleOr > arrayDefaultMaxSize {
+				if tmpBitmap == nil {
+					tmpBitmap = newBitmapContainer()
+				}
+				tmpBitmap.resetTo(keyContainers[0])
+				for _, c := range keyContainers[1:] {
+					tmpBitmap.ior(c)
+				}
+				ored = tmpBitmap
+			} else {
+				if tmpArray == nil {
+					tmpArray = newArrayContainerCapacity(maxPossibleOr)
+				}
+				tmpArray.realloc(maxPossibleOr)
+				tmpArray.resetTo(keyContainers[0])
+				for _, c := range keyContainers[1:] {
+					tmpArray.ior(c)
+				}
+				ored = tmpArray
+			}
+		}
+
+		result := x1.highlowcontainer.getWritableContainerAtIndex(basePos).iand(ored)
+		if result.getCardinality() > 0 {
+			x1.highlowcontainer.replaceKeyAndContainerAtIndex(intersections, baseKey, result, false)
+			intersections++
+		}
+
+		keyContainers = keyContainers[:0]
+		basePos = x1.highlowcontainer.advanceUntil(minNextKey, basePos)
+	}
+
+	x1.highlowcontainer.resize(intersections)
+}

vendor/github.com/RoaringBitmap/roaring/manyiterator.go

@@ -2,6 +2,7 @@ package roaring
 
 type manyIterable interface {
 	nextMany(hs uint32, buf []uint32) int
+	nextMany64(hs uint64, buf []uint64) int
 }
 
 func (si *shortIterator) nextMany(hs uint32, buf []uint32) int {
@@ -16,3 +17,16 @@ func (si *shortIterator) nextMany(hs uint32, buf []uint32) int {
 	si.loc = l
 	return n
 }
+
+func (si *shortIterator) nextMany64(hs uint64, buf []uint64) int {
+	n := 0
+	l := si.loc
+	s := si.slice
+	for n < len(buf) && l < len(s) {
+		buf[n] = uint64(s[l]) | hs
+		l++
+		n++
+	}
+	si.loc = l
+	return n
+}

vendor/github.com/RoaringBitmap/roaring/roaring.go

@@ -346,7 +346,9 @@ func newIntReverseIterator(a *Bitmap) *intReverseIterator {
 // ManyIntIterable allows you to iterate over the values in a Bitmap
 type ManyIntIterable interface {
 	// pass in a buffer to fill up with values, returns how many values were returned
-	NextMany([]uint32) int
+	NextMany(buf []uint32) int
+	// pass in a buffer to fill up with 64 bit values, returns how many values were returned
+	NextMany64(hs uint64, buf []uint64) int
 }
 
 type manyIntIterator struct {
@@ -382,6 +384,25 @@ func (ii *manyIntIterator) NextMany(buf []uint32) int {
 	return n
 }
 
+func (ii *manyIntIterator) NextMany64(hs64 uint64, buf []uint64) int {
+	n := 0
+	for n < len(buf) {
+		if ii.iter == nil {
+			break
+		}
+
+		hs := uint64(ii.hs) | hs64
+		moreN := ii.iter.nextMany64(hs, buf[n:])
+		n += moreN
+		if moreN == 0 {
+			ii.pos = ii.pos + 1
+			ii.init()
+		}
+	}
+
+	return n
+}
+
 func newManyIntIterator(a *Bitmap) *manyIntIterator {
 	p := new(manyIntIterator)
 	p.pos = 0
@@ -678,7 +699,10 @@ func (rb *Bitmap) GetCardinality() uint64 {
 	return size
 }
 
-// Rank returns the number of integers that are smaller or equal to x (Rank(infinity) would be GetCardinality())
+// Rank returns the number of integers that are smaller or equal to x (Rank(infinity) would be GetCardinality()).
+// If you pass the smallest value, you get the value 1. If you pass a value that is smaller than the smallest
+// value, you get 0. Note that this function differs in convention from the Select function since it
+// return 1 and not 0 on the smallest value.
 func (rb *Bitmap) Rank(x uint32) uint64 {
 	size := uint64(0)
 	for i := 0; i < rb.highlowcontainer.size(); i++ {
@@ -695,7 +719,9 @@ func (rb *Bitmap) Rank(x uint32) uint64 {
 	return size
 }
 
-// Select returns the xth integer in the bitmap
+// Select returns the xth integer in the bitmap. If you pass 0, you get
+// the smallest element. Note that this function differs in convention from
+// the Rank function which returns 1 on the smallest value.
 func (rb *Bitmap) Select(x uint32) (uint32, error) {
 	if rb.GetCardinality() <= uint64(x) {
 		return 0, fmt.Errorf("can't find %dth integer in a bitmap with only %d items", x, rb.GetCardinality())
@@ -1555,3 +1581,7 @@ func (rb *Bitmap) Stats() Statistics {
 	}
 	return stats
 }
+
+func (rb *Bitmap) FillLeastSignificant32bits(x []uint64, i uint64, mask uint64) {
+	rb.ManyIterator().NextMany64(mask, x[i:])
+}

vendor/github.com/RoaringBitmap/roaring/roaringarray.go

@@ -491,11 +491,11 @@ func (ra *roaringArray) writeTo(w io.Writer) (n int64, err error) {
 		binary.LittleEndian.PutUint16(buf[2:], uint16(len(ra.keys)-1))
 		nw += 2
 		// compute isRun bitmap without temporary allocation
-		var runbitmapslice = buf[nw:nw+isRunSizeInBytes]
+		var runbitmapslice = buf[nw : nw+isRunSizeInBytes]
 		for i, c := range ra.containers {
 			switch c.(type) {
 			case *runContainer16:
-				runbitmapslice[i / 8] |= 1<<(uint(i)%8)
+				runbitmapslice[i/8] |= 1 << (uint(i) % 8)
 			}
 		}
 		nw += isRunSizeInBytes

vendor/github.com/RoaringBitmap/roaring/runcontainer.go

@@ -1321,6 +1321,47 @@ func (ri *runIterator16) nextMany(hs uint32, buf []uint32) int {
 	return n
 }
 
+func (ri *runIterator16) nextMany64(hs uint64, buf []uint64) int {
+	n := 0
+
+	if !ri.hasNext() {
+		return n
+	}
+
+	// start and end are inclusive
+	for n < len(buf) {
+		moreVals := 0
+
+		if ri.rc.iv[ri.curIndex].length >= ri.curPosInIndex {
+			// add as many as you can from this seq
+			moreVals = minOfInt(int(ri.rc.iv[ri.curIndex].length-ri.curPosInIndex)+1, len(buf)-n)
+			base := uint64(ri.rc.iv[ri.curIndex].start+ri.curPosInIndex) | hs
+
+			// allows BCE
+			buf2 := buf[n : n+moreVals]
+			for i := range buf2 {
+				buf2[i] = base + uint64(i)
+			}
+
+			// update values
+			n += moreVals
+		}
+
+		if moreVals+int(ri.curPosInIndex) > int(ri.rc.iv[ri.curIndex].length) {
+			ri.curPosInIndex = 0
+			ri.curIndex++
+
+			if ri.curIndex == int64(len(ri.rc.iv)) {
+				break
+			}
+		} else {
+			ri.curPosInIndex += uint16(moreVals) //moreVals always fits in uint16
+		}
+	}
+
+	return n
+}
+
 // remove removes key from the container.
 func (rc *runContainer16) removeKey(key uint16) (wasPresent bool) {
 

vendor/github.com/RoaringBitmap/roaring/util.go

@@ -1,6 +1,7 @@
 package roaring
 
 import (
+	"math"
 	"math/rand"
 	"sort"
 )
@@ -15,7 +16,7 @@ const (
 	noOffsetThreshold          = 4
 
 	// MaxUint32 is the largest uint32 value.
-	MaxUint32 = 4294967295
+	MaxUint32 = math.MaxUint32
 
 	// MaxRange is One more than the maximum allowed bitmap bit index. For use as an upper
 	// bound for ranges.
@@ -23,7 +24,7 @@ const (
 
 	// MaxUint16 is the largest 16 bit unsigned int.
 	// This is the largest value an interval16 can store.
-	MaxUint16 = 65535
+	MaxUint16 = math.MaxUint16
 
 	// Compute wordSizeInBytes, the size of a word in bytes.
 	_m              = ^uint64(0)

vendor/github.com/alecthomas/chroma/lexers/a/awk.go

@@ -30,14 +30,14 @@ var Awk = internal.Register(MustNewLexer(
 		"root": {
 			{`^(?=\s|/)`, Text, Push("slashstartsregex")},
 			Include("commentsandwhitespace"),
-			{`\+\+|--|\|\||&&|in\b|\$|!?~|(\*\*|[-<>+*%\^/!=|])=?`, Operator, Push("slashstartsregex")},
+			{`\+\+|--|\|\||&&|in\b|\$|!?~|\|&|(\*\*|[-<>+*%\^/!=|])=?`, Operator, Push("slashstartsregex")},
 			{`[{(\[;,]`, Punctuation, Push("slashstartsregex")},
 			{`[})\].]`, Punctuation, nil},
-			{`(break|continue|do|while|exit|for|if|else|return)\b`, Keyword, Push("slashstartsregex")},
+			{`(break|continue|do|while|exit|for|if|else|return|switch|case|default)\b`, Keyword, Push("slashstartsregex")},
 			{`function\b`, KeywordDeclaration, Push("slashstartsregex")},
-			{`(atan2|cos|exp|int|log|rand|sin|sqrt|srand|gensub|gsub|index|length|match|split|sprintf|sub|substr|tolower|toupper|close|fflush|getline|next|nextfile|print|printf|strftime|systime|delete|system)\b`, KeywordReserved, nil},
+			{`(atan2|cos|exp|int|log|rand|sin|sqrt|srand|gensub|gsub|index|length|match|split|patsplit|sprintf|sub|substr|tolower|toupper|close|fflush|getline|next(file)|print|printf|strftime|systime|mktime|delete|system|strtonum|and|compl|lshift|or|rshift|asorti?|isarray|bindtextdomain|dcn?gettext|@(include|load|namespace))\b`, KeywordReserved, nil},
-			{`(ARGC|ARGIND|ARGV|BEGIN|CONVFMT|ENVIRON|END|ERRNO|FIELDWIDTHS|FILENAME|FNR|FS|IGNORECASE|NF|NR|OFMT|OFS|ORFS|RLENGTH|RS|RSTART|RT|SUBSEP)\b`, NameBuiltin, nil},
+			{`(ARGC|ARGIND|ARGV|BEGIN(FILE)?|BINMODE|CONVFMT|ENVIRON|END(FILE)?|ERRNO|FIELDWIDTHS|FILENAME|FNR|FPAT|FS|IGNORECASE|LINT|NF|NR|OFMT|OFS|ORS|PROCINFO|RLENGTH|RS|RSTART|RT|SUBSEP|TEXTDOMAIN)\b`, NameBuiltin, nil},
-			{`[$a-zA-Z_]\w*`, NameOther, nil},
+			{`[@$a-zA-Z_]\w*`, NameOther, nil},
 			{`[0-9][0-9]*\.[0-9]+([eE][0-9]+)?[fd]?`, LiteralNumberFloat, nil},
 			{`0x[0-9a-fA-F]+`, LiteralNumberHex, nil},
 			{`[0-9]+`, LiteralNumberInteger, nil},

vendor/github.com/alecthomas/chroma/lexers/e/elixir.go

@@ -28,6 +28,13 @@ var Elixir = internal.Register(MustNewLexer(
 			{`:"`, LiteralStringSymbol, Push("string_double_atom")},
 			{`:'`, LiteralStringSymbol, Push("string_single_atom")},
 			{`((?:\.\.\.|<<>>|%\{\}|%|\{\})|(?:(?:\.\.\.|[a-z_]\w*[!?]?)|[A-Z]\w*(?:\.[A-Z]\w*)*|(?:\<\<\<|\>\>\>|\|\|\||\&\&\&|\^\^\^|\~\~\~|\=\=\=|\!\=\=|\~\>\>|\<\~\>|\|\~\>|\<\|\>|\=\=|\!\=|\<\=|\>\=|\&\&|\|\||\<\>|\+\+|\-\-|\|\>|\=\~|\-\>|\<\-|\||\.|\=|\~\>|\<\~|\<|\>|\+|\-|\*|\/|\!|\^|\&)))(:)(?=\s|\n)`, ByGroups(LiteralStringSymbol, Punctuation), nil},
+			{`(fn|do|end|after|else|rescue|catch)\b`, Keyword, nil},
+			{`(not|and|or|when|in)\b`, OperatorWord, nil},
+			{`(case|cond|for|if|unless|try|receive|raise|quote|unquote|unquote_splicing|throw|super|while)\b`, Keyword, nil},
+			{`(def|defp|defmodule|defprotocol|defmacro|defmacrop|defdelegate|defexception|defstruct|defimpl|defcallback)\b`, KeywordDeclaration, nil},
+			{`(import|require|use|alias)\b`, KeywordNamespace, nil},
+			{`(nil|true|false)\b`, NameConstant, nil},
+			{`(_|__MODULE__|__DIR__|__ENV__|__CALLER__)\b`, NamePseudo, nil},
 			{`@(?:\.\.\.|[a-z_]\w*[!?]?)`, NameAttribute, nil},
 			{`(?:\.\.\.|[a-z_]\w*[!?]?)`, Name, nil},
 			{`(%?)([A-Z]\w*(?:\.[A-Z]\w*)*)`, ByGroups(Punctuation, NameClass), nil},

vendor/github.com/alecthomas/chroma/lexers/k/kotlin.go

@@ -24,32 +24,71 @@ var Kotlin = internal.Register(MustNewLexer(
 			{`//[^\n]*\n?`, CommentSingle, nil},
 			{`/[*].*?[*]/`, CommentMultiline, nil},
 			{`\n`, Text, nil},
-			{`::|!!|\?[:.]`, Operator, nil},
+			{`!==|!in|!is|===`, Operator, nil},
-			{`[~!%^&*()+=|\[\]:;,.<>/?-]`, Punctuation, nil},
+			{`%=|&&|\*=|\+\+|\+=|--|-=|->|\.\.|\/=|::|<=|==|>=|!!|!=|\|\||\?[:.]`, Operator, nil},
+			{`[~!%^&*()+=|\[\]:;,.<>\/?-]`, Punctuation, nil},
 			{`[{}]`, Punctuation, nil},
-			{`"""[^"]*"""`, LiteralString, nil},
+			{`"""`, LiteralString, Push("rawstring")},
-			{`"(\\\\|\\"|[^"\n])*["\n]`, LiteralString, nil},
+			{`"`, LiteralStringDouble, Push("string")},
+			{`(')(\\u[0-9a-fA-F]{4})(')`, ByGroups(LiteralStringChar, LiteralStringEscape, LiteralStringChar), nil},
 			{`'\\.'|'[^\\]'`, LiteralStringChar, nil},
 			{`0[xX][0-9a-fA-F]+[Uu]?[Ll]?|[0-9]+(\.[0-9]*)?([eE][+-][0-9]+)?[fF]?[Uu]?[Ll]?`, LiteralNumber, nil},
 			{`(companion)(\s+)(object)`, ByGroups(Keyword, Text, Keyword), nil},
 			{`(class|interface|object)(\s+)`, ByGroups(Keyword, Text), Push("class")},
 			{`(package|import)(\s+)`, ByGroups(Keyword, Text), Push("package")},
 			{`(val|var)(\s+)`, ByGroups(Keyword, Text), Push("property")},
-			{`(fun)(\s+)(<[^>]*>\s+)?`, ByGroups(Keyword, Text, Text), Push("function")},
+			{`(fun)(\s+)`, ByGroups(Keyword, Text), Push("function")},
-			{`(abstract|actual|annotation|as|break|by|catch|class|companion|const|constructor|continue|crossinline|data|do|dynamic|else|enum|expect|external|false|final|finally|for|fun|get|if|import|in|infix|inline|inner|interface|internal|is|lateinit|noinline|null|object|open|operator|out|override|package|private|protected|public|reified|return|sealed|set|super|suspend|tailrec|this|throw|true|try|val|var|vararg|when|where|while)\b`, Keyword, nil},
+			{`(abstract|actual|annotation|as|as\?|break|by|catch|class|companion|const|constructor|continue|crossinline|data|delegate|do|dynamic|else|enum|expect|external|false|field|file|final|finally|for|fun|get|if|import|in|infix|init|inline|inner|interface|internal|is|it|lateinit|noinline|null|object|open|operator|out|override|package|param|private|property|protected|public|receiver|reified|return|sealed|set|setparam|super|suspend|tailrec|this|throw|true|try|typealias|typeof|val|var|vararg|when|where|while)\b`, Keyword, nil},
-			{"(@?[" + kotlinIdentifier + "]*`)", Name, nil},
+			{`@[` + kotlinIdentifier + `]+`, NameDecorator, nil},
+			{`[` + kotlinIdentifier + `]+`, Name, nil},
 		},
 		"package": {
 			{`\S+`, NameNamespace, Pop(1)},
 		},
 		"class": {
-			{"(@?[" + kotlinIdentifier + "]*`)", NameClass, Pop(1)},
+			// \x60 is the back tick character (`)
+			{`\x60[^\x60]+?\x60`, NameClass, Pop(1)},
+			{`[` + kotlinIdentifier + `]+`, NameClass, Pop(1)},
 		},
 		"property": {
-			{"(@?[" + kotlinIdentifier + " ]*`)", NameProperty, Pop(1)},
+			{`\x60[^\x60]+?\x60`, NameProperty, Pop(1)},
+			{`[` + kotlinIdentifier + `]+`, NameProperty, Pop(1)},
+		},
+		"generics-specification": {
+			{`<`, Punctuation, Push("generics-specification")}, // required for generics inside generics e.g. <T : List<Int> >
+			{`>`, Punctuation, Pop(1)},
+			{`[,:*?]`, Punctuation, nil},
+			{`(in|out|reified)`, Keyword, nil},
+			{`\x60[^\x60]+?\x60`, NameClass, nil},
+			{`[` + kotlinIdentifier + `]+`, NameClass, nil},
+			{`\s+`, Text, nil},
 		},
 		"function": {
-			{"(@?[" + kotlinIdentifier + " ]*`)", NameFunction, Pop(1)},
+			{`<`, Punctuation, Push("generics-specification")},
+			{`\x60[^\x60]+?\x60`, NameFunction, Pop(1)},
+			{`[` + kotlinIdentifier + `]+`, NameFunction, Pop(1)},
+			{`\s+`, Text, nil},
+		},
+		"rawstring": {
+			// raw strings don't allow character escaping
+			{`"""`, LiteralString, Pop(1)},
+			{`(?:[^$"]+|\"{1,2}[^"])+`, LiteralString, nil},
+			Include("string-interpol"),
+			// remaining dollar signs are just a string
+			{`\$`, LiteralString, nil},
+		},
+		"string": {
+			{`\\[tbnr'"\\\$]`, LiteralStringEscape, nil},
+			{`\\u[0-9a-fA-F]{4}`, LiteralStringEscape, nil},
+			{`"`, LiteralStringDouble, Pop(1)},
+			Include("string-interpol"),
+			{`[^\n\\"$]+`, LiteralStringDouble, nil},
+			// remaining dollar signs are just a string
+			{`\$`, LiteralStringDouble, nil},
+		},
+		"string-interpol": {
+			{`\$[` + kotlinIdentifier + `]+`, LiteralStringInterpol, nil},
+			{`\${[^}\n]*}`, LiteralStringInterpol, nil},
 		},
 	},
 ))

vendor/github.com/alecthomas/chroma/lexers/y/yaml.go

@@ -23,13 +23,13 @@ var YAML = internal.Register(MustNewLexer(
 			{`&[^\s]+`, CommentPreproc, nil},
 			{`\*[^\s]+`, CommentPreproc, nil},
 			{`^%include\s+[^\n\r]+`, CommentPreproc, nil},
-			{`[>|](?:[+-])?\s(?:^(?:[ \n]{1})+.*\n?)*$`, StringDoc, nil},
 			Include("key"),
 			Include("value"),
 			{`[?:,\[\]]`, Punctuation, nil},
 			{`.`, Text, nil},
 		},
 		"value": {
+			{`([>|](?:[+-])?)(\n(^ {1,})(?:.*\n*(?:^\3 *).*)*)`, ByGroups(Punctuation, StringDoc, Whitespace), nil},
 			{Words(``, `\b`, "true", "True", "TRUE", "false", "False", "FALSE", "null",
 				"y", "Y", "yes", "Yes", "YES", "n", "N", "no", "No", "NO",
 				"on", "On", "ON", "off", "Off", "OFF"), KeywordConstant, nil},
@@ -37,6 +37,7 @@ var YAML = internal.Register(MustNewLexer(
 			{`'(?:\\.|[^'])*'`, StringSingle, nil},
 			{`\d\d\d\d-\d\d-\d\d([T ]\d\d:\d\d:\d\d(\.\d+)?(Z|\s+[-+]\d+)?)?`, LiteralDate, nil},
 			{`\b[+\-]?(0x[\da-f]+|0o[0-7]+|(\d+\.?\d*|\.?\d+)(e[\+\-]?\d+)?|\.inf|\.nan)\b`, Number, nil},
+			{`([^\{\}\[\]\?,\:\!\-\*&\@].*)( )+(#.*)`, ByGroups(Literal, Whitespace, Comment), nil},
 			{`[^\{\}\[\]\?,\:\!\-\*&\@].*`, Literal, nil},
 		},
 		"key": {

vendor/github.com/andybalholm/brotli/README.md

@@ -3,3 +3,5 @@ It was translated from the reference implementation (https://github.com/google/b
 with the `c2go` tool at https://github.com/andybalholm/c2go.
 
 I am using it in production with https://github.com/andybalholm/redwood.
+
+API documentation is found at https://pkg.go.dev/github.com/andybalholm/brotli?tab=doc.

vendor/github.com/andybalholm/brotli/backward_references.go

@@ -1,5 +1,9 @@
 package brotli
 
+import (
+	"sync"
+)
+
 /* Copyright 2013 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -31,13 +35,10 @@ func computeDistanceCode(distance uint, max_distance uint, dist_cache []int) uin
 	return distance + numDistanceShortCodes - 1
 }
 
-/* "commands" points to the next output command to write to, "*num_commands" is
+var hasherSearchResultPool sync.Pool
-   initially the total amount of commands output by previous
+
-   CreateBackwardReferences calls, and must be incremented by the amount written
+func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher hasherHandle, dist_cache []int, last_insert_len *uint, commands *[]command, num_literals *uint) {
-   by this call. */
-func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher hasherHandle, dist_cache []int, last_insert_len *uint, commands []command, num_commands *uint, num_literals *uint) {
 	var max_backward_limit uint = maxBackwardLimit(params.lgwin)
-	var orig_commands []command = commands
 	var insert_length uint = *last_insert_len
 	var pos_end uint = position + num_bytes
 	var store_end uint
@@ -57,8 +58,14 @@ func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte,
 
 	/* Minimum score to accept a backward reference. */
 	hasher.PrepareDistanceCache(dist_cache)
-	var sr2 hasherSearchResult
+	sr2, _ := hasherSearchResultPool.Get().(*hasherSearchResult)
-	var sr hasherSearchResult
+	if sr2 == nil {
+		sr2 = &hasherSearchResult{}
+	}
+	sr, _ := hasherSearchResultPool.Get().(*hasherSearchResult)
+	if sr == nil {
+		sr = &hasherSearchResult{}
+	}
 
 	for position+hasher.HashTypeLength() < pos_end {
 		var max_length uint = pos_end - position
@@ -67,7 +74,7 @@ func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte,
 		sr.len_code_delta = 0
 		sr.distance = 0
 		sr.score = kMinScore
-		hasher.FindLongestMatch(&params.dictionary, ringbuffer, ringbuffer_mask, dist_cache, position, max_length, max_distance, gap, params.dist.max_distance, &sr)
+		hasher.FindLongestMatch(&params.dictionary, ringbuffer, ringbuffer_mask, dist_cache, position, max_length, max_distance, gap, params.dist.max_distance, sr)
 		if sr.score > kMinScore {
 			/* Found a match. Let's look for something even better ahead. */
 			var delayed_backward_references_in_row int = 0
@@ -83,14 +90,14 @@ func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte,
 				sr2.distance = 0
 				sr2.score = kMinScore
 				max_distance = brotli_min_size_t(position+1, max_backward_limit)
-				hasher.FindLongestMatch(&params.dictionary, ringbuffer, ringbuffer_mask, dist_cache, position+1, max_length, max_distance, gap, params.dist.max_distance, &sr2)
+				hasher.FindLongestMatch(&params.dictionary, ringbuffer, ringbuffer_mask, dist_cache, position+1, max_length, max_distance, gap, params.dist.max_distance, sr2)
 				if sr2.score >= sr.score+cost_diff_lazy {
 					/* Ok, let's just write one byte for now and start a match from the
 					   next byte. */
 					position++
 
 					insert_length++
-					sr = sr2
+					*sr = *sr2
 					delayed_backward_references_in_row++
 					if delayed_backward_references_in_row < 4 && position+hasher.HashTypeLength() < pos_end {
 						continue
@@ -114,8 +121,7 @@ func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte,
 					hasher.PrepareDistanceCache(dist_cache)
 				}
 
-				initCommand(&commands[0], &params.dist, insert_length, sr.len, sr.len_code_delta, distance_code)
+				*commands = append(*commands, makeCommand(&params.dist, insert_length, sr.len, sr.len_code_delta, distance_code))
-				commands = commands[1:]
 			}
 
 			*num_literals += insert_length
@@ -173,5 +179,7 @@ func createBackwardReferences(num_bytes uint, position uint, ringbuffer []byte,
 
 	insert_length += pos_end - position
 	*last_insert_len = insert_length
-	*num_commands += uint(-cap(commands) + cap(orig_commands))
+
+	hasherSearchResultPool.Put(sr)
+	hasherSearchResultPool.Put(sr2)
 }

vendor/github.com/andybalholm/brotli/backward_references_hq.go

@@ -123,14 +123,13 @@ func setCost(histogram []uint32, histogram_size uint, literal_histogram bool, co
 	}
 }
 
-func zopfliCostModelSetFromCommands(self *zopfliCostModel, position uint, ringbuffer []byte, ringbuffer_mask uint, commands []command, num_commands uint, last_insert_len uint) {
+func zopfliCostModelSetFromCommands(self *zopfliCostModel, position uint, ringbuffer []byte, ringbuffer_mask uint, commands []command, last_insert_len uint) {
 	var histogram_literal [numLiteralSymbols]uint32
 	var histogram_cmd [numCommandSymbols]uint32
 	var histogram_dist [maxEffectiveDistanceAlphabetSize]uint32
 	var cost_literal [numLiteralSymbols]float32
 	var pos uint = position - last_insert_len
 	var min_cost_cmd float32 = kInfinity
-	var i uint
 	var cost_cmd []float32 = self.cost_cmd_[:]
 	var literal_costs []float32
 
@@ -138,7 +137,7 @@ func zopfliCostModelSetFromCommands(self *zopfliCostModel, position uint, ringbu
 	histogram_cmd = [numCommandSymbols]uint32{}
 	histogram_dist = [maxEffectiveDistanceAlphabetSize]uint32{}
 
-	for i = 0; i < num_commands; i++ {
+	for i := range commands {
 		var inslength uint = uint(commands[i].insert_len_)
 		var copylength uint = uint(commandCopyLen(&commands[i]))
 		var distcode uint = uint(commands[i].dist_prefix_) & 0x3FF
@@ -161,7 +160,7 @@ func zopfliCostModelSetFromCommands(self *zopfliCostModel, position uint, ringbu
 	setCost(histogram_cmd[:], numCommandSymbols, false, cost_cmd)
 	setCost(histogram_dist[:], uint(self.distance_histogram_size), false, self.cost_dist_)
 
-	for i = 0; i < numCommandSymbols; i++ {
+	for i := 0; i < numCommandSymbols; i++ {
 		min_cost_cmd = brotli_min_float(min_cost_cmd, cost_cmd[i])
 	}
 
@@ -169,10 +168,10 @@ func zopfliCostModelSetFromCommands(self *zopfliCostModel, position uint, ringbu
 	{
 		literal_costs = self.literal_costs_
 		var literal_carry float32 = 0.0
-		var num_bytes uint = self.num_bytes_
+		num_bytes := int(self.num_bytes_)
 		literal_costs[0] = 0.0
-		for i = 0; i < num_bytes; i++ {
+		for i := 0; i < num_bytes; i++ {
-			literal_carry += cost_literal[ringbuffer[(position+i)&ringbuffer_mask]]
+			literal_carry += cost_literal[ringbuffer[(position+uint(i))&ringbuffer_mask]]
 			literal_costs[i+1] = literal_costs[i] + literal_carry
 			literal_carry -= literal_costs[i+1] - literal_costs[i]
 		}
@@ -502,7 +501,9 @@ func updateNodes(num_bytes uint, block_start uint, pos uint, ringbuffer []byte,
 					var cost float32 = dist_cost + float32(getCopyExtra(copycode)) + zopfliCostModelGetCommandCost(model, cmdcode)
 					if cost < nodes[pos+len].u.cost {
 						updateZopfliNode(nodes, pos, start, uint(len), len_code, dist, 0, cost)
-						result = brotli_max_size_t(result, uint(len))
+						if len > result {
+							result = len
+						}
 					}
 				}
 			}
@@ -530,7 +531,7 @@ func computeShortestPathFromNodes(num_bytes uint, nodes []zopfliNode) uint {
 }
 
 /* REQUIRES: nodes != NULL and len(nodes) >= num_bytes + 1 */
-func zopfliCreateCommands(num_bytes uint, block_start uint, nodes []zopfliNode, dist_cache []int, last_insert_len *uint, params *encoderParams, commands []command, num_literals *uint) {
+func zopfliCreateCommands(num_bytes uint, block_start uint, nodes []zopfliNode, dist_cache []int, last_insert_len *uint, params *encoderParams, commands *[]command, num_literals *uint) {
 	var max_backward_limit uint = maxBackwardLimit(params.lgwin)
 	var pos uint = 0
 	var offset uint32 = nodes[0].u.next
@@ -552,7 +553,7 @@ func zopfliCreateCommands(num_bytes uint, block_start uint, nodes []zopfliNode,
 			var max_distance uint = brotli_min_size_t(block_start+pos, max_backward_limit)
 			var is_dictionary bool = (distance > max_distance+gap)
 			var dist_code uint = uint(zopfliNodeDistanceCode(next))
-			initCommand(&commands[i], &params.dist, insert_length, copy_length, int(len_code)-int(copy_length), dist_code)
+			*commands = append(*commands, makeCommand(&params.dist, insert_length, copy_length, int(len_code)-int(copy_length), dist_code))
 
 			if !is_dictionary && dist_code > 0 {
 				dist_cache[3] = dist_cache[2]
@@ -679,16 +680,16 @@ func zopfliComputeShortestPath(num_bytes uint, position uint, ringbuffer []byte,
 	return computeShortestPathFromNodes(num_bytes, nodes)
 }
 
-func createZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher *h10, dist_cache []int, last_insert_len *uint, commands []command, num_commands *uint, num_literals *uint) {
+func createZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher *h10, dist_cache []int, last_insert_len *uint, commands *[]command, num_literals *uint) {
 	var nodes []zopfliNode
 	nodes = make([]zopfliNode, (num_bytes + 1))
 	initZopfliNodes(nodes, num_bytes+1)
-	*num_commands += zopfliComputeShortestPath(num_bytes, position, ringbuffer, ringbuffer_mask, params, dist_cache, hasher, nodes)
+	zopfliComputeShortestPath(num_bytes, position, ringbuffer, ringbuffer_mask, params, dist_cache, hasher, nodes)
 	zopfliCreateCommands(num_bytes, position, nodes, dist_cache, last_insert_len, params, commands, num_literals)
 	nodes = nil
 }
 
-func createHqZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher hasherHandle, dist_cache []int, last_insert_len *uint, commands []command, num_commands *uint, num_literals *uint) {
+func createHqZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer []byte, ringbuffer_mask uint, params *encoderParams, hasher hasherHandle, dist_cache []int, last_insert_len *uint, commands *[]command, num_literals *uint) {
 	var max_backward_limit uint = maxBackwardLimit(params.lgwin)
 	var num_matches []uint32 = make([]uint32, num_bytes)
 	var matches_size uint = 4 * num_bytes
@@ -703,7 +704,7 @@ func createHqZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer
 	var orig_num_literals uint
 	var orig_last_insert_len uint
 	var orig_dist_cache [4]int
-	var orig_num_commands uint
+	var orig_num_commands int
 	var model zopfliCostModel
 	var nodes []zopfliNode
 	var matches []backwardMatch = make([]backwardMatch, matches_size)
@@ -769,7 +770,7 @@ func createHqZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer
 	orig_num_literals = *num_literals
 	orig_last_insert_len = *last_insert_len
 	copy(orig_dist_cache[:], dist_cache[:4])
-	orig_num_commands = *num_commands
+	orig_num_commands = len(*commands)
 	nodes = make([]zopfliNode, (num_bytes + 1))
 	initZopfliCostModel(&model, &params.dist, num_bytes)
 	for i = 0; i < 2; i++ {
@@ -777,14 +778,14 @@ func createHqZopfliBackwardReferences(num_bytes uint, position uint, ringbuffer
 		if i == 0 {
 			zopfliCostModelSetFromLiteralCosts(&model, position, ringbuffer, ringbuffer_mask)
 		} else {
-			zopfliCostModelSetFromCommands(&model, position, ringbuffer, ringbuffer_mask, commands, *num_commands-orig_num_commands, orig_last_insert_len)
+			zopfliCostModelSetFromCommands(&model, position, ringbuffer, ringbuffer_mask, (*commands)[orig_num_commands:], orig_last_insert_len)
 		}
 
-		*num_commands = orig_num_commands
+		*commands = (*commands)[:orig_num_commands]
 		*num_literals = orig_num_literals
 		*last_insert_len = orig_last_insert_len
 		copy(dist_cache, orig_dist_cache[:4])
-		*num_commands += zopfliIterate(num_bytes, position, ringbuffer, ringbuffer_mask, params, gap, dist_cache, &model, num_matches, matches, nodes)
+		zopfliIterate(num_bytes, position, ringbuffer, ringbuffer_mask, params, gap, dist_cache, &model, num_matches, matches, nodes)
 		zopfliCreateCommands(num_bytes, position, nodes, dist_cache, last_insert_len, params, commands, num_literals)
 	}
 

vendor/github.com/andybalholm/brotli/block_splitter.go

@@ -33,23 +33,21 @@ const (
 	kMinItersForRefining         uint    = 100
 )
 
-func countLiterals(cmds []command, num_commands uint) uint {
+func countLiterals(cmds []command) uint {
 	var total_length uint = 0
 	/* Count how many we have. */
 
-	var i uint
+	for i := range cmds {
-	for i = 0; i < num_commands; i++ {
 		total_length += uint(cmds[i].insert_len_)
 	}
 
 	return total_length
 }
 
-func copyLiteralsToByteArray(cmds []command, num_commands uint, data []byte, offset uint, mask uint, literals []byte) {
+func copyLiteralsToByteArray(cmds []command, data []byte, offset uint, mask uint, literals []byte) {
 	var pos uint = 0
 	var from_pos uint = offset & mask
-	var i uint
+	for i := range cmds {
-	for i = 0; i < num_commands; i++ {
 		var insert_len uint = uint(cmds[i].insert_len_)
 		if from_pos+insert_len > mask {
 			var head_size uint = mask + 1 - from_pos
@@ -90,24 +88,19 @@ const clustersPerBatch = 16
 func initBlockSplit(self *blockSplit) {
 	self.num_types = 0
 	self.num_blocks = 0
-	self.types = nil
+	self.types = self.types[:0]
-	self.lengths = nil
+	self.lengths = self.lengths[:0]
 	self.types_alloc_size = 0
 	self.lengths_alloc_size = 0
 }
 
-func destroyBlockSplit(self *blockSplit) {
+func splitBlock(cmds []command, data []byte, pos uint, mask uint, params *encoderParams, literal_split *blockSplit, insert_and_copy_split *blockSplit, dist_split *blockSplit) {
-	self.types = nil
-	self.lengths = nil
-}
-
-func splitBlock(cmds []command, num_commands uint, data []byte, pos uint, mask uint, params *encoderParams, literal_split *blockSplit, insert_and_copy_split *blockSplit, dist_split *blockSplit) {
 	{
-		var literals_count uint = countLiterals(cmds, num_commands)
+		var literals_count uint = countLiterals(cmds)
 		var literals []byte = make([]byte, literals_count)
 
 		/* Create a continuous array of literals. */
-		copyLiteralsToByteArray(cmds, num_commands, data, pos, mask, literals)
+		copyLiteralsToByteArray(cmds, data, pos, mask, literals)
 
 		/* Create the block split on the array of literals.
 		   Literal histograms have alphabet size 256. */
@@ -116,28 +109,26 @@ func splitBlock(cmds []command, num_commands uint, data []byte, pos uint, mask u
 		literals = nil
 	}
 	{
-		var insert_and_copy_codes []uint16 = make([]uint16, num_commands)
+		var insert_and_copy_codes []uint16 = make([]uint16, len(cmds))
 		/* Compute prefix codes for commands. */
 
-		var i uint
+		for i := range cmds {
-		for i = 0; i < num_commands; i++ {
 			insert_and_copy_codes[i] = cmds[i].cmd_prefix_
 		}
 
 		/* Create the block split on the array of command prefixes. */
-		splitByteVectorCommand(insert_and_copy_codes, num_commands, kSymbolsPerCommandHistogram, kMaxCommandHistograms, kCommandStrideLength, kCommandBlockSwitchCost, params, insert_and_copy_split)
+		splitByteVectorCommand(insert_and_copy_codes, kSymbolsPerCommandHistogram, kMaxCommandHistograms, kCommandStrideLength, kCommandBlockSwitchCost, params, insert_and_copy_split)
 
 		/* TODO: reuse for distances? */
 
 		insert_and_copy_codes = nil
 	}
 	{
-		var distance_prefixes []uint16 = make([]uint16, num_commands)
+		var distance_prefixes []uint16 = make([]uint16, len(cmds))
 		var j uint = 0
 		/* Create a continuous array of distance prefixes. */
 
-		var i uint
+		for i := range cmds {
-		for i = 0; i < num_commands; i++ {
 			var cmd *command = &cmds[i]
 			if commandCopyLen(cmd) != 0 && cmd.cmd_prefix_ >= 128 {
 				distance_prefixes[j] = cmd.dist_prefix_ & 0x3FF

vendor/github.com/andybalholm/brotli/block_splitter_command.go

@@ -372,7 +372,8 @@ func clusterBlocksCommand(data []uint16, length uint, num_blocks uint, block_ids
 	histogram_symbols = nil
 }
 
-func splitByteVectorCommand(data []uint16, length uint, literals_per_histogram uint, max_histograms uint, sampling_stride_length uint, block_switch_cost float64, params *encoderParams, split *blockSplit) {
+func splitByteVectorCommand(data []uint16, literals_per_histogram uint, max_histograms uint, sampling_stride_length uint, block_switch_cost float64, params *encoderParams, split *blockSplit) {
+	length := uint(len(data))
 	var data_size uint = histogramDataSizeCommand()
 	var num_histograms uint = length/literals_per_histogram + 1
 	var histograms []histogramCommand

vendor/github.com/andybalholm/brotli/command.go

@@ -194,26 +194,28 @@ type command struct {
 }
 
 /* distance_code is e.g. 0 for same-as-last short code, or 16 for offset 1. */
-func initCommand(self *command, dist *distanceParams, insertlen uint, copylen uint, copylen_code_delta int, distance_code uint) {
+func makeCommand(dist *distanceParams, insertlen uint, copylen uint, copylen_code_delta int, distance_code uint) (cmd command) {
 	/* Don't rely on signed int representation, use honest casts. */
 	var delta uint32 = uint32(byte(int8(copylen_code_delta)))
-	self.insert_len_ = uint32(insertlen)
+	cmd.insert_len_ = uint32(insertlen)
-	self.copy_len_ = uint32(uint32(copylen) | delta<<25)
+	cmd.copy_len_ = uint32(uint32(copylen) | delta<<25)
 
 	/* The distance prefix and extra bits are stored in this Command as if
 	   npostfix and ndirect were 0, they are only recomputed later after the
 	   clustering if needed. */
-	prefixEncodeCopyDistance(distance_code, uint(dist.num_direct_distance_codes), uint(dist.distance_postfix_bits), &self.dist_prefix_, &self.dist_extra_)
+	prefixEncodeCopyDistance(distance_code, uint(dist.num_direct_distance_codes), uint(dist.distance_postfix_bits), &cmd.dist_prefix_, &cmd.dist_extra_)
+	getLengthCode(insertlen, uint(int(copylen)+copylen_code_delta), (cmd.dist_prefix_&0x3FF == 0), &cmd.cmd_prefix_)
 
-	getLengthCode(insertlen, uint(int(copylen)+copylen_code_delta), (self.dist_prefix_&0x3FF == 0), &self.cmd_prefix_)
+	return cmd
 }
 
-func initInsertCommand(self *command, insertlen uint) {
+func makeInsertCommand(insertlen uint) (cmd command) {
-	self.insert_len_ = uint32(insertlen)
+	cmd.insert_len_ = uint32(insertlen)
-	self.copy_len_ = 4 << 25
+	cmd.copy_len_ = 4 << 25
-	self.dist_extra_ = 0
+	cmd.dist_extra_ = 0
-	self.dist_prefix_ = numDistanceShortCodes
+	cmd.dist_prefix_ = numDistanceShortCodes
-	getLengthCode(insertlen, 4, false, &self.cmd_prefix_)
+	getLengthCode(insertlen, 4, false, &cmd.cmd_prefix_)
+	return cmd
 }
 
 func commandRestoreDistanceCode(self *command, dist *distanceParams) uint32 {

vendor/github.com/andybalholm/brotli/compress_fragment.go

@@ -33,14 +33,8 @@ func hashBytesAtOffset5(v uint64, offset int, shift uint) uint32 {
 }
 
 func isMatch5(p1 []byte, p2 []byte) bool {
-	var i int
+	return binary.LittleEndian.Uint32(p1) == binary.LittleEndian.Uint32(p2) &&
-	for i = 0; i < 5; i++ {
+		p1[4] == p2[4]
-		if p1[i] != p2[i] {
-			return false
-		}
-	}
-
-	return true
 }
 
