Merge pull request #1342 from concourse/pr/retry-on-pg-serialization-error

retry on serialization errors

glide.lock

@@ -1,5 +1,5 @@
-hash: e5972bbdf15ad612d99ce8cd34e19537b9eacb5ff53688f339e0da285eb8ec22
+hash: 70e399f3424964c1535cefb66bce0e47af25ea6bb0f32a254e83e91bd774b5f2
-updated: 2018-11-12T19:38:56.235070564+01:00
+updated: 2018-11-20T09:49:19.83565589-05:00
 imports:
 - name: github.com/beevik/etree
   version: 4cd0dd976db869f817248477718071a28e978df0
@@ -54,7 +54,7 @@ imports:
   - diff
   - pretty
 - name: github.com/lib/pq
-  version: 50761b0867bd1d9d069276790bcd4a3bccf2324a
+  version: 9eb73efc1fcc404148b56765b0d3f61d9a5ef8ee
   subpackages:
   - oid
 - name: github.com/mattn/go-sqlite3

glide.yaml

@@ -114,7 +114,7 @@ import:
 - package: github.com/mattn/go-sqlite3
   version: 3fb7a0e792edd47bf0cf1e919dfc14e2be412e15
 - package: github.com/lib/pq
-  version: 50761b0867bd1d9d069276790bcd4a3bccf2324a
+  version: 9eb73efc1fcc404148b56765b0d3f61d9a5ef8ee
 
 # etcd driver
 - package: github.com/coreos/etcd

storage/sql/crud.go

@@ -134,7 +134,7 @@ func (c *conn) CreateAuthRequest(a storage.AuthRequest) error {
 }
 
 func (c *conn) UpdateAuthRequest(id string, updater func(a storage.AuthRequest) (storage.AuthRequest, error)) error {
-	return c.ExecTx(func(tx *trans) error {
+	err := c.ExecTx(func(tx *trans) error {
 		r, err := getAuthRequest(tx, id)
 		if err != nil {
 			return err
@@ -144,6 +144,7 @@ func (c *conn) UpdateAuthRequest(id string, updater func(a storage.AuthRequest)
 		if err != nil {
 			return err
 		}
+
 		_, err = tx.Exec(`
 			update auth_request
 			set
@@ -163,21 +164,31 @@ func (c *conn) UpdateAuthRequest(id string, updater func(a storage.AuthRequest)
 			a.ConnectorID, a.ConnectorData,
 			a.Expiry, r.ID,
 		)
-		if err != nil {
+		return err
-			return fmt.Errorf("update auth request: %v", err)
-		}
-		return nil
 	})
+	if err != nil {
+		return fmt.Errorf("update auth request: %v", err)
+	}
 
+	return nil
 }
 
 func (c *conn) GetAuthRequest(id string) (storage.AuthRequest, error) {
-	return getAuthRequest(c, id)
+	req, err := getAuthRequest(c, id)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return storage.AuthRequest{}, storage.ErrNotFound
+		}
+
+		return storage.AuthRequest{}, fmt.Errorf("select auth request: %v", err)
+	}
+
+	return req, nil
 }
 
 func getAuthRequest(q querier, id string) (a storage.AuthRequest, err error) {
 	err = q.QueryRow(`
-		select 
+		select
 			id, client_id, response_types, scopes, redirect_uri, nonce, state,
 			force_approval_prompt, logged_in,
 			claims_user_id, claims_username, claims_email, claims_email_verified,
@@ -192,10 +203,7 @@ func getAuthRequest(q querier, id string) (a storage.AuthRequest, err error) {
 		&a.ConnectorID, &a.ConnectorData, &a.Expiry,
 	)
 	if err != nil {
-		if err == sql.ErrNoRows {
+		return a, err
-			return a, storage.ErrNotFound
-		}
-		return a, fmt.Errorf("select auth request: %v", err)
 	}
 	return a, nil
 }
@@ -269,20 +277,22 @@ func (c *conn) CreateRefresh(r storage.RefreshToken) error {
 		if c.alreadyExistsCheck(err) {
 			return storage.ErrAlreadyExists
 		}
-		return fmt.Errorf("insert refresh_token: %v", err)
+		return fmt.Errorf("insert refresh token: %v", err)
 	}
 	return nil
 }
 
 func (c *conn) UpdateRefreshToken(id string, updater func(old storage.RefreshToken) (storage.RefreshToken, error)) error {
-	return c.ExecTx(func(tx *trans) error {
+	err := c.ExecTx(func(tx *trans) error {
 		r, err := getRefresh(tx, id)
 		if err != nil {
 			return err
 		}
+
 		if r, err = updater(r); err != nil {
 			return err
 		}
+
 		_, err = tx.Exec(`
 			update refresh_token
 			set
@@ -308,15 +318,25 @@ func (c *conn) UpdateRefreshToken(id string, updater func(old storage.RefreshTok
 			r.ConnectorID, r.ConnectorData,
 			r.Token, r.CreatedAt, r.LastUsed, id,
 		)
-		if err != nil {
+		return err
-			return fmt.Errorf("update refresh token: %v", err)
-		}
-		return nil
 	})
+	if err != nil {
+		return fmt.Errorf("update refresh token: %v", err)
+	}
+	return nil
 }
 
 func (c *conn) GetRefresh(id string) (storage.RefreshToken, error) {
-	return getRefresh(c, id)
+	req, err := getRefresh(c, id)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return storage.RefreshToken{}, storage.ErrNotFound
+		}
+
+		return storage.RefreshToken{}, fmt.Errorf("get refresh token: %v", err)
+	}
+
+	return req, nil
 }
 
 func getRefresh(q querier, id string) (storage.RefreshToken, error) {
@@ -342,14 +362,15 @@ func (c *conn) ListRefreshTokens() ([]storage.RefreshToken, error) {
 		from refresh_token;
 	`)
 	if err != nil {
-		return nil, fmt.Errorf("query: %v", err)
+		return nil, fmt.Errorf("select refresh tokens: %v", err)
 	}
 	var tokens []storage.RefreshToken
 	for rows.Next() {
 		r, err := scanRefresh(rows)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("scan refresh token: %s", err)
 		}
+
 		tokens = append(tokens, r)
 	}
 	if err := rows.Err(); err != nil {
@@ -367,10 +388,7 @@ func scanRefresh(s scanner) (r storage.RefreshToken, err error) {
 		&r.Token, &r.CreatedAt, &r.LastUsed,
 	)
 	if err != nil {
-		if err == sql.ErrNoRows {
+		return r, err
-			return r, storage.ErrNotFound
-		}
-		return r, fmt.Errorf("scan refresh_token: %v", err)
 	}
 	return r, nil
 }
@@ -381,12 +399,11 @@ func (c *conn) UpdateKeys(updater func(old storage.Keys) (storage.Keys, error))
 		// TODO(ericchiang): errors may cause a transaction be rolled back by the SQL
 		// server. Test this, and consider adding a COUNT() command beforehand.
 		old, err := getKeys(tx)
-		if err != nil {
+		if err == sql.ErrNoRows {
-			if err != storage.ErrNotFound {
-				return fmt.Errorf("get keys: %v", err)
-			}
 			firstUpdate = true
 			old = storage.Keys{}
+		} else if err != nil {
+			return err
 		}
 
 		nk, err := updater(old)
@@ -405,12 +422,12 @@ func (c *conn) UpdateKeys(updater func(old storage.Keys) (storage.Keys, error))
 				encoder(nk.SigningKeyPub), nk.NextRotation,
 			)
 			if err != nil {
-				return fmt.Errorf("insert: %v", err)
+				return err
 			}
 		} else {
 			_, err = tx.Exec(`
 				update keys
-				set 
+				set
 				    verification_keys = $1,
 					signing_key = $2,
 					signing_key_pub = $3,
@@ -421,15 +438,24 @@ func (c *conn) UpdateKeys(updater func(old storage.Keys) (storage.Keys, error))
 				encoder(nk.SigningKeyPub), nk.NextRotation, keysRowID,
 			)
 			if err != nil {
-				return fmt.Errorf("update: %v", err)
+				return err
 			}
 		}
 		return nil
 	})
 }
 
