forked from mystiq/dex
241 lines
6 KiB
Go
241 lines
6 KiB
Go
// Copyright 2013 Google Inc. All rights reserved.
|
|
//
|
|
// 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 pretty
|
|
|
|
import (
|
|
"encoding"
|
|
"fmt"
|
|
"reflect"
|
|
"sort"
|
|
)
|
|
|
|
func isZeroVal(val reflect.Value) bool {
|
|
if !val.CanInterface() {
|
|
return false
|
|
}
|
|
z := reflect.Zero(val.Type()).Interface()
|
|
return reflect.DeepEqual(val.Interface(), z)
|
|
}
|
|
|
|
// pointerTracker is a helper for tracking pointer chasing to detect cycles.
|
|
type pointerTracker struct {
|
|
addrs map[uintptr]int // addr[address] = seen count
|
|
|
|
lastID int
|
|
ids map[uintptr]int // ids[address] = id
|
|
}
|
|
|
|
// track tracks following a reference (pointer, slice, map, etc). Every call to
|
|
// track should be paired with a call to untrack.
|
|
func (p *pointerTracker) track(ptr uintptr) {
|
|
if p.addrs == nil {
|
|
p.addrs = make(map[uintptr]int)
|
|
}
|
|
p.addrs[ptr]++
|
|
}
|
|
|
|
// untrack registers that we have backtracked over the reference to the pointer.
|
|
func (p *pointerTracker) untrack(ptr uintptr) {
|
|
p.addrs[ptr]--
|
|
if p.addrs[ptr] == 0 {
|
|
delete(p.addrs, ptr)
|
|
}
|
|
}
|
|
|
|
// seen returns whether the pointer was previously seen along this path.
|
|
func (p *pointerTracker) seen(ptr uintptr) bool {
|
|
_, ok := p.addrs[ptr]
|
|
return ok
|
|
}
|
|
|
|
// keep allocates an ID for the given address and returns it.
|
|
func (p *pointerTracker) keep(ptr uintptr) int {
|
|
if p.ids == nil {
|
|
p.ids = make(map[uintptr]int)
|
|
}
|
|
if _, ok := p.ids[ptr]; !ok {
|
|
p.lastID++
|
|
p.ids[ptr] = p.lastID
|
|
}
|
|
return p.ids[ptr]
|
|
}
|
|
|
|
// id returns the ID for the given address.
|
|
func (p *pointerTracker) id(ptr uintptr) (int, bool) {
|
|
if p.ids == nil {
|
|
p.ids = make(map[uintptr]int)
|
|
}
|
|
id, ok := p.ids[ptr]
|
|
return id, ok
|
|
}
|
|
|
|
// reflector adds local state to the recursive reflection logic.
|
|
type reflector struct {
|
|
*Config
|
|
*pointerTracker
|
|
}
|
|
|
|
// follow handles following a possiblly-recursive reference to the given value
|
|
// from the given ptr address.
|
|
func (r *reflector) follow(ptr uintptr, val reflect.Value) node {
|
|
if r.pointerTracker == nil {
|
|
// Tracking disabled
|
|
return r.val2node(val)
|
|
}
|
|
|
|
// If a parent already followed this, emit a reference marker
|
|
if r.seen(ptr) {
|
|
id := r.keep(ptr)
|
|
return ref{id}
|
|
}
|
|
|
|
// Track the pointer we're following while on this recursive branch
|
|
r.track(ptr)
|
|
defer r.untrack(ptr)
|
|
n := r.val2node(val)
|
|
|
|
// If the recursion used this ptr, wrap it with a target marker
|
|
if id, ok := r.id(ptr); ok {
|
|
return target{id, n}
|
|
}
|
|
|
|
// Otherwise, return the node unadulterated
|
|
return n
|
|
}
|
|
|
|
func (r *reflector) val2node(val reflect.Value) node {
|
|
if !val.IsValid() {
|
|
return rawVal("nil")
|
|
}
|
|
|
|
if val.CanInterface() {
|
|
v := val.Interface()
|
|
if formatter, ok := r.Formatter[val.Type()]; ok {
|
|
if formatter != nil {
|
|
res := reflect.ValueOf(formatter).Call([]reflect.Value{val})