 /* Builds a literal prefix code into "depths" and "bits" based on the statistics
@@ -51,7 +45,7 @@ func isMatch5(p1 []byte, p2 []byte) bool {
    and thus have to assign a non-zero depth for each literal.
    Returns estimated compression ratio millibytes/char for encoding given input
    with generated code. */
-func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte, bits []uint16, storage_ix *uint, storage []byte) uint {
+func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte, bits []uint16, bw *bitWriter) uint {
 	var histogram = [256]uint32{0}
 	var histogram_total uint
 	var i uint
@@ -88,7 +82,7 @@ func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte
 	}
 
 	buildAndStoreHuffmanTreeFast(histogram[:], histogram_total, /* max_bits = */
-		8, depths, bits, storage_ix, storage)
+		8, depths, bits, bw)
 	{
 		var literal_ratio uint = 0
 		for i = 0; i < 256; i++ {
@@ -104,7 +98,7 @@ func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte
 
 /* Builds a command and distance prefix code (each 64 symbols) into "depth" and
    "bits" based on "histogram" and stores it into the bit stream. */
-func buildAndStoreCommandPrefixCode1(histogram []uint32, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
+func buildAndStoreCommandPrefixCode1(histogram []uint32, depth []byte, bits []uint16, bw *bitWriter) {
 	var tree [129]huffmanTree
 	var cmd_depth = [numCommandSymbols]byte{0}
 	/* Tree size for building a tree over 64 symbols is 2 * 64 + 1. */
@@ -151,141 +145,141 @@ func buildAndStoreCommandPrefixCode1(histogram []uint32, depth []byte, bits []ui
 			cmd_depth[448+8*i] = depth[56+i]
 		}
 
-		storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], storage_ix, storage)
+		storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], bw)
 	}
 
-	storeHuffmanTree(depth[64:], 64, tree[:], storage_ix, storage)
+	storeHuffmanTree(depth[64:], 64, tree[:], bw)
 }
 
 /* REQUIRES: insertlen < 6210 */
-func emitInsertLen1(insertlen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
+func emitInsertLen1(insertlen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
 	if insertlen < 6 {
 		var code uint = insertlen + 40
-		writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
+		bw.writeBits(uint(depth[code]), uint64(bits[code]))
 		histo[code]++
 	} else if insertlen < 130 {
 		var tail uint = insertlen - 2
 		var nbits uint32 = log2FloorNonZero(tail) - 1
 		var prefix uint = tail >> nbits
 		var inscode uint = uint((nbits << 1) + uint32(prefix) + 42)
-		writeBits(uint(depth[inscode]), uint64(bits[inscode]), storage_ix, storage)
+		bw.writeBits(uint(depth[inscode]), uint64(bits[inscode]))
-		writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits), storage_ix, storage)
+		bw.writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits))
 		histo[inscode]++
 	} else if insertlen < 2114 {
 		var tail uint = insertlen - 66
 		var nbits uint32 = log2FloorNonZero(tail)
 		var code uint = uint(nbits + 50)
-		writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
+		bw.writeBits(uint(depth[code]), uint64(bits[code]))
-		writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits), storage_ix, storage)
+		bw.writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits))
 		histo[code]++
 	} else {
-		writeBits(uint(depth[61]), uint64(bits[61]), storage_ix, storage)
+		bw.writeBits(uint(depth[61]), uint64(bits[61]))
-		writeBits(12, uint64(insertlen)-2114, storage_ix, storage)
+		bw.writeBits(12, uint64(insertlen)-2114)
 		histo[61]++
 	}
 }
 
-func emitLongInsertLen(insertlen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
+func emitLongInsertLen(insertlen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
 	if insertlen < 22594 {
-		writeBits(uint(depth[62]), uint64(bits[62]), storage_ix, storage)
+		bw.writeBits(uint(depth[62]), uint64(bits[62]))
-		writeBits(14, uint64(insertlen)-6210, storage_ix, storage)
+		bw.writeBits(14, uint64(insertlen)-6210)
 		histo[62]++
 	} else {
-		writeBits(uint(depth[63]), uint64(bits[63]), storage_ix, storage)
+		bw.writeBits(uint(depth[63]), uint64(bits[63]))
-		writeBits(24, uint64(insertlen)-22594, storage_ix, storage)
+		bw.writeBits(24, uint64(insertlen)-22594)
 		histo[63]++
 	}
 }
 
-func emitCopyLen1(copylen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
+func emitCopyLen1(copylen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
 	if copylen < 10 {
-		writeBits(uint(depth[copylen+14]), uint64(bits[copylen+14]), storage_ix, storage)
+		bw.writeBits(uint(depth[copylen+14]), uint64(bits[copylen+14]))
 		histo[copylen+14]++
 	} else if copylen < 134 {
 		var tail uint = copylen - 6
 		var nbits uint32 = log2FloorNonZero(tail) - 1
 		var prefix uint = tail >> nbits
 		var code uint = uint((nbits << 1) + uint32(prefix) + 20)
-		writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
+		bw.writeBits(uint(depth[code]), uint64(bits[code]))
-		writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits), storage_ix, storage)
+		bw.writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits))
 		histo[code]++
 	} else if copylen < 2118 {
 		var tail uint = copylen - 70
 		var nbits uint32 = log2FloorNonZero(tail)
 		var code uint = uint(nbits + 28)
-		writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
+		bw.writeBits(uint(depth[code]), uint64(bits[code]))
-		writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits), storage_ix, storage)
+		bw.writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits))
 		histo[code]++
 	} else {
-		writeBits(uint(depth[39]), uint64(bits[39]), storage_ix, storage)
+		bw.writeBits(uint(depth[39]), uint64(bits[39]))
-		writeBits(24, uint64(copylen)-2118, storage_ix, storage)
+		bw.writeBits(24, uint64(copylen)-2118)
 		histo[39]++
 	}
 }
 
-func emitCopyLenLastDistance1(copylen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
+func emitCopyLenLastDistance1(copylen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
 	if copylen < 12 {
-		writeBits(uint(depth[copylen-4]), uint64(bits[copylen-4]), storage_ix, storage)
+		bw.writeBits(uint(depth[copylen-4]), uint64(bits[copylen-4]))
 		histo[copylen-4]++
 	} else if copylen < 72 {
 		var tail uint = copylen - 8
 		var nbits uint32 = log2FloorNonZero(tail) - 1
 		var prefix uint = tail >> nbits
 		var code uint = uint((nbits << 1) + uint32(prefix) + 4)
-		writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
+		bw.writeBits(uint(depth[code]), uint64(bits[code]))
-		writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits), storage_ix, storage)
+		bw.writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits))
 		histo[code]++
 	} else if copylen < 136 {
 		var tail uint = copylen - 8
 		var code uint = (tail >> 5) + 30
-		writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
+		bw.writeBits(uint(depth[code]), uint64(bits[code]))
-		writeBits(5, uint64(tail)&31, storage_ix, storage)
+		bw.writeBits(5, uint64(tail)&31)
-		writeBits(uint(depth[64]), uint64(bits[64]), storage_ix, storage)
+		bw.writeBits(uint(depth[64]), uint64(bits[64]))
 		histo[code]++
 		histo[64]++
 	} else if copylen < 2120 {
 		var tail uint = copylen - 72
 		var nbits uint32 = log2FloorNonZero(tail)
 		var code uint = uint(nbits + 28)
-		writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
+		bw.writeBits(uint(depth[code]), uint64(bits[code]))
-		writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits), storage_ix, storage)
+		bw.writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits))
-		writeBits(uint(depth[64]), uint64(bits[64]), storage_ix, storage)
+		bw.writeBits(uint(depth[64]), uint64(bits[64]))
 		histo[code]++
 		histo[64]++
 	} else {
-		writeBits(uint(depth[39]), uint64(bits[39]), storage_ix, storage)
+		bw.writeBits(uint(depth[39]), uint64(bits[39]))
-		writeBits(24, uint64(copylen)-2120, storage_ix, storage)
+		bw.writeBits(24, uint64(copylen)-2120)
-		writeBits(uint(depth[64]), uint64(bits[64]), storage_ix, storage)
+		bw.writeBits(uint(depth[64]), uint64(bits[64]))
 		histo[39]++
 		histo[64]++
 	}
 }
 
-func emitDistance1(distance uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
+func emitDistance1(distance uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
 	var d uint = distance + 3
 	var nbits uint32 = log2FloorNonZero(d) - 1
 	var prefix uint = (d >> nbits) & 1
 	var offset uint = (2 + prefix) << nbits
 	var distcode uint = uint(2*(nbits-1) + uint32(prefix) + 80)
-	writeBits(uint(depth[distcode]), uint64(bits[distcode]), storage_ix, storage)
+	bw.writeBits(uint(depth[distcode]), uint64(bits[distcode]))
-	writeBits(uint(nbits), uint64(d)-uint64(offset), storage_ix, storage)
+	bw.writeBits(uint(nbits), uint64(d)-uint64(offset))
 	histo[distcode]++
 }
 
-func emitLiterals(input []byte, len uint, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
+func emitLiterals(input []byte, len uint, depth []byte, bits []uint16, bw *bitWriter) {
 	var j uint
 	for j = 0; j < len; j++ {
 		var lit byte = input[j]
-		writeBits(uint(depth[lit]), uint64(bits[lit]), storage_ix, storage)
+		bw.writeBits(uint(depth[lit]), uint64(bits[lit]))
 	}
 }
 
 /* REQUIRES: len <= 1 << 24. */
-func storeMetaBlockHeader1(len uint, is_uncompressed bool, storage_ix *uint, storage []byte) {
+func storeMetaBlockHeader1(len uint, is_uncompressed bool, bw *bitWriter) {
 	var nibbles uint = 6
 
 	/* ISLAST */
-	writeBits(1, 0, storage_ix, storage)
+	bw.writeBits(1, 0)
 
 	if len <= 1<<16 {
 		nibbles = 4
@@ -293,34 +287,11 @@ func storeMetaBlockHeader1(len uint, is_uncompressed bool, storage_ix *uint, sto
 		nibbles = 5
 	}
 
-	writeBits(2, uint64(nibbles)-4, storage_ix, storage)
+	bw.writeBits(2, uint64(nibbles)-4)
-	writeBits(nibbles*4, uint64(len)-1, storage_ix, storage)
+	bw.writeBits(nibbles*4, uint64(len)-1)
 
 	/* ISUNCOMPRESSED */
-	writeSingleBit(is_uncompressed, storage_ix, storage)
+	bw.writeSingleBit(is_uncompressed)
-}
-
-func updateBits(n_bits uint, bits uint32, pos uint, array []byte) {
-	for n_bits > 0 {
-		var byte_pos uint = pos >> 3
-		var n_unchanged_bits uint = pos & 7
-		var n_changed_bits uint = brotli_min_size_t(n_bits, 8-n_unchanged_bits)
-		var total_bits uint = n_unchanged_bits + n_changed_bits
-		var mask uint32 = (^((1 << total_bits) - 1)) | ((1 << n_unchanged_bits) - 1)
-		var unchanged_bits uint32 = uint32(array[byte_pos]) & mask
-		var changed_bits uint32 = bits & ((1 << n_changed_bits) - 1)
-		array[byte_pos] = byte(changed_bits<<n_unchanged_bits | unchanged_bits)
-		n_bits -= n_changed_bits
-		bits >>= n_changed_bits
-		pos += n_changed_bits
-	}
-}
-
-func rewindBitPosition1(new_storage_ix uint, storage_ix *uint, storage []byte) {
-	var bitpos uint = new_storage_ix & 7
-	var mask uint = (1 << bitpos) - 1
-	storage[new_storage_ix>>3] &= byte(mask)
-	*storage_ix = new_storage_ix
 }
 
 var shouldMergeBlock_kSampleRate uint = 43
@@ -351,151 +322,26 @@ func shouldUseUncompressedMode(metablock_start []byte, next_emit []byte, insertl
 	}
 }
 
-func emitUncompressedMetaBlock1(begin []byte, end []byte, storage_ix_start uint, storage_ix *uint, storage []byte) {
+func emitUncompressedMetaBlock1(data []byte, storage_ix_start uint, bw *bitWriter) {
-	var len uint = uint(-cap(end) + cap(begin))
+	bw.rewind(storage_ix_start)
-	rewindBitPosition1(storage_ix_start, storage_ix, storage)
+	storeMetaBlockHeader1(uint(len(data)), true, bw)
-	storeMetaBlockHeader1(uint(len), true, storage_ix, storage)
+	bw.jumpToByteBoundary()
-	*storage_ix = (*storage_ix + 7) &^ 7
+	bw.writeBytes(data)
-	copy(storage[*storage_ix>>3:], begin[:len])
-	*storage_ix += uint(len << 3)
-	storage[*storage_ix>>3] = 0
 }
 
 var kCmdHistoSeed = [128]uint32{
-	0,
+	0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1,
-	1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1,
-	1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
-	1,
+	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1,
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-	1,
+	1, 1, 1, 1, 0, 0, 0, 0,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	0,
-	0,
-	0,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	0,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	1,
-	0,
-	0,
-	0,
-	0,
 }
 
 var compressFragmentFastImpl_kFirstBlockSize uint = 3 << 15
 var compressFragmentFastImpl_kMergeBlockSize uint = 1 << 16
 
-func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []int, table_bits uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, storage_ix *uint, storage []byte) {
+func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []int, table_bits uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, bw *bitWriter) {
 	var cmd_histo [128]uint32
 	var ip_end int
 	var next_emit int = 0
@@ -506,7 +352,7 @@ func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []
 	var metablock_start int = input
 	var block_size uint = brotli_min_size_t(input_size, compressFragmentFastImpl_kFirstBlockSize)
 	var total_block_size uint = block_size
-	var mlen_storage_ix uint = *storage_ix + 3
+	var mlen_storage_ix uint = bw.getPos() + 3
 	var lit_depth [256]byte
 	var lit_bits [256]uint16
 	var literal_ratio uint
@@ -523,21 +369,21 @@ func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []
 
 	/* Save the bit position of the MLEN field of the meta-block header, so that
 	   we can update it later if we decide to extend this meta-block. */
-	storeMetaBlockHeader1(block_size, false, storage_ix, storage)
+	storeMetaBlockHeader1(block_size, false, bw)
 
 	/* No block splits, no contexts. */
-	writeBits(13, 0, storage_ix, storage)
+	bw.writeBits(13, 0)
 
-	literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], storage_ix, storage)
+	literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], bw)
 	{
 		/* Store the pre-compressed command and distance prefix codes. */
 		var i uint
 		for i = 0; i+7 < *cmd_code_numbits; i += 8 {
-			writeBits(8, uint64(cmd_code[i>>3]), storage_ix, storage)
+			bw.writeBits(8, uint64(cmd_code[i>>3]))
 		}
 	}
 
-	writeBits(*cmd_code_numbits&7, uint64(cmd_code[*cmd_code_numbits>>3]), storage_ix, storage)
+	bw.writeBits(*cmd_code_numbits&7, uint64(cmd_code[*cmd_code_numbits>>3]))
 
 	/* Initialize the command and distance histograms. We will gather
 	   statistics of command and distance codes during the processing
@@ -636,27 +482,27 @@ emit_commands:
 				var insert uint = uint(base - next_emit)
 				ip += int(matched)
 				if insert < 6210 {
-					emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+					emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
 				} else if shouldUseUncompressedMode(in[metablock_start:], in[next_emit:], insert, literal_ratio) {
-					emitUncompressedMetaBlock1(in[metablock_start:], in[base:], mlen_storage_ix-3, storage_ix, storage)
+					emitUncompressedMetaBlock1(in[metablock_start:base], mlen_storage_ix-3, bw)
 					input_size -= uint(base - input)
 					input = base
 					next_emit = input
 					goto next_block
 				} else {
-					emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+					emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
 				}
 
-				emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], storage_ix, storage)
+				emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], bw)
 				if distance == last_distance {
-					writeBits(uint(cmd_depth[64]), uint64(cmd_bits[64]), storage_ix, storage)
+					bw.writeBits(uint(cmd_depth[64]), uint64(cmd_bits[64]))
 					cmd_histo[64]++
 				} else {
-					emitDistance1(uint(distance), cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+					emitDistance1(uint(distance), cmd_depth, cmd_bits, cmd_histo[:], bw)
 					last_distance = distance
 				}
 
-				emitCopyLenLastDistance1(matched, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+				emitCopyLenLastDistance1(matched, cmd_depth, cmd_bits, cmd_histo[:], bw)
 
 				next_emit = ip
 				if ip >= ip_limit {
@@ -692,8 +538,8 @@ emit_commands:
 				}
 				ip += int(matched)
 				last_distance = int(base - candidate) /* > 0 */
-				emitCopyLen1(matched, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+				emitCopyLen1(matched, cmd_depth, cmd_bits, cmd_histo[:], bw)
-				emitDistance1(uint(last_distance), cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+				emitDistance1(uint(last_distance), cmd_depth, cmd_bits, cmd_histo[:], bw)
 
 				next_emit = ip
 				if ip >= ip_limit {
@@ -739,7 +585,7 @@ emit_remainder:
 		   nibbles. */
 		total_block_size += block_size
 
-		updateBits(20, uint32(total_block_size-1), mlen_storage_ix, storage)
+		bw.updateBits(20, uint32(total_block_size-1), mlen_storage_ix)
 		goto emit_commands
 	}
 
@@ -747,13 +593,13 @@ emit_remainder:
 	if next_emit < ip_end {
 		var insert uint = uint(ip_end - next_emit)
 		if insert < 6210 {
-			emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+			emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
-			emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], storage_ix, storage)
+			emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], bw)
 		} else if shouldUseUncompressedMode(in[metablock_start:], in[next_emit:], insert, literal_ratio) {
-			emitUncompressedMetaBlock1(in[metablock_start:], in[ip_end:], mlen_storage_ix-3, storage_ix, storage)
+			emitUncompressedMetaBlock1(in[metablock_start:ip_end], mlen_storage_ix-3, bw)
 		} else {
-			emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
+			emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
-			emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], storage_ix, storage)
+			emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], bw)
 		}
 	}
 
@@ -769,30 +615,29 @@ next_block:
 
 		/* Save the bit position of the MLEN field of the meta-block header, so that
 		   we can update it later if we decide to extend this meta-block. */
-		mlen_storage_ix = *storage_ix + 3
+		mlen_storage_ix = bw.getPos() + 3
 
-		storeMetaBlockHeader1(block_size, false, storage_ix, storage)
+		storeMetaBlockHeader1(block_size, false, bw)
 
 		/* No block splits, no contexts. */
-		writeBits(13, 0, storage_ix, storage)
+		bw.writeBits(13, 0)
 
-		literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], storage_ix, storage)
+		literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], bw)
-		buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, storage_ix, storage)
+		buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, bw)
 		goto emit_commands
 	}
 
 	if !is_last {
 		/* If this is not the last block, update the command and distance prefix
 		   codes for the next block and store the compressed forms. */
-		cmd_code[0] = 0
+		var bw bitWriter
-
+		bw.dst = cmd_code
-		*cmd_code_numbits = 0
+		buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, &bw)
-		buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, cmd_code_numbits, cmd_code)
+		*cmd_code_numbits = bw.getPos()
 	}
 }
 
-/* Compresses "input" string to the "*storage" buffer as one or more complete
+/* Compresses "input" string to bw as one or more complete meta-blocks.
-   meta-blocks, and updates the "*storage_ix" bit position.
 
    If "is_last" is 1, emits an additional empty last meta-block.
 
@@ -813,28 +658,28 @@ next_block:
    REQUIRES: "table_size" is an odd (9, 11, 13, 15) power of two
    OUTPUT: maximal copy distance <= |input_size|
    OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
-func compressFragmentFast(input []byte, input_size uint, is_last bool, table []int, table_size uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, storage_ix *uint, storage []byte) {
+func compressFragmentFast(input []byte, input_size uint, is_last bool, table []int, table_size uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, bw *bitWriter) {
-	var initial_storage_ix uint = *storage_ix
+	var initial_storage_ix uint = bw.getPos()
 	var table_bits uint = uint(log2FloorNonZero(table_size))
 
 	if input_size == 0 {
 		assert(is_last)
-		writeBits(1, 1, storage_ix, storage) /* islast */
+		bw.writeBits(1, 1) /* islast */
-		writeBits(1, 1, storage_ix, storage) /* isempty */
+		bw.writeBits(1, 1) /* isempty */
-		*storage_ix = (*storage_ix + 7) &^ 7
+		bw.jumpToByteBoundary()
 		return
 	}
 
-	compressFragmentFastImpl(input, input_size, is_last, table, table_bits, cmd_depth, cmd_bits, cmd_code_numbits, cmd_code, storage_ix, storage)
+	compressFragmentFastImpl(input, input_size, is_last, table, table_bits, cmd_depth, cmd_bits, cmd_code_numbits, cmd_code, bw)
 
 	/* If output is larger than single uncompressed block, rewrite it. */
-	if *storage_ix-initial_storage_ix > 31+(input_size<<3) {
+	if bw.getPos()-initial_storage_ix > 31+(input_size<<3) {
-		emitUncompressedMetaBlock1(input, input[input_size:], initial_storage_ix, storage_ix, storage)
+		emitUncompressedMetaBlock1(input[:input_size], initial_storage_ix, bw)
 	}
 
 	if is_last {
-		writeBits(1, 1, storage_ix, storage) /* islast */
+		bw.writeBits(1, 1) /* islast */
-		writeBits(1, 1, storage_ix, storage) /* isempty */
+		bw.writeBits(1, 1) /* isempty */
-		*storage_ix = (*storage_ix + 7) &^ 7
+		bw.jumpToByteBoundary()
 	}
 }

vendor/github.com/andybalholm/brotli/compress_fragment_two_pass.go

@@ -30,19 +30,18 @@ func hashBytesAtOffset(v uint64, offset uint, shift uint, length uint) uint32 {
 }
 
 func isMatch1(p1 []byte, p2 []byte, length uint) bool {
-	var i uint
+	if binary.LittleEndian.Uint32(p1) != binary.LittleEndian.Uint32(p2) {
-	for i = 0; i < length && i < 6; i++ {
+		return false
-		if p1[i] != p2[i] {
-			return false
-		}
 	}
-
+	if length == 4 {
-	return true
+		return true
+	}
+	return p1[4] == p2[4] && p1[5] == p2[5]
 }
 
 /* Builds a command and distance prefix code (each 64 symbols) into "depth" and
    "bits" based on "histogram" and stores it into the bit stream. */
-func buildAndStoreCommandPrefixCode(histogram []uint32, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
+func buildAndStoreCommandPrefixCode(histogram []uint32, depth []byte, bits []uint16, bw *bitWriter) {
 	var tree [129]huffmanTree
 	var cmd_depth = [numCommandSymbols]byte{0}
 	/* Tree size for building a tree over 64 symbols is 2 * 64 + 1. */
@@ -88,10 +87,10 @@ func buildAndStoreCommandPrefixCode(histogram []uint32, depth []byte, bits []uin
 			cmd_depth[448+8*i] = depth[16+i]
 		}
 
-		storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], storage_ix, storage)
+		storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], bw)
 	}
 
-	storeHuffmanTree(depth[64:], 64, tree[:], storage_ix, storage)
+	storeHuffmanTree(depth[64:], 64, tree[:], bw)
 }
 
 func emitInsertLen(insertlen uint32, commands *[]uint32) {
@@ -198,11 +197,11 @@ func emitDistance(distance uint32, commands *[]uint32) {
 }
 
 /* REQUIRES: len <= 1 << 24. */
-func storeMetaBlockHeader(len uint, is_uncompressed bool, storage_ix *uint, storage []byte) {
+func storeMetaBlockHeader(len uint, is_uncompressed bool, bw *bitWriter) {
 	var nibbles uint = 6
 
 	/* ISLAST */
-	writeBits(1, 0, storage_ix, storage)
+	bw.writeBits(1, 0)
 
 	if len <= 1<<16 {
 		nibbles = 4
@@ -210,11 +209,11 @@ func storeMetaBlockHeader(len uint, is_uncompressed bool, storage_ix *uint, stor
 		nibbles = 5
 	}
 
-	writeBits(2, uint64(nibbles)-4, storage_ix, storage)
+	bw.writeBits(2, uint64(nibbles)-4)
-	writeBits(nibbles*4, uint64(len)-1, storage_ix, storage)
+	bw.writeBits(nibbles*4, uint64(len)-1)
 
 	/* ISUNCOMPRESSED */
-	writeSingleBit(is_uncompressed, storage_ix, storage)
+	bw.writeSingleBit(is_uncompressed)
 }
 
 func createCommands(input []byte, block_size uint, input_size uint, base_ip_ptr []byte, table []int, table_bits uint, min_match uint, literals *[]byte, commands *[]uint32) {
@@ -441,163 +440,20 @@ emit_remainder:
 }
 
 var storeCommands_kNumExtraBits = [128]uint32{
-	0,
+	0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 7, 8, 9, 10, 12, 14, 24,
-	0,
+	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4,
-	0,
+	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 7, 8, 9, 10, 24,
-	0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0,
+	1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
-	0,
+	9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16,
-	1,
+	17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24,
-	1,
-	2,
-	2,
-	3,
-	3,
-	4,
-	4,
-	5,
-	5,
-	6,
-	7,
-	8,
-	9,
-	10,
-	12,
-	14,
-	24,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	1,
-	1,
-	2,
-	2,
-	3,
-	3,
-	4,
-	4,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	1,
-	1,
-	2,
-	2,
-	3,
-	3,
-	4,
-	4,
-	5,
-	5,
-	6,
-	7,
-	8,
-	9,
-	10,
-	24,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	1,
-	1,
-	2,
-	2,
-	3,
-	3,
-	4,
-	4,
-	5,
-	5,
-	6,
-	6,
-	7,
-	7,
-	8,
-	8,
-	9,
-	9,
-	10,
-	10,
-	11,
-	11,
-	12,
-	12,
-	13,
-	13,
-	14,
-	14,
-	15,
-	15,
-	16,
-	16,
-	17,
-	17,
-	18,
-	18,
-	19,
-	19,
-	20,
-	20,
-	21,
-	21,
-	22,
-	22,
-	23,
-	23,
-	24,
-	24,
 }
 var storeCommands_kInsertOffset = [24]uint32{
-	0,
+	0, 1, 2, 3, 4, 5, 6, 8, 10, 14, 18, 26, 34, 50, 66, 98, 130, 194, 322, 578,
-	1,
+	1090, 2114, 6210, 22594,
-	2,
-	3,
-	4,
-	5,
-	6,
-	8,
-	10,
-	14,
-	18,
-	26,
-	34,
-	50,
-	66,
-	98,
-	130,
-	194,
-	322,
-	578,
-	1090,
-	2114,
-	6210,
-	22594,
 }
 
-func storeCommands(literals []byte, num_literals uint, commands []uint32, num_commands uint, storage_ix *uint, storage []byte) {
+func storeCommands(literals []byte, num_literals uint, commands []uint32, num_commands uint, bw *bitWriter) {
 	var lit_depths [256]byte
 	var lit_bits [256]uint16
 	var lit_histo = [256]uint32{0}
@@ -610,7 +466,7 @@ func storeCommands(literals []byte, num_literals uint, commands []uint32, num_co
 	}
 
 	buildAndStoreHuffmanTreeFast(lit_histo[:], num_literals, /* max_bits = */
-		8, lit_depths[:], lit_bits[:], storage_ix, storage)
+		8, lit_depths[:], lit_bits[:], bw)
 
 	for i = 0; i < num_commands; i++ {
 		var code uint32 = commands[i] & 0xFF
@@ -622,21 +478,21 @@ func storeCommands(literals []byte, num_literals uint, commands []uint32, num_co
 	cmd_histo[2] += 1
 	cmd_histo[64] += 1
 	cmd_histo[84] += 1
-	buildAndStoreCommandPrefixCode(cmd_histo[:], cmd_depths[:], cmd_bits[:], storage_ix, storage)
+	buildAndStoreCommandPrefixCode(cmd_histo[:], cmd_depths[:], cmd_bits[:], bw)
 
 	for i = 0; i < num_commands; i++ {
 		var cmd uint32 = commands[i]
 		var code uint32 = cmd & 0xFF
 		var extra uint32 = cmd >> 8
 		assert(code < 128)
-		writeBits(uint(cmd_depths[code]), uint64(cmd_bits[code]), storage_ix, storage)
+		bw.writeBits(uint(cmd_depths[code]), uint64(cmd_bits[code]))
-		writeBits(uint(storeCommands_kNumExtraBits[code]), uint64(extra), storage_ix, storage)
+		bw.writeBits(uint(storeCommands_kNumExtraBits[code]), uint64(extra))
 		if code < 24 {
 			var insert uint32 = storeCommands_kInsertOffset[code] + extra
 			var j uint32
 			for j = 0; j < insert; j++ {
 				var lit byte = literals[0]
-				writeBits(uint(lit_depths[lit]), uint64(lit_bits[lit]), storage_ix, storage)
+				bw.writeBits(uint(lit_depths[lit]), uint64(lit_bits[lit]))
 				literals = literals[1:]
 			}
 		}
@@ -664,22 +520,13 @@ func shouldCompress(input []byte, input_size uint, num_literals uint) bool {
 	}
 }
 
-func rewindBitPosition(new_storage_ix uint, storage_ix *uint, storage []byte) {
+func emitUncompressedMetaBlock(input []byte, input_size uint, bw *bitWriter) {
-	var bitpos uint = new_storage_ix & 7
+	storeMetaBlockHeader(input_size, true, bw)
-	var mask uint = (1 << bitpos) - 1
+	bw.jumpToByteBoundary()
-	storage[new_storage_ix>>3] &= byte(mask)
+	bw.writeBytes(input[:input_size])
-	*storage_ix = new_storage_ix
 }
 
-func emitUncompressedMetaBlock(input []byte, input_size uint, storage_ix *uint, storage []byte) {
+func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_bits uint, min_match uint, bw *bitWriter) {
-	storeMetaBlockHeader(input_size, true, storage_ix, storage)
-	*storage_ix = (*storage_ix + 7) &^ 7
-	copy(storage[*storage_ix>>3:], input[:input_size])
-	*storage_ix += input_size << 3
-	storage[*storage_ix>>3] = 0
-}
-
-func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_bits uint, min_match uint, storage_ix *uint, storage []byte) {
 	/* Save the start of the first block for position and distance computations.
 	 */
 	var base_ip []byte = input
@@ -693,17 +540,17 @@ func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, co
 		num_literals = uint(-cap(literals) + cap(literal_buf))
 		if shouldCompress(input, block_size, num_literals) {
 			var num_commands uint = uint(-cap(commands) + cap(command_buf))
-			storeMetaBlockHeader(block_size, false, storage_ix, storage)
+			storeMetaBlockHeader(block_size, false, bw)
 
 			/* No block splits, no contexts. */
-			writeBits(13, 0, storage_ix, storage)
+			bw.writeBits(13, 0)
 
-			storeCommands(literal_buf, num_literals, command_buf, num_commands, storage_ix, storage)
+			storeCommands(literal_buf, num_literals, command_buf, num_commands, bw)
 		} else {
 			/* Since we did not find many backward references and the entropy of
 			   the data is close to 8 bits, we can simply emit an uncompressed block.
 			   This makes compression speed of uncompressible data about 3x faster. */
-			emitUncompressedMetaBlock(input, block_size, storage_ix, storage)
+			emitUncompressedMetaBlock(input, block_size, bw)
 		}
 
 		input = input[block_size:]
@@ -711,8 +558,7 @@ func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, co
 	}
 }
 
-/* Compresses "input" string to the "*storage" buffer as one or more complete
+/* Compresses "input" string to bw as one or more complete meta-blocks.
-   meta-blocks, and updates the "*storage_ix" bit position.
 
    If "is_last" is 1, emits an additional empty last meta-block.
 
@@ -724,8 +570,8 @@ func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, co
    REQUIRES: "table_size" is a power of two
    OUTPUT: maximal copy distance <= |input_size|
    OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
-func compressFragmentTwoPass(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_size uint, storage_ix *uint, storage []byte) {
+func compressFragmentTwoPass(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_size uint, bw *bitWriter) {
-	var initial_storage_ix uint = *storage_ix
+	var initial_storage_ix uint = bw.getPos()
 	var table_bits uint = uint(log2FloorNonZero(table_size))
 	var min_match uint
 	if table_bits <= 15 {
@@ -733,17 +579,17 @@ func compressFragmentTwoPass(input []byte, input_size uint, is_last bool, comman
 	} else {
 		min_match = 6
 	}
-	compressFragmentTwoPassImpl(input, input_size, is_last, command_buf, literal_buf, table, table_bits, min_match, storage_ix, storage)
+	compressFragmentTwoPassImpl(input, input_size, is_last, command_buf, literal_buf, table, table_bits, min_match, bw)
 
 	/* If output is larger than single uncompressed block, rewrite it. */
-	if *storage_ix-initial_storage_ix > 31+(input_size<<3) {
+	if bw.getPos()-initial_storage_ix > 31+(input_size<<3) {
-		rewindBitPosition(initial_storage_ix, storage_ix, storage)
+		bw.rewind(initial_storage_ix)
-		emitUncompressedMetaBlock(input, input_size, storage_ix, storage)
+		emitUncompressedMetaBlock(input, input_size, bw)
 	}
 
 	if is_last {
-		writeBits(1, 1, storage_ix, storage) /* islast */
+		bw.writeBits(1, 1) /* islast */
-		writeBits(1, 1, storage_ix, storage) /* isempty */
+		bw.writeBits(1, 1) /* isempty */
-		*storage_ix = (*storage_ix + 7) &^ 7
+		bw.jumpToByteBoundary()
 	}
 }

vendor/github.com/andybalholm/brotli/entropy_encode.go

@@ -24,7 +24,7 @@ func initHuffmanTree(self *huffmanTree, count uint32, left int16, right int16) {
 }
 
 /* Input size optimized Shell sort. */
-type huffmanTreeComparator func(*huffmanTree, *huffmanTree) bool
+type huffmanTreeComparator func(huffmanTree, huffmanTree) bool
 
 var sortHuffmanTreeItems_gaps = []uint{132, 57, 23, 10, 4, 1}
 
@@ -36,14 +36,13 @@ func sortHuffmanTreeItems(items []huffmanTree, n uint, comparator huffmanTreeCom
 			var tmp huffmanTree = items[i]
 			var k uint = i
 			var j uint = i - 1
-			for comparator(&tmp, &items[j]) {
+			for comparator(tmp, items[j]) {
 				items[k] = items[j]
 				k = j
-				tmp10 := j
+				if j == 0 {
-				j--
-				if tmp10 == 0 {
 					break
 				}
+				j--
 			}
 
 			items[k] = tmp
@@ -63,7 +62,7 @@ func sortHuffmanTreeItems(items []huffmanTree, n uint, comparator huffmanTreeCom
 			for i = gap; i < n; i++ {
 				var j uint = i
 				var tmp huffmanTree = items[i]
-				for ; j >= gap && comparator(&tmp, &items[j-gap]); j -= gap {
+				for ; j >= gap && comparator(tmp, items[j-gap]); j -= gap {
 					items[j] = items[j-gap]
 				}
 
@@ -105,7 +104,7 @@ func setDepth(p0 int, pool []huffmanTree, depth []byte, max_depth int) bool {
 }
 
 /* Sort the root nodes, least popular first. */
-func sortHuffmanTree(v0 *huffmanTree, v1 *huffmanTree) bool {
+func sortHuffmanTree(v0 huffmanTree, v1 huffmanTree) bool {
 	if v0.total_count_ != v1.total_count_ {
 		return v0.total_count_ < v1.total_count_
 	}

vendor/github.com/andybalholm/brotli/entropy_encode_static.go

@@ -778,8 +778,9 @@ var kStaticDistanceCodeDepth = [64]byte{
 
 var kCodeLengthBits = [18]uint32{0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 15, 31, 0, 11, 7}
 
-func storeStaticCodeLengthCode(storage_ix *uint, storage []byte) {
+func storeStaticCodeLengthCode(bw *bitWriter) {
-	writeBits(40, 0x0000FF55555554, storage_ix, storage)
+	bw.writeBits(32, 0x55555554)
+	bw.writeBits(8, 0xFF)
 }
 
 var kZeroRepsBits = [numCommandSymbols]uint64{
@@ -4317,9 +4318,10 @@ var kStaticCommandCodeBits = [numCommandSymbols]uint16{
 	2047,
 }
 
-func storeStaticCommandHuffmanTree(storage_ix *uint, storage []byte) {
+func storeStaticCommandHuffmanTree(bw *bitWriter) {
-	writeBits(56, 0x92624416307003, storage_ix, storage)
+	bw.writeBits(32, 0x16307003)
-	writeBits(3, 0x00000000, storage_ix, storage)
+	bw.writeBits(24, 0x926244)
+	bw.writeBits(3, 0x00000000)
 }
 
 var kStaticDistanceCodeBits = [64]uint16{
@@ -4389,6 +4391,6 @@ var kStaticDistanceCodeBits = [64]uint16{
 	63,
 }
 
-func storeStaticDistanceHuffmanTree(storage_ix *uint, storage []byte) {
+func storeStaticDistanceHuffmanTree(bw *bitWriter) {
-	writeBits(28, 0x0369DC03, storage_ix, storage)
+	bw.writeBits(28, 0x0369DC03)
 }

vendor/github.com/andybalholm/brotli/find_match_length.go

@@ -1,5 +1,11 @@
 package brotli
 
+import (
+	"encoding/binary"
+	"math/bits"
+	"runtime"
+)
+
 /* Copyright 2010 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -9,6 +15,29 @@ package brotli
 /* Function to find maximal matching prefixes of strings. */
 func findMatchLengthWithLimit(s1 []byte, s2 []byte, limit uint) uint {
 	var matched uint = 0
+	_, _ = s1[limit-1], s2[limit-1] // bounds check
+	switch runtime.GOARCH {
+	case "amd64":
+		// Compare 8 bytes at at time.
+		for matched+8 <= limit {
+			w1 := binary.LittleEndian.Uint64(s1[matched:])
+			w2 := binary.LittleEndian.Uint64(s2[matched:])
+			if w1 != w2 {
+				return matched + uint(bits.TrailingZeros64(w1^w2)>>3)
+			}
+			matched += 8
+		}
+	case "386":
+		// Compare 4 bytes at at time.
+		for matched+4 <= limit {
+			w1 := binary.LittleEndian.Uint32(s1[matched:])
+			w2 := binary.LittleEndian.Uint32(s2[matched:])
+			if w1 != w2 {
+				return matched + uint(bits.TrailingZeros32(w1^w2)>>3)
+			}
+			matched += 4
+		}
+	}
 	for matched < limit && s1[matched] == s2[matched] {
 		matched++
 	}

vendor/github.com/andybalholm/brotli/go.mod

@@ -1,5 +1,3 @@
 module github.com/andybalholm/brotli
 
 go 1.12
-
-require github.com/golang/gddo v0.0.0-20190419222130-af0f2af80721

vendor/github.com/andybalholm/brotli/go.sum

@@ -1,2 +0,0 @@
-github.com/golang/gddo v0.0.0-20190419222130-af0f2af80721 h1:KRMr9A3qfbVM7iV/WcLY/rL5LICqwMHLhwRXKu99fXw=
-github.com/golang/gddo v0.0.0-20190419222130-af0f2af80721/go.mod h1:xEhNfoBDX1hzLm2Nf80qUvZ2sVwoMZ8d6IE2SrsQfh4=

vendor/github.com/andybalholm/brotli/histogram.go

@@ -163,7 +163,7 @@ func initBlockSplitIterator(self *blockSplitIterator, split *blockSplit) {
 	self.split_ = split
 	self.idx_ = 0
 	self.type_ = 0
-	if split.lengths != nil {
+	if len(split.lengths) > 0 {
 		self.length_ = uint(split.lengths[0])
 	} else {
 		self.length_ = 0
@@ -180,17 +180,16 @@ func blockSplitIteratorNext(self *blockSplitIterator) {
 	self.length_--
 }
 