-func (c *conn) GetKeys() (keys storage.Keys, err error) {
+func (c *conn) GetKeys() (storage.Keys, error) {
-	return getKeys(c)
+	keys, err := getKeys(c)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return storage.Keys{}, storage.ErrNotFound
+		}
+
+		return storage.Keys{}, fmt.Errorf("select keys: %s", err)
+	}
+
+	return keys, nil
 }
 
 func getKeys(q querier) (keys storage.Keys, err error) {
@@ -443,20 +469,18 @@ func getKeys(q querier) (keys storage.Keys, err error) {
 		decoder(&keys.SigningKeyPub), &keys.NextRotation,
 	)
 	if err != nil {
-		if err == sql.ErrNoRows {
+		return keys, err
-			return keys, storage.ErrNotFound
-		}
-		return keys, fmt.Errorf("query keys: %v", err)
 	}
 	return keys, nil
 }
 
 func (c *conn) UpdateClient(id string, updater func(old storage.Client) (storage.Client, error)) error {
-	return c.ExecTx(func(tx *trans) error {
+	err := c.ExecTx(func(tx *trans) error {
 		cli, err := getClient(tx, id)
 		if err != nil {
 			return err
 		}
+
 		nc, err := updater(cli)
 		if err != nil {
 			return err
@@ -474,11 +498,13 @@ func (c *conn) UpdateClient(id string, updater func(old storage.Client) (storage
 			where id = $7;
 		`, nc.Secret, encoder(nc.RedirectURIs), encoder(nc.TrustedPeers), nc.Public, nc.Name, nc.LogoURL, id,
 		)
-		if err != nil {
+		return err
-			return fmt.Errorf("update client: %v", err)
-		}
-		return nil
 	})
+	if err != nil {
+		return fmt.Errorf("update client: %v", err)
+	}
+
+	return nil
 }
 
 func (c *conn) CreateClient(cli storage.Client) error {
@@ -509,7 +535,16 @@ func getClient(q querier, id string) (storage.Client, error) {
 }
 
 func (c *conn) GetClient(id string) (storage.Client, error) {
-	return getClient(c, id)
+	client, err := getClient(c, id)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return storage.Client{}, storage.ErrNotFound
+		}
+
+		return storage.Client{}, fmt.Errorf("select client: %v", err)
+	}
+
+	return client, nil
 }
 
 func (c *conn) ListClients() ([]storage.Client, error) {
@@ -525,12 +560,12 @@ func (c *conn) ListClients() ([]storage.Client, error) {
 	for rows.Next() {
 		cli, err := scanClient(rows)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("scan client: %s", err)
 		}
 		clients = append(clients, cli)
 	}
 	if err := rows.Err(); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("scan: %s", err)
 	}
 	return clients, nil
 }
@@ -541,10 +576,7 @@ func scanClient(s scanner) (cli storage.Client, err error) {
 		&cli.Public, &cli.Name, &cli.LogoURL,
 	)
 	if err != nil {
-		if err == sql.ErrNoRows {
+		return cli, err
-			return cli, storage.ErrNotFound
-		}
-		return cli, fmt.Errorf("get client: %v", err)
 	}
 	return cli, nil
 }
@@ -571,7 +603,7 @@ func (c *conn) CreatePassword(p storage.Password) error {
 }
 
 func (c *conn) UpdatePassword(email string, updater func(p storage.Password) (storage.Password, error)) error {
-	return c.ExecTx(func(tx *trans) error {
+	err := c.ExecTx(func(tx *trans) error {
 		p, err := getPassword(tx, email)
 		if err != nil {
 			return err
@@ -581,6 +613,7 @@ func (c *conn) UpdatePassword(email string, updater func(p storage.Password) (st
 		if err != nil {
 			return err
 		}
+
 		_, err = tx.Exec(`
 			update password
 			set
@@ -589,15 +622,25 @@ func (c *conn) UpdatePassword(email string, updater func(p storage.Password) (st
 		`,
 			np.Hash, np.Username, np.UserID, p.Email,
 		)
-		if err != nil {
+		return err
-			return fmt.Errorf("update password: %v", err)
-		}
-		return nil
 	})
+	if err != nil {
+		return fmt.Errorf("update password: %v", err)
+	}
+	return nil
 }
 
 func (c *conn) GetPassword(email string) (storage.Password, error) {
-	return getPassword(c, email)
+	pass, err := getPassword(c, email)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return storage.Password{}, storage.ErrNotFound
+		}
+
+		return storage.Password{}, fmt.Errorf("get password: %s", err)
+	}
+
+	return pass, nil
 }
 
 func getPassword(q querier, email string) (p storage.Password, err error) {
@@ -622,12 +665,12 @@ func (c *conn) ListPasswords() ([]storage.Password, error) {
 	for rows.Next() {
 		p, err := scanPassword(rows)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("scan password: %s", err)
 		}
 		passwords = append(passwords, p)
 	}
 	if err := rows.Err(); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("scan: %s", err)
 	}
 	return passwords, nil
 }
@@ -637,10 +680,7 @@ func scanPassword(s scanner) (p storage.Password, err error) {
 		&p.Email, &p.Hash, &p.Username, &p.UserID,
 	)
 	if err != nil {
-		if err == sql.ErrNoRows {
+		return p, err
-			return p, storage.ErrNotFound
-		}
-		return p, fmt.Errorf("select password: %v", err)
 	}
 	return p, nil
 }
@@ -666,7 +706,7 @@ func (c *conn) CreateOfflineSessions(s storage.OfflineSessions) error {
 }
 
 func (c *conn) UpdateOfflineSessions(userID string, connID string, updater func(s storage.OfflineSessions) (storage.OfflineSessions, error)) error {
-	return c.ExecTx(func(tx *trans) error {
+	err := c.ExecTx(func(tx *trans) error {
 		s, err := getOfflineSessions(tx, userID, connID)
 		if err != nil {
 			return err
@@ -676,6 +716,7 @@ func (c *conn) UpdateOfflineSessions(userID string, connID string, updater func(
 		if err != nil {
 			return err
 		}
+
 		_, err = tx.Exec(`
 			update offline_session
 			set
@@ -684,15 +725,26 @@ func (c *conn) UpdateOfflineSessions(userID string, connID string, updater func(
 		`,
 			encoder(newSession.Refresh), s.UserID, s.ConnID,
 		)
-		if err != nil {
+		return err
-			return fmt.Errorf("update offline session: %v", err)
-		}
-		return nil
 	})
+	if err != nil {
+		return fmt.Errorf("update offline session: %v", err)
+	}
+
+	return nil
 }
 
 func (c *conn) GetOfflineSessions(userID string, connID string) (storage.OfflineSessions, error) {
-	return getOfflineSessions(c, userID, connID)
+	sessions, err := getOfflineSessions(c, userID, connID)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return storage.OfflineSessions{}, storage.ErrNotFound
+		}
+
+		return storage.OfflineSessions{}, fmt.Errorf("get offline sessions: %s", err)
+	}
+
+	return sessions, nil
 }
 
 func getOfflineSessions(q querier, userID string, connID string) (storage.OfflineSessions, error) {
@@ -709,10 +761,7 @@ func scanOfflineSessions(s scanner) (o storage.OfflineSessions, err error) {
 		&o.UserID, &o.ConnID, decoder(&o.Refresh),
 	)
 	if err != nil {
-		if err == sql.ErrNoRows {
+		return o, err
-			return o, storage.ErrNotFound
-		}
-		return o, fmt.Errorf("select offline session: %v", err)
 	}
 	return o, nil
 }
@@ -738,7 +787,7 @@ func (c *conn) CreateConnector(connector storage.Connector) error {
 }
 
 func (c *conn) UpdateConnector(id string, updater func(s storage.Connector) (storage.Connector, error)) error {
-	return c.ExecTx(func(tx *trans) error {
+	err := c.ExecTx(func(tx *trans) error {
 		connector, err := getConnector(tx, id)
 		if err != nil {
 			return err
@@ -748,9 +797,10 @@ func (c *conn) UpdateConnector(id string, updater func(s storage.Connector) (sto
 		if err != nil {
 			return err
 		}
+
 		_, err = tx.Exec(`
 			update connector
-			set 
+			set
 			    type = $1,
 			    name = $2,
 			    resource_version = $3,
@@ -759,15 +809,26 @@ func (c *conn) UpdateConnector(id string, updater func(s storage.Connector) (sto
 		`,
 			newConn.Type, newConn.Name, newConn.ResourceVersion, newConn.Config, connector.ID,
 		)
-		if err != nil {
+		return err
-			return fmt.Errorf("update connector: %v", err)
-		}
-		return nil
 	})
+	if err != nil {
+		return fmt.Errorf("update connector: %v", err)
+	}
+
+	return nil
 }
 
 func (c *conn) GetConnector(id string) (storage.Connector, error) {
-	return getConnector(c, id)
+	connector, err := getConnector(c, id)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return storage.Connector{}, storage.ErrNotFound
+		}
+
+		return storage.Connector{}, fmt.Errorf("get connector: %s", err)
+	}
+
+	return connector, nil
 }
 
 func getConnector(q querier, id string) (storage.Connector, error) {
@@ -784,10 +845,7 @@ func scanConnector(s scanner) (c storage.Connector, err error) {
 		&c.ID, &c.Type, &c.Name, &c.ResourceVersion, &c.Config,
 	)
 	if err != nil {
-		if err == sql.ErrNoRows {
+		return c, err
-			return c, storage.ErrNotFound
-		}
-		return c, fmt.Errorf("select connector: %v", err)
 	}
 	return c, nil
 }
@@ -805,12 +863,12 @@ func (c *conn) ListConnectors() ([]storage.Connector, error) {
 	for rows.Next() {
 		conn, err := scanConnector(rows)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("scan connector: %s", err)
 		}
 		connectors = append(connectors, conn)
 	}
 	if err := rows.Err(); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("scan: %s", err)
 	}
 	return connectors, nil
 }

storage/sql/sql.go

@@ -2,14 +2,15 @@
 package sql
 
 import (
+	"context"
 	"database/sql"
 	"regexp"
 	"time"
 
+	"github.com/lib/pq"
 	"github.com/sirupsen/logrus"
 
 	// import third party drivers
-	_ "github.com/lib/pq"
 	_ "github.com/mattn/go-sqlite3"
 )
 
@@ -39,31 +40,66 @@ func matchLiteral(s string) *regexp.Regexp {
 	return regexp.MustCompile(`\b` + regexp.QuoteMeta(s) + `\b`)
 }
 