|
|
return rawVal(res[0].Interface().(string))
|
|
}
|
|
} else {
|
|
if s, ok := v.(fmt.Stringer); ok && r.PrintStringers {
|
|
return stringVal(s.String())
|
|
}
|
|
if t, ok := v.(encoding.TextMarshaler); ok && r.PrintTextMarshalers {
|
|
if raw, err := t.MarshalText(); err == nil { // if NOT an error
|
|
return stringVal(string(raw))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
switch kind := val.Kind(); kind {
|
|
case reflect.Ptr:
|
|
if val.IsNil() {
|
|
return rawVal("nil")
|
|
}
|
|
return r.follow(val.Pointer(), val.Elem())
|
|
case reflect.Interface:
|
|
if val.IsNil() {
|
|
return rawVal("nil")
|
|
}
|
|
return r.val2node(val.Elem())
|
|
case reflect.String:
|
|
return stringVal(val.String())
|
|
case reflect.Slice:
|
|
n := list{}
|
|
length := val.Len()
|
|
ptr := val.Pointer()
|
|
for i := 0; i < length; i++ {
|
|
n = append(n, r.follow(ptr, val.Index(i)))
|
|
}
|
|
return n
|
|
case reflect.Array:
|
|
n := list{}
|
|
length := val.Len()
|
|
for i := 0; i < length; i++ {
|
|
n = append(n, r.val2node(val.Index(i)))
|
|
}
|
|
return n
|
|
case reflect.Map:
|
|
// Extract the keys and sort them for stable iteration
|
|
keys := val.MapKeys()
|
|
pairs := make([]mapPair, 0, len(keys))
|
|
for _, key := range keys {
|
|
pairs = append(pairs, mapPair{
|
|
key: new(formatter).compactString(r.val2node(key)), // can't be cyclic
|
|
value: val.MapIndex(key),
|
|
})
|
|
}
|
|
sort.Sort(byKey(pairs))
|
|
|
|
// Process the keys into the final representation
|
|
ptr, n := val.Pointer(), keyvals{}
|
|
for _, pair := range pairs {
|
|
n = append(n, keyval{
|
|
key: pair.key,
|
|
val: r.follow(ptr, pair.value),
|
|
})
|
|
}
|
|
return n
|
|
case reflect.Struct:
|
|
n := keyvals{}
|
|
typ := val.Type()
|
|
fields := typ.NumField()
|
|
for i := 0; i < fields; i++ {
|
|
sf := typ.Field(i)
|
|
if !r.IncludeUnexported && sf.PkgPath != "" {
|
|
continue
|
|
}
|
|
field := val.Field(i)
|
|
if r.SkipZeroFields && isZeroVal(field) {
|
|
continue
|
|
}
|
|
n = append(n, keyval{sf.Name, r.val2node(field)})
|
|
}
|
|
return n
|
|
case reflect.Bool:
|
|
if val.Bool() {
|
|
return rawVal("true")
|
|
}
|
|
return rawVal("false")
|
|
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
|
|
return rawVal(fmt.Sprintf("%d", val.Int()))
|
|
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
|
|
return rawVal(fmt.Sprintf("%d", val.Uint()))
|
|
case reflect.Uintptr:
|
|
return rawVal(fmt.Sprintf("0x%X", val.Uint()))
|
|
case reflect.Float32, reflect.Float64:
|
|
return rawVal(fmt.Sprintf("%v", val.Float()))
|
|
case reflect.Complex64, reflect.Complex128:
|
|
return rawVal(fmt.Sprintf("%v", val.Complex()))
|
|
}
|
|
|
|
// Fall back to the default %#v if we can
|
|
if val.CanInterface() {
|
|
return rawVal(fmt.Sprintf("%#v", val.Interface()))
|
|
}
|
|
|
|
return rawVal(val.String())
|
|
}
|
|
|
|
type mapPair struct {
|
|
key string
|
|
value reflect.Value
|
|
}
|
|
|
|
type byKey []mapPair
|
|
|
|
func (v byKey) Len() int { return len(v) }
|
|
func (v byKey) Swap(i, j int) { v[i], v[j] = v[j], v[i] }
|
|
func (v byKey) Less(i, j int) bool { return v[i].key < v[j].key }
|