-func buildHistogramsWithContext(cmds []command, num_commands uint, literal_split *blockSplit, insert_and_copy_split *blockSplit, dist_split *blockSplit, ringbuffer []byte, start_pos uint, mask uint, prev_byte byte, prev_byte2 byte, context_modes []int, literal_histograms []histogramLiteral, insert_and_copy_histograms []histogramCommand, copy_dist_histograms []histogramDistance) {
+func buildHistogramsWithContext(cmds []command, literal_split *blockSplit, insert_and_copy_split *blockSplit, dist_split *blockSplit, ringbuffer []byte, start_pos uint, mask uint, prev_byte byte, prev_byte2 byte, context_modes []int, literal_histograms []histogramLiteral, insert_and_copy_histograms []histogramCommand, copy_dist_histograms []histogramDistance) {
 	var pos uint = start_pos
 	var literal_it blockSplitIterator
 	var insert_and_copy_it blockSplitIterator
 	var dist_it blockSplitIterator
-	var i uint
 
 	initBlockSplitIterator(&literal_it, literal_split)
 	initBlockSplitIterator(&insert_and_copy_it, insert_and_copy_split)
 	initBlockSplitIterator(&dist_it, dist_split)
-	for i = 0; i < num_commands; i++ {
+	for i := range cmds {
 		var cmd *command = &cmds[i]
 		var j uint
 		blockSplitIteratorNext(&insert_and_copy_it)

vendor/github.com/andybalholm/brotli/http.go

@@ -0,0 +1,192 @@
+package brotli
+
+import (
+	"compress/gzip"
+	"io"
+	"net/http"
+	"strings"
+)
+
+// HTTPCompressor chooses a compression method (brotli, gzip, or none) based on
+// the Accept-Encoding header, sets the Content-Encoding header, and returns a
+// WriteCloser that implements that compression. The Close method must be called
+// before the current HTTP handler returns.
+//
+// Due to https://github.com/golang/go/issues/31753, the response will not be
+// compressed unless you set a Content-Type header before you call
+// HTTPCompressor.
+func HTTPCompressor(w http.ResponseWriter, r *http.Request) io.WriteCloser {
+	if w.Header().Get("Content-Type") == "" {
+		return nopCloser{w}
+	}
+
+	if w.Header().Get("Vary") == "" {
+		w.Header().Set("Vary", "Accept-Encoding")
+	}
+
+	encoding := negotiateContentEncoding(r, []string{"br", "gzip"})
+	switch encoding {
+	case "br":
+		w.Header().Set("Content-Encoding", "br")
+		return NewWriter(w)
+	case "gzip":
+		w.Header().Set("Content-Encoding", "gzip")
+		return gzip.NewWriter(w)
+	}
+	return nopCloser{w}
+}
+
+// negotiateContentEncoding returns the best offered content encoding for the
+// request's Accept-Encoding header. If two offers match with equal weight and
+// then the offer earlier in the list is preferred. If no offers are
+// acceptable, then "" is returned.
+func negotiateContentEncoding(r *http.Request, offers []string) string {
+	bestOffer := "identity"
+	bestQ := -1.0
+	specs := parseAccept(r.Header, "Accept-Encoding")
+	for _, offer := range offers {
+		for _, spec := range specs {
+			if spec.Q > bestQ &&
+				(spec.Value == "*" || spec.Value == offer) {
+				bestQ = spec.Q
+				bestOffer = offer
+			}
+		}
+	}
+	if bestQ == 0 {
+		bestOffer = ""
+	}
+	return bestOffer
+}
+
+// acceptSpec describes an Accept* header.
+type acceptSpec struct {
+	Value string
+	Q     float64
+}
+
+// parseAccept parses Accept* headers.
+func parseAccept(header http.Header, key string) (specs []acceptSpec) {
+loop:
+	for _, s := range header[key] {
+		for {
+			var spec acceptSpec
+			spec.Value, s = expectTokenSlash(s)
+			if spec.Value == "" {
+				continue loop
+			}
+			spec.Q = 1.0
+			s = skipSpace(s)
+			if strings.HasPrefix(s, ";") {
+				s = skipSpace(s[1:])
+				if !strings.HasPrefix(s, "q=") {
+					continue loop
+				}
+				spec.Q, s = expectQuality(s[2:])
+				if spec.Q < 0.0 {
+					continue loop
+				}
+			}
+			specs = append(specs, spec)
+			s = skipSpace(s)
+			if !strings.HasPrefix(s, ",") {
+				continue loop
+			}
+			s = skipSpace(s[1:])
+		}
+	}
+	return
+}
+
+func skipSpace(s string) (rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		if octetTypes[s[i]]&isSpace == 0 {
+			break
+		}
+	}
+	return s[i:]
+}
+
+func expectTokenSlash(s string) (token, rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		b := s[i]
+		if (octetTypes[b]&isToken == 0) && b != '/' {
+			break
+		}
+	}
+	return s[:i], s[i:]
+}
+
+func expectQuality(s string) (q float64, rest string) {
+	switch {
+	case len(s) == 0:
+		return -1, ""
+	case s[0] == '0':
+		q = 0
+	case s[0] == '1':
+		q = 1
+	default:
+		return -1, ""
+	}
+	s = s[1:]
+	if !strings.HasPrefix(s, ".") {
+		return q, s
+	}
+	s = s[1:]
+	i := 0
+	n := 0
+	d := 1
+	for ; i < len(s); i++ {
+		b := s[i]
+		if b < '0' || b > '9' {
+			break
+		}
+		n = n*10 + int(b) - '0'
+		d *= 10
+	}
+	return q + float64(n)/float64(d), s[i:]
+}
+
+// Octet types from RFC 2616.
+var octetTypes [256]octetType
+
+type octetType byte
+
+const (
+	isToken octetType = 1 << iota
+	isSpace
+)
+
+func init() {
+	// OCTET      = <any 8-bit sequence of data>
+	// CHAR       = <any US-ASCII character (octets 0 - 127)>
+	// CTL        = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
+	// CR         = <US-ASCII CR, carriage return (13)>
+	// LF         = <US-ASCII LF, linefeed (10)>
+	// SP         = <US-ASCII SP, space (32)>
+	// HT         = <US-ASCII HT, horizontal-tab (9)>
+	// <">        = <US-ASCII double-quote mark (34)>
+	// CRLF       = CR LF
+	// LWS        = [CRLF] 1*( SP | HT )
+	// TEXT       = <any OCTET except CTLs, but including LWS>
+	// separators = "(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\" | <">
+	//              | "/" | "[" | "]" | "?" | "=" | "{" | "}" | SP | HT
+	// token      = 1*<any CHAR except CTLs or separators>
+	// qdtext     = <any TEXT except <">>
+
+	for c := 0; c < 256; c++ {
+		var t octetType
+		isCtl := c <= 31 || c == 127
+		isChar := 0 <= c && c <= 127
+		isSeparator := strings.IndexRune(" \t\"(),/:;<=>?@[]\\{}", rune(c)) >= 0
+		if strings.IndexRune(" \t\r\n", rune(c)) >= 0 {
+			t |= isSpace
+		}
+		if isChar && !isCtl && !isSeparator {
+			t |= isToken
+		}
+		octetTypes[c] = t
+	}
+}

vendor/github.com/andybalholm/brotli/memory.go

@@ -23,12 +23,18 @@ func brotli_ensure_capacity_uint8_t(a *[]byte, c *uint, r uint) {
 		for new_size < r {
 			new_size *= 2
 		}
-		var new_array []byte = make([]byte, new_size)
+
-		if *c != 0 {
+		if cap(*a) < int(new_size) {
-			copy(new_array, (*a)[:*c])
+			var new_array []byte = make([]byte, new_size)
+			if *c != 0 {
+				copy(new_array, (*a)[:*c])
+			}
+
+			*a = new_array
+		} else {
+			*a = (*a)[:new_size]
 		}
 
-		*a = new_array
 		*c = new_size
 	}
 }
@@ -45,12 +51,16 @@ func brotli_ensure_capacity_uint32_t(a *[]uint32, c *uint, r uint) {
 			new_size *= 2
 		}
 
-		new_array = make([]uint32, new_size)
+		if cap(*a) < int(new_size) {
-		if *c != 0 {
+			new_array = make([]uint32, new_size)
-			copy(new_array, (*a)[:*c])
+			if *c != 0 {
-		}
+				copy(new_array, (*a)[:*c])
+			}
 
-		*a = new_array
+			*a = new_array
+		} else {
+			*a = (*a)[:new_size]
+		}
 		*c = new_size
 	}
 }

vendor/github.com/andybalholm/brotli/metablock.go

@@ -1,5 +1,9 @@
 package brotli
 
+import (
+	"sync"
+)
+
 /* Copyright 2014 Google Inc. All Rights Reserved.
 
    Distributed under MIT license.
@@ -25,31 +29,30 @@ type metaBlockSplit struct {
 	distance_histograms_size  uint
 }
 
-func initMetaBlockSplit(mb *metaBlockSplit) {
+var metaBlockPool sync.Pool
-	initBlockSplit(&mb.literal_split)
+
-	initBlockSplit(&mb.command_split)
+func getMetaBlockSplit() *metaBlockSplit {
-	initBlockSplit(&mb.distance_split)
+	mb, _ := metaBlockPool.Get().(*metaBlockSplit)
-	mb.literal_context_map = nil
+
-	mb.literal_context_map_size = 0
+	if mb == nil {
-	mb.distance_context_map = nil
+		mb = &metaBlockSplit{}
-	mb.distance_context_map_size = 0
+	} else {
-	mb.literal_histograms = nil
+		initBlockSplit(&mb.literal_split)
-	mb.literal_histograms_size = 0
+		initBlockSplit(&mb.command_split)
-	mb.command_histograms = nil
+		initBlockSplit(&mb.distance_split)
-	mb.command_histograms_size = 0
+		mb.literal_context_map = mb.literal_context_map[:0]
-	mb.distance_histograms = nil
+		mb.literal_context_map_size = 0
-	mb.distance_histograms_size = 0
+		mb.distance_context_map = mb.distance_context_map[:0]
+		mb.distance_context_map_size = 0
+		mb.literal_histograms = mb.literal_histograms[:0]
+		mb.command_histograms = mb.command_histograms[:0]
+		mb.distance_histograms = mb.distance_histograms[:0]
+	}
+	return mb
 }
 
-func destroyMetaBlockSplit(mb *metaBlockSplit) {
+func freeMetaBlockSplit(mb *metaBlockSplit) {
-	destroyBlockSplit(&mb.literal_split)
+	metaBlockPool.Put(mb)
-	destroyBlockSplit(&mb.command_split)
-	destroyBlockSplit(&mb.distance_split)
-	mb.literal_context_map = nil
-	mb.distance_context_map = nil
-	mb.literal_histograms = nil
-	mb.command_histograms = nil
-	mb.distance_histograms = nil
 }
 
 func initDistanceParams(params *encoderParams, npostfix uint32, ndirect uint32) {
@@ -84,14 +87,12 @@ func initDistanceParams(params *encoderParams, npostfix uint32, ndirect uint32)
 	dist_params.max_distance = uint(max_distance)
 }
 
-func recomputeDistancePrefixes(cmds []command, num_commands uint, orig_params *distanceParams, new_params *distanceParams) {
+func recomputeDistancePrefixes(cmds []command, orig_params *distanceParams, new_params *distanceParams) {
-	var i uint
-
 	if orig_params.distance_postfix_bits == new_params.distance_postfix_bits && orig_params.num_direct_distance_codes == new_params.num_direct_distance_codes {
 		return
 	}
 
-	for i = 0; i < num_commands; i++ {
+	for i := range cmds {
 		var cmd *command = &cmds[i]
 		if commandCopyLen(cmd) != 0 && cmd.cmd_prefix_ >= 128 {
 			prefixEncodeCopyDistance(uint(commandRestoreDistanceCode(cmd, orig_params)), uint(new_params.num_direct_distance_codes), uint(new_params.distance_postfix_bits), &cmd.dist_prefix_, &cmd.dist_extra_)
@@ -99,8 +100,7 @@ func recomputeDistancePrefixes(cmds []command, num_commands uint, orig_params *d
 	}
 }
 
-func computeDistanceCost(cmds []command, num_commands uint, orig_params *distanceParams, new_params *distanceParams, cost *float64) bool {
+func computeDistanceCost(cmds []command, orig_params *distanceParams, new_params *distanceParams, cost *float64) bool {
-	var i uint
 	var equal_params bool = false
 	var dist_prefix uint16
 	var dist_extra uint32
@@ -112,8 +112,8 @@ func computeDistanceCost(cmds []command, num_commands uint, orig_params *distanc
 		equal_params = true
 	}
 
-	for i = 0; i < num_commands; i++ {
+	for i := range cmds {
-		var cmd *command = &cmds[i]
+		cmd := &cmds[i]
 		if commandCopyLen(cmd) != 0 && cmd.cmd_prefix_ >= 128 {
 			if equal_params {
 				dist_prefix = cmd.dist_prefix_
@@ -137,7 +137,7 @@ func computeDistanceCost(cmds []command, num_commands uint, orig_params *distanc
 
 var buildMetaBlock_kMaxNumberOfHistograms uint = 256
 
-func buildMetaBlock(ringbuffer []byte, pos uint, mask uint, params *encoderParams, prev_byte byte, prev_byte2 byte, cmds []command, num_commands uint, literal_context_mode int, mb *metaBlockSplit) {
+func buildMetaBlock(ringbuffer []byte, pos uint, mask uint, params *encoderParams, prev_byte byte, prev_byte2 byte, cmds []command, literal_context_mode int, mb *metaBlockSplit) {
 	var distance_histograms []histogramDistance
 	var literal_histograms []histogramLiteral
 	var literal_context_modes []int = nil
@@ -164,7 +164,7 @@ func buildMetaBlock(ringbuffer []byte, pos uint, mask uint, params *encoderParam
 				check_orig = false
 			}
 
-			skip = !computeDistanceCost(cmds, num_commands, &orig_params.dist, &new_params.dist, &dist_cost)
+			skip = !computeDistanceCost(cmds, &orig_params.dist, &new_params.dist, &dist_cost)
 			if skip || (dist_cost > best_dist_cost) {
 				break
 			}
@@ -181,7 +181,7 @@ func buildMetaBlock(ringbuffer []byte, pos uint, mask uint, params *encoderParam
 
 	if check_orig {
 		var dist_cost float64
-		computeDistanceCost(cmds, num_commands, &orig_params.dist, &orig_params.dist, &dist_cost)
+		computeDistanceCost(cmds, &orig_params.dist, &orig_params.dist, &dist_cost)
 		if dist_cost < best_dist_cost {
 			/* NB: currently unused; uncomment when more param tuning is added. */
 			/* best_dist_cost = dist_cost; */
@@ -189,9 +189,9 @@ func buildMetaBlock(ringbuffer []byte, pos uint, mask uint, params *encoderParam
 		}
 	}
 
-	recomputeDistancePrefixes(cmds, num_commands, &orig_params.dist, &params.dist)
+	recomputeDistancePrefixes(cmds, &orig_params.dist, &params.dist)
 
-	splitBlock(cmds, num_commands, ringbuffer, pos, mask, params, &mb.literal_split, &mb.command_split, &mb.distance_split)
+	splitBlock(cmds, ringbuffer, pos, mask, params, &mb.literal_split, &mb.command_split, &mb.distance_split)
 
 	if !params.disable_literal_context_modeling {
 		literal_context_multiplier = 1 << literalContextBits
@@ -209,21 +209,30 @@ func buildMetaBlock(ringbuffer []byte, pos uint, mask uint, params *encoderParam
 	distance_histograms = make([]histogramDistance, distance_histograms_size)
 	clearHistogramsDistance(distance_histograms, distance_histograms_size)
 
-	assert(mb.command_histograms == nil)
 	mb.command_histograms_size = mb.command_split.num_types
-	mb.command_histograms = make([]histogramCommand, (mb.command_histograms_size))
+	if cap(mb.command_histograms) < int(mb.command_histograms_size) {
+		mb.command_histograms = make([]histogramCommand, (mb.command_histograms_size))
+	} else {
+		mb.command_histograms = mb.command_histograms[:mb.command_histograms_size]
+	}
 	clearHistogramsCommand(mb.command_histograms, mb.command_histograms_size)
 
-	buildHistogramsWithContext(cmds, num_commands, &mb.literal_split, &mb.command_split, &mb.distance_split, ringbuffer, pos, mask, prev_byte, prev_byte2, literal_context_modes, literal_histograms, mb.command_histograms, distance_histograms)
+	buildHistogramsWithContext(cmds, &mb.literal_split, &mb.command_split, &mb.distance_split, ringbuffer, pos, mask, prev_byte, prev_byte2, literal_context_modes, literal_histograms, mb.command_histograms, distance_histograms)
 	literal_context_modes = nil
 
-	assert(mb.literal_context_map == nil)
 	mb.literal_context_map_size = mb.literal_split.num_types << literalContextBits
-	mb.literal_context_map = make([]uint32, (mb.literal_context_map_size))
+	if cap(mb.literal_context_map) < int(mb.literal_context_map_size) {
+		mb.literal_context_map = make([]uint32, (mb.literal_context_map_size))
+	} else {
+		mb.literal_context_map = mb.literal_context_map[:mb.literal_context_map_size]
+	}
 
-	assert(mb.literal_histograms == nil)
 	mb.literal_histograms_size = mb.literal_context_map_size
-	mb.literal_histograms = make([]histogramLiteral, (mb.literal_histograms_size))
+	if cap(mb.literal_histograms) < int(mb.literal_histograms_size) {
+		mb.literal_histograms = make([]histogramLiteral, (mb.literal_histograms_size))
+	} else {
+		mb.literal_histograms = mb.literal_histograms[:mb.literal_histograms_size]
+	}
 
 	clusterHistogramsLiteral(literal_histograms, literal_histograms_size, buildMetaBlock_kMaxNumberOfHistograms, mb.literal_histograms, &mb.literal_histograms_size, mb.literal_context_map)
 	literal_histograms = nil
@@ -239,13 +248,19 @@ func buildMetaBlock(ringbuffer []byte, pos uint, mask uint, params *encoderParam
 		}
 	}
 
-	assert(mb.distance_context_map == nil)
 	mb.distance_context_map_size = mb.distance_split.num_types << distanceContextBits
-	mb.distance_context_map = make([]uint32, (mb.distance_context_map_size))
+	if cap(mb.distance_context_map) < int(mb.distance_context_map_size) {
+		mb.distance_context_map = make([]uint32, (mb.distance_context_map_size))
+	} else {
+		mb.distance_context_map = mb.distance_context_map[:mb.distance_context_map_size]
+	}
 
-	assert(mb.distance_histograms == nil)
 	mb.distance_histograms_size = mb.distance_context_map_size
-	mb.distance_histograms = make([]histogramDistance, (mb.distance_histograms_size))
+	if cap(mb.distance_histograms) < int(mb.distance_histograms_size) {
+		mb.distance_histograms = make([]histogramDistance, (mb.distance_histograms_size))
+	} else {
+		mb.distance_histograms = mb.distance_histograms[:mb.distance_histograms_size]
+	}
 
 	clusterHistogramsDistance(distance_histograms, mb.distance_context_map_size, buildMetaBlock_kMaxNumberOfHistograms, mb.distance_histograms, &mb.distance_histograms_size, mb.distance_context_map)
 	distance_histograms = nil
@@ -298,9 +313,12 @@ func initContextBlockSplitter(self *contextBlockSplitter, alphabet_size uint, nu
 	brotli_ensure_capacity_uint8_t(&split.types, &split.types_alloc_size, max_num_blocks)
 	brotli_ensure_capacity_uint32_t(&split.lengths, &split.lengths_alloc_size, max_num_blocks)
 	split.num_blocks = max_num_blocks
-	assert(*histograms == nil)
 	*histograms_size = max_num_types * num_contexts
-	*histograms = make([]histogramLiteral, (*histograms_size))
+	if histograms == nil || cap(*histograms) < int(*histograms_size) {
+		*histograms = make([]histogramLiteral, (*histograms_size))
+	} else {
+		*histograms = (*histograms)[:*histograms_size]
+	}
 	self.histograms_ = *histograms
 
 	/* Clear only current histogram. */
@@ -453,9 +471,12 @@ func contextBlockSplitterAddSymbol(self *contextBlockSplitter, symbol uint, cont
 
 func mapStaticContexts(num_contexts uint, static_context_map []uint32, mb *metaBlockSplit) {
 	var i uint
-	assert(mb.literal_context_map == nil)
 	mb.literal_context_map_size = mb.literal_split.num_types << literalContextBits
-	mb.literal_context_map = make([]uint32, (mb.literal_context_map_size))
+	if cap(mb.literal_context_map) < int(mb.literal_context_map_size) {
+		mb.literal_context_map = make([]uint32, (mb.literal_context_map_size))
+	} else {
+		mb.literal_context_map = mb.literal_context_map[:mb.literal_context_map_size]
+	}
 
 	for i = 0; i < mb.literal_split.num_types; i++ {
 		var offset uint32 = uint32(i * num_contexts)
@@ -466,7 +487,7 @@ func mapStaticContexts(num_contexts uint, static_context_map []uint32, mb *metaB
 	}
 }
 
-func buildMetaBlockGreedyInternal(ringbuffer []byte, pos uint, mask uint, prev_byte byte, prev_byte2 byte, literal_context_lut contextLUT, num_contexts uint, static_context_map []uint32, commands []command, n_commands uint, mb *metaBlockSplit) {
+func buildMetaBlockGreedyInternal(ringbuffer []byte, pos uint, mask uint, prev_byte byte, prev_byte2 byte, literal_context_lut contextLUT, num_contexts uint, static_context_map []uint32, commands []command, mb *metaBlockSplit) {
 	var lit_blocks struct {
 		plain blockSplitterLiteral
 		ctx   contextBlockSplitter
@@ -474,8 +495,7 @@ func buildMetaBlockGreedyInternal(ringbuffer []byte, pos uint, mask uint, prev_b
 	var cmd_blocks blockSplitterCommand
 	var dist_blocks blockSplitterDistance
 	var num_literals uint = 0
-	var i uint
+	for i := range commands {
-	for i = 0; i < n_commands; i++ {
 		num_literals += uint(commands[i].insert_len_)
 	}
 
@@ -485,11 +505,10 @@ func buildMetaBlockGreedyInternal(ringbuffer []byte, pos uint, mask uint, prev_b
 		initContextBlockSplitter(&lit_blocks.ctx, 256, num_contexts, 512, 400.0, num_literals, &mb.literal_split, &mb.literal_histograms, &mb.literal_histograms_size)
 	}
 
-	initBlockSplitterCommand(&cmd_blocks, numCommandSymbols, 1024, 500.0, n_commands, &mb.command_split, &mb.command_histograms, &mb.command_histograms_size)
+	initBlockSplitterCommand(&cmd_blocks, numCommandSymbols, 1024, 500.0, uint(len(commands)), &mb.command_split, &mb.command_histograms, &mb.command_histograms_size)
-	initBlockSplitterDistance(&dist_blocks, 64, 512, 100.0, n_commands, &mb.distance_split, &mb.distance_histograms, &mb.distance_histograms_size)
+	initBlockSplitterDistance(&dist_blocks, 64, 512, 100.0, uint(len(commands)), &mb.distance_split, &mb.distance_histograms, &mb.distance_histograms_size)
 
-	for i = 0; i < n_commands; i++ {
+	for _, cmd := range commands {
-		var cmd command = commands[i]
 		var j uint
 		blockSplitterAddSymbolCommand(&cmd_blocks, uint(cmd.cmd_prefix_))
 		for j = uint(cmd.insert_len_); j != 0; j-- {
@@ -530,11 +549,11 @@ func buildMetaBlockGreedyInternal(ringbuffer []byte, pos uint, mask uint, prev_b
 	}
 }
 
-func buildMetaBlockGreedy(ringbuffer []byte, pos uint, mask uint, prev_byte byte, prev_byte2 byte, literal_context_lut contextLUT, num_contexts uint, static_context_map []uint32, commands []command, n_commands uint, mb *metaBlockSplit) {
+func buildMetaBlockGreedy(ringbuffer []byte, pos uint, mask uint, prev_byte byte, prev_byte2 byte, literal_context_lut contextLUT, num_contexts uint, static_context_map []uint32, commands []command, mb *metaBlockSplit) {
 	if num_contexts == 1 {
-		buildMetaBlockGreedyInternal(ringbuffer, pos, mask, prev_byte, prev_byte2, literal_context_lut, 1, nil, commands, n_commands, mb)
+		buildMetaBlockGreedyInternal(ringbuffer, pos, mask, prev_byte, prev_byte2, literal_context_lut, 1, nil, commands, mb)
 	} else {
-		buildMetaBlockGreedyInternal(ringbuffer, pos, mask, prev_byte, prev_byte2, literal_context_lut, num_contexts, static_context_map, commands, n_commands, mb)
+		buildMetaBlockGreedyInternal(ringbuffer, pos, mask, prev_byte, prev_byte2, literal_context_lut, num_contexts, static_context_map, commands, mb)
 	}
 }
 

vendor/github.com/andybalholm/brotli/metablock_command.go

@@ -43,9 +43,12 @@ func initBlockSplitterCommand(self *blockSplitterCommand, alphabet_size uint, mi
 	brotli_ensure_capacity_uint8_t(&split.types, &split.types_alloc_size, max_num_blocks)
 	brotli_ensure_capacity_uint32_t(&split.lengths, &split.lengths_alloc_size, max_num_blocks)
 	self.split_.num_blocks = max_num_blocks
-	assert(*histograms == nil)
 	*histograms_size = max_num_types
-	*histograms = make([]histogramCommand, (*histograms_size))
+	if histograms == nil || cap(*histograms) < int(*histograms_size) {
+		*histograms = make([]histogramCommand, (*histograms_size))
+	} else {
+		*histograms = (*histograms)[:*histograms_size]
+	}
 	self.histograms_ = *histograms
 
 	/* Clear only current histogram. */

vendor/github.com/andybalholm/brotli/metablock_distance.go

@@ -43,9 +43,12 @@ func initBlockSplitterDistance(self *blockSplitterDistance, alphabet_size uint,
 	brotli_ensure_capacity_uint8_t(&split.types, &split.types_alloc_size, max_num_blocks)
 	brotli_ensure_capacity_uint32_t(&split.lengths, &split.lengths_alloc_size, max_num_blocks)
 	self.split_.num_blocks = max_num_blocks
-	assert(*histograms == nil)
 	*histograms_size = max_num_types
-	*histograms = make([]histogramDistance, (*histograms_size))
+	if histograms == nil || cap(*histograms) < int(*histograms_size) {
+		*histograms = make([]histogramDistance, *histograms_size)
+	} else {
+		*histograms = (*histograms)[:*histograms_size]
+	}
 	self.histograms_ = *histograms
 
 	/* Clear only current histogram. */

vendor/github.com/andybalholm/brotli/metablock_literal.go

@@ -43,9 +43,12 @@ func initBlockSplitterLiteral(self *blockSplitterLiteral, alphabet_size uint, mi
 	brotli_ensure_capacity_uint8_t(&split.types, &split.types_alloc_size, max_num_blocks)
 	brotli_ensure_capacity_uint32_t(&split.lengths, &split.lengths_alloc_size, max_num_blocks)
 	self.split_.num_blocks = max_num_blocks
-	assert(*histograms == nil)
 	*histograms_size = max_num_types
-	*histograms = make([]histogramLiteral, (*histograms_size))
+	if histograms == nil || cap(*histograms) < int(*histograms_size) {
+		*histograms = make([]histogramLiteral, *histograms_size)
+	} else {
+		*histograms = (*histograms)[:*histograms_size]
+	}
 	self.histograms_ = *histograms
 
 	/* Clear only current histogram. */

vendor/github.com/andybalholm/brotli/ringbuffer.go

@@ -27,10 +27,7 @@ type ringBuffer struct {
 }
 
 func ringBufferInit(rb *ringBuffer) {
-	rb.cur_size_ = 0
 	rb.pos_ = 0
-	rb.data_ = nil
-	rb.buffer_ = nil
 }
 
 func ringBufferSetup(params *encoderParams, rb *ringBuffer) {
@@ -47,11 +44,16 @@ const kSlackForEightByteHashingEverywhere uint = 7
 /* Allocates or re-allocates data_ to the given length + plus some slack
    region before and after. Fills the slack regions with zeros. */
 func ringBufferInitBuffer(buflen uint32, rb *ringBuffer) {
-	var new_data []byte = make([]byte, (2 + uint(buflen) + kSlackForEightByteHashingEverywhere))
+	var new_data []byte
 	var i uint
+	size := 2 + int(buflen) + int(kSlackForEightByteHashingEverywhere)
+	if cap(rb.data_) < size {
+		new_data = make([]byte, size)
+	} else {
+		new_data = rb.data_[:size]
+	}
 	if rb.data_ != nil {
 		copy(new_data, rb.data_[:2+rb.cur_size_+uint32(kSlackForEightByteHashingEverywhere)])
-		rb.data_ = nil
 	}
 
 	rb.data_ = new_data

vendor/github.com/andybalholm/brotli/write_bits.go

@@ -8,49 +8,87 @@ package brotli
 
 /* Write bits into a byte array. */
 
-/* This function writes bits into bytes in increasing addresses, and within
+type bitWriter struct {
-   a byte least-significant-bit first.
+	dst []byte
 
-   The function can write up to 56 bits in one go with WriteBits
+	// Data waiting to be written is the low nbits of bits.
-   Example: let's assume that 3 bits (Rs below) have been written already:
+	bits  uint64
-
+	nbits uint
-   BYTE-0     BYTE+1       BYTE+2
-
-   0000 0RRR    0000 0000    0000 0000
-
-   Now, we could write 5 or less bits in MSB by just sifting by 3
-   and OR'ing to BYTE-0.
-
-   For n bits, we take the last 5 bits, OR that with high bits in BYTE-0,
-   and locate the rest in BYTE+1, BYTE+2, etc. */
-func writeBits(n_bits uint, bits uint64, pos *uint, array []byte) {
-	var array_pos []byte = array[*pos>>3:]
-	var bits_reserved_in_first_byte uint = (*pos & 7)
-	/* implicit & 0xFF is assumed for uint8_t arithmetics */
-
-	var bits_left_to_write uint
-	bits <<= bits_reserved_in_first_byte
-	array_pos[0] |= byte(bits)
-	array_pos = array_pos[1:]
-	for bits_left_to_write = n_bits + bits_reserved_in_first_byte; bits_left_to_write >= 9; bits_left_to_write -= 8 {
-		bits >>= 8
-		array_pos[0] = byte(bits)
-		array_pos = array_pos[1:]
-	}
-
-	array_pos[0] = 0
-	*pos += n_bits
 }
 
-func writeSingleBit(bit bool, pos *uint, array []byte) {
+func (w *bitWriter) writeBits(nb uint, b uint64) {
+	w.bits |= b << w.nbits
+	w.nbits += nb
+	if w.nbits >= 32 {
+		bits := w.bits
+		w.bits >>= 32
+		w.nbits -= 32
+		w.dst = append(w.dst,
+			byte(bits),
+			byte(bits>>8),
+			byte(bits>>16),
+			byte(bits>>24),
+		)
+	}
+}
+
+func (w *bitWriter) writeSingleBit(bit bool) {
 	if bit {
-		writeBits(1, 1, pos, array)
+		w.writeBits(1, 1)
 	} else {
-		writeBits(1, 0, pos, array)
+		w.writeBits(1, 0)
 	}
 }
 
-func writeBitsPrepareStorage(pos uint, array []byte) {
+func (w *bitWriter) jumpToByteBoundary() {
-	assert(pos&7 == 0)
+	dst := w.dst
-	array[pos>>3] = 0
+	for w.nbits != 0 {
+		dst = append(dst, byte(w.bits))
+		w.bits >>= 8
+		if w.nbits > 8 { // Avoid underflow
+			w.nbits -= 8
+		} else {
+			w.nbits = 0
+		}
+	}
+	w.bits = 0
+	w.dst = dst
+}
+
+func (w *bitWriter) writeBytes(b []byte) {
+	if w.nbits&7 != 0 {
+		panic("writeBytes with unfinished bits")
+	}
+	for w.nbits != 0 {
+		w.dst = append(w.dst, byte(w.bits))
+		w.bits >>= 8
+		w.nbits -= 8
+	}
+	w.dst = append(w.dst, b...)
+}
+
+func (w *bitWriter) getPos() uint {
+	return uint(len(w.dst)<<3) + w.nbits
+}
+
+func (w *bitWriter) rewind(p uint) {
+	w.bits = uint64(w.dst[p>>3] & byte((1<<(p&7))-1))
+	w.nbits = p & 7
+	w.dst = w.dst[:p>>3]
+}
+
+func (w *bitWriter) updateBits(n_bits uint, bits uint32, pos uint) {
+	for n_bits > 0 {
+		var byte_pos uint = pos >> 3
+		var n_unchanged_bits uint = pos & 7
+		var n_changed_bits uint = brotli_min_size_t(n_bits, 8-n_unchanged_bits)
+		var total_bits uint = n_unchanged_bits + n_changed_bits
+		var mask uint32 = (^((1 << total_bits) - 1)) | ((1 << n_unchanged_bits) - 1)
+		var unchanged_bits uint32 = uint32(w.dst[byte_pos]) & mask
+		var changed_bits uint32 = bits & ((1 << n_changed_bits) - 1)
+		w.dst[byte_pos] = byte(changed_bits<<n_unchanged_bits | unchanged_bits)
+		n_bits -= n_changed_bits
+		bits >>= n_changed_bits
+		pos += n_changed_bits
+	}
 }

vendor/github.com/andybalholm/brotli/writer.go

@@ -1,12 +1,8 @@
 package brotli
 
 import (
-	"compress/gzip"
 	"errors"
 	"io"
-	"net/http"
-
-	"github.com/golang/gddo/httputil"
 )
 
 const (
@@ -50,11 +46,8 @@ func NewWriterLevel(dst io.Writer, level int) *Writer {
 // NewWriterOptions is like NewWriter but specifies WriterOptions
 func NewWriterOptions(dst io.Writer, options WriterOptions) *Writer {
 	w := new(Writer)
+	w.options = options
 	w.Reset(dst)
-	w.params.quality = options.Quality
-	if options.LGWin > 0 {
-		w.params.lgwin = uint(options.LGWin)
-	}
 	return w
 }
 
@@ -63,6 +56,10 @@ func NewWriterOptions(dst io.Writer, options WriterOptions) *Writer {
 // instead. This permits reusing a Writer rather than allocating a new one.
 func (w *Writer) Reset(dst io.Writer) {
 	encoderInitState(w)
+	w.params.quality = w.options.Quality
+	if w.options.LGWin > 0 {
+		w.params.lgwin = uint(w.options.LGWin)
+	}
 	w.dst = dst
 }
 
@@ -70,6 +67,9 @@ func (w *Writer) writeChunk(p []byte, op int) (n int, err error) {
 	if w.dst == nil {
 		return 0, errWriterClosed
 	}
+	if w.err != nil {
+		return 0, w.err
+	}
 
 	for {
 		availableIn := uint(len(p))
@@ -82,16 +82,8 @@ func (w *Writer) writeChunk(p []byte, op int) (n int, err error) {
 			return n, errEncode
 		}
 
-		outputData := encoderTakeOutput(w)
+		if len(p) == 0 || w.err != nil {
-
+			return n, w.err
-		if len(outputData) > 0 {
-			_, err = w.dst.Write(outputData)
-			if err != nil {
-				return n, err
-			}
-		}
-		if len(p) == 0 {
-			return n, nil
 		}
 	}
 }
@@ -124,32 +116,3 @@ type nopCloser struct {
 }
 
 func (nopCloser) Close() error { return nil }
-
-// HTTPCompressor chooses a compression method (brotli, gzip, or none) based on
-// the Accept-Encoding header, sets the Content-Encoding header, and returns a
-// WriteCloser that implements that compression. The Close method must be called
-// before the current HTTP handler returns.
-//
-// Due to https://github.com/golang/go/issues/31753, the response will not be
-// compressed unless you set a Content-Type header before you call
-// HTTPCompressor.
-func HTTPCompressor(w http.ResponseWriter, r *http.Request) io.WriteCloser {
-	if w.Header().Get("Content-Type") == "" {
-		return nopCloser{w}
-	}
-
-	if w.Header().Get("Vary") == "" {
-		w.Header().Set("Vary", "Accept-Encoding")
-	}
-
-	encoding := httputil.NegotiateContentEncoding(r, []string{"br", "gzip"})
-	switch encoding {
-	case "br":
-		w.Header().Set("Content-Encoding", "br")
-		return NewWriter(w)
-	case "gzip":
-		w.Header().Set("Content-Encoding", "gzip")
-		return gzip.NewWriter(w)
-	}
-	return nopCloser{w}
-}