+// Detect a serialization failure, which should trigger retrying the
+// transaction according to PostgreSQL docs:
+//
+// https://www.postgresql.org/docs/current/transaction-iso.html#XACT-SERIALIZABLE
+//
+// "applications using this level must be prepared to retry transactions due to
+// serialization failures"
+func isRetryableSerializationFailure(err error) bool {
+	if pqErr, ok := err.(*pq.Error); ok {
+		return pqErr.Code.Name() == "serialization_failure"
+	}
+
+	return false
+}
+
 var (
 	// The "github.com/lib/pq" driver is the default flavor. All others are
 	// translations of this.
 	flavorPostgres = flavor{
-		// The default behavior for Postgres transactions is consistent reads, not consistent writes.
+		// The default behavior for Postgres transactions is consistent reads, not
-		// For each transaction opened, ensure it has the correct isolation level.
+		// consistent writes. For each transaction opened, ensure it has the
+		// correct isolation level.
 		//
 		// See: https://www.postgresql.org/docs/9.3/static/sql-set-transaction.html
 		//
-		// NOTE(ericchiang): For some reason using `SET SESSION CHARACTERISTICS AS TRANSACTION` at a
+		// Be careful not to wrap sql errors in the callback 'fn', otherwise
-		// session level didn't work for some edge cases. Might be something worth exploring.
+		// serialization failures will not be detected and retried.
 		executeTx: func(db *sql.DB, fn func(sqlTx *sql.Tx) error) error {
-			tx, err := db.Begin()
+			ctx, cancel := context.WithCancel(context.TODO())
-			if err != nil {
+			defer cancel()
-				return err
-			}
-			defer tx.Rollback()
 
-			if _, err := tx.Exec(`SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;`); err != nil {
+			opts := &sql.TxOptions{
-				return err
+				Isolation: sql.LevelSerializable,
 			}
-			if err := fn(tx); err != nil {
+
-				return err
+			for {
+				tx, err := db.BeginTx(ctx, opts)
+				if err != nil {
+					return err
+				}
+
+				if err := fn(tx); err != nil {
+					if isRetryableSerializationFailure(err) {
+						continue
+					}
+
+					return err
+				}
+
+				err = tx.Commit()
+				if err != nil {
+					if isRetryableSerializationFailure(err) {
+						continue
+					}
+
+					return err
+				}
+
+				return nil
 			}
-			return tx.Commit()
 		},
 
 		supportsTimezones: true,

vendor/github.com/lib/pq/array.go

@@ -13,7 +13,7 @@ import (
 
 var typeByteSlice = reflect.TypeOf([]byte{})
 var typeDriverValuer = reflect.TypeOf((*driver.Valuer)(nil)).Elem()
-var typeSqlScanner = reflect.TypeOf((*sql.Scanner)(nil)).Elem()
+var typeSQLScanner = reflect.TypeOf((*sql.Scanner)(nil)).Elem()
 
 // Array returns the optimal driver.Valuer and sql.Scanner for an array or
 // slice of any dimension.
@@ -70,6 +70,9 @@ func (a *BoolArray) Scan(src interface{}) error {
 		return a.scanBytes(src)
 	case string:
 		return a.scanBytes([]byte(src))
+	case nil:
+		*a = nil
+		return nil
 	}
 
 	return fmt.Errorf("pq: cannot convert %T to BoolArray", src)
@@ -80,7 +83,7 @@ func (a *BoolArray) scanBytes(src []byte) error {
 	if err != nil {
 		return err
 	}
-	if len(elems) == 0 {
+	if *a != nil && len(elems) == 0 {
 		*a = (*a)[:0]
 	} else {
 		b := make(BoolArray, len(elems))
@@ -141,6 +144,9 @@ func (a *ByteaArray) Scan(src interface{}) error {
 		return a.scanBytes(src)
 	case string:
 		return a.scanBytes([]byte(src))
+	case nil:
+		*a = nil
+		return nil
 	}
 
 	return fmt.Errorf("pq: cannot convert %T to ByteaArray", src)
@@ -151,7 +157,7 @@ func (a *ByteaArray) scanBytes(src []byte) error {
 	if err != nil {
 		return err
 	}
-	if len(elems) == 0 {
+	if *a != nil && len(elems) == 0 {
 		*a = (*a)[:0]
 	} else {
 		b := make(ByteaArray, len(elems))
@@ -210,6 +216,9 @@ func (a *Float64Array) Scan(src interface{}) error {
 		return a.scanBytes(src)
 	case string:
 		return a.scanBytes([]byte(src))
+	case nil:
+		*a = nil
+		return nil
 	}
 
 	return fmt.Errorf("pq: cannot convert %T to Float64Array", src)
@@ -220,7 +229,7 @@ func (a *Float64Array) scanBytes(src []byte) error {
 	if err != nil {
 		return err
 	}
-	if len(elems) == 0 {
+	if *a != nil && len(elems) == 0 {
 		*a = (*a)[:0]
 	} else {
 		b := make(Float64Array, len(elems))
@@ -269,7 +278,7 @@ func (GenericArray) evaluateDestination(rt reflect.Type) (reflect.Type, func([]b
 	// TODO calculate the assign function for other types
 	// TODO repeat this section on the element type of arrays or slices (multidimensional)
 	{
-		if reflect.PtrTo(rt).Implements(typeSqlScanner) {
+		if reflect.PtrTo(rt).Implements(typeSQLScanner) {
 			// dest is always addressable because it is an element of a slice.
 			assign = func(src []byte, dest reflect.Value) (err error) {
 				ss := dest.Addr().Interface().(sql.Scanner)
@@ -320,6 +329,11 @@ func (a GenericArray) Scan(src interface{}) error {
 		return a.scanBytes(src, dv)
 	case string:
 		return a.scanBytes([]byte(src), dv)
+	case nil:
+		if dv.Kind() == reflect.Slice {
+			dv.Set(reflect.Zero(dv.Type()))
+			return nil
+		}
 	}
 
 	return fmt.Errorf("pq: cannot convert %T to %s", src, dv.Type())
@@ -386,7 +400,13 @@ func (a GenericArray) Value() (driver.Value, error) {
 
 	rv := reflect.ValueOf(a.A)
 
-	if k := rv.Kind(); k != reflect.Array && k != reflect.Slice {
+	switch rv.Kind() {
+	case reflect.Slice:
+		if rv.IsNil() {
+			return nil, nil
+		}
+	case reflect.Array:
+	default:
 		return nil, fmt.Errorf("pq: Unable to convert %T to array", a.A)
 	}
 
@@ -412,6 +432,9 @@ func (a *Int64Array) Scan(src interface{}) error {
 		return a.scanBytes(src)
 	case string:
 		return a.scanBytes([]byte(src))
+	case nil:
+		*a = nil
+		return nil
 	}
 
 	return fmt.Errorf("pq: cannot convert %T to Int64Array", src)
@@ -422,7 +445,7 @@ func (a *Int64Array) scanBytes(src []byte) error {
 	if err != nil {
 		return err
 	}
-	if len(elems) == 0 {
+	if *a != nil && len(elems) == 0 {
 		*a = (*a)[:0]
 	} else {
 		b := make(Int64Array, len(elems))
@@ -470,6 +493,9 @@ func (a *StringArray) Scan(src interface{}) error {
 		return a.scanBytes(src)
 	case string:
 		return a.scanBytes([]byte(src))
+	case nil:
+		*a = nil
+		return nil
 	}
 
 	return fmt.Errorf("pq: cannot convert %T to StringArray", src)
@@ -480,7 +506,7 @@ func (a *StringArray) scanBytes(src []byte) error {
 	if err != nil {
 		return err
 	}
-	if len(elems) == 0 {
+	if *a != nil && len(elems) == 0 {
 		*a = (*a)[:0]
 	} else {
 		b := make(StringArray, len(elems))
@@ -561,7 +587,7 @@ func appendArrayElement(b []byte, rv reflect.Value) ([]byte, string, error) {
 		}
 	}
 
-	var del string = ","
+	var del = ","
 	var err error
 	var iv interface{} = rv.Interface()
 