vendor/github.com/anmitsu/go-shlex/README.md

@@ -31,6 +31,13 @@ func main() {
     }
 }
 ```
+output
+
+    cp
+    -Rdp
+    file name
+    file name2
+    dir name
 
 ## Documentation
 

vendor/github.com/anmitsu/go-shlex/go.mod

@@ -0,0 +1,3 @@
+module github.com/anmitsu/go-shlex
+
+go 1.13

vendor/github.com/blevesearch/bleve/config.go

@@ -43,9 +43,16 @@ type configuration struct {
 }
 
 func (c *configuration) SetAnalysisQueueSize(n int) {
+	if c.analysisQueue != nil {
+		c.analysisQueue.Close()
+	}
 	c.analysisQueue = index.NewAnalysisQueue(n)
 }
 
+func (c *configuration) Shutdown() {
+	c.SetAnalysisQueueSize(0)
+}
+
 func newConfiguration() *configuration {
 	return &configuration{
 		Cache:         registry.NewCache(),

vendor/github.com/blevesearch/bleve/go.mod

@@ -8,10 +8,11 @@ require (
 	github.com/blevesearch/go-porterstemmer v1.0.3
 	github.com/blevesearch/segment v0.9.0
 	github.com/blevesearch/snowballstem v0.9.0
-	github.com/blevesearch/zap/v11 v11.0.10
+	github.com/blevesearch/zap/v11 v11.0.12
-	github.com/blevesearch/zap/v12 v12.0.10
+	github.com/blevesearch/zap/v12 v12.0.12
-	github.com/blevesearch/zap/v13 v13.0.2
+	github.com/blevesearch/zap/v13 v13.0.4
-	github.com/blevesearch/zap/v14 v14.0.1
+	github.com/blevesearch/zap/v14 v14.0.3
+	github.com/blevesearch/zap/v15 v15.0.1
 	github.com/couchbase/moss v0.1.0
 	github.com/couchbase/vellum v1.0.2
 	github.com/golang/protobuf v1.3.2

vendor/github.com/blevesearch/bleve/index/scorch/scorch.go

@@ -515,21 +515,17 @@ func (s *Scorch) diskFileStats(rootSegmentPaths map[string]struct{}) (uint64,
 	return numFilesOnDisk, numBytesUsedDisk, numBytesOnDiskByRoot
 }
 
-func (s *Scorch) rootDiskSegmentsPaths() map[string]struct{} {
-	rv := make(map[string]struct{}, len(s.root.segment))
-	for _, segmentSnapshot := range s.root.segment {
-		if seg, ok := segmentSnapshot.segment.(segment.PersistedSegment); ok {
-			rv[seg.Path()] = struct{}{}
-		}
-	}
-	return rv
-}
-
 func (s *Scorch) StatsMap() map[string]interface{} {
 	m := s.stats.ToMap()
 
+	indexSnapshot := s.currentSnapshot()
+	defer func() {
+		_ = indexSnapshot.Close()
+	}()
+
+	rootSegPaths := indexSnapshot.diskSegmentsPaths()
+
 	s.rootLock.RLock()
-	rootSegPaths := s.rootDiskSegmentsPaths()
 	m["CurFilesIneligibleForRemoval"] = uint64(len(s.ineligibleForRemoval))
 	s.rootLock.RUnlock()
 
@@ -556,6 +552,10 @@ func (s *Scorch) StatsMap() map[string]interface{} {
 	m["num_bytes_used_disk"] = numBytesUsedDisk
 	// total disk bytes by the latest root index, exclusive of older snapshots
 	m["num_bytes_used_disk_by_root"] = numBytesOnDiskByRoot
+	// num_bytes_used_disk_by_root_reclaimable is an approximation about the
+	// reclaimable disk space in an index. (eg: from a full compaction)
+	m["num_bytes_used_disk_by_root_reclaimable"] = uint64(float64(numBytesOnDiskByRoot) *
+		indexSnapshot.reClaimableDocsRatio())
 	m["num_files_on_disk"] = numFilesOnDisk
 	m["num_root_memorysegments"] = m["TotMemorySegmentsAtRoot"]
 	m["num_root_filesegments"] = m["TotFileSegmentsAtRoot"]

vendor/github.com/blevesearch/bleve/index/scorch/segment_plugin.go

@@ -23,6 +23,7 @@ import (
 	zapv12 "github.com/blevesearch/zap/v12"
 	zapv13 "github.com/blevesearch/zap/v13"
 	zapv14 "github.com/blevesearch/zap/v14"
+	zapv15 "github.com/blevesearch/zap/v15"
 )
 
 var supportedSegmentPlugins map[string]map[uint32]segment.Plugin
@@ -30,6 +31,7 @@ var defaultSegmentPlugin segment.Plugin
 
 func init() {
 	ResetPlugins()
+	RegisterPlugin(zapv15.Plugin(), false)
 	RegisterPlugin(zapv14.Plugin(), false)
 	RegisterPlugin(zapv13.Plugin(), false)
 	RegisterPlugin(zapv12.Plugin(), false)

vendor/github.com/blevesearch/bleve/index/scorch/snapshot_index.go

@@ -708,6 +708,33 @@ func (i *IndexSnapshot) DumpFields() chan interface{} {
 	return rv
 }
 
+func (i *IndexSnapshot) diskSegmentsPaths() map[string]struct{} {
+	rv := make(map[string]struct{}, len(i.segment))
+	for _, segmentSnapshot := range i.segment {
+		if seg, ok := segmentSnapshot.segment.(segment.PersistedSegment); ok {
+			rv[seg.Path()] = struct{}{}
+		}
+	}
+	return rv
+}
+
+// reClaimableDocsRatio gives a ratio about the obsoleted or
+// reclaimable documents present in a given index snapshot.
+func (i *IndexSnapshot) reClaimableDocsRatio() float64 {
+	var totalCount, liveCount uint64
+	for _, segmentSnapshot := range i.segment {
+		if _, ok := segmentSnapshot.segment.(segment.PersistedSegment); ok {
+			totalCount += uint64(segmentSnapshot.FullSize())
+			liveCount += uint64(segmentSnapshot.Count())
+		}
+	}
+
+	if totalCount > 0 {
+		return float64(totalCount-liveCount) / float64(totalCount)
+	}
+	return 0
+}
+
 // subtractStrings returns set a minus elements of set b.
 func subtractStrings(a, b []string) []string {
 	if len(b) == 0 {

vendor/github.com/blevesearch/bleve/index_impl.go

@@ -112,6 +112,11 @@ func newIndexUsing(path string, mapping mapping.IndexMapping, indexType string,
 		}
 		return nil, err
 	}
+	defer func(rv *indexImpl) {
+		if !rv.open {
+			rv.i.Close()
+		}
+	}(&rv)
 
 	// now persist the mapping
 	mappingBytes, err := json.Marshal(mapping)
@@ -177,6 +182,11 @@ func openIndexUsing(path string, runtimeConfig map[string]interface{}) (rv *inde
 		}
 		return nil, err
 	}
+	defer func(rv *indexImpl) {
+		if !rv.open {
+			rv.i.Close()
+		}
+	}(rv)
 
 	// now load the mapping
 	indexReader, err := rv.i.Reader()

vendor/github.com/blevesearch/bleve/search/highlight/format/html/html.go

@@ -15,6 +15,8 @@
 package html
 
 import (
+	"html"
+
 	"github.com/blevesearch/bleve/registry"
 	"github.com/blevesearch/bleve/search/highlight"
 )
@@ -54,18 +56,18 @@ func (a *FragmentFormatter) Format(f *highlight.Fragment, orderedTermLocations h
 			break
 		}
 		// add the stuff before this location
-		rv += string(f.Orig[curr:termLocation.Start])
+		rv += html.EscapeString(string(f.Orig[curr:termLocation.Start]))
-		// add the color
+		// start the <mark> tag
 		rv += a.before
 		// add the term itself
 		rv += string(f.Orig[termLocation.Start:termLocation.End])
-		// reset the color
+		// end the <mark> tag
 		rv += a.after
 		// update current
 		curr = termLocation.End
 	}
 	// add any remaining text after the last token
-	rv += string(f.Orig[curr:f.End])
+	rv += html.EscapeString(string(f.Orig[curr:f.End]))
 
 	return rv
 }

vendor/github.com/blevesearch/zap/v11/go.mod

@@ -4,7 +4,7 @@ go 1.12
 
 require (
 	github.com/RoaringBitmap/roaring v0.4.23
-	github.com/blevesearch/bleve v1.0.10
+	github.com/blevesearch/bleve v1.0.12
 	github.com/blevesearch/mmap-go v1.0.2
 	github.com/couchbase/vellum v1.0.2
 	github.com/golang/snappy v0.0.1

vendor/github.com/blevesearch/zap/v12/go.mod

@@ -4,7 +4,7 @@ go 1.12
 
 require (
 	github.com/RoaringBitmap/roaring v0.4.23
-	github.com/blevesearch/bleve v1.0.10
+	github.com/blevesearch/bleve v1.0.12
 	github.com/blevesearch/mmap-go v1.0.2
 	github.com/couchbase/vellum v1.0.2
 	github.com/golang/snappy v0.0.1

vendor/github.com/blevesearch/zap/v13/go.mod

@@ -4,7 +4,7 @@ go 1.12
 
 require (
 	github.com/RoaringBitmap/roaring v0.4.23
-	github.com/blevesearch/bleve v1.0.10
+	github.com/blevesearch/bleve v1.0.12
 	github.com/blevesearch/mmap-go v1.0.2
 	github.com/couchbase/vellum v1.0.2
 	github.com/golang/snappy v0.0.1

vendor/github.com/blevesearch/zap/v14/go.mod

@@ -4,7 +4,7 @@ go 1.12
 
 require (
 	github.com/RoaringBitmap/roaring v0.4.23
-	github.com/blevesearch/bleve v1.0.10
+	github.com/blevesearch/bleve v1.0.12
 	github.com/blevesearch/mmap-go v1.0.2
 	github.com/couchbase/vellum v1.0.2
 	github.com/golang/snappy v0.0.1

vendor/github.com/blevesearch/zap/v15/.gitignore

@@ -0,0 +1,12 @@
+#*
+*.sublime-*
+*~
+.#*
+.project
+.settings
+**/.idea/
+**/*.iml
+.DS_Store
+/cmd/zap/zap
+*.test
+tags

vendor/github.com/blevesearch/zap/v15/LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
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+
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
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+      the terms of any separate license agreement you may have executed
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+
+   6. Trademarks. This License does not grant permission to use the trade
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+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
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+
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+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
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+      file or class name and description of purpose be included on the
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+   Copyright [yyyy] [name of copyright owner]
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+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
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+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/blevesearch/zap/v15/README.md

@@ -0,0 +1,158 @@
+# zap file format
+
+Advanced ZAP File Format Documentation is [here](zap.md).
+
+The file is written in the reverse order that we typically access data.  This helps us write in one pass since later sections of the file require file offsets of things we've already written.
+
+Current usage:
+
+- mmap the entire file
+- crc-32 bytes and version are in fixed position at end of the file
+- reading remainder of footer could be version specific
+- remainder of footer gives us:
+  - 3 important offsets (docValue , fields index and stored data index)
+  - 2 important values (number of docs and chunk factor)
+- field data is processed once and memoized onto the heap so that we never have to go back to disk for it
+- access to stored data by doc number means first navigating to the stored data index, then accessing a fixed position offset into that slice, which gives us the actual address of the data.  the first bytes of that section tell us the size of data so that we know where it ends.
+- access to all other indexed data follows the following pattern:
+  - first know the field name -> convert to id
+  - next navigate to term dictionary for that field
+    - some operations stop here and do dictionary ops
+  - next use dictionary to navigate to posting list for a specific term
+  - walk posting list
+  - if necessary, walk posting details as we go
+  - if location info is desired, consult location bitmap to see if it is there
+
+## stored fields section
+
+- for each document
+  - preparation phase:
+    - produce a slice of metadata bytes and data bytes
+    - produce these slices in field id order
+    - field value is appended to the data slice
+    - metadata slice is varint encoded with the following values for each field value
+      - field id (uint16)
+      - field type (byte)
+      - field value start offset in uncompressed data slice (uint64)
+      - field value length (uint64)
+      - field number of array positions (uint64)
+      - one additional value for each array position (uint64)
+      - compress the data slice using snappy
+  - file writing phase:
+    - remember the start offset for this document
+    - write out meta data length (varint uint64)
+    - write out compressed data length (varint uint64)
+    - write out the metadata bytes
+    - write out the compressed data bytes
+
+## stored fields idx
+
+- for each document
+  - write start offset (remembered from previous section) of stored data (big endian uint64)
+
+With this index and a known document number, we have direct access to all the stored field data.
+
+## posting details (freq/norm) section
+
+- for each posting list
+  - produce a slice containing multiple consecutive chunks (each chunk is varint stream)
+  - produce a slice remembering offsets of where each chunk starts
+  - preparation phase:
+    - for each hit in the posting list
+    - if this hit is in next chunk close out encoding of last chunk and record offset start of next
+    - encode term frequency (uint64)
+    - encode norm factor (float32)
+  - file writing phase:
+    - remember start position for this posting list details
+    - write out number of chunks that follow (varint uint64)
+    - write out length of each chunk (each a varint uint64)
+    - write out the byte slice containing all the chunk data
+
+If you know the doc number you're interested in, this format lets you jump to the correct chunk (docNum/chunkFactor) directly and then seek within that chunk until you find it.
+
+## posting details (location) section
+
+- for each posting list
+  - produce a slice containing multiple consecutive chunks (each chunk is varint stream)
+  - produce a slice remembering offsets of where each chunk starts
+  - preparation phase:
+    - for each hit in the posting list
+    - if this hit is in next chunk close out encoding of last chunk and record offset start of next
+    - encode field (uint16)
+    - encode field pos (uint64)
+    - encode field start (uint64)
+    - encode field end (uint64)
+    - encode number of array positions to follow (uint64)
+    - encode each array position (each uint64)
+  - file writing phase:
+    - remember start position for this posting list details
+    - write out number of chunks that follow (varint uint64)
+    - write out length of each chunk (each a varint uint64)
+    - write out the byte slice containing all the chunk data
+
+If you know the doc number you're interested in, this format lets you jump to the correct chunk (docNum/chunkFactor) directly and then seek within that chunk until you find it.
+
+## postings list section
+
+- for each posting list
+  - preparation phase:
+    - encode roaring bitmap posting list to bytes (so we know the length)
+  - file writing phase:
+    - remember the start position for this posting list
+    - write freq/norm details offset (remembered from previous, as varint uint64)
+    - write location details offset (remembered from previous, as varint uint64)
+    - write length of encoded roaring bitmap
+    - write the serialized roaring bitmap data
+
+## dictionary
+
+- for each field
+  - preparation phase:
+    - encode vellum FST with dictionary data pointing to file offset of posting list (remembered from previous)
+  - file writing phase:
+    - remember the start position of this persistDictionary
+    - write length of vellum data (varint uint64)
+    - write out vellum data
+
+## fields section
+
+- for each field
+  - file writing phase:
+    - remember start offset for each field
+    - write dictionary address (remembered from previous) (varint uint64)
+    - write length of field name (varint uint64)
+    - write field name bytes
+
+## fields idx
+
+- for each field
+  - file writing phase:
+    - write big endian uint64 of start offset for each field
+
+NOTE: currently we don't know or record the length of this fields index.  Instead we rely on the fact that we know it immediately precedes a footer of known size.
+
+## fields DocValue
+
+- for each field
+  - preparation phase:
+    - produce a slice containing multiple consecutive chunks, where each chunk is composed of a meta section followed by compressed columnar field data
+    - produce a slice remembering the length of each chunk
+  - file writing phase:
+    - remember the start position of this first field DocValue offset in the footer
+    - write out number of chunks that follow (varint uint64)
+    - write out length of each chunk (each a varint uint64)
+    - write out the byte slice containing all the chunk data
+
+NOTE: currently the meta header inside each chunk gives clue to the location offsets and size of the data pertaining to a given docID and any
+read operation leverage that meta information to extract the document specific data from the file.
+
+## footer
+
+- file writing phase
+  - write number of docs (big endian uint64)
+  - write stored field index location (big endian uint64)
+  - write field index location (big endian uint64)
+  - write field docValue location (big endian uint64)
+  - write out chunk factor (big endian uint32)
+  - write out version (big endian uint32)
+  - write out file CRC of everything preceding this (big endian uint32)

vendor/github.com/blevesearch/zap/v15/build.go

@@ -0,0 +1,156 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bufio"
+	"math"
+	"os"
+
+	"github.com/couchbase/vellum"
+)
+
+const Version uint32 = 15
+
+const Type string = "zap"
+
+const fieldNotUninverted = math.MaxUint64
+
+func (sb *SegmentBase) Persist(path string) error {
+	return PersistSegmentBase(sb, path)
+}
+
+// PersistSegmentBase persists SegmentBase in the zap file format.
+func PersistSegmentBase(sb *SegmentBase, path string) error {
+	flag := os.O_RDWR | os.O_CREATE
+
+	f, err := os.OpenFile(path, flag, 0600)
+	if err != nil {
+		return err
+	}
+
+	cleanup := func() {
+		_ = f.Close()
+		_ = os.Remove(path)
+	}
+
+	br := bufio.NewWriter(f)
+
+	_, err = br.Write(sb.mem)
+	if err != nil {
+		cleanup()
+		return err
+	}
+
+	err = persistFooter(sb.numDocs, sb.storedIndexOffset, sb.fieldsIndexOffset, sb.docValueOffset,
+		sb.chunkMode, sb.memCRC, br)
+	if err != nil {
+		cleanup()
+		return err
+	}
+
+	err = br.Flush()
+	if err != nil {
+		cleanup()
+		return err
+	}
+
+	err = f.Sync()
+	if err != nil {
+		cleanup()
+		return err
+	}
+
+	err = f.Close()
+	if err != nil {
+		cleanup()
+		return err
+	}
+
+	return nil
+}
+
+func persistStoredFieldValues(fieldID int,
+	storedFieldValues [][]byte, stf []byte, spf [][]uint64,
+	curr int, metaEncode varintEncoder, data []byte) (
+	int, []byte, error) {
+	for i := 0; i < len(storedFieldValues); i++ {
+		// encode field
+		_, err := metaEncode(uint64(fieldID))
+		if err != nil {
+			return 0, nil, err
+		}
+		// encode type
+		_, err = metaEncode(uint64(stf[i]))
+		if err != nil {
+			return 0, nil, err
+		}
+		// encode start offset
+		_, err = metaEncode(uint64(curr))
+		if err != nil {
+			return 0, nil, err
+		}
+		// end len
+		_, err = metaEncode(uint64(len(storedFieldValues[i])))
+		if err != nil {
+			return 0, nil, err
+		}
+		// encode number of array pos
+		_, err = metaEncode(uint64(len(spf[i])))
+		if err != nil {
+			return 0, nil, err
+		}
+		// encode all array positions
+		for _, pos := range spf[i] {
+			_, err = metaEncode(pos)
+			if err != nil {
+				return 0, nil, err
+			}
+		}
+
+		data = append(data, storedFieldValues[i]...)
+		curr += len(storedFieldValues[i])
+	}
+
+	return curr, data, nil
+}
+
+func InitSegmentBase(mem []byte, memCRC uint32, chunkMode uint32,
+	fieldsMap map[string]uint16, fieldsInv []string, numDocs uint64,
+	storedIndexOffset uint64, fieldsIndexOffset uint64, docValueOffset uint64,
+	dictLocs []uint64) (*SegmentBase, error) {
+	sb := &SegmentBase{
+		mem:               mem,
+		memCRC:            memCRC,
+		chunkMode:         chunkMode,
+		fieldsMap:         fieldsMap,
+		fieldsInv:         fieldsInv,
+		numDocs:           numDocs,
+		storedIndexOffset: storedIndexOffset,
+		fieldsIndexOffset: fieldsIndexOffset,
+		docValueOffset:    docValueOffset,
+		dictLocs:          dictLocs,
+		fieldDvReaders:    make(map[uint16]*docValueReader),
+		fieldFSTs:         make(map[uint16]*vellum.FST),
+	}
+	sb.updateSize()
+
+	err := sb.loadDvReaders()
+	if err != nil {
+		return nil, err
+	}
+
+	return sb, nil
+}

vendor/github.com/blevesearch/zap/v15/chunk.go

@@ -0,0 +1,67 @@
+//  Copyright (c) 2019 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//              http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"fmt"
+)
+
+// LegacyChunkMode was the original chunk mode (always chunk size 1024)
+// this mode is still used for chunking doc values.
+var LegacyChunkMode uint32 = 1024
+
+// DefaultChunkMode is the most recent improvement to chunking and should
+// be used by default.
+var DefaultChunkMode uint32 = 1026
+
+func getChunkSize(chunkMode uint32, cardinality uint64, maxDocs uint64) (uint64, error) {
+	switch {
+	// any chunkMode <= 1024 will always chunk with chunkSize=chunkMode
+	case chunkMode <= 1024:
+		// legacy chunk size
+		return uint64(chunkMode), nil
+
+	case chunkMode == 1025:
+		// attempt at simple improvement
+		// theory - the point of chunking is to put a bound on the maximum number of
+		// calls to Next() needed to find a random document.  ie, you should be able
+		// to do one jump to the correct chunk, and then walk through at most
+		// chunk-size items
+		// previously 1024 was chosen as the chunk size, but this is particularly
+		// wasteful for low cardinality terms.  the observation is that if there
+		// are less than 1024 items, why not put them all in one chunk,
+		// this way you'll still achieve the same goal of visiting at most
+		// chunk-size items.
+		// no attempt is made to tweak any other case
+		if cardinality <= 1024 {
+			return maxDocs, nil
+		}
+		return 1024, nil
+
+	case chunkMode == 1026:
+		// improve upon the ideas tested in chunkMode 1025
+		// the observation that the fewest number of dense chunks is the most
+		// desirable layout, given the built-in assumptions of chunking
+		// (that we want to put an upper-bound on the number of items you must
+		//  walk over without skipping, currently tuned to 1024)
+		//
+		// 1.  compute the number of chunks needed (max 1024/chunk)
+		// 2.  convert to chunkSize, dividing into maxDocs
+		numChunks := (cardinality / 1024) + 1
+		chunkSize := maxDocs / numChunks
+		return chunkSize, nil
+	}
+	return 0, fmt.Errorf("unknown chunk mode %d", chunkMode)
+}

vendor/github.com/blevesearch/zap/v15/contentcoder.go

@@ -0,0 +1,243 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"reflect"
+
+	"github.com/golang/snappy"
+)
+
+var reflectStaticSizeMetaData int
+
+func init() {
+	var md MetaData
+	reflectStaticSizeMetaData = int(reflect.TypeOf(md).Size())
+}
+
+var termSeparator byte = 0xff
+var termSeparatorSplitSlice = []byte{termSeparator}
+
+type chunkedContentCoder struct {
+	final     []byte
+	chunkSize uint64
+	currChunk uint64
+	chunkLens []uint64
+
+	w                io.Writer
+	progressiveWrite bool
+
+	chunkMetaBuf bytes.Buffer
+	chunkBuf     bytes.Buffer
+
+	chunkMeta []MetaData
+
+	compressed []byte // temp buf for snappy compression
+}
+
+// MetaData represents the data information inside a
+// chunk.
+type MetaData struct {
+	DocNum      uint64 // docNum of the data inside the chunk
+	DocDvOffset uint64 // offset of data inside the chunk for the given docid
+}
+
+// newChunkedContentCoder returns a new chunk content coder which
+// packs data into chunks based on the provided chunkSize
+func newChunkedContentCoder(chunkSize uint64, maxDocNum uint64,
+	w io.Writer, progressiveWrite bool) *chunkedContentCoder {
+	total := maxDocNum/chunkSize + 1
+	rv := &chunkedContentCoder{
+		chunkSize:        chunkSize,
+		chunkLens:        make([]uint64, total),
+		chunkMeta:        make([]MetaData, 0, total),
+		w:                w,
+		progressiveWrite: progressiveWrite,
+	}
+
+	return rv
+}
+
+// Reset lets you reuse this chunked content coder. Buffers are reset
+// and re used. You cannot change the chunk size.
+func (c *chunkedContentCoder) Reset() {
+	c.currChunk = 0
+	c.final = c.final[:0]
+	c.chunkBuf.Reset()
+	c.chunkMetaBuf.Reset()
+	for i := range c.chunkLens {
+		c.chunkLens[i] = 0
+	}
+	c.chunkMeta = c.chunkMeta[:0]
+}
+
+func (c *chunkedContentCoder) SetChunkSize(chunkSize uint64, maxDocNum uint64) {
+	total := int(maxDocNum/chunkSize + 1)
+	c.chunkSize = chunkSize
+	if cap(c.chunkLens) < total {
+		c.chunkLens = make([]uint64, total)
+	} else {
+		c.chunkLens = c.chunkLens[:total]
+	}
+	if cap(c.chunkMeta) < total {
+		c.chunkMeta = make([]MetaData, 0, total)
+	}
+}
+
+// Close indicates you are done calling Add() this allows
+// the final chunk to be encoded.
+func (c *chunkedContentCoder) Close() error {
+	return c.flushContents()
+}
+
+func (c *chunkedContentCoder) flushContents() error {
+	// flush the contents, with meta information at first
+	buf := make([]byte, binary.MaxVarintLen64)
+	n := binary.PutUvarint(buf, uint64(len(c.chunkMeta)))
+	_, err := c.chunkMetaBuf.Write(buf[:n])
+	if err != nil {
+		return err
+	}
+
+	// write out the metaData slice
+	for _, meta := range c.chunkMeta {
+		_, err := writeUvarints(&c.chunkMetaBuf, meta.DocNum, meta.DocDvOffset)
+		if err != nil {
+			return err
+		}
+	}
+
+	// write the metadata to final data
+	metaData := c.chunkMetaBuf.Bytes()
+	c.final = append(c.final, c.chunkMetaBuf.Bytes()...)
+	// write the compressed data to the final data
+	c.compressed = snappy.Encode(c.compressed[:cap(c.compressed)], c.chunkBuf.Bytes())
+	c.final = append(c.final, c.compressed...)
+
+	c.chunkLens[c.currChunk] = uint64(len(c.compressed) + len(metaData))
+
+	if c.progressiveWrite {
+		_, err := c.w.Write(c.final)
+		if err != nil {
+			return err
+		}
+		c.final = c.final[:0]
+	}
+
+	return nil
+}
+
+// Add encodes the provided byte slice into the correct chunk for the provided
+// doc num.  You MUST call Add() with increasing docNums.
+func (c *chunkedContentCoder) Add(docNum uint64, vals []byte) error {
+	chunk := docNum / c.chunkSize
+	if chunk != c.currChunk {
+		// flush out the previous chunk details
+		err := c.flushContents()
+		if err != nil {
+			return err
+		}
+		// clearing the chunk specific meta for next chunk
+		c.chunkBuf.Reset()
+		c.chunkMetaBuf.Reset()
+		c.chunkMeta = c.chunkMeta[:0]
+		c.currChunk = chunk
+	}
+
+	// get the starting offset for this doc
+	dvOffset := c.chunkBuf.Len()
+	dvSize, err := c.chunkBuf.Write(vals)
+	if err != nil {
+		return err
+	}
+
+	c.chunkMeta = append(c.chunkMeta, MetaData{
+		DocNum:      docNum,
+		DocDvOffset: uint64(dvOffset + dvSize),
+	})
+	return nil
+}
+
+// Write commits all the encoded chunked contents to the provided writer.
+//
+// | ..... data ..... | chunk offsets (varints)
+// | position of chunk offsets (uint64) | number of offsets (uint64) |
+//
+func (c *chunkedContentCoder) Write() (int, error) {
+	var tw int
+
+	if c.final != nil {
+		// write out the data section first
+		nw, err := c.w.Write(c.final)
+		tw += nw
+		if err != nil {
+			return tw, err
+		}
+	}
+
+	chunkOffsetsStart := uint64(tw)
+
+	if cap(c.final) < binary.MaxVarintLen64 {
+		c.final = make([]byte, binary.MaxVarintLen64)
+	} else {
+		c.final = c.final[0:binary.MaxVarintLen64]
+	}
+	chunkOffsets := modifyLengthsToEndOffsets(c.chunkLens)
+	// write out the chunk offsets
+	for _, chunkOffset := range chunkOffsets {
+		n := binary.PutUvarint(c.final, chunkOffset)
+		nw, err := c.w.Write(c.final[:n])
+		tw += nw
+		if err != nil {
+			return tw, err
+		}
+	}
+
+	chunkOffsetsLen := uint64(tw) - chunkOffsetsStart
+
+	c.final = c.final[0:8]
+	// write out the length of chunk offsets
+	binary.BigEndian.PutUint64(c.final, chunkOffsetsLen)
+	nw, err := c.w.Write(c.final)
+	tw += nw
+	if err != nil {
+		return tw, err
+	}
+
+	// write out the number of chunks
+	binary.BigEndian.PutUint64(c.final, uint64(len(c.chunkLens)))
+	nw, err = c.w.Write(c.final)
+	tw += nw
+	if err != nil {
+		return tw, err
+	}
+
+	c.final = c.final[:0]
+
+	return tw, nil
+}
+
+// ReadDocValueBoundary elicits the start, end offsets from a
+// metaData header slice
+func ReadDocValueBoundary(chunk int, metaHeaders []MetaData) (uint64, uint64) {
+	var start uint64
+	if chunk > 0 {
+		start = metaHeaders[chunk-1].DocDvOffset
+	}
+	return start, metaHeaders[chunk].DocDvOffset
+}

vendor/github.com/blevesearch/zap/v15/count.go

@@ -0,0 +1,61 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"hash/crc32"
+	"io"
+
+	"github.com/blevesearch/bleve/index/scorch/segment"
+)
+
+// CountHashWriter is a wrapper around a Writer which counts the number of
+// bytes which have been written and computes a crc32 hash
+type CountHashWriter struct {
+	w   io.Writer
+	crc uint32
+	n   int
+	s   segment.StatsReporter
+}
+
+// NewCountHashWriter returns a CountHashWriter which wraps the provided Writer
+func NewCountHashWriter(w io.Writer) *CountHashWriter {
+	return &CountHashWriter{w: w}
+}
+
+func NewCountHashWriterWithStatsReporter(w io.Writer, s segment.StatsReporter) *CountHashWriter {
+	return &CountHashWriter{w: w, s: s}
+}
+
+// Write writes the provided bytes to the wrapped writer and counts the bytes
+func (c *CountHashWriter) Write(b []byte) (int, error) {
+	n, err := c.w.Write(b)
+	c.crc = crc32.Update(c.crc, crc32.IEEETable, b[:n])
+	c.n += n
+	if c.s != nil {
+		c.s.ReportBytesWritten(uint64(n))
+	}
+	return n, err
+}
+
+// Count returns the number of bytes written
+func (c *CountHashWriter) Count() int {
+	return c.n
+}
+
+// Sum32 returns the CRC-32 hash of the content written to this writer
+func (c *CountHashWriter) Sum32() uint32 {
+	return c.crc
+}

vendor/github.com/blevesearch/zap/v15/dict.go

@@ -0,0 +1,263 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/RoaringBitmap/roaring"
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/index/scorch/segment"
+	"github.com/couchbase/vellum"
+)
+
+// Dictionary is the zap representation of the term dictionary
+type Dictionary struct {
+	sb        *SegmentBase
+	field     string
+	fieldID   uint16
+	fst       *vellum.FST
+	fstReader *vellum.Reader
+}
+
+// PostingsList returns the postings list for the specified term
+func (d *Dictionary) PostingsList(term []byte, except *roaring.Bitmap,
+	prealloc segment.PostingsList) (segment.PostingsList, error) {
+	var preallocPL *PostingsList
+	pl, ok := prealloc.(*PostingsList)
+	if ok && pl != nil {
+		preallocPL = pl
+	}
+	return d.postingsList(term, except, preallocPL)
+}
+
+func (d *Dictionary) postingsList(term []byte, except *roaring.Bitmap, rv *PostingsList) (*PostingsList, error) {
+	if d.fstReader == nil {
+		if rv == nil || rv == emptyPostingsList {
+			return emptyPostingsList, nil
+		}
+		return d.postingsListInit(rv, except), nil
+	}
+
+	postingsOffset, exists, err := d.fstReader.Get(term)
+	if err != nil {
+		return nil, fmt.Errorf("vellum err: %v", err)
+	}
+	if !exists {
+		if rv == nil || rv == emptyPostingsList {
+			return emptyPostingsList, nil
+		}
+		return d.postingsListInit(rv, except), nil
+	}
+
+	return d.postingsListFromOffset(postingsOffset, except, rv)
+}
+
+func (d *Dictionary) postingsListFromOffset(postingsOffset uint64, except *roaring.Bitmap, rv *PostingsList) (*PostingsList, error) {
+	rv = d.postingsListInit(rv, except)
+
+	err := rv.read(postingsOffset, d)
+	if err != nil {
+		return nil, err
+	}
+
+	return rv, nil
+}
+
+func (d *Dictionary) postingsListInit(rv *PostingsList, except *roaring.Bitmap) *PostingsList {
+	if rv == nil || rv == emptyPostingsList {
+		rv = &PostingsList{}
+	} else {
+		postings := rv.postings
+		if postings != nil {
+			postings.Clear()
+		}
+
+		*rv = PostingsList{} // clear the struct
+
+		rv.postings = postings
+	}
+	rv.sb = d.sb
+	rv.except = except
+	return rv
+}
+
+func (d *Dictionary) Contains(key []byte) (bool, error) {
+	return d.fst.Contains(key)
+}
+
+// Iterator returns an iterator for this dictionary
+func (d *Dictionary) Iterator() segment.DictionaryIterator {
+	rv := &DictionaryIterator{
+		d: d,
+	}
+
+	if d.fst != nil {
+		itr, err := d.fst.Iterator(nil, nil)
+		if err == nil {
+			rv.itr = itr
+		} else if err != vellum.ErrIteratorDone {
+			rv.err = err
+		}
+	}
+
+	return rv
+}
+
+// PrefixIterator returns an iterator which only visits terms having the
+// the specified prefix
+func (d *Dictionary) PrefixIterator(prefix string) segment.DictionaryIterator {
+	rv := &DictionaryIterator{
+		d: d,
+	}
+
+	kBeg := []byte(prefix)
+	kEnd := segment.IncrementBytes(kBeg)
+
+	if d.fst != nil {
+		itr, err := d.fst.Iterator(kBeg, kEnd)
+		if err == nil {
+			rv.itr = itr
+		} else if err != vellum.ErrIteratorDone {
+			rv.err = err
+		}
+	}
+
+	return rv
+}
+
+// RangeIterator returns an iterator which only visits terms between the
+// start and end terms.  NOTE: bleve.index API specifies the end is inclusive.
+func (d *Dictionary) RangeIterator(start, end string) segment.DictionaryIterator {
+	rv := &DictionaryIterator{
+		d: d,
+	}
+
+	// need to increment the end position to be inclusive
+	var endBytes []byte
+	if len(end) > 0 {
+		endBytes = []byte(end)
+		if endBytes[len(endBytes)-1] < 0xff {
+			endBytes[len(endBytes)-1]++
+		} else {
+			endBytes = append(endBytes, 0xff)
+		}
+	}
+
+	if d.fst != nil {
+		itr, err := d.fst.Iterator([]byte(start), endBytes)
+		if err == nil {
+			rv.itr = itr
+		} else if err != vellum.ErrIteratorDone {
+			rv.err = err
+		}
+	}
+
+	return rv
+}
+
+// AutomatonIterator returns an iterator which only visits terms
+// having the the vellum automaton and start/end key range
+func (d *Dictionary) AutomatonIterator(a vellum.Automaton,
+	startKeyInclusive, endKeyExclusive []byte) segment.DictionaryIterator {
+	rv := &DictionaryIterator{
+		d: d,
+	}
+
+	if d.fst != nil {
+		itr, err := d.fst.Search(a, startKeyInclusive, endKeyExclusive)
+		if err == nil {
+			rv.itr = itr
+		} else if err != vellum.ErrIteratorDone {
+			rv.err = err
+		}
+	}
+
+	return rv
+}
+
+func (d *Dictionary) OnlyIterator(onlyTerms [][]byte,
+	includeCount bool) segment.DictionaryIterator {
+
+	rv := &DictionaryIterator{
+		d:         d,
+		omitCount: !includeCount,
+	}
+
+	var buf bytes.Buffer
+	builder, err := vellum.New(&buf, nil)
+	if err != nil {
+		rv.err = err
+		return rv
+	}
+	for _, term := range onlyTerms {
+		err = builder.Insert(term, 0)
+		if err != nil {
+			rv.err = err
+			return rv
+		}
+	}
+	err = builder.Close()
+	if err != nil {
+		rv.err = err
+		return rv
+	}
+
+	onlyFST, err := vellum.Load(buf.Bytes())
+	if err != nil {
+		rv.err = err
+		return rv
+	}
+
+	itr, err := d.fst.Search(onlyFST, nil, nil)
+	if err == nil {
+		rv.itr = itr
+	} else if err != vellum.ErrIteratorDone {
+		rv.err = err
+	}
+
+	return rv
+}
+
+// DictionaryIterator is an iterator for term dictionary
+type DictionaryIterator struct {
+	d         *Dictionary
+	itr       vellum.Iterator
+	err       error
+	tmp       PostingsList
+	entry     index.DictEntry
+	omitCount bool
+}
+
+// Next returns the next entry in the dictionary
+func (i *DictionaryIterator) Next() (*index.DictEntry, error) {
+	if i.err != nil && i.err != vellum.ErrIteratorDone {
+		return nil, i.err
+	} else if i.itr == nil || i.err == vellum.ErrIteratorDone {
+		return nil, nil
+	}
+	term, postingsOffset := i.itr.Current()
+	i.entry.Term = string(term)
+	if !i.omitCount {
+		i.err = i.tmp.read(postingsOffset, i.d)
+		if i.err != nil {
+			return nil, i.err
+		}
+		i.entry.Count = i.tmp.Count()
+	}
+	i.err = i.itr.Next()
+	return &i.entry, nil
+}

vendor/github.com/blevesearch/zap/v15/docvalues.go

@@ -0,0 +1,312 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math"
+	"reflect"
+	"sort"
+
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/index/scorch/segment"
+	"github.com/blevesearch/bleve/size"
+	"github.com/golang/snappy"
+)
+
+var reflectStaticSizedocValueReader int
+
+func init() {
+	var dvi docValueReader
+	reflectStaticSizedocValueReader = int(reflect.TypeOf(dvi).Size())
+}
+
+type docNumTermsVisitor func(docNum uint64, terms []byte) error
+
+type docVisitState struct {
+	dvrs    map[uint16]*docValueReader
+	segment *SegmentBase
+}
+
+type docValueReader struct {
+	field          string
+	curChunkNum    uint64
+	chunkOffsets   []uint64
+	dvDataLoc      uint64
+	curChunkHeader []MetaData
+	curChunkData   []byte // compressed data cache
+	uncompressed   []byte // temp buf for snappy decompression
+}
+
+func (di *docValueReader) size() int {
+	return reflectStaticSizedocValueReader + size.SizeOfPtr +
+		len(di.field) +
+		len(di.chunkOffsets)*size.SizeOfUint64 +
+		len(di.curChunkHeader)*reflectStaticSizeMetaData +
+		len(di.curChunkData)
+}
+
+func (di *docValueReader) cloneInto(rv *docValueReader) *docValueReader {
+	if rv == nil {
+		rv = &docValueReader{}
+	}
+
+	rv.field = di.field
+	rv.curChunkNum = math.MaxUint64
+	rv.chunkOffsets = di.chunkOffsets // immutable, so it's sharable
+	rv.dvDataLoc = di.dvDataLoc
+	rv.curChunkHeader = rv.curChunkHeader[:0]
+	rv.curChunkData = nil
+	rv.uncompressed = rv.uncompressed[:0]
+
+	return rv
+}
+
+func (di *docValueReader) curChunkNumber() uint64 {
+	return di.curChunkNum
+}
+
+func (s *SegmentBase) loadFieldDocValueReader(field string,
+	fieldDvLocStart, fieldDvLocEnd uint64) (*docValueReader, error) {
+	// get the docValue offset for the given fields
+	if fieldDvLocStart == fieldNotUninverted {
+		// no docValues found, nothing to do
+		return nil, nil
+	}
+
+	// read the number of chunks, and chunk offsets position
+	var numChunks, chunkOffsetsPosition uint64
+
+	if fieldDvLocEnd-fieldDvLocStart > 16 {
+		numChunks = binary.BigEndian.Uint64(s.mem[fieldDvLocEnd-8 : fieldDvLocEnd])
+		// read the length of chunk offsets
+		chunkOffsetsLen := binary.BigEndian.Uint64(s.mem[fieldDvLocEnd-16 : fieldDvLocEnd-8])
+		// acquire position of chunk offsets
+		chunkOffsetsPosition = (fieldDvLocEnd - 16) - chunkOffsetsLen
+	} else {
+		return nil, fmt.Errorf("loadFieldDocValueReader: fieldDvLoc too small: %d-%d", fieldDvLocEnd, fieldDvLocStart)
+	}
+
+	fdvIter := &docValueReader{
+		curChunkNum:  math.MaxUint64,
+		field:        field,
+		chunkOffsets: make([]uint64, int(numChunks)),
+	}
+
+	// read the chunk offsets
+	var offset uint64
+	for i := 0; i < int(numChunks); i++ {
+		loc, read := binary.Uvarint(s.mem[chunkOffsetsPosition+offset : chunkOffsetsPosition+offset+binary.MaxVarintLen64])
+		if read <= 0 {
+			return nil, fmt.Errorf("corrupted chunk offset during segment load")
+		}
+		fdvIter.chunkOffsets[i] = loc
+		offset += uint64(read)
+	}
+
+	// set the data offset
+	fdvIter.dvDataLoc = fieldDvLocStart
+
+	return fdvIter, nil
+}
+
+func (di *docValueReader) loadDvChunk(chunkNumber uint64, s *SegmentBase) error {
+	// advance to the chunk where the docValues
+	// reside for the given docNum
+	destChunkDataLoc, curChunkEnd := di.dvDataLoc, di.dvDataLoc
+	start, end := readChunkBoundary(int(chunkNumber), di.chunkOffsets)
+	if start >= end {
+		di.curChunkHeader = di.curChunkHeader[:0]
+		di.curChunkData = nil
+		di.curChunkNum = chunkNumber
+		di.uncompressed = di.uncompressed[:0]
+		return nil
+	}
+
+	destChunkDataLoc += start
+	curChunkEnd += end
+
+	// read the number of docs reside in the chunk
+	numDocs, read := binary.Uvarint(s.mem[destChunkDataLoc : destChunkDataLoc+binary.MaxVarintLen64])
+	if read <= 0 {
+		return fmt.Errorf("failed to read the chunk")
+	}
+	chunkMetaLoc := destChunkDataLoc + uint64(read)
+
+	offset := uint64(0)
+	if cap(di.curChunkHeader) < int(numDocs) {
+		di.curChunkHeader = make([]MetaData, int(numDocs))
+	} else {
+		di.curChunkHeader = di.curChunkHeader[:int(numDocs)]
+	}
+	for i := 0; i < int(numDocs); i++ {
+		di.curChunkHeader[i].DocNum, read = binary.Uvarint(s.mem[chunkMetaLoc+offset : chunkMetaLoc+offset+binary.MaxVarintLen64])
+		offset += uint64(read)
+		di.curChunkHeader[i].DocDvOffset, read = binary.Uvarint(s.mem[chunkMetaLoc+offset : chunkMetaLoc+offset+binary.MaxVarintLen64])
+		offset += uint64(read)
+	}
+
+	compressedDataLoc := chunkMetaLoc + offset
+	dataLength := curChunkEnd - compressedDataLoc
+	di.curChunkData = s.mem[compressedDataLoc : compressedDataLoc+dataLength]
+	di.curChunkNum = chunkNumber
+	di.uncompressed = di.uncompressed[:0]
+	return nil
+}
+
+func (di *docValueReader) iterateAllDocValues(s *SegmentBase, visitor docNumTermsVisitor) error {
+	for i := 0; i < len(di.chunkOffsets); i++ {
+		err := di.loadDvChunk(uint64(i), s)
+		if err != nil {
+			return err
+		}
+		if di.curChunkData == nil || len(di.curChunkHeader) == 0 {
+			continue
+		}
+
+		// uncompress the already loaded data
+		uncompressed, err := snappy.Decode(di.uncompressed[:cap(di.uncompressed)], di.curChunkData)
+		if err != nil {
+			return err
+		}
+		di.uncompressed = uncompressed
+
+		start := uint64(0)
+		for _, entry := range di.curChunkHeader {
+			err = visitor(entry.DocNum, uncompressed[start:entry.DocDvOffset])
+			if err != nil {
+				return err
+			}
+
+			start = entry.DocDvOffset
+		}
+	}
+
+	return nil
+}
+
+func (di *docValueReader) visitDocValues(docNum uint64,
+	visitor index.DocumentFieldTermVisitor) error {
+	// binary search the term locations for the docNum
+	start, end := di.getDocValueLocs(docNum)
+	if start == math.MaxUint64 || end == math.MaxUint64 || start == end {
+		return nil
+	}
+
+	var uncompressed []byte
+	var err error
+	// use the uncompressed copy if available
+	if len(di.uncompressed) > 0 {
+		uncompressed = di.uncompressed
+	} else {
+		// uncompress the already loaded data
+		uncompressed, err = snappy.Decode(di.uncompressed[:cap(di.uncompressed)], di.curChunkData)
+		if err != nil {
+			return err
+		}
+		di.uncompressed = uncompressed
+	}
+
+	// pick the terms for the given docNum
+	uncompressed = uncompressed[start:end]
+	for {
+		i := bytes.Index(uncompressed, termSeparatorSplitSlice)
+		if i < 0 {
+			break
+		}
+
+		visitor(di.field, uncompressed[0:i])
+		uncompressed = uncompressed[i+1:]
+	}
+
+	return nil
+}
+
+func (di *docValueReader) getDocValueLocs(docNum uint64) (uint64, uint64) {
+	i := sort.Search(len(di.curChunkHeader), func(i int) bool {
+		return di.curChunkHeader[i].DocNum >= docNum
+	})
+	if i < len(di.curChunkHeader) && di.curChunkHeader[i].DocNum == docNum {
+		return ReadDocValueBoundary(i, di.curChunkHeader)
+	}
+	return math.MaxUint64, math.MaxUint64
+}
+
+// VisitDocumentFieldTerms is an implementation of the
+// DocumentFieldTermVisitable interface
+func (s *SegmentBase) VisitDocumentFieldTerms(localDocNum uint64, fields []string,
+	visitor index.DocumentFieldTermVisitor, dvsIn segment.DocVisitState) (
+	segment.DocVisitState, error) {
+	dvs, ok := dvsIn.(*docVisitState)
+	if !ok || dvs == nil {
+		dvs = &docVisitState{}
+	} else {
+		if dvs.segment != s {
+			dvs.segment = s
+			dvs.dvrs = nil
+		}
+	}
+
+	var fieldIDPlus1 uint16
+	if dvs.dvrs == nil {
+		dvs.dvrs = make(map[uint16]*docValueReader, len(fields))
+		for _, field := range fields {
+			if fieldIDPlus1, ok = s.fieldsMap[field]; !ok {
+				continue
+			}
+			fieldID := fieldIDPlus1 - 1
+			if dvIter, exists := s.fieldDvReaders[fieldID]; exists &&
+				dvIter != nil {
+				dvs.dvrs[fieldID] = dvIter.cloneInto(dvs.dvrs[fieldID])
+			}
+		}
+	}
+
+	// find the chunkNumber where the docValues are stored
+	// NOTE: doc values continue to use legacy chunk mode
+	chunkFactor, err := getChunkSize(LegacyChunkMode, 0, 0)
+	if err != nil {
+		return nil, err
+	}
+	docInChunk := localDocNum / chunkFactor
+	var dvr *docValueReader
+	for _, field := range fields {
+		if fieldIDPlus1, ok = s.fieldsMap[field]; !ok {
+			continue
+		}
+		fieldID := fieldIDPlus1 - 1
+		if dvr, ok = dvs.dvrs[fieldID]; ok && dvr != nil {
+			// check if the chunk is already loaded
+			if docInChunk != dvr.curChunkNumber() {
+				err := dvr.loadDvChunk(docInChunk, s)
+				if err != nil {
+					return dvs, err
+				}
+			}
+
+			_ = dvr.visitDocValues(localDocNum, visitor)
+		}
+	}
+	return dvs, nil
+}
+
+// VisitableDocValueFields returns the list of fields with
+// persisted doc value terms ready to be visitable using the
+// VisitDocumentFieldTerms method.
+func (s *SegmentBase) VisitableDocValueFields() ([]string, error) {
+	return s.fieldDvNames, nil
+}

vendor/github.com/blevesearch/zap/v15/enumerator.go

@@ -0,0 +1,138 @@
+//  Copyright (c) 2018 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+
+	"github.com/couchbase/vellum"
+)
+
+// enumerator provides an ordered traversal of multiple vellum
+// iterators.  Like JOIN of iterators, the enumerator produces a
+// sequence of (key, iteratorIndex, value) tuples, sorted by key ASC,
+// then iteratorIndex ASC, where the same key might be seen or
+// repeated across multiple child iterators.
+type enumerator struct {
+	itrs   []vellum.Iterator
+	currKs [][]byte
+	currVs []uint64
+
+	lowK    []byte
+	lowIdxs []int
+	lowCurr int
+}
+
+// newEnumerator returns a new enumerator over the vellum Iterators
+func newEnumerator(itrs []vellum.Iterator) (*enumerator, error) {
+	rv := &enumerator{
+		itrs:    itrs,
+		currKs:  make([][]byte, len(itrs)),
+		currVs:  make([]uint64, len(itrs)),
+		lowIdxs: make([]int, 0, len(itrs)),
+	}
+	for i, itr := range rv.itrs {
+		rv.currKs[i], rv.currVs[i] = itr.Current()
+	}
+	rv.updateMatches(false)
+	if rv.lowK == nil && len(rv.lowIdxs) == 0 {
+		return rv, vellum.ErrIteratorDone
+	}
+	return rv, nil
+}
+
+// updateMatches maintains the low key matches based on the currKs
+func (m *enumerator) updateMatches(skipEmptyKey bool) {
+	m.lowK = nil
+	m.lowIdxs = m.lowIdxs[:0]
+	m.lowCurr = 0
+
+	for i, key := range m.currKs {
+		if (key == nil && m.currVs[i] == 0) || // in case of empty iterator
+			(len(key) == 0 && skipEmptyKey) { // skip empty keys
+			continue
+		}
+
+		cmp := bytes.Compare(key, m.lowK)
+		if cmp < 0 || len(m.lowIdxs) == 0 {
+			// reached a new low
+			m.lowK = key
+			m.lowIdxs = m.lowIdxs[:0]
+			m.lowIdxs = append(m.lowIdxs, i)
+		} else if cmp == 0 {
+			m.lowIdxs = append(m.lowIdxs, i)
+		}
+	}
+}
+
+// Current returns the enumerator's current key, iterator-index, and
+// value.  If the enumerator is not pointing at a valid value (because
+// Next returned an error previously), Current will return nil,0,0.
+func (m *enumerator) Current() ([]byte, int, uint64) {
+	var i int
+	var v uint64
+	if m.lowCurr < len(m.lowIdxs) {
+		i = m.lowIdxs[m.lowCurr]
+		v = m.currVs[i]
+	}
+	return m.lowK, i, v
+}
+
+// GetLowIdxsAndValues will return all of the iterator indices
+// which point to the current key, and their corresponding
+// values.  This can be used by advanced caller which may need
+// to peek into these other sets of data before processing.
+func (m *enumerator) GetLowIdxsAndValues() ([]int, []uint64) {
+	values := make([]uint64, 0, len(m.lowIdxs))
+	for _, idx := range m.lowIdxs {
+		values = append(values, m.currVs[idx])
+	}
+	return m.lowIdxs, values
+}
+
+// Next advances the enumerator to the next key/iterator/value result,
+// else vellum.ErrIteratorDone is returned.
+func (m *enumerator) Next() error {
+	m.lowCurr += 1
+	if m.lowCurr >= len(m.lowIdxs) {
+		// move all the current low iterators forwards
+		for _, vi := range m.lowIdxs {
+			err := m.itrs[vi].Next()
+			if err != nil && err != vellum.ErrIteratorDone {
+				return err
+			}
+			m.currKs[vi], m.currVs[vi] = m.itrs[vi].Current()
+		}
+		// can skip any empty keys encountered at this point
+		m.updateMatches(true)
+	}
+	if m.lowK == nil && len(m.lowIdxs) == 0 {
+		return vellum.ErrIteratorDone
+	}
+	return nil
+}
+
+// Close all the underlying Iterators.  The first error, if any, will
+// be returned.
+func (m *enumerator) Close() error {
+	var rv error
+	for _, itr := range m.itrs {
+		err := itr.Close()
+		if rv == nil {
+			rv = err
+		}
+	}
+	return rv
+}

vendor/github.com/blevesearch/zap/v15/go.mod

@@ -0,0 +1,12 @@
+module github.com/blevesearch/zap/v15
+
+go 1.12
+
+require (
+	github.com/RoaringBitmap/roaring v0.4.23
+	github.com/blevesearch/bleve v1.0.12
+	github.com/blevesearch/mmap-go v1.0.2
+	github.com/couchbase/vellum v1.0.2
+	github.com/golang/snappy v0.0.1
+	github.com/spf13/cobra v0.0.5
+)

vendor/github.com/blevesearch/zap/v15/intDecoder.go

@@ -0,0 +1,118 @@
+//  Copyright (c) 2019 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"encoding/binary"
+	"fmt"
+
+	"github.com/blevesearch/bleve/index/scorch/segment"
+)
+
+type chunkedIntDecoder struct {
+	startOffset     uint64
+	dataStartOffset uint64
+	chunkOffsets    []uint64
+	curChunkBytes   []byte
+	data            []byte
+	r               *segment.MemUvarintReader
+}
+
+// newChunkedIntDecoder expects an optional or reset chunkedIntDecoder for better reuse.
+func newChunkedIntDecoder(buf []byte, offset uint64, rv *chunkedIntDecoder) *chunkedIntDecoder {
+	if rv == nil {
+		rv = &chunkedIntDecoder{startOffset: offset, data: buf}
+	} else {
+		rv.startOffset = offset
+		rv.data = buf
+	}
+
+	var n, numChunks uint64
+	var read int
+	if offset == termNotEncoded {
+		numChunks = 0
+	} else {
+		numChunks, read = binary.Uvarint(buf[offset+n : offset+n+binary.MaxVarintLen64])
+	}
+
+	n += uint64(read)
+	if cap(rv.chunkOffsets) >= int(numChunks) {
+		rv.chunkOffsets = rv.chunkOffsets[:int(numChunks)]
+	} else {
+		rv.chunkOffsets = make([]uint64, int(numChunks))
+	}
+	for i := 0; i < int(numChunks); i++ {
+		rv.chunkOffsets[i], read = binary.Uvarint(buf[offset+n : offset+n+binary.MaxVarintLen64])
+		n += uint64(read)
+	}
+	rv.dataStartOffset = offset + n
+	return rv
+}
+
+func (d *chunkedIntDecoder) loadChunk(chunk int) error {
+	if d.startOffset == termNotEncoded {
+		d.r = segment.NewMemUvarintReader([]byte(nil))
+		return nil
+	}
+
+	if chunk >= len(d.chunkOffsets) {
+		return fmt.Errorf("tried to load freq chunk that doesn't exist %d/(%d)",
+			chunk, len(d.chunkOffsets))
+	}
+
+	end, start := d.dataStartOffset, d.dataStartOffset
+	s, e := readChunkBoundary(chunk, d.chunkOffsets)
+	start += s
+	end += e
+	d.curChunkBytes = d.data[start:end]
+	if d.r == nil {
+		d.r = segment.NewMemUvarintReader(d.curChunkBytes)
+	} else {
+		d.r.Reset(d.curChunkBytes)
+	}
+
+	return nil
+}
+
+func (d *chunkedIntDecoder) reset() {
+	d.startOffset = 0
+	d.dataStartOffset = 0
+	d.chunkOffsets = d.chunkOffsets[:0]
+	d.curChunkBytes = d.curChunkBytes[:0]
+	d.data = d.data[:0]
+	if d.r != nil {
+		d.r.Reset([]byte(nil))
+	}
+}
+
+func (d *chunkedIntDecoder) isNil() bool {
+	return d.curChunkBytes == nil || len(d.curChunkBytes) == 0
+}
+
+func (d *chunkedIntDecoder) readUvarint() (uint64, error) {
+	return d.r.ReadUvarint()
+}
+
+func (d *chunkedIntDecoder) SkipUvarint() {
+	d.r.SkipUvarint()
+}
+
+func (d *chunkedIntDecoder) SkipBytes(count int) {
+	d.r.SkipBytes(count)
+}
+
+func (d *chunkedIntDecoder) Len() int {
+	return d.r.Len()
+}

vendor/github.com/blevesearch/zap/v15/intcoder.go

@@ -0,0 +1,206 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+)
+
+// We can safely use 0 to represent termNotEncoded since 0
+// could never be a valid address for term location information.
+// (stored field index is always non-empty and earlier in the
+// file)
+const termNotEncoded = 0
+
+type chunkedIntCoder struct {
+	final     []byte
+	chunkSize uint64
+	chunkBuf  bytes.Buffer
+	chunkLens []uint64
+	currChunk uint64
+
+	buf []byte
+}
+
+// newChunkedIntCoder returns a new chunk int coder which packs data into
+// chunks based on the provided chunkSize and supports up to the specified
+// maxDocNum
+func newChunkedIntCoder(chunkSize uint64, maxDocNum uint64) *chunkedIntCoder {
+	total := maxDocNum/chunkSize + 1
+	rv := &chunkedIntCoder{
+		chunkSize: chunkSize,
+		chunkLens: make([]uint64, total),
+		final:     make([]byte, 0, 64),
+	}
+
+	return rv
+}
+
+// Reset lets you reuse this chunked int coder.  buffers are reset and reused
+// from previous use.  you cannot change the chunk size or max doc num.
+func (c *chunkedIntCoder) Reset() {
+	c.final = c.final[:0]
+	c.chunkBuf.Reset()
+	c.currChunk = 0
+	for i := range c.chunkLens {
+		c.chunkLens[i] = 0
+	}
+}
+
+// SetChunkSize changes the chunk size.  It is only valid to do so
+// with a new chunkedIntCoder, or immediately after calling Reset()
+func (c *chunkedIntCoder) SetChunkSize(chunkSize uint64, maxDocNum uint64) {
+	total := int(maxDocNum/chunkSize + 1)
+	c.chunkSize = chunkSize
+	if cap(c.chunkLens) < total {
+		c.chunkLens = make([]uint64, total)
+	} else {
+		c.chunkLens = c.chunkLens[:total]
+	}
+}
+
+// Add encodes the provided integers into the correct chunk for the provided
+// doc num.  You MUST call Add() with increasing docNums.
+func (c *chunkedIntCoder) Add(docNum uint64, vals ...uint64) error {
+	chunk := docNum / c.chunkSize
+	if chunk != c.currChunk {
+		// starting a new chunk
+		c.Close()
+		c.chunkBuf.Reset()
+		c.currChunk = chunk
+	}
+
+	if len(c.buf) < binary.MaxVarintLen64 {
+		c.buf = make([]byte, binary.MaxVarintLen64)
+	}
+
+	for _, val := range vals {
+		wb := binary.PutUvarint(c.buf, val)
+		_, err := c.chunkBuf.Write(c.buf[:wb])
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (c *chunkedIntCoder) AddBytes(docNum uint64, buf []byte) error {
+	chunk := docNum / c.chunkSize
+	if chunk != c.currChunk {
+		// starting a new chunk
+		c.Close()
+		c.chunkBuf.Reset()
+		c.currChunk = chunk
+	}
+
+	_, err := c.chunkBuf.Write(buf)
+	return err
+}
+
+// Close indicates you are done calling Add() this allows the final chunk
+// to be encoded.
+func (c *chunkedIntCoder) Close() {
+	encodingBytes := c.chunkBuf.Bytes()
+	c.chunkLens[c.currChunk] = uint64(len(encodingBytes))
+	c.final = append(c.final, encodingBytes...)
+	c.currChunk = uint64(cap(c.chunkLens)) // sentinel to detect double close
+}
+
+// Write commits all the encoded chunked integers to the provided writer.
+func (c *chunkedIntCoder) Write(w io.Writer) (int, error) {
+	bufNeeded := binary.MaxVarintLen64 * (1 + len(c.chunkLens))
+	if len(c.buf) < bufNeeded {
+		c.buf = make([]byte, bufNeeded)
+	}
+	buf := c.buf
+
+	// convert the chunk lengths into chunk offsets
+	chunkOffsets := modifyLengthsToEndOffsets(c.chunkLens)
+
+	// write out the number of chunks & each chunk offsets
+	n := binary.PutUvarint(buf, uint64(len(chunkOffsets)))
+	for _, chunkOffset := range chunkOffsets {
+		n += binary.PutUvarint(buf[n:], chunkOffset)
+	}
+
+	tw, err := w.Write(buf[:n])
+	if err != nil {
+		return tw, err
+	}
+
+	// write out the data
+	nw, err := w.Write(c.final)
+	tw += nw
+	if err != nil {
+		return tw, err
+	}
+	return tw, nil
+}
+
+// writeAt commits all the encoded chunked integers to the provided writer
+// and returns the starting offset, total bytes written and an error
+func (c *chunkedIntCoder) writeAt(w io.Writer) (uint64, int, error) {
+	startOffset := uint64(termNotEncoded)
+	if len(c.final) <= 0 {
+		return startOffset, 0, nil
+	}
+
+	if chw := w.(*CountHashWriter); chw != nil {
+		startOffset = uint64(chw.Count())
+	}
+
+	tw, err := c.Write(w)
+	return startOffset, tw, err
+}
+
+func (c *chunkedIntCoder) FinalSize() int {
+	return len(c.final)
+}
+
+// modifyLengthsToEndOffsets converts the chunk length array
+// to a chunk offset array. The readChunkBoundary
+// will figure out the start and end of every chunk from
+// these offsets. Starting offset of i'th index is stored
+// in i-1'th position except for 0'th index and ending offset
+// is stored at i'th index position.
+// For 0'th element, starting position is always zero.
+// eg:
+// Lens ->  5 5 5 5 => 5 10 15 20
+// Lens ->  0 5 0 5 => 0 5 5 10
+// Lens ->  0 0 0 5 => 0 0 0 5
+// Lens ->  5 0 0 0 => 5 5 5 5
+// Lens ->  0 5 0 0 => 0 5 5 5
+// Lens ->  0 0 5 0 => 0 0 5 5
+func modifyLengthsToEndOffsets(lengths []uint64) []uint64 {
+	var runningOffset uint64
+	var index, i int
+	for i = 1; i <= len(lengths); i++ {
+		runningOffset += lengths[i-1]
+		lengths[index] = runningOffset
+		index++
+	}
+	return lengths
+}
+
+func readChunkBoundary(chunk int, offsets []uint64) (uint64, uint64) {
+	var start uint64
+	if chunk > 0 {
+		start = offsets[chunk-1]
+	}
+	return start, offsets[chunk]
+}

vendor/github.com/blevesearch/zap/v15/merge.go

@@ -0,0 +1,852 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math"
+	"os"
+	"sort"
+
+	"github.com/RoaringBitmap/roaring"
+	seg "github.com/blevesearch/bleve/index/scorch/segment"
+	"github.com/couchbase/vellum"
+	"github.com/golang/snappy"
+)
+
+var DefaultFileMergerBufferSize = 1024 * 1024
+
+const docDropped = math.MaxUint64 // sentinel docNum to represent a deleted doc
+
+// Merge takes a slice of segments and bit masks describing which
+// documents may be dropped, and creates a new segment containing the
+// remaining data.  This new segment is built at the specified path.
+func (*ZapPlugin) Merge(segments []seg.Segment, drops []*roaring.Bitmap, path string,
+	closeCh chan struct{}, s seg.StatsReporter) (
+	[][]uint64, uint64, error) {
+
+	segmentBases := make([]*SegmentBase, len(segments))
+	for segmenti, segment := range segments {
+		switch segmentx := segment.(type) {
+		case *Segment:
+			segmentBases[segmenti] = &segmentx.SegmentBase
+		case *SegmentBase:
+			segmentBases[segmenti] = segmentx
+		default:
+			panic(fmt.Sprintf("oops, unexpected segment type: %T", segment))
+		}
+	}
+	return mergeSegmentBases(segmentBases, drops, path, DefaultChunkMode, closeCh, s)
+}
+
+func mergeSegmentBases(segmentBases []*SegmentBase, drops []*roaring.Bitmap, path string,
+	chunkMode uint32, closeCh chan struct{}, s seg.StatsReporter) (
+	[][]uint64, uint64, error) {
+	flag := os.O_RDWR | os.O_CREATE
+
+	f, err := os.OpenFile(path, flag, 0600)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	cleanup := func() {
+		_ = f.Close()
+		_ = os.Remove(path)
+	}
+
+	// buffer the output
+	br := bufio.NewWriterSize(f, DefaultFileMergerBufferSize)
+
+	// wrap it for counting (tracking offsets)
+	cr := NewCountHashWriterWithStatsReporter(br, s)
+
+	newDocNums, numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset, _, _, _, err :=
+		MergeToWriter(segmentBases, drops, chunkMode, cr, closeCh)
+	if err != nil {
+		cleanup()
+		return nil, 0, err
+	}
+
+	err = persistFooter(numDocs, storedIndexOffset, fieldsIndexOffset,
+		docValueOffset, chunkMode, cr.Sum32(), cr)
+	if err != nil {
+		cleanup()
+		return nil, 0, err
+	}
+
+	err = br.Flush()
+	if err != nil {
+		cleanup()
+		return nil, 0, err
+	}
+
+	err = f.Sync()
+	if err != nil {
+		cleanup()
+		return nil, 0, err
+	}
+
+	err = f.Close()
+	if err != nil {
+		cleanup()
+		return nil, 0, err
+	}
+
+	return newDocNums, uint64(cr.Count()), nil
+}
+
+func MergeToWriter(segments []*SegmentBase, drops []*roaring.Bitmap,
+	chunkMode uint32, cr *CountHashWriter, closeCh chan struct{}) (
+	newDocNums [][]uint64,
+	numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset uint64,
+	dictLocs []uint64, fieldsInv []string, fieldsMap map[string]uint16,
+	err error) {
+	docValueOffset = uint64(fieldNotUninverted)
+
+	var fieldsSame bool
+	fieldsSame, fieldsInv = mergeFields(segments)
+	fieldsMap = mapFields(fieldsInv)
+
+	numDocs = computeNewDocCount(segments, drops)
+
+	if isClosed(closeCh) {
+		return nil, 0, 0, 0, 0, nil, nil, nil, seg.ErrClosed
+	}
+
+	if numDocs > 0 {
+		storedIndexOffset, newDocNums, err = mergeStoredAndRemap(segments, drops,
+			fieldsMap, fieldsInv, fieldsSame, numDocs, cr, closeCh)
+		if err != nil {
+			return nil, 0, 0, 0, 0, nil, nil, nil, err
+		}
+
+		dictLocs, docValueOffset, err = persistMergedRest(segments, drops,
+			fieldsInv, fieldsMap, fieldsSame,
+			newDocNums, numDocs, chunkMode, cr, closeCh)
+		if err != nil {
+			return nil, 0, 0, 0, 0, nil, nil, nil, err
+		}
+	} else {
+		dictLocs = make([]uint64, len(fieldsInv))
+	}
+
+	fieldsIndexOffset, err = persistFields(fieldsInv, cr, dictLocs)
+	if err != nil {
+		return nil, 0, 0, 0, 0, nil, nil, nil, err
+	}
+
+	return newDocNums, numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset, dictLocs, fieldsInv, fieldsMap, nil
+}
+
+// mapFields takes the fieldsInv list and returns a map of fieldName
+// to fieldID+1
+func mapFields(fields []string) map[string]uint16 {
+	rv := make(map[string]uint16, len(fields))
+	for i, fieldName := range fields {
+		rv[fieldName] = uint16(i) + 1
+	}
+	return rv
+}
+
+// computeNewDocCount determines how many documents will be in the newly
+// merged segment when obsoleted docs are dropped
+func computeNewDocCount(segments []*SegmentBase, drops []*roaring.Bitmap) uint64 {
+	var newDocCount uint64
+	for segI, segment := range segments {
+		newDocCount += segment.numDocs
+		if drops[segI] != nil {
+			newDocCount -= drops[segI].GetCardinality()
+		}
+	}
+	return newDocCount
+}
+
+func persistMergedRest(segments []*SegmentBase, dropsIn []*roaring.Bitmap,
+	fieldsInv []string, fieldsMap map[string]uint16, fieldsSame bool,
+	newDocNumsIn [][]uint64, newSegDocCount uint64, chunkMode uint32,
+	w *CountHashWriter, closeCh chan struct{}) ([]uint64, uint64, error) {
+
+	var bufMaxVarintLen64 []byte = make([]byte, binary.MaxVarintLen64)
+	var bufLoc []uint64
+
+	var postings *PostingsList
+	var postItr *PostingsIterator
+
+	rv := make([]uint64, len(fieldsInv))
+	fieldDvLocsStart := make([]uint64, len(fieldsInv))
+	fieldDvLocsEnd := make([]uint64, len(fieldsInv))
+
+	// these int coders are initialized with chunk size 1024
+	// however this will be reset to the correct chunk size
+	// while processing each individual field-term section
+	tfEncoder := newChunkedIntCoder(1024, newSegDocCount-1)
+	locEncoder := newChunkedIntCoder(1024, newSegDocCount-1)
+
+	var vellumBuf bytes.Buffer
+	newVellum, err := vellum.New(&vellumBuf, nil)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	newRoaring := roaring.NewBitmap()
+
+	// for each field
+	for fieldID, fieldName := range fieldsInv {
+
+		// collect FST iterators from all active segments for this field
+		var newDocNums [][]uint64
+		var drops []*roaring.Bitmap
+		var dicts []*Dictionary
+		var itrs []vellum.Iterator
+
+		var segmentsInFocus []*SegmentBase
+
+		for segmentI, segment := range segments {
+
+			// check for the closure in meantime
+			if isClosed(closeCh) {
+				return nil, 0, seg.ErrClosed
+			}
+
+			dict, err2 := segment.dictionary(fieldName)
+			if err2 != nil {
+				return nil, 0, err2
+			}
+			if dict != nil && dict.fst != nil {
+				itr, err2 := dict.fst.Iterator(nil, nil)
+				if err2 != nil && err2 != vellum.ErrIteratorDone {
+					return nil, 0, err2
+				}
+				if itr != nil {
+					newDocNums = append(newDocNums, newDocNumsIn[segmentI])
+					if dropsIn[segmentI] != nil && !dropsIn[segmentI].IsEmpty() {
+						drops = append(drops, dropsIn[segmentI])
+					} else {
+						drops = append(drops, nil)
+					}
+					dicts = append(dicts, dict)
+					itrs = append(itrs, itr)
+					segmentsInFocus = append(segmentsInFocus, segment)
+				}
+			}
+		}
+
+		var prevTerm []byte
+
+		newRoaring.Clear()
+
+		var lastDocNum, lastFreq, lastNorm uint64
+
+		// determines whether to use "1-hit" encoding optimization
+		// when a term appears in only 1 doc, with no loc info,
+		// has freq of 1, and the docNum fits into 31-bits
+		use1HitEncoding := func(termCardinality uint64) (bool, uint64, uint64) {
+			if termCardinality == uint64(1) && locEncoder.FinalSize() <= 0 {
+				docNum := uint64(newRoaring.Minimum())
+				if under32Bits(docNum) && docNum == lastDocNum && lastFreq == 1 {
+					return true, docNum, lastNorm
+				}
+			}
+			return false, 0, 0
+		}
+
+		finishTerm := func(term []byte) error {
+			tfEncoder.Close()
+			locEncoder.Close()
+
+			postingsOffset, err := writePostings(newRoaring,
+				tfEncoder, locEncoder, use1HitEncoding, w, bufMaxVarintLen64)
+			if err != nil {
+				return err
+			}
+
+			if postingsOffset > 0 {
+				err = newVellum.Insert(term, postingsOffset)
+				if err != nil {
+					return err
+				}
+			}
+
+			newRoaring.Clear()
+
+			tfEncoder.Reset()
+			locEncoder.Reset()
+
+			lastDocNum = 0
+			lastFreq = 0
+			lastNorm = 0
+
+			return nil
+		}
+
+		enumerator, err := newEnumerator(itrs)
+
+		for err == nil {
+			term, itrI, postingsOffset := enumerator.Current()
+
+			if !bytes.Equal(prevTerm, term) {
+				// check for the closure in meantime
+				if isClosed(closeCh) {
+					return nil, 0, seg.ErrClosed
+				}
+
+				// if the term changed, write out the info collected
+				// for the previous term
+				err = finishTerm(prevTerm)
+				if err != nil {
+					return nil, 0, err
+				}
+			}
+			if !bytes.Equal(prevTerm, term) || prevTerm == nil {
+				// compute cardinality of field-term in new seg
+				var newCard uint64
+				lowItrIdxs, lowItrVals := enumerator.GetLowIdxsAndValues()
+				for i, idx := range lowItrIdxs {
+					pl, err := dicts[idx].postingsListFromOffset(lowItrVals[i], drops[idx], nil)
+					if err != nil {
+						return nil, 0, err
+					}
+					newCard += pl.Count()
+				}
+				// compute correct chunk size with this
+				chunkSize, err := getChunkSize(chunkMode, newCard, newSegDocCount)
+				if err != nil {
+					return nil, 0, err
+				}
+				// update encoders chunk
+				tfEncoder.SetChunkSize(chunkSize, newSegDocCount-1)
+				locEncoder.SetChunkSize(chunkSize, newSegDocCount-1)
+			}
+
+			postings, err = dicts[itrI].postingsListFromOffset(
+				postingsOffset, drops[itrI], postings)
+			if err != nil {
+				return nil, 0, err
+			}
+
+			postItr = postings.iterator(true, true, true, postItr)
+
+			// can no longer optimize by copying, since chunk factor could have changed
+			lastDocNum, lastFreq, lastNorm, bufLoc, err = mergeTermFreqNormLocs(
+				fieldsMap, term, postItr, newDocNums[itrI], newRoaring,
+				tfEncoder, locEncoder, bufLoc)
+
+			if err != nil {
+				return nil, 0, err
+			}
+
+			prevTerm = prevTerm[:0] // copy to prevTerm in case Next() reuses term mem
+			prevTerm = append(prevTerm, term...)
+
+			err = enumerator.Next()
+		}
+		if err != vellum.ErrIteratorDone {
+			return nil, 0, err
+		}
+
+		err = finishTerm(prevTerm)
+		if err != nil {
+			return nil, 0, err
+		}
+
+		dictOffset := uint64(w.Count())
+
+		err = newVellum.Close()
+		if err != nil {
+			return nil, 0, err
+		}
+		vellumData := vellumBuf.Bytes()
+
+		// write out the length of the vellum data
+		n := binary.PutUvarint(bufMaxVarintLen64, uint64(len(vellumData)))
+		_, err = w.Write(bufMaxVarintLen64[:n])
+		if err != nil {
+			return nil, 0, err
+		}
+
+		// write this vellum to disk
+		_, err = w.Write(vellumData)
+		if err != nil {
+			return nil, 0, err
+		}
+
+		rv[fieldID] = dictOffset
+
+		// get the field doc value offset (start)
+		fieldDvLocsStart[fieldID] = uint64(w.Count())
+
+		// update the field doc values
+		// NOTE: doc values continue to use legacy chunk mode
+		chunkSize, err := getChunkSize(LegacyChunkMode, 0, 0)
+		if err != nil {
+			return nil, 0, err
+		}
+		fdvEncoder := newChunkedContentCoder(chunkSize, newSegDocCount-1, w, true)
+
+		fdvReadersAvailable := false
+		var dvIterClone *docValueReader
+		for segmentI, segment := range segmentsInFocus {
+			// check for the closure in meantime
+			if isClosed(closeCh) {
+				return nil, 0, seg.ErrClosed
+			}
+
+			fieldIDPlus1 := uint16(segment.fieldsMap[fieldName])
+			if dvIter, exists := segment.fieldDvReaders[fieldIDPlus1-1]; exists &&
+				dvIter != nil {
+				fdvReadersAvailable = true
+				dvIterClone = dvIter.cloneInto(dvIterClone)
+				err = dvIterClone.iterateAllDocValues(segment, func(docNum uint64, terms []byte) error {
+					if newDocNums[segmentI][docNum] == docDropped {
+						return nil
+					}
+					err := fdvEncoder.Add(newDocNums[segmentI][docNum], terms)
+					if err != nil {
+						return err
+					}
+					return nil
+				})
+				if err != nil {
+					return nil, 0, err
+				}
+			}
+		}
+
+		if fdvReadersAvailable {
+			err = fdvEncoder.Close()
+			if err != nil {
+				return nil, 0, err
+			}
+
+			// persist the doc value details for this field
+			_, err = fdvEncoder.Write()
+			if err != nil {
+				return nil, 0, err
+			}
+
+			// get the field doc value offset (end)
+			fieldDvLocsEnd[fieldID] = uint64(w.Count())
+		} else {
+			fieldDvLocsStart[fieldID] = fieldNotUninverted
+			fieldDvLocsEnd[fieldID] = fieldNotUninverted
+		}
+
+		// reset vellum buffer and vellum builder
+		vellumBuf.Reset()
+		err = newVellum.Reset(&vellumBuf)
+		if err != nil {
+			return nil, 0, err
+		}
+	}
+
+	fieldDvLocsOffset := uint64(w.Count())
+
+	buf := bufMaxVarintLen64
+	for i := 0; i < len(fieldDvLocsStart); i++ {
+		n := binary.PutUvarint(buf, fieldDvLocsStart[i])
+		_, err := w.Write(buf[:n])
+		if err != nil {
+			return nil, 0, err
+		}
+		n = binary.PutUvarint(buf, fieldDvLocsEnd[i])
+		_, err = w.Write(buf[:n])
+		if err != nil {
+			return nil, 0, err
+		}
+	}
+
+	return rv, fieldDvLocsOffset, nil
+}
+
+func mergeTermFreqNormLocs(fieldsMap map[string]uint16, term []byte, postItr *PostingsIterator,
+	newDocNums []uint64, newRoaring *roaring.Bitmap,
+	tfEncoder *chunkedIntCoder, locEncoder *chunkedIntCoder, bufLoc []uint64) (
+	lastDocNum uint64, lastFreq uint64, lastNorm uint64, bufLocOut []uint64, err error) {
+	next, err := postItr.Next()
+	for next != nil && err == nil {
+		hitNewDocNum := newDocNums[next.Number()]
+		if hitNewDocNum == docDropped {
+			return 0, 0, 0, nil, fmt.Errorf("see hit with dropped docNum")
+		}
+
+		newRoaring.Add(uint32(hitNewDocNum))
+
+		nextFreq := next.Frequency()
+		var nextNorm uint64
+		if pi, ok := next.(*Posting); ok {
+			nextNorm = pi.NormUint64()
+		} else {
+			return 0, 0, 0, nil, fmt.Errorf("unexpected posting type %T", next)
+		}
+
+		locs := next.Locations()
+
+		err = tfEncoder.Add(hitNewDocNum,
+			encodeFreqHasLocs(nextFreq, len(locs) > 0), nextNorm)
+		if err != nil {
+			return 0, 0, 0, nil, err
+		}
+
+		if len(locs) > 0 {
+			numBytesLocs := 0
+			for _, loc := range locs {
+				ap := loc.ArrayPositions()
+				numBytesLocs += totalUvarintBytes(uint64(fieldsMap[loc.Field()]-1),
+					loc.Pos(), loc.Start(), loc.End(), uint64(len(ap)), ap)
+			}
+
+			err = locEncoder.Add(hitNewDocNum, uint64(numBytesLocs))
+			if err != nil {
+				return 0, 0, 0, nil, err
+			}
+
+			for _, loc := range locs {
+				ap := loc.ArrayPositions()
+				if cap(bufLoc) < 5+len(ap) {
+					bufLoc = make([]uint64, 0, 5+len(ap))
+				}
+				args := bufLoc[0:5]
+				args[0] = uint64(fieldsMap[loc.Field()] - 1)
+				args[1] = loc.Pos()
+				args[2] = loc.Start()
+				args[3] = loc.End()
+				args[4] = uint64(len(ap))
+				args = append(args, ap...)
+				err = locEncoder.Add(hitNewDocNum, args...)
+				if err != nil {
+					return 0, 0, 0, nil, err
+				}
+			}
+		}
+
+		lastDocNum = hitNewDocNum
+		lastFreq = nextFreq
+		lastNorm = nextNorm
+
+		next, err = postItr.Next()
+	}
+
+	return lastDocNum, lastFreq, lastNorm, bufLoc, err
+}
+
+func writePostings(postings *roaring.Bitmap, tfEncoder, locEncoder *chunkedIntCoder,
+	use1HitEncoding func(uint64) (bool, uint64, uint64),
+	w *CountHashWriter, bufMaxVarintLen64 []byte) (
+	offset uint64, err error) {
+	termCardinality := postings.GetCardinality()
+	if termCardinality <= 0 {
+		return 0, nil
+	}
+
+	if use1HitEncoding != nil {
+		encodeAs1Hit, docNum1Hit, normBits1Hit := use1HitEncoding(termCardinality)
+		if encodeAs1Hit {
+			return FSTValEncode1Hit(docNum1Hit, normBits1Hit), nil
+		}
+	}
+
+	var tfOffset uint64
+	tfOffset, _, err = tfEncoder.writeAt(w)
+	if err != nil {
+		return 0, err
+	}
+
+	var locOffset uint64
+	locOffset, _, err = locEncoder.writeAt(w)
+	if err != nil {
+		return 0, err
+	}
+
+	postingsOffset := uint64(w.Count())
+
+	n := binary.PutUvarint(bufMaxVarintLen64, tfOffset)
+	_, err = w.Write(bufMaxVarintLen64[:n])
+	if err != nil {
+		return 0, err
+	}
+
+	n = binary.PutUvarint(bufMaxVarintLen64, locOffset)
+	_, err = w.Write(bufMaxVarintLen64[:n])
+	if err != nil {
+		return 0, err
+	}
+
+	_, err = writeRoaringWithLen(postings, w, bufMaxVarintLen64)
+	if err != nil {
+		return 0, err
+	}
+
+	return postingsOffset, nil
+}
+
+type varintEncoder func(uint64) (int, error)
+
+func mergeStoredAndRemap(segments []*SegmentBase, drops []*roaring.Bitmap,
+	fieldsMap map[string]uint16, fieldsInv []string, fieldsSame bool, newSegDocCount uint64,
+	w *CountHashWriter, closeCh chan struct{}) (uint64, [][]uint64, error) {
+	var rv [][]uint64 // The remapped or newDocNums for each segment.
+
+	var newDocNum uint64
+
+	var curr int
+	var data, compressed []byte
+	var metaBuf bytes.Buffer
+	varBuf := make([]byte, binary.MaxVarintLen64)
+	metaEncode := func(val uint64) (int, error) {
+		wb := binary.PutUvarint(varBuf, val)
+		return metaBuf.Write(varBuf[:wb])
+	}
+
+	vals := make([][][]byte, len(fieldsInv))
+	typs := make([][]byte, len(fieldsInv))
+	poss := make([][][]uint64, len(fieldsInv))
+
+	var posBuf []uint64
+
+	docNumOffsets := make([]uint64, newSegDocCount)
+
+	vdc := visitDocumentCtxPool.Get().(*visitDocumentCtx)
+	defer visitDocumentCtxPool.Put(vdc)
+
+	// for each segment
+	for segI, segment := range segments {
+		// check for the closure in meantime
+		if isClosed(closeCh) {
+			return 0, nil, seg.ErrClosed
+		}
+
+		segNewDocNums := make([]uint64, segment.numDocs)
+
+		dropsI := drops[segI]
+
+		// optimize when the field mapping is the same across all
+		// segments and there are no deletions, via byte-copying
+		// of stored docs bytes directly to the writer
+		if fieldsSame && (dropsI == nil || dropsI.GetCardinality() == 0) {
+			err := segment.copyStoredDocs(newDocNum, docNumOffsets, w)
+			if err != nil {
+				return 0, nil, err
+			}
+
+			for i := uint64(0); i < segment.numDocs; i++ {
+				segNewDocNums[i] = newDocNum
+				newDocNum++
+			}
+			rv = append(rv, segNewDocNums)
+
+			continue
+		}
+
+		// for each doc num
+		for docNum := uint64(0); docNum < segment.numDocs; docNum++ {
+			// TODO: roaring's API limits docNums to 32-bits?
+			if dropsI != nil && dropsI.Contains(uint32(docNum)) {
+				segNewDocNums[docNum] = docDropped
+				continue
+			}
+
+			segNewDocNums[docNum] = newDocNum
+
+			curr = 0
+			metaBuf.Reset()
+			data = data[:0]
+
+			posTemp := posBuf
+
+			// collect all the data
+			for i := 0; i < len(fieldsInv); i++ {
+				vals[i] = vals[i][:0]
+				typs[i] = typs[i][:0]
+				poss[i] = poss[i][:0]
+			}
+			err := segment.visitDocument(vdc, docNum, func(field string, typ byte, value []byte, pos []uint64) bool {
+				fieldID := int(fieldsMap[field]) - 1
+				vals[fieldID] = append(vals[fieldID], value)
+				typs[fieldID] = append(typs[fieldID], typ)
+
+				// copy array positions to preserve them beyond the scope of this callback
+				var curPos []uint64
+				if len(pos) > 0 {
+					if cap(posTemp) < len(pos) {
+						posBuf = make([]uint64, len(pos)*len(fieldsInv))
+						posTemp = posBuf
+					}
+					curPos = posTemp[0:len(pos)]
+					copy(curPos, pos)
+					posTemp = posTemp[len(pos):]
+				}
+				poss[fieldID] = append(poss[fieldID], curPos)
+
+				return true
+			})
+			if err != nil {
+				return 0, nil, err
+			}
+
+			// _id field special case optimizes ExternalID() lookups
+			idFieldVal := vals[uint16(0)][0]
+			_, err = metaEncode(uint64(len(idFieldVal)))
+			if err != nil {
+				return 0, nil, err
+			}
+
+			// now walk the non-"_id" fields in order
+			for fieldID := 1; fieldID < len(fieldsInv); fieldID++ {
+				storedFieldValues := vals[fieldID]
+
+				stf := typs[fieldID]
+				spf := poss[fieldID]
+
+				var err2 error
+				curr, data, err2 = persistStoredFieldValues(fieldID,
+					storedFieldValues, stf, spf, curr, metaEncode, data)
+				if err2 != nil {
+					return 0, nil, err2
+				}
+			}
+
+			metaBytes := metaBuf.Bytes()
+
+			compressed = snappy.Encode(compressed[:cap(compressed)], data)
+
+			// record where we're about to start writing
+			docNumOffsets[newDocNum] = uint64(w.Count())
+
+			// write out the meta len and compressed data len
+			_, err = writeUvarints(w,
+				uint64(len(metaBytes)),
+				uint64(len(idFieldVal)+len(compressed)))
+			if err != nil {
+				return 0, nil, err
+			}
+			// now write the meta
+			_, err = w.Write(metaBytes)
+			if err != nil {
+				return 0, nil, err
+			}
+			// now write the _id field val (counted as part of the 'compressed' data)
+			_, err = w.Write(idFieldVal)
+			if err != nil {
+				return 0, nil, err
+			}
+			// now write the compressed data
+			_, err = w.Write(compressed)
+			if err != nil {
+				return 0, nil, err
+			}
+
+			newDocNum++
+		}
+
+		rv = append(rv, segNewDocNums)
+	}
+
+	// return value is the start of the stored index
+	storedIndexOffset := uint64(w.Count())
+
+	// now write out the stored doc index
+	for _, docNumOffset := range docNumOffsets {
+		err := binary.Write(w, binary.BigEndian, docNumOffset)
+		if err != nil {
+			return 0, nil, err
+		}
+	}
+
+	return storedIndexOffset, rv, nil
+}
+
+// copyStoredDocs writes out a segment's stored doc info, optimized by
+// using a single Write() call for the entire set of bytes.  The
+// newDocNumOffsets is filled with the new offsets for each doc.
+func (s *SegmentBase) copyStoredDocs(newDocNum uint64, newDocNumOffsets []uint64,
+	w *CountHashWriter) error {
+	if s.numDocs <= 0 {
+		return nil
+	}
+
+	indexOffset0, storedOffset0, _, _, _ :=
+		s.getDocStoredOffsets(0) // the segment's first doc
+
+	indexOffsetN, storedOffsetN, readN, metaLenN, dataLenN :=
+		s.getDocStoredOffsets(s.numDocs - 1) // the segment's last doc
+
+	storedOffset0New := uint64(w.Count())
+
+	storedBytes := s.mem[storedOffset0 : storedOffsetN+readN+metaLenN+dataLenN]
+	_, err := w.Write(storedBytes)
+	if err != nil {
+		return err
+	}
+
+	// remap the storedOffset's for the docs into new offsets relative
+	// to storedOffset0New, filling the given docNumOffsetsOut array
+	for indexOffset := indexOffset0; indexOffset <= indexOffsetN; indexOffset += 8 {
+		storedOffset := binary.BigEndian.Uint64(s.mem[indexOffset : indexOffset+8])
+		storedOffsetNew := storedOffset - storedOffset0 + storedOffset0New
+		newDocNumOffsets[newDocNum] = storedOffsetNew
+		newDocNum += 1
+	}
+
+	return nil
+}
+
+// mergeFields builds a unified list of fields used across all the
+// input segments, and computes whether the fields are the same across
+// segments (which depends on fields to be sorted in the same way
+// across segments)
+func mergeFields(segments []*SegmentBase) (bool, []string) {
+	fieldsSame := true
+
+	var segment0Fields []string
+	if len(segments) > 0 {
+		segment0Fields = segments[0].Fields()
+	}
+
+	fieldsExist := map[string]struct{}{}
+	for _, segment := range segments {
+		fields := segment.Fields()
+		for fieldi, field := range fields {
+			fieldsExist[field] = struct{}{}
+			if len(segment0Fields) != len(fields) || segment0Fields[fieldi] != field {
+				fieldsSame = false
+			}
+		}
+	}
+
+	rv := make([]string, 0, len(fieldsExist))
+	// ensure _id stays first
+	rv = append(rv, "_id")
+	for k := range fieldsExist {
+		if k != "_id" {
+			rv = append(rv, k)
+		}
+	}
+
+	sort.Strings(rv[1:]) // leave _id as first
+
+	return fieldsSame, rv
+}
+
+func isClosed(closeCh chan struct{}) bool {
+	select {
+	case <-closeCh:
+		return true
+	default:
+		return false
+	}
+}

vendor/github.com/blevesearch/zap/v15/new.go

@@ -0,0 +1,860 @@
+//  Copyright (c) 2018 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+	"encoding/binary"
+	"math"
+	"sort"
+	"sync"
+
+	"github.com/RoaringBitmap/roaring"
+	"github.com/blevesearch/bleve/analysis"
+	"github.com/blevesearch/bleve/document"
+	"github.com/blevesearch/bleve/index"
+	"github.com/blevesearch/bleve/index/scorch/segment"
+	"github.com/couchbase/vellum"
+	"github.com/golang/snappy"
+)
+
+var NewSegmentBufferNumResultsBump int = 100
+var NewSegmentBufferNumResultsFactor float64 = 1.0
+var NewSegmentBufferAvgBytesPerDocFactor float64 = 1.0
+
+// ValidateDocFields can be set by applications to perform additional checks
+// on fields in a document being added to a new segment, by default it does
+// nothing.
+// This API is experimental and may be removed at any time.
+var ValidateDocFields = func(field document.Field) error {
+	return nil
+}
+
+// AnalysisResultsToSegmentBase produces an in-memory zap-encoded
+// SegmentBase from analysis results
+func (z *ZapPlugin) New(results []*index.AnalysisResult) (
+	segment.Segment, uint64, error) {
+	return z.newWithChunkMode(results, DefaultChunkMode)
+}
+
+func (*ZapPlugin) newWithChunkMode(results []*index.AnalysisResult,
+	chunkMode uint32) (segment.Segment, uint64, error) {
+	s := interimPool.Get().(*interim)
+
+	var br bytes.Buffer
+	if s.lastNumDocs > 0 {
+		// use previous results to initialize the buf with an estimate
+		// size, but note that the interim instance comes from a
+		// global interimPool, so multiple scorch instances indexing
+		// different docs can lead to low quality estimates
+		estimateAvgBytesPerDoc := int(float64(s.lastOutSize/s.lastNumDocs) *
+			NewSegmentBufferNumResultsFactor)
+		estimateNumResults := int(float64(len(results)+NewSegmentBufferNumResultsBump) *
+			NewSegmentBufferAvgBytesPerDocFactor)
+		br.Grow(estimateAvgBytesPerDoc * estimateNumResults)
+	}
+
+	s.results = results
+	s.chunkMode = chunkMode
+	s.w = NewCountHashWriter(&br)
+
+	storedIndexOffset, fieldsIndexOffset, fdvIndexOffset, dictOffsets,
+		err := s.convert()
+	if err != nil {
+		return nil, uint64(0), err
+	}
+
+	sb, err := InitSegmentBase(br.Bytes(), s.w.Sum32(), chunkMode,
+		s.FieldsMap, s.FieldsInv, uint64(len(results)),
+		storedIndexOffset, fieldsIndexOffset, fdvIndexOffset, dictOffsets)
+
+	if err == nil && s.reset() == nil {
+		s.lastNumDocs = len(results)
+		s.lastOutSize = len(br.Bytes())
+		interimPool.Put(s)
+	}
+
+	return sb, uint64(len(br.Bytes())), err
+}
+
+var interimPool = sync.Pool{New: func() interface{} { return &interim{} }}
+
+// interim holds temporary working data used while converting from
+// analysis results to a zap-encoded segment
+type interim struct {
+	results []*index.AnalysisResult
+
+	chunkMode uint32
+
+	w *CountHashWriter
+
+	// FieldsMap adds 1 to field id to avoid zero value issues
+	//  name -> field id + 1
+	FieldsMap map[string]uint16
+
+	// FieldsInv is the inverse of FieldsMap
+	//  field id -> name
+	FieldsInv []string
+
+	// Term dictionaries for each field
+	//  field id -> term -> postings list id + 1
+	Dicts []map[string]uint64
+
+	// Terms for each field, where terms are sorted ascending
+	//  field id -> []term
+	DictKeys [][]string
+
+	// Fields whose IncludeDocValues is true
+	//  field id -> bool
+	IncludeDocValues []bool
+
+	// postings id -> bitmap of docNums
+	Postings []*roaring.Bitmap
+
+	// postings id -> freq/norm's, one for each docNum in postings
+	FreqNorms        [][]interimFreqNorm
+	freqNormsBacking []interimFreqNorm
+
+	// postings id -> locs, one for each freq
+	Locs        [][]interimLoc
+	locsBacking []interimLoc
+
+	numTermsPerPostingsList []int // key is postings list id
+	numLocsPerPostingsList  []int // key is postings list id
+
+	builder    *vellum.Builder
+	builderBuf bytes.Buffer
+
+	metaBuf bytes.Buffer
+
+	tmp0 []byte
+	tmp1 []byte
+
+	lastNumDocs int
+	lastOutSize int
+}
+
+func (s *interim) reset() (err error) {
+	s.results = nil
+	s.chunkMode = 0
+	s.w = nil
+	s.FieldsMap = nil
+	s.FieldsInv = nil
+	for i := range s.Dicts {
+		s.Dicts[i] = nil
+	}
+	s.Dicts = s.Dicts[:0]
+	for i := range s.DictKeys {
+		s.DictKeys[i] = s.DictKeys[i][:0]
+	}
+	s.DictKeys = s.DictKeys[:0]
+	for i := range s.IncludeDocValues {
+		s.IncludeDocValues[i] = false
+	}
+	s.IncludeDocValues = s.IncludeDocValues[:0]
+	for _, idn := range s.Postings {
+		idn.Clear()
+	}
+	s.Postings = s.Postings[:0]
+	s.FreqNorms = s.FreqNorms[:0]
+	for i := range s.freqNormsBacking {
+		s.freqNormsBacking[i] = interimFreqNorm{}
+	}
+	s.freqNormsBacking = s.freqNormsBacking[:0]
+	s.Locs = s.Locs[:0]
+	for i := range s.locsBacking {
+		s.locsBacking[i] = interimLoc{}
+	}
+	s.locsBacking = s.locsBacking[:0]
+	s.numTermsPerPostingsList = s.numTermsPerPostingsList[:0]
+	s.numLocsPerPostingsList = s.numLocsPerPostingsList[:0]
+	s.builderBuf.Reset()
+	if s.builder != nil {
+		err = s.builder.Reset(&s.builderBuf)
+	}
+	s.metaBuf.Reset()
+	s.tmp0 = s.tmp0[:0]
+	s.tmp1 = s.tmp1[:0]
+	s.lastNumDocs = 0
+	s.lastOutSize = 0
+
+	return err
+}
+
+func (s *interim) grabBuf(size int) []byte {
+	buf := s.tmp0
+	if cap(buf) < size {
+		buf = make([]byte, size)
+		s.tmp0 = buf
+	}
+	return buf[0:size]
+}
+
+type interimStoredField struct {
+	vals      [][]byte
+	typs      []byte
+	arrayposs [][]uint64 // array positions
+}
+
+type interimFreqNorm struct {
+	freq    uint64
+	norm    float32
+	numLocs int
+}
+
+type interimLoc struct {
+	fieldID   uint16
+	pos       uint64
+	start     uint64
+	end       uint64
+	arrayposs []uint64
+}
+
+func (s *interim) convert() (uint64, uint64, uint64, []uint64, error) {
+	s.FieldsMap = map[string]uint16{}
+
+	s.getOrDefineField("_id") // _id field is fieldID 0
+
+	for _, result := range s.results {
+		for _, field := range result.Document.CompositeFields {
+			s.getOrDefineField(field.Name())
+		}
+		for _, field := range result.Document.Fields {
+			s.getOrDefineField(field.Name())
+		}
+	}
+
+	sort.Strings(s.FieldsInv[1:]) // keep _id as first field
+
+	for fieldID, fieldName := range s.FieldsInv {
+		s.FieldsMap[fieldName] = uint16(fieldID + 1)
+	}
+
+	if cap(s.IncludeDocValues) >= len(s.FieldsInv) {
+		s.IncludeDocValues = s.IncludeDocValues[:len(s.FieldsInv)]
+	} else {
+		s.IncludeDocValues = make([]bool, len(s.FieldsInv))
+	}
+
+	s.prepareDicts()
+
+	for _, dict := range s.DictKeys {
+		sort.Strings(dict)
+	}
+
+	s.processDocuments()
+
+	storedIndexOffset, err := s.writeStoredFields()
+	if err != nil {
+		return 0, 0, 0, nil, err
+	}
+
+	var fdvIndexOffset uint64
+	var dictOffsets []uint64
+
+	if len(s.results) > 0 {
+		fdvIndexOffset, dictOffsets, err = s.writeDicts()
+		if err != nil {
+			return 0, 0, 0, nil, err
+		}
+	} else {
+		dictOffsets = make([]uint64, len(s.FieldsInv))
+	}
+
+	fieldsIndexOffset, err := persistFields(s.FieldsInv, s.w, dictOffsets)
+	if err != nil {
+		return 0, 0, 0, nil, err
+	}
+
+	return storedIndexOffset, fieldsIndexOffset, fdvIndexOffset, dictOffsets, nil
+}
+
+func (s *interim) getOrDefineField(fieldName string) int {
+	fieldIDPlus1, exists := s.FieldsMap[fieldName]
+	if !exists {
+		fieldIDPlus1 = uint16(len(s.FieldsInv) + 1)
+		s.FieldsMap[fieldName] = fieldIDPlus1
+		s.FieldsInv = append(s.FieldsInv, fieldName)
+
+		s.Dicts = append(s.Dicts, make(map[string]uint64))
+
+		n := len(s.DictKeys)
+		if n < cap(s.DictKeys) {
+			s.DictKeys = s.DictKeys[:n+1]
+			s.DictKeys[n] = s.DictKeys[n][:0]
+		} else {
+			s.DictKeys = append(s.DictKeys, []string(nil))
+		}
+	}
+
+	return int(fieldIDPlus1 - 1)
+}
+
+// fill Dicts and DictKeys from analysis results
+func (s *interim) prepareDicts() {
+	var pidNext int
+
+	var totTFs int
+	var totLocs int
+
+	visitField := func(fieldID uint16, tfs analysis.TokenFrequencies) {
+		dict := s.Dicts[fieldID]
+		dictKeys := s.DictKeys[fieldID]
+
+		for term, tf := range tfs {
+			pidPlus1, exists := dict[term]
+			if !exists {
+				pidNext++
+				pidPlus1 = uint64(pidNext)
+
+				dict[term] = pidPlus1
+				dictKeys = append(dictKeys, term)
+
+				s.numTermsPerPostingsList = append(s.numTermsPerPostingsList, 0)
+				s.numLocsPerPostingsList = append(s.numLocsPerPostingsList, 0)
+			}
+
+			pid := pidPlus1 - 1
+
+			s.numTermsPerPostingsList[pid] += 1
+			s.numLocsPerPostingsList[pid] += len(tf.Locations)
+
+			totLocs += len(tf.Locations)
+		}
+
+		totTFs += len(tfs)
+
+		s.DictKeys[fieldID] = dictKeys
+	}
+
+	for _, result := range s.results {
+		// walk each composite field
+		for _, field := range result.Document.CompositeFields {
+			fieldID := uint16(s.getOrDefineField(field.Name()))
+			_, tf := field.Analyze()
+			visitField(fieldID, tf)
+		}
+
+		// walk each field
+		for i, field := range result.Document.Fields {
+			fieldID := uint16(s.getOrDefineField(field.Name()))
+			tf := result.Analyzed[i]
+			visitField(fieldID, tf)
+		}
+	}
+
+	numPostingsLists := pidNext
+
+	if cap(s.Postings) >= numPostingsLists {
+		s.Postings = s.Postings[:numPostingsLists]
+	} else {
+		postings := make([]*roaring.Bitmap, numPostingsLists)
+		copy(postings, s.Postings[:cap(s.Postings)])
+		for i := 0; i < numPostingsLists; i++ {
+			if postings[i] == nil {
+				postings[i] = roaring.New()
+			}
+		}
+		s.Postings = postings
+	}
+
+	if cap(s.FreqNorms) >= numPostingsLists {
+		s.FreqNorms = s.FreqNorms[:numPostingsLists]
+	} else {
+		s.FreqNorms = make([][]interimFreqNorm, numPostingsLists)
+	}
+
+	if cap(s.freqNormsBacking) >= totTFs {
+		s.freqNormsBacking = s.freqNormsBacking[:totTFs]
+	} else {
+		s.freqNormsBacking = make([]interimFreqNorm, totTFs)
+	}
+
+	freqNormsBacking := s.freqNormsBacking
+	for pid, numTerms := range s.numTermsPerPostingsList {
+		s.FreqNorms[pid] = freqNormsBacking[0:0]
+		freqNormsBacking = freqNormsBacking[numTerms:]
+	}
+
+	if cap(s.Locs) >= numPostingsLists {
+		s.Locs = s.Locs[:numPostingsLists]
+	} else {
+		s.Locs = make([][]interimLoc, numPostingsLists)
+	}
+
+	if cap(s.locsBacking) >= totLocs {
+		s.locsBacking = s.locsBacking[:totLocs]
+	} else {
+		s.locsBacking = make([]interimLoc, totLocs)
+	}
+
+	locsBacking := s.locsBacking
+	for pid, numLocs := range s.numLocsPerPostingsList {
+		s.Locs[pid] = locsBacking[0:0]
+		locsBacking = locsBacking[numLocs:]
+	}
+}
+
+func (s *interim) processDocuments() {
+	numFields := len(s.FieldsInv)
+	reuseFieldLens := make([]int, numFields)
+	reuseFieldTFs := make([]analysis.TokenFrequencies, numFields)