@@ -639,6 +665,9 @@ Element:
 	for i < len(src) {
 		switch src[i] {
 		case '{':
+			if depth == len(dims) {
+				break Element
+			}
 			depth++
 			dims[depth-1] = 0
 			i++
@@ -680,11 +709,11 @@ Element:
 	}
 
 	for i < len(src) {
-		if bytes.HasPrefix(src[i:], del) {
+		if bytes.HasPrefix(src[i:], del) && depth > 0 {
 			dims[depth-1]++
 			i += len(del)
 			goto Element
-		} else if src[i] == '}' {
+		} else if src[i] == '}' && depth > 0 {
 			dims[depth-1]++
 			depth--
 			i++

vendor/github.com/lib/pq/conn_go18.go

@@ -0,0 +1,129 @@
+package pq
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"fmt"
+	"io"
+	"io/ioutil"
+)
+
+// Implement the "QueryerContext" interface
+func (cn *conn) QueryContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Rows, error) {
+	list := make([]driver.Value, len(args))
+	for i, nv := range args {
+		list[i] = nv.Value
+	}
+	finish := cn.watchCancel(ctx)
+	r, err := cn.query(query, list)
+	if err != nil {
+		if finish != nil {
+			finish()
+		}
+		return nil, err
+	}
+	r.finish = finish
+	return r, nil
+}
+
+// Implement the "ExecerContext" interface
+func (cn *conn) ExecContext(ctx context.Context, query string, args []driver.NamedValue) (driver.Result, error) {
+	list := make([]driver.Value, len(args))
+	for i, nv := range args {
+		list[i] = nv.Value
+	}
+
+	if finish := cn.watchCancel(ctx); finish != nil {
+		defer finish()
+	}
+
+	return cn.Exec(query, list)
+}
+
+// Implement the "ConnBeginTx" interface
+func (cn *conn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx, error) {
+	var mode string
+
+	switch sql.IsolationLevel(opts.Isolation) {
+	case sql.LevelDefault:
+		// Don't touch mode: use the server's default
+	case sql.LevelReadUncommitted:
+		mode = " ISOLATION LEVEL READ UNCOMMITTED"
+	case sql.LevelReadCommitted:
+		mode = " ISOLATION LEVEL READ COMMITTED"
+	case sql.LevelRepeatableRead:
+		mode = " ISOLATION LEVEL REPEATABLE READ"
+	case sql.LevelSerializable:
+		mode = " ISOLATION LEVEL SERIALIZABLE"
+	default:
+		return nil, fmt.Errorf("pq: isolation level not supported: %d", opts.Isolation)
+	}
+
+	if opts.ReadOnly {
+		mode += " READ ONLY"
+	} else {
+		mode += " READ WRITE"
+	}
+
+	tx, err := cn.begin(mode)
+	if err != nil {
+		return nil, err
+	}
+	cn.txnFinish = cn.watchCancel(ctx)
+	return tx, nil
+}
+
+func (cn *conn) watchCancel(ctx context.Context) func() {
+	if done := ctx.Done(); done != nil {
+		finished := make(chan struct{})
+		go func() {
+			select {
+			case <-done:
+				_ = cn.cancel()
+				finished <- struct{}{}
+			case <-finished:
+			}
+		}()
+		return func() {
+			select {
+			case <-finished:
+			case finished <- struct{}{}:
+			}
+		}
+	}
+	return nil
+}
+
+func (cn *conn) cancel() error {
+	c, err := dial(cn.dialer, cn.opts)
+	if err != nil {
+		return err
+	}
+	defer c.Close()
+
+	{
+		can := conn{
+			c: c,
+		}
+		err = can.ssl(cn.opts)
+		if err != nil {
+			return err
+		}
+
+		w := can.writeBuf(0)
+		w.int32(80877102) // cancel request code
+		w.int32(cn.processID)
+		w.int32(cn.secretKey)
+
+		if err := can.sendStartupPacket(w); err != nil {
+			return err
+		}
+	}
+
+	// Read until EOF to ensure that the server received the cancel.
+	{
+		_, err := io.Copy(ioutil.Discard, c)
+		return err
+	}
+}

vendor/github.com/lib/pq/connector.go

@@ -0,0 +1,43 @@
+// +build go1.10
+
+package pq
+
+import (
+	"context"
+	"database/sql/driver"
+)
+
+// Connector represents a fixed configuration for the pq driver with a given
+// name. Connector satisfies the database/sql/driver Connector interface and
+// can be used to create any number of DB Conn's via the database/sql OpenDB
+// function.
+//
+// See https://golang.org/pkg/database/sql/driver/#Connector.
+// See https://golang.org/pkg/database/sql/#OpenDB.
+type connector struct {
+	name string
+}
+
+// Connect returns a connection to the database using the fixed configuration
+// of this Connector. Context is not used.
+func (c *connector) Connect(_ context.Context) (driver.Conn, error) {
+	return (&Driver{}).Open(c.name)
+}
+
+// Driver returnst the underlying driver of this Connector.
+func (c *connector) Driver() driver.Driver {
+	return &Driver{}
+}
+
+var _ driver.Connector = &connector{}
+
+// NewConnector returns a connector for the pq driver in a fixed configuration
+// with the given name. The returned connector can be used to create any number
+// of equivalent Conn's. The returned connector is intended to be used with
+// database/sql.OpenDB.
+//
+// See https://golang.org/pkg/database/sql/driver/#Connector.
+// See https://golang.org/pkg/database/sql/#OpenDB.
+func NewConnector(name string) (driver.Connector, error) {
+	return &connector{name: name}, nil
+}

vendor/github.com/lib/pq/copy.go

@@ -13,6 +13,7 @@ var (
 	errBinaryCopyNotSupported     = errors.New("pq: only text format supported for COPY")
 	errCopyToNotSupported         = errors.New("pq: COPY TO is not supported")
 	errCopyNotSupportedOutsideTxn = errors.New("pq: COPY is only allowed inside a transaction")
+	errCopyInProgress             = errors.New("pq: COPY in progress")
 )
 
 // CopyIn creates a COPY FROM statement which can be prepared with
@@ -96,13 +97,13 @@ awaitCopyInResponse:
 			err = parseError(r)
 		case 'Z':
 			if err == nil {
-				cn.bad = true
+				ci.setBad()
 				errorf("unexpected ReadyForQuery in response to COPY")
 			}
 			cn.processReadyForQuery(r)
 			return nil, err
 		default:
-			cn.bad = true
+			ci.setBad()
 			errorf("unknown response for copy query: %q", t)
 		}
 	}
@@ -121,7 +122,7 @@ awaitCopyInResponse:
 			cn.processReadyForQuery(r)
 			return nil, err
 		default:
-			cn.bad = true
+			ci.setBad()
 			errorf("unknown response for CopyFail: %q", t)
 		}
 	}
@@ -142,7 +143,7 @@ func (ci *copyin) resploop() {
 		var r readBuf
 		t, err := ci.cn.recvMessage(&r)
 		if err != nil {
-			ci.cn.bad = true
+			ci.setBad()
 			ci.setError(err)
 			ci.done <- true
 			return
@@ -160,7 +161,7 @@ func (ci *copyin) resploop() {
 			err := parseError(&r)
 			ci.setError(err)
 		default:
-			ci.cn.bad = true
+			ci.setBad()
 			ci.setError(fmt.Errorf("unknown response during CopyIn: %q", t))
 			ci.done <- true
 			return
@@ -168,6 +169,19 @@ func (ci *copyin) resploop() {
 	}
 }
 
+func (ci *copyin) setBad() {
+	ci.Lock()
+	ci.cn.bad = true
+	ci.Unlock()
+}
+
+func (ci *copyin) isBad() bool {
+	ci.Lock()
+	b := ci.cn.bad
+	ci.Unlock()
+	return b
+}
+
 func (ci *copyin) isErrorSet() bool {
 	ci.Lock()
 	isSet := (ci.err != nil)
@@ -205,7 +219,7 @@ func (ci *copyin) Exec(v []driver.Value) (r driver.Result, err error) {
 		return nil, errCopyInClosed
 	}
 
-	if ci.cn.bad {
+	if ci.isBad() {
 		return nil, driver.ErrBadConn
 	}
 	defer ci.cn.errRecover(&err)
@@ -243,7 +257,7 @@ func (ci *copyin) Close() (err error) {
 	}
 	ci.closed = true
 
-	if ci.cn.bad {
+	if ci.isBad() {
 		return driver.ErrBadConn
 	}
 	defer ci.cn.errRecover(&err)
@@ -258,6 +272,7 @@ func (ci *copyin) Close() (err error) {
 	}
 
 	<-ci.done
+	ci.cn.inCopy = false
 
 	if ci.isErrorSet() {
 		err = ci.err

vendor/github.com/lib/pq/doc.go

@@ -11,7 +11,8 @@ using this package directly. For example:
 	)
 
 	func main() {
-		db, err := sql.Open("postgres", "user=pqgotest dbname=pqgotest sslmode=verify-full")
+		connStr := "user=pqgotest dbname=pqgotest sslmode=verify-full"
+		db, err := sql.Open("postgres", connStr)
 		if err != nil {
 			log.Fatal(err)
 		}
@@ -23,7 +24,8 @@ using this package directly. For example:
 
 You can also connect to a database using a URL. For example:
 
-	db, err := sql.Open("postgres", "postgres://pqgotest:password@localhost/pqgotest?sslmode=verify-full")
+	connStr := "postgres://pqgotest:password@localhost/pqgotest?sslmode=verify-full"
+	db, err := sql.Open("postgres", connStr)
 
 
 Connection String Parameters
@@ -43,21 +45,28 @@ supported:
 	* dbname - The name of the database to connect to
 	* user - The user to sign in as
 	* password - The user's password
-	* host - The host to connect to. Values that start with / are for unix domain sockets. (default is localhost)
+	* host - The host to connect to. Values that start with / are for unix
+	  domain sockets. (default is localhost)
 	* port - The port to bind to. (default is 5432)
-	* sslmode - Whether or not to use SSL (default is require, this is not the default for libpq)
+	* sslmode - Whether or not to use SSL (default is require, this is not
+	  the default for libpq)
 	* fallback_application_name - An application_name to fall back to if one isn't provided.
-	* connect_timeout - Maximum wait for connection, in seconds. Zero or not specified means wait indefinitely.
+	* connect_timeout - Maximum wait for connection, in seconds. Zero or
+	  not specified means wait indefinitely.
 	* sslcert - Cert file location. The file must contain PEM encoded data.
 	* sslkey - Key file location. The file must contain PEM encoded data.
-	* sslrootcert - The location of the root certificate file. The file must contain PEM encoded data.
+	* sslrootcert - The location of the root certificate file. The file
+	  must contain PEM encoded data.
 