+
+	for docNum, result := range s.results {
+		for i := 0; i < numFields; i++ { // clear these for reuse
+			reuseFieldLens[i] = 0
+			reuseFieldTFs[i] = nil
+		}
+
+		s.processDocument(uint64(docNum), result,
+			reuseFieldLens, reuseFieldTFs)
+	}
+}
+
+func (s *interim) processDocument(docNum uint64,
+	result *index.AnalysisResult,
+	fieldLens []int, fieldTFs []analysis.TokenFrequencies) {
+	visitField := func(fieldID uint16, fieldName string,
+		ln int, tf analysis.TokenFrequencies) {
+		fieldLens[fieldID] += ln
+
+		existingFreqs := fieldTFs[fieldID]
+		if existingFreqs != nil {
+			existingFreqs.MergeAll(fieldName, tf)
+		} else {
+			fieldTFs[fieldID] = tf
+		}
+	}
+
+	// walk each composite field
+	for _, field := range result.Document.CompositeFields {
+		fieldID := uint16(s.getOrDefineField(field.Name()))
+		ln, tf := field.Analyze()
+		visitField(fieldID, field.Name(), ln, tf)
+	}
+
+	// walk each field
+	for i, field := range result.Document.Fields {
+		fieldID := uint16(s.getOrDefineField(field.Name()))
+		ln := result.Length[i]
+		tf := result.Analyzed[i]
+		visitField(fieldID, field.Name(), ln, tf)
+	}
+
+	// now that it's been rolled up into fieldTFs, walk that
+	for fieldID, tfs := range fieldTFs {
+		dict := s.Dicts[fieldID]
+		norm := math.Float32frombits(uint32(fieldLens[fieldID]))
+
+		for term, tf := range tfs {
+			pid := dict[term] - 1
+			bs := s.Postings[pid]
+			bs.Add(uint32(docNum))
+
+			s.FreqNorms[pid] = append(s.FreqNorms[pid],
+				interimFreqNorm{
+					freq:    uint64(tf.Frequency()),
+					norm:    norm,
+					numLocs: len(tf.Locations),
+				})
+
+			if len(tf.Locations) > 0 {
+				locs := s.Locs[pid]
+
+				for _, loc := range tf.Locations {
+					var locf = uint16(fieldID)
+					if loc.Field != "" {
+						locf = uint16(s.getOrDefineField(loc.Field))
+					}
+					var arrayposs []uint64
+					if len(loc.ArrayPositions) > 0 {
+						arrayposs = loc.ArrayPositions
+					}
+					locs = append(locs, interimLoc{
+						fieldID:   locf,
+						pos:       uint64(loc.Position),
+						start:     uint64(loc.Start),
+						end:       uint64(loc.End),
+						arrayposs: arrayposs,
+					})
+				}
+
+				s.Locs[pid] = locs
+			}
+		}
+	}
+}
+
+func (s *interim) writeStoredFields() (
+	storedIndexOffset uint64, err error) {
+	varBuf := make([]byte, binary.MaxVarintLen64)
+	metaEncode := func(val uint64) (int, error) {
+		wb := binary.PutUvarint(varBuf, val)
+		return s.metaBuf.Write(varBuf[:wb])
+	}
+
+	data, compressed := s.tmp0[:0], s.tmp1[:0]
+	defer func() { s.tmp0, s.tmp1 = data, compressed }()
+
+	// keyed by docNum
+	docStoredOffsets := make([]uint64, len(s.results))
+
+	// keyed by fieldID, for the current doc in the loop
+	docStoredFields := map[uint16]interimStoredField{}
+
+	for docNum, result := range s.results {
+		for fieldID := range docStoredFields { // reset for next doc
+			delete(docStoredFields, fieldID)
+		}
+
+		for _, field := range result.Document.Fields {
+			fieldID := uint16(s.getOrDefineField(field.Name()))
+
+			opts := field.Options()
+
+			if opts.IsStored() {
+				isf := docStoredFields[fieldID]
+				isf.vals = append(isf.vals, field.Value())
+				isf.typs = append(isf.typs, encodeFieldType(field))
+				isf.arrayposs = append(isf.arrayposs, field.ArrayPositions())
+				docStoredFields[fieldID] = isf
+			}
+
+			if opts.IncludeDocValues() {
+				s.IncludeDocValues[fieldID] = true
+			}
+
+			err := ValidateDocFields(field)
+			if err != nil {
+				return 0, err
+			}
+		}
+
+		var curr int
+
+		s.metaBuf.Reset()
+		data = data[:0]
+
+		// _id field special case optimizes ExternalID() lookups
+		idFieldVal := docStoredFields[uint16(0)].vals[0]
+		_, err = metaEncode(uint64(len(idFieldVal)))
+		if err != nil {
+			return 0, err
+		}
+
+		// handle non-"_id" fields
+		for fieldID := 1; fieldID < len(s.FieldsInv); fieldID++ {
+			isf, exists := docStoredFields[uint16(fieldID)]
+			if exists {
+				curr, data, err = persistStoredFieldValues(
+					fieldID, isf.vals, isf.typs, isf.arrayposs,
+					curr, metaEncode, data)
+				if err != nil {
+					return 0, err
+				}
+			}
+		}
+
+		metaBytes := s.metaBuf.Bytes()
+
+		compressed = snappy.Encode(compressed[:cap(compressed)], data)
+
+		docStoredOffsets[docNum] = uint64(s.w.Count())
+
+		_, err := writeUvarints(s.w,
+			uint64(len(metaBytes)),
+			uint64(len(idFieldVal)+len(compressed)))
+		if err != nil {
+			return 0, err
+		}
+
+		_, err = s.w.Write(metaBytes)
+		if err != nil {
+			return 0, err
+		}
+
+		_, err = s.w.Write(idFieldVal)
+		if err != nil {
+			return 0, err
+		}
+
+		_, err = s.w.Write(compressed)
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	storedIndexOffset = uint64(s.w.Count())
+
+	for _, docStoredOffset := range docStoredOffsets {
+		err = binary.Write(s.w, binary.BigEndian, docStoredOffset)
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	return storedIndexOffset, nil
+}
+
+func (s *interim) writeDicts() (fdvIndexOffset uint64, dictOffsets []uint64, err error) {
+	dictOffsets = make([]uint64, len(s.FieldsInv))
+
+	fdvOffsetsStart := make([]uint64, len(s.FieldsInv))
+	fdvOffsetsEnd := make([]uint64, len(s.FieldsInv))
+
+	buf := s.grabBuf(binary.MaxVarintLen64)
+
+	// these int coders are initialized with chunk size 1024
+	// however this will be reset to the correct chunk size
+	// while processing each individual field-term section
+	tfEncoder := newChunkedIntCoder(1024, uint64(len(s.results)-1))
+	locEncoder := newChunkedIntCoder(1024, uint64(len(s.results)-1))
+
+	var docTermMap [][]byte
+
+	if s.builder == nil {
+		s.builder, err = vellum.New(&s.builderBuf, nil)
+		if err != nil {
+			return 0, nil, err
+		}
+	}
+
+	for fieldID, terms := range s.DictKeys {
+		if cap(docTermMap) < len(s.results) {
+			docTermMap = make([][]byte, len(s.results))
+		} else {
+			docTermMap = docTermMap[0:len(s.results)]
+			for docNum := range docTermMap { // reset the docTermMap
+				docTermMap[docNum] = docTermMap[docNum][:0]
+			}
+		}
+
+		dict := s.Dicts[fieldID]
+
+		for _, term := range terms { // terms are already sorted
+			pid := dict[term] - 1
+
+			postingsBS := s.Postings[pid]
+
+			freqNorms := s.FreqNorms[pid]
+			freqNormOffset := 0
+
+			locs := s.Locs[pid]
+			locOffset := 0
+
+			chunkSize, err := getChunkSize(s.chunkMode, postingsBS.GetCardinality(), uint64(len(s.results)))
+			if err != nil {
+				return 0, nil, err
+			}
+			tfEncoder.SetChunkSize(chunkSize, uint64(len(s.results)-1))
+			locEncoder.SetChunkSize(chunkSize, uint64(len(s.results)-1))
+
+			postingsItr := postingsBS.Iterator()
+			for postingsItr.HasNext() {
+				docNum := uint64(postingsItr.Next())
+
+				freqNorm := freqNorms[freqNormOffset]
+
+				err = tfEncoder.Add(docNum,
+					encodeFreqHasLocs(freqNorm.freq, freqNorm.numLocs > 0),
+					uint64(math.Float32bits(freqNorm.norm)))
+				if err != nil {
+					return 0, nil, err
+				}
+
+				if freqNorm.numLocs > 0 {
+					numBytesLocs := 0
+					for _, loc := range locs[locOffset : locOffset+freqNorm.numLocs] {
+						numBytesLocs += totalUvarintBytes(
+							uint64(loc.fieldID), loc.pos, loc.start, loc.end,
+							uint64(len(loc.arrayposs)), loc.arrayposs)
+					}
+
+					err = locEncoder.Add(docNum, uint64(numBytesLocs))
+					if err != nil {
+						return 0, nil, err
+					}
+
+					for _, loc := range locs[locOffset : locOffset+freqNorm.numLocs] {
+						err = locEncoder.Add(docNum,
+							uint64(loc.fieldID), loc.pos, loc.start, loc.end,
+							uint64(len(loc.arrayposs)))
+						if err != nil {
+							return 0, nil, err
+						}
+
+						err = locEncoder.Add(docNum, loc.arrayposs...)
+						if err != nil {
+							return 0, nil, err
+						}
+					}
+
+					locOffset += freqNorm.numLocs
+				}
+
+				freqNormOffset++
+
+				docTermMap[docNum] = append(
+					append(docTermMap[docNum], term...),
+					termSeparator)
+			}
+
+			tfEncoder.Close()
+			locEncoder.Close()
+
+			postingsOffset, err :=
+				writePostings(postingsBS, tfEncoder, locEncoder, nil, s.w, buf)
+			if err != nil {
+				return 0, nil, err
+			}
+
+			if postingsOffset > uint64(0) {
+				err = s.builder.Insert([]byte(term), postingsOffset)
+				if err != nil {
+					return 0, nil, err
+				}
+			}
+
+			tfEncoder.Reset()
+			locEncoder.Reset()
+		}
+
+		err = s.builder.Close()
+		if err != nil {
+			return 0, nil, err
+		}
+
+		// record where this dictionary starts
+		dictOffsets[fieldID] = uint64(s.w.Count())
+
+		vellumData := s.builderBuf.Bytes()
+
+		// write out the length of the vellum data
+		n := binary.PutUvarint(buf, uint64(len(vellumData)))
+		_, err = s.w.Write(buf[:n])
+		if err != nil {
+			return 0, nil, err
+		}
+
+		// write this vellum to disk
+		_, err = s.w.Write(vellumData)
+		if err != nil {
+			return 0, nil, err
+		}
+
+		// reset vellum for reuse
+		s.builderBuf.Reset()
+
+		err = s.builder.Reset(&s.builderBuf)
+		if err != nil {
+			return 0, nil, err
+		}
+
+		// write the field doc values
+		// NOTE: doc values continue to use legacy chunk mode
+		chunkSize, err := getChunkSize(LegacyChunkMode, 0, 0)
+		if err != nil {
+			return 0, nil, err
+		}
+		fdvEncoder := newChunkedContentCoder(chunkSize, uint64(len(s.results)-1), s.w, false)
+		if s.IncludeDocValues[fieldID] {
+			for docNum, docTerms := range docTermMap {
+				if len(docTerms) > 0 {
+					err = fdvEncoder.Add(uint64(docNum), docTerms)
+					if err != nil {
+						return 0, nil, err
+					}
+				}
+			}
+			err = fdvEncoder.Close()
+			if err != nil {
+				return 0, nil, err
+			}
+
+			fdvOffsetsStart[fieldID] = uint64(s.w.Count())
+
+			_, err = fdvEncoder.Write()
+			if err != nil {
+				return 0, nil, err
+			}
+
+			fdvOffsetsEnd[fieldID] = uint64(s.w.Count())
+
+			fdvEncoder.Reset()
+		} else {
+			fdvOffsetsStart[fieldID] = fieldNotUninverted
+			fdvOffsetsEnd[fieldID] = fieldNotUninverted
+		}
+	}
+
+	fdvIndexOffset = uint64(s.w.Count())
+
+	for i := 0; i < len(fdvOffsetsStart); i++ {
+		n := binary.PutUvarint(buf, fdvOffsetsStart[i])
+		_, err := s.w.Write(buf[:n])
+		if err != nil {
+			return 0, nil, err
+		}
+		n = binary.PutUvarint(buf, fdvOffsetsEnd[i])
+		_, err = s.w.Write(buf[:n])
+		if err != nil {
+			return 0, nil, err
+		}
+	}
+
+	return fdvIndexOffset, dictOffsets, nil
+}
+
+func encodeFieldType(f document.Field) byte {
+	fieldType := byte('x')
+	switch f.(type) {
+	case *document.TextField:
+		fieldType = 't'
+	case *document.NumericField:
+		fieldType = 'n'
+	case *document.DateTimeField:
+		fieldType = 'd'
+	case *document.BooleanField:
+		fieldType = 'b'
+	case *document.GeoPointField:
+		fieldType = 'g'
+	case *document.CompositeField:
+		fieldType = 'c'
+	}
+	return fieldType
+}
+
+// returns the total # of bytes needed to encode the given uint64's
+// into binary.PutUVarint() encoding
+func totalUvarintBytes(a, b, c, d, e uint64, more []uint64) (n int) {
+	n = numUvarintBytes(a)
+	n += numUvarintBytes(b)
+	n += numUvarintBytes(c)
+	n += numUvarintBytes(d)
+	n += numUvarintBytes(e)
+	for _, v := range more {
+		n += numUvarintBytes(v)
+	}
+	return n
+}
+
+// returns # of bytes needed to encode x in binary.PutUvarint() encoding
+func numUvarintBytes(x uint64) (n int) {
+	for x >= 0x80 {
+		x >>= 7
+		n++
+	}
+	return n + 1
+}

vendor/github.com/blevesearch/zap/v15/plugin.go

@@ -0,0 +1,37 @@
+//  Copyright (c) 2020 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"github.com/blevesearch/bleve/index/scorch/segment"
+)
+
+// ZapPlugin implements the Plugin interface of
+// the blevesearch/bleve/index/scorch/segment pkg
+type ZapPlugin struct{}
+
+func (*ZapPlugin) Type() string {
+	return Type
+}
+
+func (*ZapPlugin) Version() uint32 {
+	return Version
+}
+
+// Plugin returns an instance segment.Plugin for use
+// by the Scorch indexing scheme
+func Plugin() segment.Plugin {
+	return &ZapPlugin{}
+}

vendor/github.com/blevesearch/zap/v15/posting.go

@@ -0,0 +1,801 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math"
+	"reflect"
+
+	"github.com/RoaringBitmap/roaring"
+	"github.com/blevesearch/bleve/index/scorch/segment"
+	"github.com/blevesearch/bleve/size"
+)
+
+var reflectStaticSizePostingsList int
+var reflectStaticSizePostingsIterator int
+var reflectStaticSizePosting int
+var reflectStaticSizeLocation int
+
+func init() {
+	var pl PostingsList
+	reflectStaticSizePostingsList = int(reflect.TypeOf(pl).Size())
+	var pi PostingsIterator
+	reflectStaticSizePostingsIterator = int(reflect.TypeOf(pi).Size())
+	var p Posting
+	reflectStaticSizePosting = int(reflect.TypeOf(p).Size())
+	var l Location
+	reflectStaticSizeLocation = int(reflect.TypeOf(l).Size())
+}
+
+// FST or vellum value (uint64) encoding is determined by the top two
+// highest-order or most significant bits...
+//
+//  encoding  : MSB
+//  name      : 63  62  61...to...bit #0 (LSB)
+//  ----------+---+---+---------------------------------------------------
+//   general  : 0 | 0 | 62-bits of postingsOffset.
+//   ~        : 0 | 1 | reserved for future.
+//   1-hit    : 1 | 0 | 31-bits of positive float31 norm | 31-bits docNum.
+//   ~        : 1 | 1 | reserved for future.
+//
+// Encoding "general" is able to handle all cases, where the
+// postingsOffset points to more information about the postings for
+// the term.
+//
+// Encoding "1-hit" is used to optimize a commonly seen case when a
+// term has only a single hit.  For example, a term in the _id field
+// will have only 1 hit.  The "1-hit" encoding is used for a term
+// in a field when...
+//
+// - term vector info is disabled for that field;
+// - and, the term appears in only a single doc for that field;
+// - and, the term's freq is exactly 1 in that single doc for that field;
+// - and, the docNum must fit into 31-bits;
+//
+// Otherwise, the "general" encoding is used instead.
+//
+// In the "1-hit" encoding, the field in that single doc may have
+// other terms, which is supported in the "1-hit" encoding by the
+// positive float31 norm.
+
+const FSTValEncodingMask = uint64(0xc000000000000000)
+const FSTValEncodingGeneral = uint64(0x0000000000000000)
+const FSTValEncoding1Hit = uint64(0x8000000000000000)
+
+func FSTValEncode1Hit(docNum uint64, normBits uint64) uint64 {
+	return FSTValEncoding1Hit | ((mask31Bits & normBits) << 31) | (mask31Bits & docNum)
+}
+
+func FSTValDecode1Hit(v uint64) (docNum uint64, normBits uint64) {
+	return (mask31Bits & v), (mask31Bits & (v >> 31))
+}
+
+const mask31Bits = uint64(0x000000007fffffff)
+
+func under32Bits(x uint64) bool {
+	return x <= mask31Bits
+}
+
+const DocNum1HitFinished = math.MaxUint64
+
+var NormBits1Hit = uint64(1)
+
+// PostingsList is an in-memory representation of a postings list
+type PostingsList struct {
+	sb             *SegmentBase
+	postingsOffset uint64
+	freqOffset     uint64
+	locOffset      uint64
+	postings       *roaring.Bitmap
+	except         *roaring.Bitmap
+
+	// when normBits1Hit != 0, then this postings list came from a
+	// 1-hit encoding, and only the docNum1Hit & normBits1Hit apply
+	docNum1Hit   uint64
+	normBits1Hit uint64
+
+	chunkSize uint64
+}
+
+// represents an immutable, empty postings list
+var emptyPostingsList = &PostingsList{}
+
+func (p *PostingsList) Size() int {
+	sizeInBytes := reflectStaticSizePostingsList + size.SizeOfPtr
+
+	if p.except != nil {
+		sizeInBytes += int(p.except.GetSizeInBytes())
+	}
+
+	return sizeInBytes
+}
+
+func (p *PostingsList) OrInto(receiver *roaring.Bitmap) {
+	if p.normBits1Hit != 0 {
+		receiver.Add(uint32(p.docNum1Hit))
+		return
+	}
+
+	if p.postings != nil {
+		receiver.Or(p.postings)
+	}
+}
+
+// Iterator returns an iterator for this postings list
+func (p *PostingsList) Iterator(includeFreq, includeNorm, includeLocs bool,
+	prealloc segment.PostingsIterator) segment.PostingsIterator {
+	if p.normBits1Hit == 0 && p.postings == nil {
+		return emptyPostingsIterator
+	}
+
+	var preallocPI *PostingsIterator
+	pi, ok := prealloc.(*PostingsIterator)
+	if ok && pi != nil {
+		preallocPI = pi
+	}
+	if preallocPI == emptyPostingsIterator {
+		preallocPI = nil
+	}
+
+	return p.iterator(includeFreq, includeNorm, includeLocs, preallocPI)
+}
+
+func (p *PostingsList) iterator(includeFreq, includeNorm, includeLocs bool,
+	rv *PostingsIterator) *PostingsIterator {
+	if rv == nil {
+		rv = &PostingsIterator{}
+	} else {
+		freqNormReader := rv.freqNormReader
+		if freqNormReader != nil {
+			freqNormReader.reset()
+		}
+
+		locReader := rv.locReader
+		if locReader != nil {
+			locReader.reset()
+		}
+
+		nextLocs := rv.nextLocs[:0]
+		nextSegmentLocs := rv.nextSegmentLocs[:0]
+
+		buf := rv.buf
+
+		*rv = PostingsIterator{} // clear the struct
+
+		rv.freqNormReader = freqNormReader
+		rv.locReader = locReader
+
+		rv.nextLocs = nextLocs
+		rv.nextSegmentLocs = nextSegmentLocs
+
+		rv.buf = buf
+	}
+
+	rv.postings = p
+	rv.includeFreqNorm = includeFreq || includeNorm || includeLocs
+	rv.includeLocs = includeLocs
+
+	if p.normBits1Hit != 0 {
+		// "1-hit" encoding
+		rv.docNum1Hit = p.docNum1Hit
+		rv.normBits1Hit = p.normBits1Hit
+
+		if p.except != nil && p.except.Contains(uint32(rv.docNum1Hit)) {
+			rv.docNum1Hit = DocNum1HitFinished
+		}
+
+		return rv
+	}
+
+	// "general" encoding, check if empty
+	if p.postings == nil {
+		return rv
+	}
+
+	// initialize freq chunk reader
+	if rv.includeFreqNorm {
+		rv.freqNormReader = newChunkedIntDecoder(p.sb.mem, p.freqOffset, rv.freqNormReader)
+	}
+
+	// initialize the loc chunk reader
+	if rv.includeLocs {
+		rv.locReader = newChunkedIntDecoder(p.sb.mem, p.locOffset, rv.locReader)
+	}
+
+	rv.all = p.postings.Iterator()
+	if p.except != nil {
+		rv.ActualBM = roaring.AndNot(p.postings, p.except)
+		rv.Actual = rv.ActualBM.Iterator()
+	} else {
+		rv.ActualBM = p.postings
+		rv.Actual = rv.all // Optimize to use same iterator for all & Actual.
+	}
+
+	return rv
+}
+
+// Count returns the number of items on this postings list
+func (p *PostingsList) Count() uint64 {
+	var n, e uint64
+	if p.normBits1Hit != 0 {
+		n = 1
+		if p.except != nil && p.except.Contains(uint32(p.docNum1Hit)) {
+			e = 1
+		}
+	} else if p.postings != nil {
+		n = p.postings.GetCardinality()
+		if p.except != nil {
+			e = p.postings.AndCardinality(p.except)
+		}
+	}
+	return n - e
+}
+
+func (rv *PostingsList) read(postingsOffset uint64, d *Dictionary) error {
+	rv.postingsOffset = postingsOffset
+
+	// handle "1-hit" encoding special case
+	if rv.postingsOffset&FSTValEncodingMask == FSTValEncoding1Hit {
+		return rv.init1Hit(postingsOffset)
+	}
+
+	// read the location of the freq/norm details
+	var n uint64
+	var read int
+
+	rv.freqOffset, read = binary.Uvarint(d.sb.mem[postingsOffset+n : postingsOffset+binary.MaxVarintLen64])
+	n += uint64(read)
+
+	rv.locOffset, read = binary.Uvarint(d.sb.mem[postingsOffset+n : postingsOffset+n+binary.MaxVarintLen64])
+	n += uint64(read)
+
+	var postingsLen uint64
+	postingsLen, read = binary.Uvarint(d.sb.mem[postingsOffset+n : postingsOffset+n+binary.MaxVarintLen64])
+	n += uint64(read)
+
+	roaringBytes := d.sb.mem[postingsOffset+n : postingsOffset+n+postingsLen]
+
+	if rv.postings == nil {
+		rv.postings = roaring.NewBitmap()
+	}
+	_, err := rv.postings.FromBuffer(roaringBytes)
+	if err != nil {
+		return fmt.Errorf("error loading roaring bitmap: %v", err)
+	}
+
+	rv.chunkSize, err = getChunkSize(d.sb.chunkMode,
+		rv.postings.GetCardinality(), d.sb.numDocs)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (rv *PostingsList) init1Hit(fstVal uint64) error {
+	docNum, normBits := FSTValDecode1Hit(fstVal)
+
+	rv.docNum1Hit = docNum
+	rv.normBits1Hit = normBits
+
+	return nil
+}
+
+// PostingsIterator provides a way to iterate through the postings list
+type PostingsIterator struct {
+	postings *PostingsList
+	all      roaring.IntPeekable
+	Actual   roaring.IntPeekable
+	ActualBM *roaring.Bitmap
+
+	currChunk      uint32
+	freqNormReader *chunkedIntDecoder
+	locReader      *chunkedIntDecoder
+
+	next            Posting            // reused across Next() calls
+	nextLocs        []Location         // reused across Next() calls
+	nextSegmentLocs []segment.Location // reused across Next() calls
+
+	docNum1Hit   uint64
+	normBits1Hit uint64
+
+	buf []byte
+
+	includeFreqNorm bool
+	includeLocs     bool
+}
+
+var emptyPostingsIterator = &PostingsIterator{}
+
+func (i *PostingsIterator) Size() int {
+	sizeInBytes := reflectStaticSizePostingsIterator + size.SizeOfPtr +
+		i.next.Size()
+	// account for freqNormReader, locReader if we start using this.
+	for _, entry := range i.nextLocs {
+		sizeInBytes += entry.Size()
+	}
+
+	return sizeInBytes
+}
+
+func (i *PostingsIterator) loadChunk(chunk int) error {
+	if i.includeFreqNorm {
+		err := i.freqNormReader.loadChunk(chunk)
+		if err != nil {
+			return err
+		}
+	}
+
+	if i.includeLocs {
+		err := i.locReader.loadChunk(chunk)
+		if err != nil {
+			return err
+		}
+	}
+
+	i.currChunk = uint32(chunk)
+	return nil
+}
+
+func (i *PostingsIterator) readFreqNormHasLocs() (uint64, uint64, bool, error) {
+	if i.normBits1Hit != 0 {
+		return 1, i.normBits1Hit, false, nil
+	}
+
+	freqHasLocs, err := i.freqNormReader.readUvarint()
+	if err != nil {
+		return 0, 0, false, fmt.Errorf("error reading frequency: %v", err)
+	}
+
+	freq, hasLocs := decodeFreqHasLocs(freqHasLocs)
+
+	normBits, err := i.freqNormReader.readUvarint()
+	if err != nil {
+		return 0, 0, false, fmt.Errorf("error reading norm: %v", err)
+	}
+
+	return freq, normBits, hasLocs, nil
+}
+
+func (i *PostingsIterator) skipFreqNormReadHasLocs() (bool, error) {
+	if i.normBits1Hit != 0 {
+		return false, nil
+	}
+
+	freqHasLocs, err := i.freqNormReader.readUvarint()
+	if err != nil {
+		return false, fmt.Errorf("error reading freqHasLocs: %v", err)
+	}
+
+	i.freqNormReader.SkipUvarint() // Skip normBits.
+
+	return freqHasLocs&0x01 != 0, nil // See decodeFreqHasLocs() / hasLocs.
+}
+
+func encodeFreqHasLocs(freq uint64, hasLocs bool) uint64 {
+	rv := freq << 1
+	if hasLocs {
+		rv = rv | 0x01 // 0'th LSB encodes whether there are locations
+	}
+	return rv
+}
+
+func decodeFreqHasLocs(freqHasLocs uint64) (uint64, bool) {
+	freq := freqHasLocs >> 1
+	hasLocs := freqHasLocs&0x01 != 0
+	return freq, hasLocs
+}
+
+// readLocation processes all the integers on the stream representing a single
+// location.
+func (i *PostingsIterator) readLocation(l *Location) error {
+	// read off field
+	fieldID, err := i.locReader.readUvarint()
+	if err != nil {
+		return fmt.Errorf("error reading location field: %v", err)
+	}
+	// read off pos
+	pos, err := i.locReader.readUvarint()
+	if err != nil {
+		return fmt.Errorf("error reading location pos: %v", err)
+	}
+	// read off start
+	start, err := i.locReader.readUvarint()
+	if err != nil {
+		return fmt.Errorf("error reading location start: %v", err)
+	}
+	// read off end
+	end, err := i.locReader.readUvarint()
+	if err != nil {
+		return fmt.Errorf("error reading location end: %v", err)
+	}
+	// read off num array pos
+	numArrayPos, err := i.locReader.readUvarint()
+	if err != nil {
+		return fmt.Errorf("error reading location num array pos: %v", err)
+	}
+
+	l.field = i.postings.sb.fieldsInv[fieldID]
+	l.pos = pos
+	l.start = start
+	l.end = end
+
+	if cap(l.ap) < int(numArrayPos) {
+		l.ap = make([]uint64, int(numArrayPos))
+	} else {
+		l.ap = l.ap[:int(numArrayPos)]
+	}
+
+	// read off array positions
+	for k := 0; k < int(numArrayPos); k++ {
+		ap, err := i.locReader.readUvarint()
+		if err != nil {
+			return fmt.Errorf("error reading array position: %v", err)
+		}
+
+		l.ap[k] = ap
+	}
+
+	return nil
+}
+
+// Next returns the next posting on the postings list, or nil at the end
+func (i *PostingsIterator) Next() (segment.Posting, error) {
+	return i.nextAtOrAfter(0)
+}
+
+// Advance returns the posting at the specified docNum or it is not present
+// the next posting, or if the end is reached, nil
+func (i *PostingsIterator) Advance(docNum uint64) (segment.Posting, error) {
+	return i.nextAtOrAfter(docNum)
+}
+
+// Next returns the next posting on the postings list, or nil at the end
+func (i *PostingsIterator) nextAtOrAfter(atOrAfter uint64) (segment.Posting, error) {
+	docNum, exists, err := i.nextDocNumAtOrAfter(atOrAfter)
+	if err != nil || !exists {
+		return nil, err
+	}
+
+	i.next = Posting{} // clear the struct
+	rv := &i.next
+	rv.docNum = docNum
+
+	if !i.includeFreqNorm {
+		return rv, nil
+	}
+
+	var normBits uint64
+	var hasLocs bool
+
+	rv.freq, normBits, hasLocs, err = i.readFreqNormHasLocs()
+	if err != nil {
+		return nil, err
+	}
+
+	rv.norm = math.Float32frombits(uint32(normBits))
+
+	if i.includeLocs && hasLocs {
+		// prepare locations into reused slices, where we assume
+		// rv.freq >= "number of locs", since in a composite field,
+		// some component fields might have their IncludeTermVector
+		// flags disabled while other component fields are enabled
+		if cap(i.nextLocs) >= int(rv.freq) {
+			i.nextLocs = i.nextLocs[0:rv.freq]
+		} else {
+			i.nextLocs = make([]Location, rv.freq, rv.freq*2)
+		}
+		if cap(i.nextSegmentLocs) < int(rv.freq) {
+			i.nextSegmentLocs = make([]segment.Location, rv.freq, rv.freq*2)
+		}
+		rv.locs = i.nextSegmentLocs[:0]
+
+		numLocsBytes, err := i.locReader.readUvarint()
+		if err != nil {
+			return nil, fmt.Errorf("error reading location numLocsBytes: %v", err)
+		}
+
+		j := 0
+		startBytesRemaining := i.locReader.Len() // # bytes remaining in the locReader
+		for startBytesRemaining-i.locReader.Len() < int(numLocsBytes) {
+			err := i.readLocation(&i.nextLocs[j])
+			if err != nil {
+				return nil, err
+			}
+			rv.locs = append(rv.locs, &i.nextLocs[j])
+			j++
+		}
+	}
+
+	return rv, nil
+}
+
+// nextDocNum returns the next docNum on the postings list, and also
+// sets up the currChunk / loc related fields of the iterator.
+func (i *PostingsIterator) nextDocNumAtOrAfter(atOrAfter uint64) (uint64, bool, error) {
+	if i.normBits1Hit != 0 {
+		if i.docNum1Hit == DocNum1HitFinished {
+			return 0, false, nil
+		}
+		if i.docNum1Hit < atOrAfter {
+			// advanced past our 1-hit
+			i.docNum1Hit = DocNum1HitFinished // consume our 1-hit docNum
+			return 0, false, nil
+		}
+		docNum := i.docNum1Hit
+		i.docNum1Hit = DocNum1HitFinished // consume our 1-hit docNum
+		return docNum, true, nil
+	}
+
+	if i.Actual == nil || !i.Actual.HasNext() {
+		return 0, false, nil
+	}
+
+	if i.postings == nil || i.postings.postings == i.ActualBM {
+		return i.nextDocNumAtOrAfterClean(atOrAfter)
+	}
+
+	i.Actual.AdvanceIfNeeded(uint32(atOrAfter))
+
+	if !i.Actual.HasNext() {
+		// couldn't find anything
+		return 0, false, nil
+	}
+
+	n := i.Actual.Next()
+	allN := i.all.Next()
+	nChunk := n / uint32(i.postings.chunkSize)
+
+	// when allN becomes >= to here, then allN is in the same chunk as nChunk.
+	allNReachesNChunk := nChunk * uint32(i.postings.chunkSize)
+
+	// n is the next actual hit (excluding some postings), and
+	// allN is the next hit in the full postings, and
+	// if they don't match, move 'all' forwards until they do
+	for allN != n {
+		// we've reached same chunk, so move the freq/norm/loc decoders forward
+		if i.includeFreqNorm && allN >= allNReachesNChunk {
+			err := i.currChunkNext(nChunk)
+			if err != nil {
+				return 0, false, err
+			}
+		}
+
+		allN = i.all.Next()
+	}
+
+	if i.includeFreqNorm && (i.currChunk != nChunk || i.freqNormReader.isNil()) {
+		err := i.loadChunk(int(nChunk))
+		if err != nil {
+			return 0, false, fmt.Errorf("error loading chunk: %v", err)
+		}
+	}
+
+	return uint64(n), true, nil
+}
+
+// optimization when the postings list is "clean" (e.g., no updates &
+// no deletions) where the all bitmap is the same as the actual bitmap
+func (i *PostingsIterator) nextDocNumAtOrAfterClean(
+	atOrAfter uint64) (uint64, bool, error) {
+
+	if !i.includeFreqNorm {
+		i.Actual.AdvanceIfNeeded(uint32(atOrAfter))
+
+		if !i.Actual.HasNext() {
+			return 0, false, nil // couldn't find anything
+		}
+
+		return uint64(i.Actual.Next()), true, nil
+	}
+
+	// freq-norm's needed, so maintain freq-norm chunk reader
+	sameChunkNexts := 0 // # of times we called Next() in the same chunk
+	n := i.Actual.Next()
+	nChunk := n / uint32(i.postings.chunkSize)
+
+	for uint64(n) < atOrAfter && i.Actual.HasNext() {
+		n = i.Actual.Next()
+
+		nChunkPrev := nChunk
+		nChunk = n / uint32(i.postings.chunkSize)
+
+		if nChunk != nChunkPrev {
+			sameChunkNexts = 0
+		} else {
+			sameChunkNexts += 1
+		}
+	}
+
+	if uint64(n) < atOrAfter {
+		// couldn't find anything
+		return 0, false, nil
+	}
+
+	for j := 0; j < sameChunkNexts; j++ {
+		err := i.currChunkNext(nChunk)
+		if err != nil {
+			return 0, false, fmt.Errorf("error optimized currChunkNext: %v", err)
+		}
+	}
+
+	if i.currChunk != nChunk || i.freqNormReader.isNil() {
+		err := i.loadChunk(int(nChunk))
+		if err != nil {
+			return 0, false, fmt.Errorf("error loading chunk: %v", err)
+		}
+	}
+
+	return uint64(n), true, nil
+}
+
+func (i *PostingsIterator) currChunkNext(nChunk uint32) error {
+	if i.currChunk != nChunk || i.freqNormReader.isNil() {
+		err := i.loadChunk(int(nChunk))
+		if err != nil {
+			return fmt.Errorf("error loading chunk: %v", err)
+		}
+	}
+
+	// read off freq/offsets even though we don't care about them
+	hasLocs, err := i.skipFreqNormReadHasLocs()
+	if err != nil {
+		return err
+	}
+
+	if i.includeLocs && hasLocs {
+		numLocsBytes, err := i.locReader.readUvarint()
+		if err != nil {
+			return fmt.Errorf("error reading location numLocsBytes: %v", err)
+		}
+
+		// skip over all the location bytes
+		i.locReader.SkipBytes(int(numLocsBytes))
+	}
+
+	return nil
+}
+
+// DocNum1Hit returns the docNum and true if this is "1-hit" optimized
+// and the docNum is available.
+func (p *PostingsIterator) DocNum1Hit() (uint64, bool) {
+	if p.normBits1Hit != 0 && p.docNum1Hit != DocNum1HitFinished {
+		return p.docNum1Hit, true
+	}
+	return 0, false
+}
+
+// ActualBitmap returns the underlying actual bitmap
+// which can be used up the stack for optimizations
+func (p *PostingsIterator) ActualBitmap() *roaring.Bitmap {
+	return p.ActualBM
+}
+
+// ReplaceActual replaces the ActualBM with the provided
+// bitmap
+func (p *PostingsIterator) ReplaceActual(abm *roaring.Bitmap) {
+	p.ActualBM = abm
+	p.Actual = abm.Iterator()
+}
+
+// PostingsIteratorFromBitmap constructs a PostingsIterator given an
+// "actual" bitmap.
+func PostingsIteratorFromBitmap(bm *roaring.Bitmap,
+	includeFreqNorm, includeLocs bool) (segment.PostingsIterator, error) {
+	return &PostingsIterator{
+		ActualBM:        bm,
+		Actual:          bm.Iterator(),
+		includeFreqNorm: includeFreqNorm,
+		includeLocs:     includeLocs,
+	}, nil
+}
+
+// PostingsIteratorFrom1Hit constructs a PostingsIterator given a
+// 1-hit docNum.
+func PostingsIteratorFrom1Hit(docNum1Hit uint64,
+	includeFreqNorm, includeLocs bool) (segment.PostingsIterator, error) {
+	return &PostingsIterator{
+		docNum1Hit:      docNum1Hit,
+		normBits1Hit:    NormBits1Hit,
+		includeFreqNorm: includeFreqNorm,
+		includeLocs:     includeLocs,
+	}, nil
+}
+
+// Posting is a single entry in a postings list
+type Posting struct {
+	docNum uint64
+	freq   uint64
+	norm   float32
+	locs   []segment.Location
+}
+
+func (p *Posting) Size() int {
+	sizeInBytes := reflectStaticSizePosting
+
+	for _, entry := range p.locs {
+		sizeInBytes += entry.Size()
+	}
+
+	return sizeInBytes
+}
+
+// Number returns the document number of this posting in this segment
+func (p *Posting) Number() uint64 {
+	return p.docNum
+}
+
+// Frequency returns the frequencies of occurrence of this term in this doc/field
+func (p *Posting) Frequency() uint64 {
+	return p.freq
+}
+
+// Norm returns the normalization factor for this posting
+func (p *Posting) Norm() float64 {
+	return float64(float32(1.0 / math.Sqrt(float64(math.Float32bits(p.norm)))))
+}
+
+// Locations returns the location information for each occurrence
+func (p *Posting) Locations() []segment.Location {
+	return p.locs
+}
+
+// NormUint64 returns the norm value as uint64
+func (p *Posting) NormUint64() uint64 {
+	return uint64(math.Float32bits(p.norm))
+}
+
+// Location represents the location of a single occurrence
+type Location struct {
+	field string
+	pos   uint64
+	start uint64
+	end   uint64
+	ap    []uint64
+}
+
+func (l *Location) Size() int {
+	return reflectStaticSizeLocation +
+		len(l.field) +
+		len(l.ap)*size.SizeOfUint64
+}
+
+// Field returns the name of the field (useful in composite fields to know
+// which original field the value came from)
+func (l *Location) Field() string {
+	return l.field
+}
+
+// Start returns the start byte offset of this occurrence
+func (l *Location) Start() uint64 {
+	return l.start
+}
+
+// End returns the end byte offset of this occurrence
+func (l *Location) End() uint64 {
+	return l.end
+}
+
+// Pos returns the 1-based phrase position of this occurrence
+func (l *Location) Pos() uint64 {
+	return l.pos
+}
+
+// ArrayPositions returns the array position vector associated with this occurrence
+func (l *Location) ArrayPositions() []uint64 {
+	return l.ap
+}

vendor/github.com/blevesearch/zap/v15/read.go

@@ -0,0 +1,43 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import "encoding/binary"
+
+func (s *SegmentBase) getDocStoredMetaAndCompressed(docNum uint64) ([]byte, []byte) {
+	_, storedOffset, n, metaLen, dataLen := s.getDocStoredOffsets(docNum)
+
+	meta := s.mem[storedOffset+n : storedOffset+n+metaLen]
+	data := s.mem[storedOffset+n+metaLen : storedOffset+n+metaLen+dataLen]
+
+	return meta, data
+}
+
+func (s *SegmentBase) getDocStoredOffsets(docNum uint64) (
+	uint64, uint64, uint64, uint64, uint64) {
+	indexOffset := s.storedIndexOffset + (8 * docNum)
+
+	storedOffset := binary.BigEndian.Uint64(s.mem[indexOffset : indexOffset+8])
+
+	var n uint64
+
+	metaLen, read := binary.Uvarint(s.mem[storedOffset : storedOffset+binary.MaxVarintLen64])
+	n += uint64(read)
+
+	dataLen, read := binary.Uvarint(s.mem[storedOffset+n : storedOffset+n+binary.MaxVarintLen64])
+	n += uint64(read)
+
+	return indexOffset, storedOffset, n, metaLen, dataLen
+}

vendor/github.com/blevesearch/zap/v15/segment.go

@@ -0,0 +1,572 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"sync"
+	"unsafe"
+
+	"github.com/RoaringBitmap/roaring"
+	"github.com/blevesearch/bleve/index/scorch/segment"
+	"github.com/blevesearch/bleve/size"
+	"github.com/couchbase/vellum"
+	mmap "github.com/blevesearch/mmap-go"
+	"github.com/golang/snappy"
+)
+
+var reflectStaticSizeSegmentBase int
+
+func init() {
+	var sb SegmentBase
+	reflectStaticSizeSegmentBase = int(unsafe.Sizeof(sb))
+}
+
+// Open returns a zap impl of a segment
+func (*ZapPlugin) Open(path string) (segment.Segment, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	mm, err := mmap.Map(f, mmap.RDONLY, 0)
+	if err != nil {
+		// mmap failed, try to close the file
+		_ = f.Close()
+		return nil, err
+	}
+
+	rv := &Segment{
+		SegmentBase: SegmentBase{
+			mem:            mm[0 : len(mm)-FooterSize],
+			fieldsMap:      make(map[string]uint16),
+			fieldDvReaders: make(map[uint16]*docValueReader),
+			fieldFSTs:      make(map[uint16]*vellum.FST),
+		},
+		f:    f,
+		mm:   mm,
+		path: path,
+		refs: 1,
+	}
+	rv.SegmentBase.updateSize()
+
+	err = rv.loadConfig()
+	if err != nil {
+		_ = rv.Close()
+		return nil, err
+	}
+
+	err = rv.loadFields()
+	if err != nil {
+		_ = rv.Close()
+		return nil, err
+	}
+
+	err = rv.loadDvReaders()
+	if err != nil {
+		_ = rv.Close()
+		return nil, err
+	}
+
+	return rv, nil
+}
+
+// SegmentBase is a memory only, read-only implementation of the
+// segment.Segment interface, using zap's data representation.
+type SegmentBase struct {
+	mem               []byte
+	memCRC            uint32
+	chunkMode         uint32
+	fieldsMap         map[string]uint16 // fieldName -> fieldID+1
+	fieldsInv         []string          // fieldID -> fieldName
+	numDocs           uint64
+	storedIndexOffset uint64
+	fieldsIndexOffset uint64
+	docValueOffset    uint64
+	dictLocs          []uint64
+	fieldDvReaders    map[uint16]*docValueReader // naive chunk cache per field
+	fieldDvNames      []string                   // field names cached in fieldDvReaders
+	size              uint64
+
+	m         sync.Mutex
+	fieldFSTs map[uint16]*vellum.FST
+}
+
+func (sb *SegmentBase) Size() int {
+	return int(sb.size)
+}
+
+func (sb *SegmentBase) updateSize() {
+	sizeInBytes := reflectStaticSizeSegmentBase +
+		cap(sb.mem)
+
+	// fieldsMap
+	for k := range sb.fieldsMap {
+		sizeInBytes += (len(k) + size.SizeOfString) + size.SizeOfUint16
+	}
+
+	// fieldsInv, dictLocs
+	for _, entry := range sb.fieldsInv {
+		sizeInBytes += len(entry) + size.SizeOfString
+	}
+	sizeInBytes += len(sb.dictLocs) * size.SizeOfUint64
+
+	// fieldDvReaders
+	for _, v := range sb.fieldDvReaders {
+		sizeInBytes += size.SizeOfUint16 + size.SizeOfPtr
+		if v != nil {
+			sizeInBytes += v.size()
+		}
+	}
+
+	sb.size = uint64(sizeInBytes)
+}
+
+func (sb *SegmentBase) AddRef()             {}
+func (sb *SegmentBase) DecRef() (err error) { return nil }
+func (sb *SegmentBase) Close() (err error)  { return nil }
+
+// Segment implements a persisted segment.Segment interface, by
+// embedding an mmap()'ed SegmentBase.
+type Segment struct {
+	SegmentBase
+
+	f       *os.File
+	mm      mmap.MMap
+	path    string
+	version uint32
+	crc     uint32
+
+	m    sync.Mutex // Protects the fields that follow.
+	refs int64
+}
+
+func (s *Segment) Size() int {
+	// 8 /* size of file pointer */
+	// 4 /* size of version -> uint32 */
+	// 4 /* size of crc -> uint32 */
+	sizeOfUints := 16
+
+	sizeInBytes := (len(s.path) + size.SizeOfString) + sizeOfUints
+
+	// mutex, refs -> int64
+	sizeInBytes += 16
+
+	// do not include the mmap'ed part
+	return sizeInBytes + s.SegmentBase.Size() - cap(s.mem)
+}
+
+func (s *Segment) AddRef() {
+	s.m.Lock()
+	s.refs++
+	s.m.Unlock()
+}
+
+func (s *Segment) DecRef() (err error) {
+	s.m.Lock()
+	s.refs--
+	if s.refs == 0 {
+		err = s.closeActual()
+	}
+	s.m.Unlock()
+	return err
+}
+
+func (s *Segment) loadConfig() error {
+	crcOffset := len(s.mm) - 4
+	s.crc = binary.BigEndian.Uint32(s.mm[crcOffset : crcOffset+4])
+
+	verOffset := crcOffset - 4
+	s.version = binary.BigEndian.Uint32(s.mm[verOffset : verOffset+4])
+	if s.version != Version {
+		return fmt.Errorf("unsupported version %d", s.version)
+	}
+
+	chunkOffset := verOffset - 4
+	s.chunkMode = binary.BigEndian.Uint32(s.mm[chunkOffset : chunkOffset+4])
+
+	docValueOffset := chunkOffset - 8
+	s.docValueOffset = binary.BigEndian.Uint64(s.mm[docValueOffset : docValueOffset+8])
+
+	fieldsIndexOffset := docValueOffset - 8
+	s.fieldsIndexOffset = binary.BigEndian.Uint64(s.mm[fieldsIndexOffset : fieldsIndexOffset+8])
+
+	storedIndexOffset := fieldsIndexOffset - 8
+	s.storedIndexOffset = binary.BigEndian.Uint64(s.mm[storedIndexOffset : storedIndexOffset+8])
+
+	numDocsOffset := storedIndexOffset - 8
+	s.numDocs = binary.BigEndian.Uint64(s.mm[numDocsOffset : numDocsOffset+8])
+	return nil
+}
+
+func (s *SegmentBase) loadFields() error {
+	// NOTE for now we assume the fields index immediately precedes
+	// the footer, and if this changes, need to adjust accordingly (or
+	// store explicit length), where s.mem was sliced from s.mm in Open().
+	fieldsIndexEnd := uint64(len(s.mem))
+
+	// iterate through fields index
+	var fieldID uint64
+	for s.fieldsIndexOffset+(8*fieldID) < fieldsIndexEnd {
+		addr := binary.BigEndian.Uint64(s.mem[s.fieldsIndexOffset+(8*fieldID) : s.fieldsIndexOffset+(8*fieldID)+8])
+
+		dictLoc, read := binary.Uvarint(s.mem[addr:fieldsIndexEnd])
+		n := uint64(read)
+		s.dictLocs = append(s.dictLocs, dictLoc)
+
+		var nameLen uint64
+		nameLen, read = binary.Uvarint(s.mem[addr+n : fieldsIndexEnd])
+		n += uint64(read)
+
+		name := string(s.mem[addr+n : addr+n+nameLen])
+		s.fieldsInv = append(s.fieldsInv, name)
+		s.fieldsMap[name] = uint16(fieldID + 1)
+
+		fieldID++
+	}
+	return nil
+}
+
+// Dictionary returns the term dictionary for the specified field
+func (s *SegmentBase) Dictionary(field string) (segment.TermDictionary, error) {
+	dict, err := s.dictionary(field)
+	if err == nil && dict == nil {
+		return &segment.EmptyDictionary{}, nil
+	}
+	return dict, err
+}
+
+func (sb *SegmentBase) dictionary(field string) (rv *Dictionary, err error) {
+	fieldIDPlus1 := sb.fieldsMap[field]
+	if fieldIDPlus1 > 0 {
+		rv = &Dictionary{
+			sb:      sb,
+			field:   field,
+			fieldID: fieldIDPlus1 - 1,
+		}
+
+		dictStart := sb.dictLocs[rv.fieldID]
+		if dictStart > 0 {
+			var ok bool
+			sb.m.Lock()
+			if rv.fst, ok = sb.fieldFSTs[rv.fieldID]; !ok {
+				// read the length of the vellum data
+				vellumLen, read := binary.Uvarint(sb.mem[dictStart : dictStart+binary.MaxVarintLen64])
+				fstBytes := sb.mem[dictStart+uint64(read) : dictStart+uint64(read)+vellumLen]
+				rv.fst, err = vellum.Load(fstBytes)
+				if err != nil {
+					sb.m.Unlock()
+					return nil, fmt.Errorf("dictionary field %s vellum err: %v", field, err)
+				}
+
+				sb.fieldFSTs[rv.fieldID] = rv.fst
+			}
+
+			sb.m.Unlock()
+			rv.fstReader, err = rv.fst.Reader()
+			if err != nil {
+				return nil, fmt.Errorf("dictionary field %s vellum reader err: %v", field, err)
+			}
+
+		}
+	}
+
+	return rv, nil
+}
+
+// visitDocumentCtx holds data structures that are reusable across
+// multiple VisitDocument() calls to avoid memory allocations
+type visitDocumentCtx struct {
+	buf      []byte
+	reader   bytes.Reader
+	arrayPos []uint64
+}
+
+var visitDocumentCtxPool = sync.Pool{
+	New: func() interface{} {
+		reuse := &visitDocumentCtx{}
+		return reuse
+	},
+}
+
+// VisitDocument invokes the DocFieldValueVistor for each stored field
+// for the specified doc number
+func (s *SegmentBase) VisitDocument(num uint64, visitor segment.DocumentFieldValueVisitor) error {
+	vdc := visitDocumentCtxPool.Get().(*visitDocumentCtx)
+	defer visitDocumentCtxPool.Put(vdc)
+	return s.visitDocument(vdc, num, visitor)
+}
+
+func (s *SegmentBase) visitDocument(vdc *visitDocumentCtx, num uint64,
+	visitor segment.DocumentFieldValueVisitor) error {
+	// first make sure this is a valid number in this segment
+	if num < s.numDocs {
+		meta, compressed := s.getDocStoredMetaAndCompressed(num)
+
+		vdc.reader.Reset(meta)
+
+		// handle _id field special case
+		idFieldValLen, err := binary.ReadUvarint(&vdc.reader)
+		if err != nil {
+			return err
+		}
+		idFieldVal := compressed[:idFieldValLen]
+
+		keepGoing := visitor("_id", byte('t'), idFieldVal, nil)
+		if !keepGoing {
+			visitDocumentCtxPool.Put(vdc)
+			return nil
+		}
+
+		// handle non-"_id" fields
+		compressed = compressed[idFieldValLen:]
+
+		uncompressed, err := snappy.Decode(vdc.buf[:cap(vdc.buf)], compressed)
+		if err != nil {
+			return err
+		}
+
+		for keepGoing {
+			field, err := binary.ReadUvarint(&vdc.reader)
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return err
+			}
+			typ, err := binary.ReadUvarint(&vdc.reader)
+			if err != nil {
+				return err
+			}
+			offset, err := binary.ReadUvarint(&vdc.reader)
+			if err != nil {
+				return err
+			}
+			l, err := binary.ReadUvarint(&vdc.reader)
+			if err != nil {
+				return err
+			}
+			numap, err := binary.ReadUvarint(&vdc.reader)
+			if err != nil {
+				return err
+			}
+			var arrayPos []uint64
+			if numap > 0 {
+				if cap(vdc.arrayPos) < int(numap) {
+					vdc.arrayPos = make([]uint64, numap)
+				}
+				arrayPos = vdc.arrayPos[:numap]
+				for i := 0; i < int(numap); i++ {
+					ap, err := binary.ReadUvarint(&vdc.reader)
+					if err != nil {
+						return err
+					}
+					arrayPos[i] = ap
+				}
+			}
+
+			value := uncompressed[offset : offset+l]
+			keepGoing = visitor(s.fieldsInv[field], byte(typ), value, arrayPos)
+		}
+
+		vdc.buf = uncompressed
+	}
+	return nil
+}
+
+// DocID returns the value of the _id field for the given docNum
+func (s *SegmentBase) DocID(num uint64) ([]byte, error) {
+	if num >= s.numDocs {
+		return nil, nil
+	}
+
+	vdc := visitDocumentCtxPool.Get().(*visitDocumentCtx)
+
+	meta, compressed := s.getDocStoredMetaAndCompressed(num)
+
+	vdc.reader.Reset(meta)
+
+	// handle _id field special case
+	idFieldValLen, err := binary.ReadUvarint(&vdc.reader)
+	if err != nil {
+		return nil, err
+	}
+	idFieldVal := compressed[:idFieldValLen]
+
+	visitDocumentCtxPool.Put(vdc)
+
+	return idFieldVal, nil
+}
+
+// Count returns the number of documents in this segment.
+func (s *SegmentBase) Count() uint64 {
+	return s.numDocs
+}
+
+// DocNumbers returns a bitset corresponding to the doc numbers of all the
+// provided _id strings
+func (s *SegmentBase) DocNumbers(ids []string) (*roaring.Bitmap, error) {
+	rv := roaring.New()
+
+	if len(s.fieldsMap) > 0 {
+		idDict, err := s.dictionary("_id")
+		if err != nil {
+			return nil, err
+		}
+
+		postingsList := emptyPostingsList
+
+		sMax, err := idDict.fst.GetMaxKey()
+		if err != nil {
+			return nil, err
+		}
+		sMaxStr := string(sMax)
+		filteredIds := make([]string, 0, len(ids))
+		for _, id := range ids {
+			if id <= sMaxStr {
+				filteredIds = append(filteredIds, id)
+			}
+		}
+
+		for _, id := range filteredIds {
+			postingsList, err = idDict.postingsList([]byte(id), nil, postingsList)
+			if err != nil {
+				return nil, err
+			}
+			postingsList.OrInto(rv)
+		}
+	}
+
+	return rv, nil
+}
+
+// Fields returns the field names used in this segment
+func (s *SegmentBase) Fields() []string {
+	return s.fieldsInv
+}
+
+// Path returns the path of this segment on disk
+func (s *Segment) Path() string {
+	return s.path
+}
+
+// Close releases all resources associated with this segment
+func (s *Segment) Close() (err error) {
+	return s.DecRef()
+}
+
+func (s *Segment) closeActual() (err error) {
+	if s.mm != nil {
+		err = s.mm.Unmap()
+	}
+	// try to close file even if unmap failed
+	if s.f != nil {
+		err2 := s.f.Close()
+		if err == nil {
+			// try to return first error
+			err = err2
+		}
+	}
+	return
+}
+
+// some helpers i started adding for the command-line utility
+
+// Data returns the underlying mmaped data slice
+func (s *Segment) Data() []byte {
+	return s.mm
+}
+
+// CRC returns the CRC value stored in the file footer
+func (s *Segment) CRC() uint32 {
+	return s.crc
+}
+
+// Version returns the file version in the file footer
+func (s *Segment) Version() uint32 {
+	return s.version
+}
+
+// ChunkFactor returns the chunk factor in the file footer
+func (s *Segment) ChunkMode() uint32 {
+	return s.chunkMode
+}
+
+// FieldsIndexOffset returns the fields index offset in the file footer
+func (s *Segment) FieldsIndexOffset() uint64 {
+	return s.fieldsIndexOffset
+}
+
+// StoredIndexOffset returns the stored value index offset in the file footer
+func (s *Segment) StoredIndexOffset() uint64 {
+	return s.storedIndexOffset
+}
+
+// DocValueOffset returns the docValue offset in the file footer
+func (s *Segment) DocValueOffset() uint64 {
+	return s.docValueOffset
+}
+
+// NumDocs returns the number of documents in the file footer
+func (s *Segment) NumDocs() uint64 {
+	return s.numDocs
+}
+
+// DictAddr is a helper function to compute the file offset where the
+// dictionary is stored for the specified field.
+func (s *Segment) DictAddr(field string) (uint64, error) {
+	fieldIDPlus1, ok := s.fieldsMap[field]
+	if !ok {
+		return 0, fmt.Errorf("no such field '%s'", field)
+	}
+
+	return s.dictLocs[fieldIDPlus1-1], nil
+}
+
+func (s *SegmentBase) loadDvReaders() error {
+	if s.docValueOffset == fieldNotUninverted || s.numDocs == 0 {
+		return nil
+	}
+
+	var read uint64
+	for fieldID, field := range s.fieldsInv {
+		var fieldLocStart, fieldLocEnd uint64
+		var n int
+		fieldLocStart, n = binary.Uvarint(s.mem[s.docValueOffset+read : s.docValueOffset+read+binary.MaxVarintLen64])
+		if n <= 0 {
+			return fmt.Errorf("loadDvReaders: failed to read the docvalue offset start for field %d", fieldID)
+		}
+		read += uint64(n)
+		fieldLocEnd, n = binary.Uvarint(s.mem[s.docValueOffset+read : s.docValueOffset+read+binary.MaxVarintLen64])
+		if n <= 0 {
+			return fmt.Errorf("loadDvReaders: failed to read the docvalue offset end for field %d", fieldID)
+		}
+		read += uint64(n)
+
+		fieldDvReader, err := s.loadFieldDocValueReader(field, fieldLocStart, fieldLocEnd)
+		if err != nil {
+			return err
+		}
+		if fieldDvReader != nil {
+			s.fieldDvReaders[uint16(fieldID)] = fieldDvReader
+			s.fieldDvNames = append(s.fieldDvNames, field)
+		}
+	}
+
+	return nil
+}

vendor/github.com/blevesearch/zap/v15/write.go

@@ -0,0 +1,145 @@
+//  Copyright (c) 2017 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package zap
+
+import (
+	"encoding/binary"
+	"io"
+
+	"github.com/RoaringBitmap/roaring"
+)
+
+// writes out the length of the roaring bitmap in bytes as varint
+// then writes out the roaring bitmap itself
+func writeRoaringWithLen(r *roaring.Bitmap, w io.Writer,
+	reuseBufVarint []byte) (int, error) {
+	buf, err := r.ToBytes()
+	if err != nil {
+		return 0, err
+	}
+
+	var tw int
+
+	// write out the length
+	n := binary.PutUvarint(reuseBufVarint, uint64(len(buf)))
+	nw, err := w.Write(reuseBufVarint[:n])
+	tw += nw
+	if err != nil {
+		return tw, err
+	}
+
+	// write out the roaring bytes
+	nw, err = w.Write(buf)
+	tw += nw
+	if err != nil {
+		return tw, err
+	}
+
+	return tw, nil
+}
+
+func persistFields(fieldsInv []string, w *CountHashWriter, dictLocs []uint64) (uint64, error) {
+	var rv uint64
+	var fieldsOffsets []uint64
+
+	for fieldID, fieldName := range fieldsInv {
+		// record start of this field
+		fieldsOffsets = append(fieldsOffsets, uint64(w.Count()))
+
+		// write out the dict location and field name length
+		_, err := writeUvarints(w, dictLocs[fieldID], uint64(len(fieldName)))
+		if err != nil {
+			return 0, err
+		}
+
+		// write out the field name
+		_, err = w.Write([]byte(fieldName))
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	// now write out the fields index
+	rv = uint64(w.Count())
+	for fieldID := range fieldsInv {
+		err := binary.Write(w, binary.BigEndian, fieldsOffsets[fieldID])
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	return rv, nil
+}
+
+// FooterSize is the size of the footer record in bytes
+// crc + ver + chunk + field offset + stored offset + num docs + docValueOffset
+const FooterSize = 4 + 4 + 4 + 8 + 8 + 8 + 8
+
+func persistFooter(numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset uint64,
+	chunkMode uint32, crcBeforeFooter uint32, writerIn io.Writer) error {
+	w := NewCountHashWriter(writerIn)
+	w.crc = crcBeforeFooter
+
+	// write out the number of docs
+	err := binary.Write(w, binary.BigEndian, numDocs)
+	if err != nil {
+		return err
+	}
+	// write out the stored field index location:
+	err = binary.Write(w, binary.BigEndian, storedIndexOffset)
+	if err != nil {
+		return err
+	}
+	// write out the field index location
+	err = binary.Write(w, binary.BigEndian, fieldsIndexOffset)
+	if err != nil {
+		return err
+	}
+	// write out the fieldDocValue location
+	err = binary.Write(w, binary.BigEndian, docValueOffset)
+	if err != nil {
+		return err
+	}
+	// write out 32-bit chunk factor
+	err = binary.Write(w, binary.BigEndian, chunkMode)
+	if err != nil {
+		return err
+	}
+	// write out 32-bit version
+	err = binary.Write(w, binary.BigEndian, Version)
+	if err != nil {
+		return err
+	}
+	// write out CRC-32 of everything upto but not including this CRC
+	err = binary.Write(w, binary.BigEndian, w.crc)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func writeUvarints(w io.Writer, vals ...uint64) (tw int, err error) {
+	buf := make([]byte, binary.MaxVarintLen64)
+	for _, val := range vals {
+		n := binary.PutUvarint(buf, val)
+		var nw int
+		nw, err = w.Write(buf[:n])
+		tw += nw
+		if err != nil {
+			return tw, err
+		}
+	}
+	return tw, err
+}

vendor/github.com/blevesearch/zap/v15/zap.md

@@ -0,0 +1,177 @@
+# ZAP File Format 
+
+## Legend
+
+### Sections
+
+    |========|
+    |        | section
+    |========|
+    
+### Fixed-size fields
+
+    |--------|        |----|        |--|        |-|
+    |        | uint64 |    | uint32 |  | uint16 | | uint8
+    |--------|        |----|        |--|        |-|
+
+### Varints
+
+    |~~~~~~~~|
+    |        | varint(up to uint64)
+    |~~~~~~~~|
+
+### Arbitrary-length fields
+
+    |--------...---|
+    |              | arbitrary-length field (string, vellum, roaring bitmap)
+    |--------...---|
+
+### Chunked data
+
+	[--------]
+	[        ]
+	[--------]
+
+## Overview
+
+Footer section describes the configuration of particular ZAP file. The format of footer is version-dependent, so it is necessary to check `V` field before the parsing.
+
+            |==================================================|
+            | Stored Fields                                    |
+            |==================================================|
+    |-----> | Stored Fields Index                              |
+    |       |==================================================|   
+    |       | Dictionaries + Postings + DocValues              | 
+    |       |==================================================|
+    | |---> | DocValues Index                                  |
+    | |     |==================================================|   
+    | |     | Fields                                           |
+    | |     |==================================================|
+    | | |-> | Fields Index                                     |
+    | | |   |========|========|========|========|====|====|====|
+    | | |   |     D# |     SF |      F |    FDV | CF |  V | CC | (Footer)
+    | | |   |========|====|===|====|===|====|===|====|====|====|
+    | | |                 |        |        |
+    |-+-+-----------------|        |        |
+      | |--------------------------|        |
+      |-------------------------------------|
+
+     D#. Number of Docs.
+     SF. Stored Fields Index Offset.
+      F. Field Index Offset.
+    FDV. Field DocValue Offset.
+     CF. Chunk Factor.
+      V. Version.
+     CC. CRC32.
+
+## Stored Fields
+
+Stored Fields Index is `D#` consecutive 64-bit unsigned integers - offsets, where relevant Stored Fields Data records are located.
+
+    0                                [SF]                   [SF + D# * 8]
+    | Stored Fields                  | Stored Fields Index              |
+    |================================|==================================|
+    |                                |                                  |
+    |       |--------------------|   ||--------|--------|. . .|--------||
+    |   |-> | Stored Fields Data |   ||      0 |      1 |     | D# - 1 ||
+    |   |   |--------------------|   ||--------|----|---|. . .|--------||
+    |   |                            |              |                   |
+    |===|============================|==============|===================|
+        |                                           |
+        |-------------------------------------------|
+
+Stored Fields Data is an arbitrary size record, which consists of metadata and [Snappy](https://github.com/golang/snappy)-compressed data.
+
+    Stored Fields Data
+    |~~~~~~~~|~~~~~~~~|~~~~~~~~...~~~~~~~~|~~~~~~~~...~~~~~~~~|
+    |    MDS |    CDS |                MD |                CD |
+    |~~~~~~~~|~~~~~~~~|~~~~~~~~...~~~~~~~~|~~~~~~~~...~~~~~~~~|
+    
+    MDS. Metadata size.
+    CDS. Compressed data size.
+    MD. Metadata.
+    CD. Snappy-compressed data.
+
+## Fields
+
+Fields Index section located between addresses `F` and `len(file) - len(footer)` and consist of `uint64` values (`F1`, `F2`, ...) which are offsets to records in Fields section. We have `F# = (len(file) - len(footer) - F) / sizeof(uint64)` fields.
+
+
+    (...)                            [F]                       [F + F#]
+    | Fields                         | Fields Index.                  |
+    |================================|================================|
+    |                                |                                |
+    |   |~~~~~~~~|~~~~~~~~|---...---|||--------|--------|...|--------||
+    ||->|   Dict | Length |    Name |||      0 |      1 |   | F# - 1 ||
+    ||  |~~~~~~~~|~~~~~~~~|---...---|||--------|----|---|...|--------||
+    ||                               |              |                 |
+    ||===============================|==============|=================|
+     |                                              |
+     |----------------------------------------------|
+        
+
+## Dictionaries + Postings
+
+Each of fields has its own dictionary, encoded in [Vellum](https://github.com/couchbase/vellum) format. Dictionary consists of pairs `(term, offset)`, where `offset` indicates the position of postings (list of documents) for this particular term.
+
+	|================================================================|- Dictionaries + 
+	|                                                                |   Postings +
+	|                                                                |    DocValues
+	|    Freq/Norm (chunked)                                         |
+	|    [~~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~]                      |
+	| |->[ Freq | Norm (float32 under varint) ]                      |
+	| |  [~~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~]                      |
+	| |                                                              |
+	| |------------------------------------------------------------| |
+	|    Location Details (chunked)                                | |
+	|    [~~~~~~|~~~~~|~~~~~~~|~~~~~|~~~~~~|~~~~~~~~|~~~~~]        | |
+	| |->[ Size | Pos | Start | End | Arr# | ArrPos | ... ]        | |
+	| |  [~~~~~~|~~~~~|~~~~~~~|~~~~~|~~~~~~|~~~~~~~~|~~~~~]        | |
+	| |                                                            | |
+	| |----------------------|                                     | |
+	|          Postings List |                                     | |
+	|         |~~~~~~~~|~~~~~|~~|~~~~~~~~|-----------...--|        | |
+	|      |->|    F/N |     LD | Length | ROARING BITMAP |        | |
+	|      |  |~~~~~|~~|~~~~~~~~|~~~~~~~~|-----------...--|        | |
+	|      |        |----------------------------------------------| |
+	|      |--------------------------------------|                  |
+	|          Dictionary                         |                  |
+	|         |~~~~~~~~|--------------------------|-...-|            |
+	|      |->| Length | VELLUM DATA : (TERM -> OFFSET) |            |
+	|      |  |~~~~~~~~|----------------------------...-|            |
+	|      |                                                         |
+	|======|=========================================================|- DocValues Index
+	|      |                                                         |
+	|======|=========================================================|- Fields
+	|      |                                                         |
+	| |~~~~|~~~|~~~~~~~~|---...---|                                  |
+	| |   Dict | Length |    Name |                                  |
+	| |~~~~~~~~|~~~~~~~~|---...---|                                  |
+	|                                                                |
+	|================================================================|
+
+## DocValues
+
+DocValues Index is `F#` pairs of varints, one pair per field. Each pair of varints indicates start and end point of DocValues slice.
+
+	|================================================================|
+	|     |------...--|                                              |
+	|  |->| DocValues |<-|                                           |
+	|  |  |------...--|  |                                           |
+	|==|=================|===========================================|- DocValues Index
+	||~|~~~~~~~~~|~~~~~~~|~~|           |~~~~~~~~~~~~~~|~~~~~~~~~~~~||
+	|| DV1 START | DV1 STOP | . . . . . | DV(F#) START | DV(F#) END ||
+	||~~~~~~~~~~~|~~~~~~~~~~|           |~~~~~~~~~~~~~~|~~~~~~~~~~~~||
+	|================================================================|
+
+DocValues is chunked Snappy-compressed values for each document and field.
+
+    [~~~~~~~~~~~~~~~|~~~~~~|~~~~~~~~~|-...-|~~~~~~|~~~~~~~~~|--------------------...-]
+    [ Doc# in Chunk | Doc1 | Offset1 | ... | DocN | OffsetN | SNAPPY COMPRESSED DATA ]
+    [~~~~~~~~~~~~~~~|~~~~~~|~~~~~~~~~|-...-|~~~~~~|~~~~~~~~~|--------------------...-]
+
+Last 16 bytes are description of chunks.
+
+    |~~~~~~~~~~~~...~|----------------|----------------|
+    |   Chunk Sizes  | Chunk Size Arr |         Chunk# |
+    |~~~~~~~~~~~~...~|----------------|----------------|

vendor/github.com/cespare/xxhash/v2/.travis.yml

@@ -0,0 +1,8 @@
+language: go
+go:
+  - "1.x"
+  - master
+env:
+  - TAGS=""
+  - TAGS="-tags purego"
+script: go test $TAGS -v ./...

vendor/github.com/cespare/xxhash/v2/LICENSE.txt

@@ -0,0 +1,22 @@
+Copyright (c) 2016 Caleb Spare
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/cespare/xxhash/v2/README.md

@@ -0,0 +1,67 @@
+# xxhash
+
+[![GoDoc](https://godoc.org/github.com/cespare/xxhash?status.svg)](https://godoc.org/github.com/cespare/xxhash)
+[![Build Status](https://travis-ci.org/cespare/xxhash.svg?branch=master)](https://travis-ci.org/cespare/xxhash)
+
+xxhash is a Go implementation of the 64-bit
+[xxHash](http://cyan4973.github.io/xxHash/) algorithm, XXH64. This is a
+high-quality hashing algorithm that is much faster than anything in the Go
+standard library.
+
+This package provides a straightforward API:
+
+```
+func Sum64(b []byte) uint64
+func Sum64String(s string) uint64
+type Digest struct{ ... }
+    func New() *Digest
+```
+
+The `Digest` type implements hash.Hash64. Its key methods are:
+
+```
+func (*Digest) Write([]byte) (int, error)
+func (*Digest) WriteString(string) (int, error)
+func (*Digest) Sum64() uint64
+```
+
+This implementation provides a fast pure-Go implementation and an even faster
+assembly implementation for amd64.
+
+## Compatibility
+
+This package is in a module and the latest code is in version 2 of the module.
+You need a version of Go with at least "minimal module compatibility" to use
+github.com/cespare/xxhash/v2:
+
+* 1.9.7+ for Go 1.9
+* 1.10.3+ for Go 1.10
+* Go 1.11 or later
+
+I recommend using the latest release of Go.
+
+## Benchmarks
+
+Here are some quick benchmarks comparing the pure-Go and assembly
+implementations of Sum64.
+
+| input size | purego | asm |
+| --- | --- | --- |
+| 5 B   |  979.66 MB/s |  1291.17 MB/s  |
+| 100 B | 7475.26 MB/s | 7973.40 MB/s  |
+| 4 KB  | 17573.46 MB/s | 17602.65 MB/s |
+| 10 MB | 17131.46 MB/s | 17142.16 MB/s |
+
+These numbers were generated on Ubuntu 18.04 with an Intel i7-8700K CPU using
+the following commands under Go 1.11.2:
+
+```
+$ go test -tags purego -benchtime 10s -bench '/xxhash,direct,bytes'
+$ go test -benchtime 10s -bench '/xxhash,direct,bytes'
+```
+
+## Projects using this package
+
+- [InfluxDB](https://github.com/influxdata/influxdb)
+- [Prometheus](https://github.com/prometheus/prometheus)
+- [FreeCache](https://github.com/coocood/freecache)

vendor/github.com/cespare/xxhash/v2/go.mod

@@ -0,0 +1,3 @@
+module github.com/cespare/xxhash/v2
+
+go 1.11

vendor/github.com/cespare/xxhash/v2/xxhash.go

@@ -0,0 +1,236 @@
+// Package xxhash implements the 64-bit variant of xxHash (XXH64) as described
+// at http://cyan4973.github.io/xxHash/.
+package xxhash
+
+import (
+	"encoding/binary"
+	"errors"
+	"math/bits"
+)
+
+const (
+	prime1 uint64 = 11400714785074694791
+	prime2 uint64 = 14029467366897019727
+	prime3 uint64 = 1609587929392839161
+	prime4 uint64 = 9650029242287828579
+	prime5 uint64 = 2870177450012600261
+)
+
+// NOTE(caleb): I'm using both consts and vars of the primes. Using consts where
+// possible in the Go code is worth a small (but measurable) performance boost
+// by avoiding some MOVQs. Vars are needed for the asm and also are useful for
+// convenience in the Go code in a few places where we need to intentionally
+// avoid constant arithmetic (e.g., v1 := prime1 + prime2 fails because the
+// result overflows a uint64).
+var (
+	prime1v = prime1
+	prime2v = prime2
+	prime3v = prime3
+	prime4v = prime4
+	prime5v = prime5
+)
+
+// Digest implements hash.Hash64.
+type Digest struct {
+	v1    uint64
+	v2    uint64
+	v3    uint64
+	v4    uint64
+	total uint64
+	mem   [32]byte
+	n     int // how much of mem is used
+}
+
+// New creates a new Digest that computes the 64-bit xxHash algorithm.
+func New() *Digest {
+	var d Digest
+	d.Reset()
+	return &d
+}
+
+// Reset clears the Digest's state so that it can be reused.
+func (d *Digest) Reset() {
+	d.v1 = prime1v + prime2
+	d.v2 = prime2
+	d.v3 = 0
+	d.v4 = -prime1v
+	d.total = 0
+	d.n = 0
+}
+
+// Size always returns 8 bytes.
+func (d *Digest) Size() int { return 8 }
+
+// BlockSize always returns 32 bytes.
+func (d *Digest) BlockSize() int { return 32 }
+
+// Write adds more data to d. It always returns len(b), nil.
+func (d *Digest) Write(b []byte) (n int, err error) {
+	n = len(b)
+	d.total += uint64(n)
+
+	if d.n+n < 32 {
+		// This new data doesn't even fill the current block.
+		copy(d.mem[d.n:], b)
+		d.n += n
+		return
+	}
+
+	if d.n > 0 {
+		// Finish off the partial block.
+		copy(d.mem[d.n:], b)
+		d.v1 = round(d.v1, u64(d.mem[0:8]))
+		d.v2 = round(d.v2, u64(d.mem[8:16]))
+		d.v3 = round(d.v3, u64(d.mem[16:24]))
+		d.v4 = round(d.v4, u64(d.mem[24:32]))
+		b = b[32-d.n:]
+		d.n = 0
+	}
+
+	if len(b) >= 32 {
+		// One or more full blocks left.
+		nw := writeBlocks(d, b)
+		b = b[nw:]
+	}
+
+	// Store any remaining partial block.
+	copy(d.mem[:], b)
+	d.n = len(b)
+
+	return
+}
+
+// Sum appends the current hash to b and returns the resulting slice.
+func (d *Digest) Sum(b []byte) []byte {
+	s := d.Sum64()
+	return append(
+		b,
+		byte(s>>56),
+		byte(s>>48),
+		byte(s>>40),
+		byte(s>>32),
+		byte(s>>24),
+		byte(s>>16),
+		byte(s>>8),
+		byte(s),
+	)
+}
+
+// Sum64 returns the current hash.
+func (d *Digest) Sum64() uint64 {
+	var h uint64
+
+	if d.total >= 32 {
+		v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
+		h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4)
+		h = mergeRound(h, v1)
+		h = mergeRound(h, v2)
+		h = mergeRound(h, v3)
+		h = mergeRound(h, v4)
+	} else {
+		h = d.v3 + prime5
+	}
+
+	h += d.total
+
+	i, end := 0, d.n
+	for ; i+8 <= end; i += 8 {
+		k1 := round(0, u64(d.mem[i:i+8]))
+		h ^= k1
+		h = rol27(h)*prime1 + prime4
+	}
+	if i+4 <= end {
+		h ^= uint64(u32(d.mem[i:i+4])) * prime1
+		h = rol23(h)*prime2 + prime3
+		i += 4
+	}
+	for i < end {
+		h ^= uint64(d.mem[i]) * prime5
+		h = rol11(h) * prime1
+		i++
+	}
+
+	h ^= h >> 33
+	h *= prime2
+	h ^= h >> 29
+	h *= prime3
+	h ^= h >> 32
+
+	return h
+}
+
+const (
+	magic         = "xxh\x06"
+	marshaledSize = len(magic) + 8*5 + 32
+)
+
+// MarshalBinary implements the encoding.BinaryMarshaler interface.
+func (d *Digest) MarshalBinary() ([]byte, error) {
+	b := make([]byte, 0, marshaledSize)
+	b = append(b, magic...)
+	b = appendUint64(b, d.v1)
+	b = appendUint64(b, d.v2)
+	b = appendUint64(b, d.v3)
+	b = appendUint64(b, d.v4)
+	b = appendUint64(b, d.total)
+	b = append(b, d.mem[:d.n]...)
+	b = b[:len(b)+len(d.mem)-d.n]
+	return b, nil
+}
+
+// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.
+func (d *Digest) UnmarshalBinary(b []byte) error {
+	if len(b) < len(magic) || string(b[:len(magic)]) != magic {
+		return errors.New("xxhash: invalid hash state identifier")
+	}
+	if len(b) != marshaledSize {
+		return errors.New("xxhash: invalid hash state size")
+	}
+	b = b[len(magic):]
+	b, d.v1 = consumeUint64(b)
+	b, d.v2 = consumeUint64(b)
+	b, d.v3 = consumeUint64(b)
+	b, d.v4 = consumeUint64(b)
+	b, d.total = consumeUint64(b)
+	copy(d.mem[:], b)
+	b = b[len(d.mem):]
+	d.n = int(d.total % uint64(len(d.mem)))
+	return nil
+}
+
+func appendUint64(b []byte, x uint64) []byte {
+	var a [8]byte
+	binary.LittleEndian.PutUint64(a[:], x)
+	return append(b, a[:]...)
+}
+
+func consumeUint64(b []byte) ([]byte, uint64) {
+	x := u64(b)
+	return b[8:], x
+}
+
+func u64(b []byte) uint64 { return binary.LittleEndian.Uint64(b) }
+func u32(b []byte) uint32 { return binary.LittleEndian.Uint32(b) }
+
+func round(acc, input uint64) uint64 {
+	acc += input * prime2
+	acc = rol31(acc)
+	acc *= prime1
+	return acc
+}
+
+func mergeRound(acc, val uint64) uint64 {
+	val = round(0, val)
+	acc ^= val
+	acc = acc*prime1 + prime4
+	return acc
+}
+
+func rol1(x uint64) uint64  { return bits.RotateLeft64(x, 1) }
+func rol7(x uint64) uint64  { return bits.RotateLeft64(x, 7) }
+func rol11(x uint64) uint64 { return bits.RotateLeft64(x, 11) }
+func rol12(x uint64) uint64 { return bits.RotateLeft64(x, 12) }
+func rol18(x uint64) uint64 { return bits.RotateLeft64(x, 18) }
+func rol23(x uint64) uint64 { return bits.RotateLeft64(x, 23) }
+func rol27(x uint64) uint64 { return bits.RotateLeft64(x, 27) }
+func rol31(x uint64) uint64 { return bits.RotateLeft64(x, 31) }

vendor/github.com/cespare/xxhash/v2/xxhash_amd64.go

@@ -0,0 +1,13 @@
+// +build !appengine
+// +build gc
+// +build !purego
+
+package xxhash
+
+// Sum64 computes the 64-bit xxHash digest of b.
+//
+//go:noescape
+func Sum64(b []byte) uint64
+
+//go:noescape
+func writeBlocks(d *Digest, b []byte) int

vendor/github.com/cespare/xxhash/v2/xxhash_amd64.s

@@ -0,0 +1,215 @@
+// +build !appengine
+// +build gc
+// +build !purego
+
+#include "textflag.h"
+
+// Register allocation:
+// AX	h
+// CX	pointer to advance through b
+// DX	n
+// BX	loop end
+// R8	v1, k1
+// R9	v2
+// R10	v3
+// R11	v4
+// R12	tmp
+// R13	prime1v
+// R14	prime2v
+// R15	prime4v
+
+// round reads from and advances the buffer pointer in CX.
+// It assumes that R13 has prime1v and R14 has prime2v.
+#define round(r) \
+	MOVQ  (CX), R12 \
+	ADDQ  $8, CX    \
+	IMULQ R14, R12  \
+	ADDQ  R12, r    \
+	ROLQ  $31, r    \
+	IMULQ R13, r
+
+// mergeRound applies a merge round on the two registers acc and val.
+// It assumes that R13 has prime1v, R14 has prime2v, and R15 has prime4v.
+#define mergeRound(acc, val) \
+	IMULQ R14, val \
+	ROLQ  $31, val \
+	IMULQ R13, val \
+	XORQ  val, acc \
+	IMULQ R13, acc \
+	ADDQ  R15, acc
+
+// func Sum64(b []byte) uint64
+TEXT ·Sum64(SB), NOSPLIT, $0-32
+	// Load fixed primes.
+	MOVQ ·prime1v(SB), R13
+	MOVQ ·prime2v(SB), R14
+	MOVQ ·prime4v(SB), R15
+
+	// Load slice.
+	MOVQ b_base+0(FP), CX
+	MOVQ b_len+8(FP), DX
+	LEAQ (CX)(DX*1), BX
+
+	// The first loop limit will be len(b)-32.
+	SUBQ $32, BX
+
+	// Check whether we have at least one block.
+	CMPQ DX, $32
+	JLT  noBlocks
+
+	// Set up initial state (v1, v2, v3, v4).
+	MOVQ R13, R8
+	ADDQ R14, R8
+	MOVQ R14, R9
+	XORQ R10, R10
+	XORQ R11, R11
+	SUBQ R13, R11
+
+	// Loop until CX > BX.
+blockLoop:
+	round(R8)
+	round(R9)
+	round(R10)
+	round(R11)
+
+	CMPQ CX, BX
+	JLE  blockLoop
+
+	MOVQ R8, AX
+	ROLQ $1, AX
+	MOVQ R9, R12
+	ROLQ $7, R12
+	ADDQ R12, AX
+	MOVQ R10, R12
+	ROLQ $12, R12
+	ADDQ R12, AX
+	MOVQ R11, R12
+	ROLQ $18, R12
+	ADDQ R12, AX
+
+	mergeRound(AX, R8)
+	mergeRound(AX, R9)
+	mergeRound(AX, R10)
+	mergeRound(AX, R11)
+
+	JMP afterBlocks
+
+noBlocks:
+	MOVQ ·prime5v(SB), AX
+
+afterBlocks:
+	ADDQ DX, AX
+
+	// Right now BX has len(b)-32, and we want to loop until CX > len(b)-8.
+	ADDQ $24, BX
+
+	CMPQ CX, BX
+	JG   fourByte
+
+wordLoop:
+	// Calculate k1.
+	MOVQ  (CX), R8
+	ADDQ  $8, CX
+	IMULQ R14, R8
+	ROLQ  $31, R8
+	IMULQ R13, R8
+
+	XORQ  R8, AX
+	ROLQ  $27, AX
+	IMULQ R13, AX
+	ADDQ  R15, AX
+
+	CMPQ CX, BX
+	JLE  wordLoop
+
+fourByte:
+	ADDQ $4, BX
+	CMPQ CX, BX
+	JG   singles
+
+	MOVL  (CX), R8
+	ADDQ  $4, CX
+	IMULQ R13, R8
+	XORQ  R8, AX
+
+	ROLQ  $23, AX
+	IMULQ R14, AX
+	ADDQ  ·prime3v(SB), AX
+
+singles:
+	ADDQ $4, BX
+	CMPQ CX, BX
+	JGE  finalize
+
+singlesLoop:
+	MOVBQZX (CX), R12
+	ADDQ    $1, CX
+	IMULQ   ·prime5v(SB), R12
+	XORQ    R12, AX
+
+	ROLQ  $11, AX
+	IMULQ R13, AX
+
+	CMPQ CX, BX
+	JL   singlesLoop
+
+finalize:
+	MOVQ  AX, R12
+	SHRQ  $33, R12
+	XORQ  R12, AX
+	IMULQ R14, AX
+	MOVQ  AX, R12
+	SHRQ  $29, R12
+	XORQ  R12, AX
+	IMULQ ·prime3v(SB), AX
+	MOVQ  AX, R12
+	SHRQ  $32, R12
+	XORQ  R12, AX
+
+	MOVQ AX, ret+24(FP)
+	RET
+
+// writeBlocks uses the same registers as above except that it uses AX to store
+// the d pointer.
+
+// func writeBlocks(d *Digest, b []byte) int
+TEXT ·writeBlocks(SB), NOSPLIT, $0-40
+	// Load fixed primes needed for round.
+	MOVQ ·prime1v(SB), R13
+	MOVQ ·prime2v(SB), R14
+
+	// Load slice.
+	MOVQ b_base+8(FP), CX
+	MOVQ b_len+16(FP), DX
+	LEAQ (CX)(DX*1), BX
+	SUBQ $32, BX
+
+	// Load vN from d.
+	MOVQ d+0(FP), AX
+	MOVQ 0(AX), R8   // v1
+	MOVQ 8(AX), R9   // v2
+	MOVQ 16(AX), R10 // v3
+	MOVQ 24(AX), R11 // v4
+
+	// We don't need to check the loop condition here; this function is
+	// always called with at least one block of data to process.
+blockLoop:
+	round(R8)
+	round(R9)
+	round(R10)
+	round(R11)
+
+	CMPQ CX, BX
+	JLE  blockLoop
+
+	// Copy vN back to d.
+	MOVQ R8, 0(AX)
+	MOVQ R9, 8(AX)
+	MOVQ R10, 16(AX)
+	MOVQ R11, 24(AX)
+
+	// The number of bytes written is CX minus the old base pointer.
+	SUBQ b_base+8(FP), CX
+	MOVQ CX, ret+32(FP)
+
+	RET

vendor/github.com/cespare/xxhash/v2/xxhash_other.go

@@ -0,0 +1,76 @@
+// +build !amd64 appengine !gc purego
+
+package xxhash
+
+// Sum64 computes the 64-bit xxHash digest of b.
+func Sum64(b []byte) uint64 {
+	// A simpler version would be
+	//   d := New()
+	//   d.Write(b)
+	//   return d.Sum64()
+	// but this is faster, particularly for small inputs.
+
+	n := len(b)
+	var h uint64
+
+	if n >= 32 {
+		v1 := prime1v + prime2
+		v2 := prime2
+		v3 := uint64(0)
+		v4 := -prime1v
+		for len(b) >= 32 {
+			v1 = round(v1, u64(b[0:8:len(b)]))
+			v2 = round(v2, u64(b[8:16:len(b)]))
+			v3 = round(v3, u64(b[16:24:len(b)]))
+			v4 = round(v4, u64(b[24:32:len(b)]))
+			b = b[32:len(b):len(b)]
+		}
+		h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4)
+		h = mergeRound(h, v1)
+		h = mergeRound(h, v2)
+		h = mergeRound(h, v3)
+		h = mergeRound(h, v4)
+	} else {
+		h = prime5
+	}
+
+	h += uint64(n)
+
+	i, end := 0, len(b)
+	for ; i+8 <= end; i += 8 {
+		k1 := round(0, u64(b[i:i+8:len(b)]))
+		h ^= k1
+		h = rol27(h)*prime1 + prime4
+	}
+	if i+4 <= end {
+		h ^= uint64(u32(b[i:i+4:len(b)])) * prime1
+		h = rol23(h)*prime2 + prime3
+		i += 4
+	}
+	for ; i < end; i++ {
+		h ^= uint64(b[i]) * prime5
+		h = rol11(h) * prime1
+	}
+
+	h ^= h >> 33
+	h *= prime2
+	h ^= h >> 29
+	h *= prime3
+	h ^= h >> 32
+
+	return h
+}
+
+func writeBlocks(d *Digest, b []byte) int {
+	v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
+	n := len(b)
+	for len(b) >= 32 {
+		v1 = round(v1, u64(b[0:8:len(b)]))
+		v2 = round(v2, u64(b[8:16:len(b)]))
+		v3 = round(v3, u64(b[16:24:len(b)]))
+		v4 = round(v4, u64(b[24:32:len(b)]))
+		b = b[32:len(b):len(b)]
+	}
+	d.v1, d.v2, d.v3, d.v4 = v1, v2, v3, v4
+	return n - len(b)
+}

vendor/github.com/cespare/xxhash/v2/xxhash_safe.go

@@ -0,0 +1,15 @@
+// +build appengine
+
+// This file contains the safe implementations of otherwise unsafe-using code.
+
+package xxhash
+
+// Sum64String computes the 64-bit xxHash digest of s.
+func Sum64String(s string) uint64 {
+	return Sum64([]byte(s))
+}
+
+// WriteString adds more data to d. It always returns len(s), nil.
+func (d *Digest) WriteString(s string) (n int, err error) {
+	return d.Write([]byte(s))
+}

vendor/github.com/cespare/xxhash/v2/xxhash_unsafe.go

@@ -0,0 +1,46 @@
+// +build !appengine
+
+// This file encapsulates usage of unsafe.
+// xxhash_safe.go contains the safe implementations.
+
+package xxhash
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// Notes:
+//
+// See https://groups.google.com/d/msg/golang-nuts/dcjzJy-bSpw/tcZYBzQqAQAJ
+// for some discussion about these unsafe conversions.
+//
+// In the future it's possible that compiler optimizations will make these
+// unsafe operations unnecessary: https://golang.org/issue/2205.
+//
+// Both of these wrapper functions still incur function call overhead since they
+// will not be inlined. We could write Go/asm copies of Sum64 and Digest.Write
+// for strings to squeeze out a bit more speed. Mid-stack inlining should
+// eventually fix this.
+
+// Sum64String computes the 64-bit xxHash digest of s.
+// It may be faster than Sum64([]byte(s)) by avoiding a copy.
+func Sum64String(s string) uint64 {
+	var b []byte
+	bh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+	bh.Data = (*reflect.StringHeader)(unsafe.Pointer(&s)).Data
+	bh.Len = len(s)
+	bh.Cap = len(s)
+	return Sum64(b)
+}
+
+// WriteString adds more data to d. It always returns len(s), nil.
+// It may be faster than Write([]byte(s)) by avoiding a copy.
+func (d *Digest) WriteString(s string) (n int, err error) {
+	var b []byte
+	bh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
+	bh.Data = (*reflect.StringHeader)(unsafe.Pointer(&s)).Data
+	bh.Len = len(s)
+	bh.Cap = len(s)
+	return d.Write(b)
+}

vendor/github.com/cpuguy83/go-md2man/v2/LICENSE.md

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Brian Goff
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/cpuguy83/go-md2man/v2/md2man/md2man.go

@@ -0,0 +1,14 @@
+package md2man
+
+import (
+	"github.com/russross/blackfriday/v2"
+)
+
+// Render converts a markdown document into a roff formatted document.
+func Render(doc []byte) []byte {
+	renderer := NewRoffRenderer()
+
+	return blackfriday.Run(doc,
+		[]blackfriday.Option{blackfriday.WithRenderer(renderer),
+			blackfriday.WithExtensions(renderer.GetExtensions())}...)
+}

vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go

@@ -0,0 +1,345 @@
+package md2man
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/russross/blackfriday/v2"
+)
+
+// roffRenderer implements the blackfriday.Renderer interface for creating
+// roff format (manpages) from markdown text
+type roffRenderer struct {
+	extensions   blackfriday.Extensions
+	listCounters []int
+	firstHeader  bool
+	defineTerm   bool
+	listDepth    int
+}
+
+const (
+	titleHeader      = ".TH "
+	topLevelHeader   = "\n\n.SH "
+	secondLevelHdr   = "\n.SH "
+	otherHeader      = "\n.SS "
+	crTag            = "\n"
+	emphTag          = "\\fI"
+	emphCloseTag     = "\\fP"
+	strongTag        = "\\fB"
+	strongCloseTag   = "\\fP"
+	breakTag         = "\n.br\n"
+	paraTag          = "\n.PP\n"
+	hruleTag         = "\n.ti 0\n\\l'\\n(.lu'\n"
+	linkTag          = "\n\\[la]"
+	linkCloseTag     = "\\[ra]"
+	codespanTag      = "\\fB\\fC"
+	codespanCloseTag = "\\fR"
+	codeTag          = "\n.PP\n.RS\n\n.nf\n"
+	codeCloseTag     = "\n.fi\n.RE\n"
+	quoteTag         = "\n.PP\n.RS\n"
+	quoteCloseTag    = "\n.RE\n"
+	listTag          = "\n.RS\n"
+	listCloseTag     = "\n.RE\n"
+	arglistTag       = "\n.TP\n"
+	tableStart       = "\n.TS\nallbox;\n"
+	tableEnd         = ".TE\n"
+	tableCellStart   = "T{\n"
+	tableCellEnd     = "\nT}\n"
+)
+
+// NewRoffRenderer creates a new blackfriday Renderer for generating roff documents
+// from markdown
+func NewRoffRenderer() *roffRenderer { // nolint: golint
+	var extensions blackfriday.Extensions
+
+	extensions |= blackfriday.NoIntraEmphasis
+	extensions |= blackfriday.Tables
+	extensions |= blackfriday.FencedCode
+	extensions |= blackfriday.SpaceHeadings
+	extensions |= blackfriday.Footnotes
+	extensions |= blackfriday.Titleblock
+	extensions |= blackfriday.DefinitionLists
+	return &roffRenderer{
+		extensions: extensions,
+	}
+}
+
+// GetExtensions returns the list of extensions used by this renderer implementation
+func (r *roffRenderer) GetExtensions() blackfriday.Extensions {
+	return r.extensions
+}
+
+// RenderHeader handles outputting the header at document start
+func (r *roffRenderer) RenderHeader(w io.Writer, ast *blackfriday.Node) {
+	// disable hyphenation
+	out(w, ".nh\n")
+}
+
+// RenderFooter handles outputting the footer at the document end; the roff
+// renderer has no footer information
+func (r *roffRenderer) RenderFooter(w io.Writer, ast *blackfriday.Node) {
+}
+
+// RenderNode is called for each node in a markdown document; based on the node
+// type the equivalent roff output is sent to the writer
+func (r *roffRenderer) RenderNode(w io.Writer, node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
+
+	var walkAction = blackfriday.GoToNext
+
+	switch node.Type {
+	case blackfriday.Text:
+		r.handleText(w, node, entering)
+	case blackfriday.Softbreak:
+		out(w, crTag)
+	case blackfriday.Hardbreak:
+		out(w, breakTag)
+	case blackfriday.Emph:
+		if entering {
+			out(w, emphTag)
+		} else {
+			out(w, emphCloseTag)
+		}
+	case blackfriday.Strong:
+		if entering {
+			out(w, strongTag)
+		} else {
+			out(w, strongCloseTag)
+		}
+	case blackfriday.Link:
+		if !entering {
+			out(w, linkTag+string(node.LinkData.Destination)+linkCloseTag)
+		}
+	case blackfriday.Image:
+		// ignore images
+		walkAction = blackfriday.SkipChildren
+	case blackfriday.Code:
+		out(w, codespanTag)
+		escapeSpecialChars(w, node.Literal)
+		out(w, codespanCloseTag)
+	case blackfriday.Document:
+		break
+	case blackfriday.Paragraph:
+		// roff .PP markers break lists
+		if r.listDepth > 0 {
+			return blackfriday.GoToNext
+		}
+		if entering {
+			out(w, paraTag)
+		} else {
+			out(w, crTag)
+		}
+	case blackfriday.BlockQuote:
+		if entering {
+			out(w, quoteTag)
+		} else {
+			out(w, quoteCloseTag)
+		}
+	case blackfriday.Heading:
+		r.handleHeading(w, node, entering)
+	case blackfriday.HorizontalRule:
+		out(w, hruleTag)
+	case blackfriday.List:
+		r.handleList(w, node, entering)
+	case blackfriday.Item:
+		r.handleItem(w, node, entering)
+	case blackfriday.CodeBlock:
+		out(w, codeTag)
+		escapeSpecialChars(w, node.Literal)
+		out(w, codeCloseTag)
+	case blackfriday.Table:
+		r.handleTable(w, node, entering)
+	case blackfriday.TableCell:
+		r.handleTableCell(w, node, entering)
+	case blackfriday.TableHead:
+	case blackfriday.TableBody:
+	case blackfriday.TableRow:
+		// no action as cell entries do all the nroff formatting
+		return blackfriday.GoToNext
+	default:
+		fmt.Fprintln(os.Stderr, "WARNING: go-md2man does not handle node type "+node.Type.String())
+	}
+	return walkAction
+}
+
+func (r *roffRenderer) handleText(w io.Writer, node *blackfriday.Node, entering bool) {
+	var (
+		start, end string
+	)
+	// handle special roff table cell text encapsulation
+	if node.Parent.Type == blackfriday.TableCell {
+		if len(node.Literal) > 30 {
+			start = tableCellStart
+			end = tableCellEnd
+		} else {
+			// end rows that aren't terminated by "tableCellEnd" with a cr if end of row
+			if node.Parent.Next == nil && !node.Parent.IsHeader {
+				end = crTag
+			}
+		}
+	}
+	out(w, start)
+	escapeSpecialChars(w, node.Literal)
+	out(w, end)
+}
+
+func (r *roffRenderer) handleHeading(w io.Writer, node *blackfriday.Node, entering bool) {
+	if entering {
+		switch node.Level {
+		case 1:
+			if !r.firstHeader {
+				out(w, titleHeader)
+				r.firstHeader = true
+				break
+			}
+			out(w, topLevelHeader)
+		case 2:
+			out(w, secondLevelHdr)
+		default:
+			out(w, otherHeader)
+		}
+	}
+}
+
+func (r *roffRenderer) handleList(w io.Writer, node *blackfriday.Node, entering bool) {
+	openTag := listTag
+	closeTag := listCloseTag
+	if node.ListFlags&blackfriday.ListTypeDefinition != 0 {
+		// tags for definition lists handled within Item node
+		openTag = ""
+		closeTag = ""
+	}
+	if entering {
+		r.listDepth++
+		if node.ListFlags&blackfriday.ListTypeOrdered != 0 {
+			r.listCounters = append(r.listCounters, 1)
+		}
+		out(w, openTag)
+	} else {
+		if node.ListFlags&blackfriday.ListTypeOrdered != 0 {
+			r.listCounters = r.listCounters[:len(r.listCounters)-1]
+		}
+		out(w, closeTag)
+		r.listDepth--
+	}
+}
+
+func (r *roffRenderer) handleItem(w io.Writer, node *blackfriday.Node, entering bool) {
+	if entering {
+		if node.ListFlags&blackfriday.ListTypeOrdered != 0 {
+			out(w, fmt.Sprintf(".IP \"%3d.\" 5\n", r.listCounters[len(r.listCounters)-1]))
+			r.listCounters[len(r.listCounters)-1]++
+		} else if node.ListFlags&blackfriday.ListTypeDefinition != 0 {
+			// state machine for handling terms and following definitions
+			// since blackfriday does not distinguish them properly, nor
+			// does it seperate them into separate lists as it should
+			if !r.defineTerm {
+				out(w, arglistTag)
+				r.defineTerm = true
+			} else {
+				r.defineTerm = false
+			}
+		} else {
+			out(w, ".IP \\(bu 2\n")
+		}
+	} else {
+		out(w, "\n")
+	}
+}
+
+func (r *roffRenderer) handleTable(w io.Writer, node *blackfriday.Node, entering bool) {
+	if entering {
+		out(w, tableStart)
+		//call walker to count cells (and rows?) so format section can be produced
+		columns := countColumns(node)
+		out(w, strings.Repeat("l ", columns)+"\n")
+		out(w, strings.Repeat("l ", columns)+".\n")
+	} else {
+		out(w, tableEnd)
+	}
+}
+
+func (r *roffRenderer) handleTableCell(w io.Writer, node *blackfriday.Node, entering bool) {
+	var (
+		start, end string
+	)
+	if node.IsHeader {
+		start = codespanTag
+		end = codespanCloseTag
+	}
+	if entering {
+		if node.Prev != nil && node.Prev.Type == blackfriday.TableCell {
+			out(w, "\t"+start)
+		} else {
+			out(w, start)
+		}
+	} else {
+		// need to carriage return if we are at the end of the header row
+		if node.IsHeader && node.Next == nil {
+			end = end + crTag
+		}
+		out(w, end)
+	}
+}
+
+// because roff format requires knowing the column count before outputting any table
+// data we need to walk a table tree and count the columns
+func countColumns(node *blackfriday.Node) int {
+	var columns int
+
+	node.Walk(func(node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
+		switch node.Type {
+		case blackfriday.TableRow:
+			if !entering {
+				return blackfriday.Terminate
+			}
+		case blackfriday.TableCell:
+			if entering {
+				columns++
+			}
+		default:
+		}
+		return blackfriday.GoToNext
+	})
+	return columns
+}
+
+func out(w io.Writer, output string) {
+	io.WriteString(w, output) // nolint: errcheck
+}
+
+func needsBackslash(c byte) bool {
+	for _, r := range []byte("-_&\\~") {
+		if c == r {
+			return true
+		}
+	}
+	return false
+}
+
+func escapeSpecialChars(w io.Writer, text []byte) {
+	for i := 0; i < len(text); i++ {
+		// escape initial apostrophe or period
+		if len(text) >= 1 && (text[0] == '\'' || text[0] == '.') {
+			out(w, "\\&")
+		}
+
+		// directly copy normal characters
+		org := i
+
+		for i < len(text) && !needsBackslash(text[i]) {
+			i++
+		}
+		if i > org {
+			w.Write(text[org:i]) // nolint: errcheck
+		}
+
+		// escape a character
+		if i >= len(text) {
+			break
+		}
+
+		w.Write([]byte{'\\', text[i]}) // nolint: errcheck
+	}
+}

vendor/github.com/dlclark/regexp2/README.md

@@ -43,8 +43,8 @@ The __last__ capture is embedded in each group, so `g.String()` will return the
 | Category | regexp | regexp2 |
 | --- | --- | --- |
 | Catastrophic backtracking possible | no, constant execution time guarantees | yes, if your pattern is at risk you can use the `re.MatchTimeout` field |
-| Python-style capture groups `(P<name>re)` | yes | no |
+| Python-style capture groups `(?P<name>re)` | yes | no (yes in RE2 compat mode) |
-| .NET-style capture groups `(<name>re)` or `('name're)` | no | yes |
+| .NET-style capture groups `(?<name>re)` or `(?'name're)` | no | yes |
 | comments `(?#comment)` | no | yes |
 | branch numbering reset `(?\|a\|b)` | no | no |
 | possessive match `(?>re)` | no | yes |
@@ -54,14 +54,15 @@ The __last__ capture is embedded in each group, so `g.String()` will return the
 | negative lookbehind `(?<!re)` | no | yes |
 | back reference `\1` | no | yes |
 | named back reference `\k'name'` | no | yes |
-| named ascii character class `[[:foo:]]`| yes | no |
+| named ascii character class `[[:foo:]]`| yes | no (yes in RE2 compat mode) |
-| conditionals `((expr)yes\|no)` | no | yes |
+| conditionals `(?(expr)yes\|no)` | no | yes |
 
 ## RE2 compatibility mode
 The default behavior of `regexp2` is to match the .NET regexp engine, however the `RE2` option is provided to change the parsing to increase compatibility with RE2.  Using the `RE2` option when compiling a regexp will not take away any features, but will change the following behaviors:
 * add support for named ascii character classes (e.g. `[[:foo:]]`)
 * add support for python-style capture groups (e.g. `(P<name>re)`)
-
+* change singleline behavior for `$` to only match end of string (like RE2) (see [#24](https://github.com/dlclark/regexp2/issues/24))
+ 
 ```go
 re := regexp2.MustCompile(`Your RE2-compatible pattern`, regexp2.RE2)
 if isMatch, _ := re.MatchString(`Something to match`); isMatch {