 Valid values for sslmode are:
 
 	* disable - No SSL
 	* require - Always SSL (skip verification)
-	* verify-ca - Always SSL (verify that the certificate presented by the server was signed by a trusted CA)
+	* verify-ca - Always SSL (verify that the certificate presented by the
-	* verify-full - Always SSL (verify that the certification presented by the server was signed by a trusted CA and the server host name matches the one in the certificate)
+	  server was signed by a trusted CA)
+	* verify-full - Always SSL (verify that the certification presented by
+	  the server was signed by a trusted CA and the server host name
+	  matches the one in the certificate)
 
 See http://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-CONNSTRING
 for more information about connection string parameters.
@@ -68,7 +77,7 @@ Use single quotes for values that contain whitespace:
 
 A backslash will escape the next character in values:
 
-    "user=space\ man password='it\'s valid'
+    "user=space\ man password='it\'s valid'"
 
 Note that the connection parameter client_encoding (which sets the
 text encoding for the connection) may be set but must be "UTF8",
@@ -89,8 +98,10 @@ provided connection parameters.
 The pgpass mechanism as described in http://www.postgresql.org/docs/current/static/libpq-pgpass.html
 is supported, but on Windows PGPASSFILE must be specified explicitly.
 
+
 Queries
 
+
 database/sql does not dictate any specific format for parameter
 markers in query strings, and pq uses the Postgres-native ordinal markers,
 as shown above. The same marker can be reused for the same parameter:
@@ -114,8 +125,30 @@ For more details on RETURNING, see the Postgres documentation:
 
 For additional instructions on querying see the documentation for the database/sql package.
 
+
+Data Types
+
+
+Parameters pass through driver.DefaultParameterConverter before they are handled
+by this package. When the binary_parameters connection option is enabled,
+[]byte values are sent directly to the backend as data in binary format.
+
+This package returns the following types for values from the PostgreSQL backend:
+
+	- integer types smallint, integer, and bigint are returned as int64
+	- floating-point types real and double precision are returned as float64
+	- character types char, varchar, and text are returned as string
+	- temporal types date, time, timetz, timestamp, and timestamptz are
+	  returned as time.Time
+	- the boolean type is returned as bool
+	- the bytea type is returned as []byte
+
+All other types are returned directly from the backend as []byte values in text format.
+
+
 Errors
 
+
 pq may return errors of type *pq.Error which can be interrogated for error details:
 
         if err, ok := err.(*pq.Error); ok {
@@ -206,7 +239,7 @@ for more information).  Note that the channel name will be truncated to 63
 bytes by the PostgreSQL server.
 
 You can find a complete, working example of Listener usage at
-http://godoc.org/github.com/lib/pq/listen_example.
+https://godoc.org/github.com/lib/pq/example/listen.
 
 */
 package pq

vendor/github.com/lib/pq/encode.go

@@ -76,6 +76,12 @@ func binaryDecode(parameterStatus *parameterStatus, s []byte, typ oid.Oid) inter
 		return int64(int32(binary.BigEndian.Uint32(s)))
 	case oid.T_int2:
 		return int64(int16(binary.BigEndian.Uint16(s)))
+	case oid.T_uuid:
+		b, err := decodeUUIDBinary(s)
+		if err != nil {
+			panic(err)
+		}
+		return b
 
 	default:
 		errorf("don't know how to decode binary parameter of type %d", uint32(typ))
@@ -361,8 +367,15 @@ func ParseTimestamp(currentLocation *time.Location, str string) (time.Time, erro
 	timeSep := daySep + 3
 	day := p.mustAtoi(str, daySep+1, timeSep)
 
+	minLen := monSep + len("01-01") + 1
+
+	isBC := strings.HasSuffix(str, " BC")
+	if isBC {
+		minLen += 3
+	}
+
 	var hour, minute, second int
-	if len(str) > monSep+len("01-01")+1 {
+	if len(str) > minLen {
 		p.expect(str, ' ', timeSep)
 		minSep := timeSep + 3
 		p.expect(str, ':', minSep)
@@ -418,7 +431,8 @@ func ParseTimestamp(currentLocation *time.Location, str string) (time.Time, erro
 		tzOff = tzSign * ((tzHours * 60 * 60) + (tzMin * 60) + tzSec)
 	}
 	var isoYear int
-	if remainderIdx+3 <= len(str) && str[remainderIdx:remainderIdx+3] == " BC" {
+
+	if isBC {
 		isoYear = 1 - year
 		remainderIdx += 3
 	} else {
@@ -471,7 +485,7 @@ func FormatTimestamp(t time.Time) []byte {
 		t = t.AddDate((-t.Year())*2+1, 0, 0)
 		bc = true
 	}
-	b := []byte(t.Format(time.RFC3339Nano))
+	b := []byte(t.Format("2006-01-02 15:04:05.999999999Z07:00"))
 
 	_, offset := t.Zone()
 	offset = offset % 60

vendor/github.com/lib/pq/error.go

@@ -153,6 +153,7 @@ var errorCodeNames = map[ErrorCode]string{
 	"22004": "null_value_not_allowed",
 	"22002": "null_value_no_indicator_parameter",
 	"22003": "numeric_value_out_of_range",
+	"2200H": "sequence_generator_limit_exceeded",
 	"22026": "string_data_length_mismatch",
 	"22001": "string_data_right_truncation",
 	"22011": "substring_error",
@@ -459,6 +460,11 @@ func errorf(s string, args ...interface{}) {
 	panic(fmt.Errorf("pq: %s", fmt.Sprintf(s, args...)))
 }
 
+// TODO(ainar-g) Rename to errorf after removing panics.
+func fmterrorf(s string, args ...interface{}) error {
+	return fmt.Errorf("pq: %s", fmt.Sprintf(s, args...))
+}
+
 func errRecoverNoErrBadConn(err *error) {
 	e := recover()
 	if e == nil {
@@ -487,7 +493,8 @@ func (c *conn) errRecover(err *error) {
 			*err = v
 		}
 	case *net.OpError:
-		*err = driver.ErrBadConn
+		c.bad = true
+		*err = v
 	case error:
 		if v == io.EOF || v.(error).Error() == "remote error: handshake failure" {
 			*err = driver.ErrBadConn

vendor/github.com/lib/pq/notify.go

@@ -60,7 +60,7 @@ type ListenerConn struct {
 	replyChan chan message
 }
 
-// Creates a new ListenerConn.  Use NewListener instead.
+// NewListenerConn creates a new ListenerConn. Use NewListener instead.
 func NewListenerConn(name string, notificationChan chan<- *Notification) (*ListenerConn, error) {
 	return newDialListenerConn(defaultDialer{}, name, notificationChan)
 }
@@ -214,17 +214,17 @@ func (l *ListenerConn) listenerConnMain() {
 	// this ListenerConn is done
 }
 
-// Send a LISTEN query to the server.  See ExecSimpleQuery.
+// Listen sends a LISTEN query to the server. See ExecSimpleQuery.
 func (l *ListenerConn) Listen(channel string) (bool, error) {
 	return l.ExecSimpleQuery("LISTEN " + QuoteIdentifier(channel))
 }
 
-// Send an UNLISTEN query to the server.  See ExecSimpleQuery.
+// Unlisten sends an UNLISTEN query to the server. See ExecSimpleQuery.
 func (l *ListenerConn) Unlisten(channel string) (bool, error) {
 	return l.ExecSimpleQuery("UNLISTEN " + QuoteIdentifier(channel))
 }
 
-// Send `UNLISTEN *` to the server.  See ExecSimpleQuery.
+// UnlistenAll sends an `UNLISTEN *` query to the server. See ExecSimpleQuery.
 func (l *ListenerConn) UnlistenAll() (bool, error) {
 	return l.ExecSimpleQuery("UNLISTEN *")
 }
@@ -267,8 +267,8 @@ func (l *ListenerConn) sendSimpleQuery(q string) (err error) {
 	return nil
 }
 
-// Execute a "simple query" (i.e. one with no bindable parameters) on the
+// ExecSimpleQuery executes a "simple query" (i.e. one with no bindable
-// connection.  The possible return values are:
+// parameters) on the connection. The possible return values are:
 //   1) "executed" is true; the query was executed to completion on the
 //      database server.  If the query failed, err will be set to the error
 //      returned by the database, otherwise err will be nil.
@@ -333,6 +333,7 @@ func (l *ListenerConn) ExecSimpleQuery(q string) (executed bool, err error) {
 	}
 }
 
+// Close closes the connection.
 func (l *ListenerConn) Close() error {
 	l.connectionLock.Lock()
 	if l.err != nil {
@@ -346,7 +347,7 @@ func (l *ListenerConn) Close() error {
 	return l.cn.c.Close()
 }
 
-// Err() returns the reason the connection was closed.  It is not safe to call
+// Err returns the reason the connection was closed. It is not safe to call
 // this function until l.Notify has been closed.
 func (l *ListenerConn) Err() error {
 	return l.err
@@ -354,32 +355,43 @@ func (l *ListenerConn) Err() error {
 
 var errListenerClosed = errors.New("pq: Listener has been closed")
 
+// ErrChannelAlreadyOpen is returned from Listen when a channel is already
+// open.
 var ErrChannelAlreadyOpen = errors.New("pq: channel is already open")
+
+// ErrChannelNotOpen is returned from Unlisten when a channel is not open.
 var ErrChannelNotOpen = errors.New("pq: channel is not open")
 
+// ListenerEventType is an enumeration of listener event types.
 type ListenerEventType int
 
 const (
-	// Emitted only when the database connection has been initially
+	// ListenerEventConnected is emitted only when the database connection
-	// initialized.  err will always be nil.
+	// has been initially initialized. The err argument of the callback
+	// will always be nil.
 	ListenerEventConnected ListenerEventType = iota
 
-	// Emitted after a database connection has been lost, either because of an
+	// ListenerEventDisconnected is emitted after a database connection has
-	// error or because Close has been called.  err will be set to the reason
+	// been lost, either because of an error or because Close has been
-	// the database connection was lost.
+	// called. The err argument will be set to the reason the database
+	// connection was lost.
 	ListenerEventDisconnected
 
-	// Emitted after a database connection has been re-established after
+	// ListenerEventReconnected is emitted after a database connection has
-	// connection loss.  err will always be nil.  After this event has been
+	// been re-established after connection loss. The err argument of the
-	// emitted, a nil pq.Notification is sent on the Listener.Notify channel.
+	// callback will always be nil. After this event has been emitted, a
+	// nil pq.Notification is sent on the Listener.Notify channel.
 	ListenerEventReconnected
 
-	// Emitted after a connection to the database was attempted, but failed.
+	// ListenerEventConnectionAttemptFailed is emitted after a connection
-	// err will be set to an error describing why the connection attempt did
+	// to the database was attempted, but failed. The err argument will be
-	// not succeed.
+	// set to an error describing why the connection attempt did not
+	// succeed.
 	ListenerEventConnectionAttemptFailed
 )
 
+// EventCallbackType is the event callback type. See also ListenerEventType
+// constants' documentation.
 type EventCallbackType func(event ListenerEventType, err error)
 
 // Listener provides an interface for listening to notifications from a
@@ -454,9 +466,9 @@ func NewDialListener(d Dialer,
 	return l
 }
 
-// Returns the notification channel for this listener.  This is the same
+// NotificationChannel returns the notification channel for this listener.
-// channel as Notify, and will not be recreated during the life time of the
+// This is the same channel as Notify, and will not be recreated during the
-// Listener.
+// life time of the Listener.
 func (l *Listener) NotificationChannel() <-chan *Notification {
 	return l.Notify
 }
@@ -625,7 +637,7 @@ func (l *Listener) disconnectCleanup() error {
 // after the connection has been established.
 func (l *Listener) resync(cn *ListenerConn, notificationChan <-chan *Notification) error {
 	doneChan := make(chan error)
-	go func() {
+	go func(notificationChan <-chan *Notification) {
 		for channel := range l.channels {
 			// If we got a response, return that error to our caller as it's
 			// going to be more descriptive than cn.Err().
@@ -639,14 +651,14 @@ func (l *Listener) resync(cn *ListenerConn, notificationChan <-chan *Notificatio
 			// close and then return the error message from the connection, as
 			// per ListenerConn's interface.
 			if err != nil {
-				for _ = range notificationChan {
+				for range notificationChan {
 				}
 				doneChan <- cn.Err()
 				return
 			}
 		}
 		doneChan <- nil
-	}()
+	}(notificationChan)
 
 	// Ignore notifications while synchronization is going on to avoid
 	// deadlocks.  We have to send a nil notification over Notify anyway as
@@ -713,6 +725,9 @@ func (l *Listener) Close() error {
 	}
 	l.isClosed = true
 
+	// Unblock calls to Listen()
+	l.reconnectCond.Broadcast()
+
 	return nil
 }
 
@@ -772,7 +787,7 @@ func (l *Listener) listenerConnLoop() {
 		}
 		l.emitEvent(ListenerEventDisconnected, err)
 
-		time.Sleep(nextReconnect.Sub(time.Now()))
+		time.Sleep(time.Until(nextReconnect))
 	}
 }
 

vendor/github.com/lib/pq/oid/gen.go

@@ -10,10 +10,22 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"strings"
 
 	_ "github.com/lib/pq"
 )
 
+// OID represent a postgres Object Identifier Type.
+type OID struct {
+	ID   int
+	Type string
+}
+
+// Name returns an upper case version of the oid type.
+func (o OID) Name() string {
+	return strings.ToUpper(o.Type)
+}
+
 func main() {
 	datname := os.Getenv("PGDATABASE")
 	sslmode := os.Getenv("PGSSLMODE")
@@ -30,6 +42,25 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
+	rows, err := db.Query(`
+		SELECT typname, oid
+		FROM pg_type WHERE oid < 10000
+		ORDER BY oid;
+	`)
+	if err != nil {
+		log.Fatal(err)
+	}
+	oids := make([]*OID, 0)
+	for rows.Next() {
+		var oid OID
+		if err = rows.Scan(&oid.Type, &oid.ID); err != nil {
+			log.Fatal(err)
+		}
+		oids = append(oids, &oid)
+	}
+	if err = rows.Err(); err != nil {
+		log.Fatal(err)
+	}
 	cmd := exec.Command("gofmt")
 	cmd.Stderr = os.Stderr
 	w, err := cmd.StdinPipe()
@@ -45,30 +76,18 @@ func main() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	fmt.Fprintln(w, "// generated by 'go run gen.go'; do not edit")
+	fmt.Fprintln(w, "// Code generated by gen.go. DO NOT EDIT.")
 	fmt.Fprintln(w, "\npackage oid")
 	fmt.Fprintln(w, "const (")
-	rows, err := db.Query(`
+	for _, oid := range oids {
-		SELECT typname, oid
+		fmt.Fprintf(w, "T_%s Oid = %d\n", oid.Type, oid.ID)
-		FROM pg_type WHERE oid < 10000
-		ORDER BY oid;
-	`)
-	if err != nil {
-		log.Fatal(err)
-	}
-	var name string
-	var oid int
-	for rows.Next() {
-		err = rows.Scan(&name, &oid)
-		if err != nil {
-			log.Fatal(err)
-		}
-		fmt.Fprintf(w, "T_%s Oid = %d\n", name, oid)
-	}
-	if err = rows.Err(); err != nil {
-		log.Fatal(err)
 	}
 	fmt.Fprintln(w, ")")
+	fmt.Fprintln(w, "var TypeName = map[Oid]string{")
+	for _, oid := range oids {
+		fmt.Fprintf(w, "T_%s: \"%s\",\n", oid.Type, oid.Name())
+	}
+	fmt.Fprintln(w, "}")
 	w.Close()
 	cmd.Wait()
 }

vendor/github.com/lib/pq/oid/types.go

@@ -1,4 +1,4 @@
-// generated by 'go run gen.go'; do not edit
+// Code generated by gen.go. DO NOT EDIT.
 