vendor/github.com/dlclark/regexp2/runner.go

@@ -566,9 +566,22 @@ func (r *runner) execute() error {
 			continue
 
 		case syntax.EndZ:
-			if r.rightchars() > 1 || r.rightchars() == 1 && r.charAt(r.textPos()) != '\n' {
+			rchars := r.rightchars()
+			if rchars > 1 {
 				break
 			}
+			// RE2 and EcmaScript define $ as "asserts position at the end of the string"
+			// PCRE/.NET adds "or before the line terminator right at the end of the string (if any)"
+			if (r.re.options & (RE2 | ECMAScript)) != 0 {
+				// RE2/Ecmascript mode
+				if rchars > 0 {
+					break
+				}
+			} else if rchars == 1 && r.charAt(r.textPos()) != '\n' {
+				// "regular" mode
+				break
+			}
+
 			r.advance(0)
 			continue
 
@@ -938,8 +951,8 @@ func (r *runner) advance(i int) {
 }
 
 func (r *runner) goTo(newpos int) {
-	// when branching backward, ensure storage
+	// when branching backward or in place, ensure storage
-	if newpos < r.codepos {
+	if newpos <= r.codepos {
 		r.ensureStorage()
 	}
 

vendor/github.com/dlclark/regexp2/syntax/parser.go

@@ -1648,7 +1648,7 @@ func (p *parser) scanOptions() {
 }
 
 // Scans \ code for escape codes that map to single unicode chars.
-func (p *parser) scanCharEscape() (rune, error) {
+func (p *parser) scanCharEscape() (r rune, err error) {
 
 	ch := p.moveRightGetChar()
 
@@ -1657,16 +1657,22 @@ func (p *parser) scanCharEscape() (rune, error) {
 		return p.scanOctal(), nil
 	}
 
+	pos := p.textpos()
+
 	switch ch {
 	case 'x':
 		// support for \x{HEX} syntax from Perl and PCRE
 		if p.charsRight() > 0 && p.rightChar(0) == '{' {
+			if p.useOptionE() {
+				return ch, nil
+			}
 			p.moveRight(1)
 			return p.scanHexUntilBrace()
+		} else {
+			r, err = p.scanHex(2)
 		}
-		return p.scanHex(2)
 	case 'u':
-		return p.scanHex(4)
+		r, err = p.scanHex(4)
 	case 'a':
 		return '\u0007', nil
 	case 'b':
@@ -1684,13 +1690,18 @@ func (p *parser) scanCharEscape() (rune, error) {
 	case 'v':
 		return '\u000B', nil
 	case 'c':
-		return p.scanControl()
+		r, err = p.scanControl()
 	default:
 		if !p.useOptionE() && IsWordChar(ch) {
 			return 0, p.getErr(ErrUnrecognizedEscape, string(ch))
 		}
 		return ch, nil
 	}
+	if err != nil && p.useOptionE() {
+		p.textto(pos)
+		return ch, nil
+	}
+	return
 }
 
 // Grabs and converts an ascii control character
@@ -1807,7 +1818,7 @@ func (p *parser) scanOctal() rune {
 	//we know the first char is good because the caller had to check
 	i := 0
 	d := int(p.rightChar(0) - '0')
-	for c > 0 && d <= 7 {
+	for c > 0 && d <= 7 && d >= 0 {
 		if i >= 0x20 && p.useOptionE() {
 			break
 		}

vendor/github.com/editorconfig/editorconfig-core-go/v2/.editorconfig

@@ -1,4 +1,4 @@
-; http://editorconfig.org/
+; https://editorconfig.org/
 
 root = true
 
@@ -9,6 +9,15 @@ trim_trailing_whitespace = true
 indent_style = space
 indent_size = 2
 
-[{Makefile,go.mod,go.sum,*.go}]
+[{Makefile,go.mod,go.sum,*.go,.gitmodules}]
 indent_style = tab
 indent_size = 8
+
+[*.md]
+indent_size = 4
+trim_trailing_whitespace = false
+
+eclint_indent_style = unset
+
+[Dockerfile]
+indent_size = 4

vendor/github.com/editorconfig/editorconfig-core-go/v2/.golangci.yml

@@ -0,0 +1,19 @@
+linters-settings:
+  golint:
+    min-confidence: 0.3
+
+linters:
+  enable:
+    - goconst
+    - gocyclo
+    - goerr113
+    - gofmt
+    - godox
+    - golint
+    - gocritic
+    - megacheck
+    - misspell
+    - prealloc
+    - unparam
+    - scopelint
+    - wsl

vendor/github.com/editorconfig/editorconfig-core-go/v2/.goreleaser.yml

@@ -0,0 +1,74 @@
+project_name: editorconfig-core-go
+
+before:
+  hooks:
+  - go mod tidy
+
+builds:
+- id: editorconfig
+  main: ./cmd/editorconfig/main.go
+  binary: editorconfig
+  env:
+  - CGO_ENABLED=0
+  goos:
+  - linux
+  - darwin
+  - windows
+
+archives:
+- id: tarball
+  builds:
+  - editorconfig
+  format_overrides:
+  - goos: windows
+    format: zip
+  files:
+  - none*
+
+dockers:
+- image_templates:
+  - docker.pkg.github.com/editorconfig/editorconfig-core-go/editorconfig:latest
+  - docker.pkg.github.com/editorconfig/editorconfig-core-go/editorconfig:{{ .Tag }}
+  - docker.pkg.github.com/editorconfig/editorconfig-core-go/editorconfig:v{{ .Major }}
+  - docker.pkg.github.com/editorconfig/editorconfig-core-go/editorconfig:v{{ .Major }}.{{ .Minor }}
+  goos: linux
+  goarch: amd64
+  binaries:
+  - editorconfig
+  build_flag_templates:
+  - "--pull"
+  - "--label=org.label-schema.schema-version=1.0"
+  - "--label=org.label-schema.version={{ .Version }}"
+  - "--label=org.label-schema.name={{ .ProjectName }}"
+
+nfpms:
+- vendor: EditorConfig
+  homepage: https://github.com/editorconfig/editorconfig-core-go
+  maintainer: Yoan Blanc <yoan@dosimple.ch>
+  formats:
+    - deb
+    - rpm
+  epoch: 1
+  release: 1
+
+checksum:
+  name_template: 'checksums.txt'
+
+signs:
+- artifacts: checksum
+
+snapshot:
+  name_template: "{{ .Tag }}-development"
+
+changelog:
+  sort: asc
+  filters:
+    exclude:
+    - '^docs:'
+    - '^test:'
+
+release:
+  github:
+    owner: editorconfig
+    name: editorconfig-core-go
+  draft: true