 package oid
 
@@ -18,6 +18,7 @@ const (
 	T_xid              Oid = 28
 	T_cid              Oid = 29
 	T_oidvector        Oid = 30
+	T_pg_ddl_command   Oid = 32
 	T_pg_type          Oid = 71
 	T_pg_attribute     Oid = 75
 	T_pg_proc          Oid = 81
@@ -28,6 +29,7 @@ const (
 	T_pg_node_tree     Oid = 194
 	T__json            Oid = 199
 	T_smgr             Oid = 210
+	T_index_am_handler Oid = 325
 	T_point            Oid = 600
 	T_lseg             Oid = 601
 	T_path             Oid = 602
@@ -133,6 +135,9 @@ const (
 	T__uuid            Oid = 2951
 	T_txid_snapshot    Oid = 2970
 	T_fdw_handler      Oid = 3115
+	T_pg_lsn           Oid = 3220
+	T__pg_lsn          Oid = 3221
+	T_tsm_handler      Oid = 3310
 	T_anyenum          Oid = 3500
 	T_tsvector         Oid = 3614
 	T_tsquery          Oid = 3615
@@ -144,6 +149,8 @@ const (
 	T__regconfig       Oid = 3735
 	T_regdictionary    Oid = 3769
 	T__regdictionary   Oid = 3770
+	T_jsonb            Oid = 3802
+	T__jsonb           Oid = 3807
 	T_anyrange         Oid = 3831
 	T_event_trigger    Oid = 3838
 	T_int4range        Oid = 3904
@@ -158,4 +165,179 @@ const (
 	T__daterange       Oid = 3913
 	T_int8range        Oid = 3926
 	T__int8range       Oid = 3927
+	T_pg_shseclabel    Oid = 4066
+	T_regnamespace     Oid = 4089
+	T__regnamespace    Oid = 4090
+	T_regrole          Oid = 4096
+	T__regrole         Oid = 4097
 )
+
+var TypeName = map[Oid]string{
+	T_bool:             "BOOL",
+	T_bytea:            "BYTEA",
+	T_char:             "CHAR",
+	T_name:             "NAME",
+	T_int8:             "INT8",
+	T_int2:             "INT2",
+	T_int2vector:       "INT2VECTOR",
+	T_int4:             "INT4",
+	T_regproc:          "REGPROC",
+	T_text:             "TEXT",
+	T_oid:              "OID",
+	T_tid:              "TID",
+	T_xid:              "XID",
+	T_cid:              "CID",
+	T_oidvector:        "OIDVECTOR",
+	T_pg_ddl_command:   "PG_DDL_COMMAND",
+	T_pg_type:          "PG_TYPE",
+	T_pg_attribute:     "PG_ATTRIBUTE",
+	T_pg_proc:          "PG_PROC",
+	T_pg_class:         "PG_CLASS",
+	T_json:             "JSON",
+	T_xml:              "XML",
+	T__xml:             "_XML",
+	T_pg_node_tree:     "PG_NODE_TREE",
+	T__json:            "_JSON",
+	T_smgr:             "SMGR",
+	T_index_am_handler: "INDEX_AM_HANDLER",
+	T_point:            "POINT",
+	T_lseg:             "LSEG",
+	T_path:             "PATH",
+	T_box:              "BOX",
+	T_polygon:          "POLYGON",
+	T_line:             "LINE",
+	T__line:            "_LINE",
+	T_cidr:             "CIDR",
+	T__cidr:            "_CIDR",
+	T_float4:           "FLOAT4",
+	T_float8:           "FLOAT8",
+	T_abstime:          "ABSTIME",
+	T_reltime:          "RELTIME",
+	T_tinterval:        "TINTERVAL",
+	T_unknown:          "UNKNOWN",
+	T_circle:           "CIRCLE",
+	T__circle:          "_CIRCLE",
+	T_money:            "MONEY",
+	T__money:           "_MONEY",
+	T_macaddr:          "MACADDR",
+	T_inet:             "INET",
+	T__bool:            "_BOOL",
+	T__bytea:           "_BYTEA",
+	T__char:            "_CHAR",
+	T__name:            "_NAME",
+	T__int2:            "_INT2",
+	T__int2vector:      "_INT2VECTOR",
+	T__int4:            "_INT4",
+	T__regproc:         "_REGPROC",
+	T__text:            "_TEXT",
+	T__tid:             "_TID",
+	T__xid:             "_XID",
+	T__cid:             "_CID",
+	T__oidvector:       "_OIDVECTOR",
+	T__bpchar:          "_BPCHAR",
+	T__varchar:         "_VARCHAR",
+	T__int8:            "_INT8",
+	T__point:           "_POINT",
+	T__lseg:            "_LSEG",
+	T__path:            "_PATH",
+	T__box:             "_BOX",
+	T__float4:          "_FLOAT4",
+	T__float8:          "_FLOAT8",
+	T__abstime:         "_ABSTIME",
+	T__reltime:         "_RELTIME",
+	T__tinterval:       "_TINTERVAL",
+	T__polygon:         "_POLYGON",
+	T__oid:             "_OID",
+	T_aclitem:          "ACLITEM",
+	T__aclitem:         "_ACLITEM",
+	T__macaddr:         "_MACADDR",
+	T__inet:            "_INET",
+	T_bpchar:           "BPCHAR",
+	T_varchar:          "VARCHAR",
+	T_date:             "DATE",
+	T_time:             "TIME",
+	T_timestamp:        "TIMESTAMP",
+	T__timestamp:       "_TIMESTAMP",
+	T__date:            "_DATE",
+	T__time:            "_TIME",
+	T_timestamptz:      "TIMESTAMPTZ",
+	T__timestamptz:     "_TIMESTAMPTZ",
+	T_interval:         "INTERVAL",
+	T__interval:        "_INTERVAL",
+	T__numeric:         "_NUMERIC",
+	T_pg_database:      "PG_DATABASE",
+	T__cstring:         "_CSTRING",
+	T_timetz:           "TIMETZ",
+	T__timetz:          "_TIMETZ",
+	T_bit:              "BIT",
+	T__bit:             "_BIT",
+	T_varbit:           "VARBIT",
+	T__varbit:          "_VARBIT",
+	T_numeric:          "NUMERIC",
+	T_refcursor:        "REFCURSOR",
+	T__refcursor:       "_REFCURSOR",
+	T_regprocedure:     "REGPROCEDURE",
+	T_regoper:          "REGOPER",
+	T_regoperator:      "REGOPERATOR",
+	T_regclass:         "REGCLASS",
+	T_regtype:          "REGTYPE",
+	T__regprocedure:    "_REGPROCEDURE",
+	T__regoper:         "_REGOPER",
+	T__regoperator:     "_REGOPERATOR",
+	T__regclass:        "_REGCLASS",
+	T__regtype:         "_REGTYPE",
+	T_record:           "RECORD",
+	T_cstring:          "CSTRING",
+	T_any:              "ANY",
+	T_anyarray:         "ANYARRAY",
+	T_void:             "VOID",
+	T_trigger:          "TRIGGER",
+	T_language_handler: "LANGUAGE_HANDLER",
+	T_internal:         "INTERNAL",
+	T_opaque:           "OPAQUE",
+	T_anyelement:       "ANYELEMENT",
+	T__record:          "_RECORD",
+	T_anynonarray:      "ANYNONARRAY",
+	T_pg_authid:        "PG_AUTHID",
+	T_pg_auth_members:  "PG_AUTH_MEMBERS",
+	T__txid_snapshot:   "_TXID_SNAPSHOT",
+	T_uuid:             "UUID",
+	T__uuid:            "_UUID",
+	T_txid_snapshot:    "TXID_SNAPSHOT",
+	T_fdw_handler:      "FDW_HANDLER",
+	T_pg_lsn:           "PG_LSN",
+	T__pg_lsn:          "_PG_LSN",
+	T_tsm_handler:      "TSM_HANDLER",
+	T_anyenum:          "ANYENUM",
+	T_tsvector:         "TSVECTOR",
+	T_tsquery:          "TSQUERY",
+	T_gtsvector:        "GTSVECTOR",
+	T__tsvector:        "_TSVECTOR",
+	T__gtsvector:       "_GTSVECTOR",
+	T__tsquery:         "_TSQUERY",
+	T_regconfig:        "REGCONFIG",
+	T__regconfig:       "_REGCONFIG",
+	T_regdictionary:    "REGDICTIONARY",
+	T__regdictionary:   "_REGDICTIONARY",
+	T_jsonb:            "JSONB",
+	T__jsonb:           "_JSONB",
+	T_anyrange:         "ANYRANGE",
+	T_event_trigger:    "EVENT_TRIGGER",
+	T_int4range:        "INT4RANGE",
+	T__int4range:       "_INT4RANGE",
+	T_numrange:         "NUMRANGE",
+	T__numrange:        "_NUMRANGE",
+	T_tsrange:          "TSRANGE",
+	T__tsrange:         "_TSRANGE",
+	T_tstzrange:        "TSTZRANGE",
+	T__tstzrange:       "_TSTZRANGE",
+	T_daterange:        "DATERANGE",
+	T__daterange:       "_DATERANGE",
+	T_int8range:        "INT8RANGE",
+	T__int8range:       "_INT8RANGE",
+	T_pg_shseclabel:    "PG_SHSECLABEL",
+	T_regnamespace:     "REGNAMESPACE",
+	T__regnamespace:    "_REGNAMESPACE",
+	T_regrole:          "REGROLE",
+	T__regrole:         "_REGROLE",
+}

vendor/github.com/lib/pq/rows.go

@@ -0,0 +1,93 @@
+package pq
+
+import (
+	"math"
+	"reflect"
+	"time"
+
+	"github.com/lib/pq/oid"
+)
+
+const headerSize = 4
+
+type fieldDesc struct {
+	// The object ID of the data type.
+	OID oid.Oid
+	// The data type size (see pg_type.typlen).
+	// Note that negative values denote variable-width types.
+	Len int
+	// The type modifier (see pg_attribute.atttypmod).
+	// The meaning of the modifier is type-specific.
+	Mod int
+}
+
+func (fd fieldDesc) Type() reflect.Type {
+	switch fd.OID {
+	case oid.T_int8:
+		return reflect.TypeOf(int64(0))
+	case oid.T_int4:
+		return reflect.TypeOf(int32(0))
+	case oid.T_int2:
+		return reflect.TypeOf(int16(0))
+	case oid.T_varchar, oid.T_text:
+		return reflect.TypeOf("")
+	case oid.T_bool:
+		return reflect.TypeOf(false)
+	case oid.T_date, oid.T_time, oid.T_timetz, oid.T_timestamp, oid.T_timestamptz:
+		return reflect.TypeOf(time.Time{})
+	case oid.T_bytea:
+		return reflect.TypeOf([]byte(nil))
+	default:
+		return reflect.TypeOf(new(interface{})).Elem()
+	}
+}
+
+func (fd fieldDesc) Name() string {
+	return oid.TypeName[fd.OID]
+}
+
+func (fd fieldDesc) Length() (length int64, ok bool) {
+	switch fd.OID {
+	case oid.T_text, oid.T_bytea:
+		return math.MaxInt64, true
+	case oid.T_varchar, oid.T_bpchar:
+		return int64(fd.Mod - headerSize), true
+	default:
+		return 0, false
+	}
+}
+
+func (fd fieldDesc) PrecisionScale() (precision, scale int64, ok bool) {
+	switch fd.OID {
+	case oid.T_numeric, oid.T__numeric:
+		mod := fd.Mod - headerSize
+		precision = int64((mod >> 16) & 0xffff)
+		scale = int64(mod & 0xffff)
+		return precision, scale, true
+	default:
+		return 0, 0, false
+	}
+}
+
+// ColumnTypeScanType returns the value type that can be used to scan types into.
+func (rs *rows) ColumnTypeScanType(index int) reflect.Type {
+	return rs.colTyps[index].Type()
+}
+
+// ColumnTypeDatabaseTypeName return the database system type name.
+func (rs *rows) ColumnTypeDatabaseTypeName(index int) string {
+	return rs.colTyps[index].Name()
+}
+
+// ColumnTypeLength returns the length of the column type if the column is a
+// variable length type. If the column is not a variable length type ok
+// should return false.
+func (rs *rows) ColumnTypeLength(index int) (length int64, ok bool) {
+	return rs.colTyps[index].Length()
+}
+
+// ColumnTypePrecisionScale should return the precision and scale for decimal
+// types. If not applicable, ok should be false.
+func (rs *rows) ColumnTypePrecisionScale(index int) (precision, scale int64, ok bool) {
+	return rs.colTyps[index].PrecisionScale()
+}

vendor/github.com/lib/pq/ssl.go

@@ -0,0 +1,175 @@
+package pq
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"io/ioutil"
+	"net"
+	"os"
+	"os/user"
+	"path/filepath"
+)
+
+// ssl generates a function to upgrade a net.Conn based on the "sslmode" and
+// related settings. The function is nil when no upgrade should take place.
+func ssl(o values) (func(net.Conn) (net.Conn, error), error) {
+	verifyCaOnly := false
+	tlsConf := tls.Config{}
+	switch mode := o["sslmode"]; mode {
+	// "require" is the default.
+	case "", "require":
+		// We must skip TLS's own verification since it requires full
+		// verification since Go 1.3.
+		tlsConf.InsecureSkipVerify = true
+
+		// From http://www.postgresql.org/docs/current/static/libpq-ssl.html:
+		//
+		// Note: For backwards compatibility with earlier versions of
+		// PostgreSQL, if a root CA file exists, the behavior of
+		// sslmode=require will be the same as that of verify-ca, meaning the
+		// server certificate is validated against the CA. Relying on this
+		// behavior is discouraged, and applications that need certificate
+		// validation should always use verify-ca or verify-full.
+		if sslrootcert, ok := o["sslrootcert"]; ok {
+			if _, err := os.Stat(sslrootcert); err == nil {
+				verifyCaOnly = true
+			} else {
+				delete(o, "sslrootcert")
+			}
+		}
+	case "verify-ca":
+		// We must skip TLS's own verification since it requires full
+		// verification since Go 1.3.
+		tlsConf.InsecureSkipVerify = true
+		verifyCaOnly = true
+	case "verify-full":
+		tlsConf.ServerName = o["host"]
+	case "disable":
+		return nil, nil
+	default:
+		return nil, fmterrorf(`unsupported sslmode %q; only "require" (default), "verify-full", "verify-ca", and "disable" supported`, mode)
+	}
+
+	err := sslClientCertificates(&tlsConf, o)
+	if err != nil {
+		return nil, err
+	}
+	err = sslCertificateAuthority(&tlsConf, o)
+	if err != nil {
+		return nil, err
+	}
+
+	// Accept renegotiation requests initiated by the backend.
+	//
+	// Renegotiation was deprecated then removed from PostgreSQL 9.5, but
+	// the default configuration of older versions has it enabled. Redshift
+	// also initiates renegotiations and cannot be reconfigured.
+	tlsConf.Renegotiation = tls.RenegotiateFreelyAsClient
+
+	return func(conn net.Conn) (net.Conn, error) {
+		client := tls.Client(conn, &tlsConf)
+		if verifyCaOnly {
+			err := sslVerifyCertificateAuthority(client, &tlsConf)
+			if err != nil {
+				return nil, err
+			}
+		}
+		return client, nil
+	}, nil
+}
+
+// sslClientCertificates adds the certificate specified in the "sslcert" and
+// "sslkey" settings, or if they aren't set, from the .postgresql directory
+// in the user's home directory. The configured files must exist and have
+// the correct permissions.
+func sslClientCertificates(tlsConf *tls.Config, o values) error {
+	// user.Current() might fail when cross-compiling. We have to ignore the
+	// error and continue without home directory defaults, since we wouldn't
+	// know from where to load them.
+	user, _ := user.Current()
+
+	// In libpq, the client certificate is only loaded if the setting is not blank.
+	//
+	// https://github.com/postgres/postgres/blob/REL9_6_2/src/interfaces/libpq/fe-secure-openssl.c#L1036-L1037
+	sslcert := o["sslcert"]
+	if len(sslcert) == 0 && user != nil {
+		sslcert = filepath.Join(user.HomeDir, ".postgresql", "postgresql.crt")
+	}
+	// https://github.com/postgres/postgres/blob/REL9_6_2/src/interfaces/libpq/fe-secure-openssl.c#L1045
+	if len(sslcert) == 0 {
+		return nil
+	}
+	// https://github.com/postgres/postgres/blob/REL9_6_2/src/interfaces/libpq/fe-secure-openssl.c#L1050:L1054
+	if _, err := os.Stat(sslcert); os.IsNotExist(err) {
+		return nil
+	} else if err != nil {
+		return err
+	}
+
+	// In libpq, the ssl key is only loaded if the setting is not blank.
+	//
+	// https://github.com/postgres/postgres/blob/REL9_6_2/src/interfaces/libpq/fe-secure-openssl.c#L1123-L1222
+	sslkey := o["sslkey"]
+	if len(sslkey) == 0 && user != nil {
+		sslkey = filepath.Join(user.HomeDir, ".postgresql", "postgresql.key")
+	}
+
+	if len(sslkey) > 0 {
+		if err := sslKeyPermissions(sslkey); err != nil {
+			return err
+		}
+	}
+
+	cert, err := tls.LoadX509KeyPair(sslcert, sslkey)
+	if err != nil {
+		return err
+	}
+
+	tlsConf.Certificates = []tls.Certificate{cert}
+	return nil
+}
+
+// sslCertificateAuthority adds the RootCA specified in the "sslrootcert" setting.
+func sslCertificateAuthority(tlsConf *tls.Config, o values) error {
+	// In libpq, the root certificate is only loaded if the setting is not blank.
+	//
+	// https://github.com/postgres/postgres/blob/REL9_6_2/src/interfaces/libpq/fe-secure-openssl.c#L950-L951
+	if sslrootcert := o["sslrootcert"]; len(sslrootcert) > 0 {
+		tlsConf.RootCAs = x509.NewCertPool()
+
+		cert, err := ioutil.ReadFile(sslrootcert)
+		if err != nil {
+			return err
+		}
+
+		if !tlsConf.RootCAs.AppendCertsFromPEM(cert) {
+			return fmterrorf("couldn't parse pem in sslrootcert")
+		}
+	}
+
+	return nil
+}
+
+// sslVerifyCertificateAuthority carries out a TLS handshake to the server and
+// verifies the presented certificate against the CA, i.e. the one specified in
+// sslrootcert or the system CA if sslrootcert was not specified.
+func sslVerifyCertificateAuthority(client *tls.Conn, tlsConf *tls.Config) error {
+	err := client.Handshake()
+	if err != nil {
+		return err
+	}
+	certs := client.ConnectionState().PeerCertificates
+	opts := x509.VerifyOptions{
+		DNSName:       client.ConnectionState().ServerName,
+		Intermediates: x509.NewCertPool(),
+		Roots:         tlsConf.RootCAs,
+	}
+	for i, cert := range certs {
+		if i == 0 {
+			continue
+		}
+		opts.Intermediates.AddCert(cert)
+	}
+	_, err = certs[0].Verify(opts)
+	return err
+}

vendor/github.com/lib/pq/ssl_permissions.go

@@ -0,0 +1,20 @@
+// +build !windows
+
+package pq
+
+import "os"
+
+// sslKeyPermissions checks the permissions on user-supplied ssl key files.
+// The key file should have very little access.
+//
+// libpq does not check key file permissions on Windows.
+func sslKeyPermissions(sslkey string) error {
+	info, err := os.Stat(sslkey)
+	if err != nil {
+		return err
+	}
+	if info.Mode().Perm()&0077 != 0 {
+		return ErrSSLKeyHasWorldPermissions
+	}
+	return nil
+}

vendor/github.com/lib/pq/ssl_windows.go

@@ -0,0 +1,9 @@
+// +build windows
+
+package pq
+
+// sslKeyPermissions checks the permissions on user-supplied ssl key files.
+// The key file should have very little access.
+//
+// libpq does not check key file permissions on Windows.
+func sslKeyPermissions(string) error { return nil }

vendor/github.com/lib/pq/uuid.go

@@ -0,0 +1,23 @@
+package pq
+
+import (
+	"encoding/hex"
+	"fmt"
+)
+
+// decodeUUIDBinary interprets the binary format of a uuid, returning it in text format.
+func decodeUUIDBinary(src []byte) ([]byte, error) {
+	if len(src) != 16 {
+		return nil, fmt.Errorf("pq: unable to decode uuid; bad length: %d", len(src))
+	}
+
+	dst := make([]byte, 36)
+	dst[8], dst[13], dst[18], dst[23] = '-', '-', '-', '-'
+	hex.Encode(dst[0:], src[0:4])
+	hex.Encode(dst[9:], src[4:6])
+	hex.Encode(dst[14:], src[6:8])
+	hex.Encode(dst[19:], src[8:10])
+	hex.Encode(dst[24:], src[10:16])
+
+	return dst, nil
+}