Add postgres

This commits adds support for postgres database.
Currently two fields are stored: the bloom filter and the topic.
Only the bloom filter is actually used to query, but potentially we will
use also the topic in the future, so easier to separate it now in order
to avoid a migration.

.codeclimate.yml

@@ -41,4 +41,5 @@ exclude_patterns:
   - vendor/
   - static/
   - t/
-  
+  - mailserver/migrations
+  - services/shhext/chat/migrations

Gopkg.lock

@@ -373,6 +373,18 @@
   pruneopts = "T"
   revision = "f00545f9f3748e591590be3732d913c77525b10f"
 
+[[projects]]
+  branch = "master"
+  digest = "1:f8a9f7e4b9da760c589c6b4ce06a4b7b88085850605f8a9b88cd0d8dd523f614"
+  name = "github.com/lib/pq"
+  packages = [
+    ".",
+    "oid",
+    "scram",
+  ]
+  pruneopts = "NUT"
+  revision = "2ff3cb3adc01768e0a552b3a02575a6df38a9bea"
+
 [[projects]]
   digest = "1:7f9d01bc5289296160042e42e146052ae9fb8fdb92be6dd11b0e5d4916784f6d"
   name = "github.com/libp2p/go-addr-util"
@@ -822,10 +834,11 @@
   version = "v1.0.0"
 
 [[projects]]
-  digest = "1:7607ae0e3b67bdf37a65dc42f866a90bcbe543308e92184c51e33a4cca842ecb"
+  digest = "1:e93ff99796affffb8cfd16ff6fb8b54b089c3edac11b82d3ee2f17ffb2a0f7a2"
   name = "github.com/status-im/migrate"
   packages = [
     ".",
+    "database/postgres",
     "database/sqlcipher",
     "source/go_bindata",
   ]
@@ -1112,6 +1125,7 @@
     "github.com/ethereum/go-ethereum/rpc",
     "github.com/golang/mock/gomock",
     "github.com/golang/protobuf/proto",
+    "github.com/lib/pq",
     "github.com/libp2p/go-libp2p-crypto",
     "github.com/multiformats/go-multiaddr",
     "github.com/mutecomm/go-sqlcipher",
@@ -1120,6 +1134,7 @@
     "github.com/status-im/doubleratchet",
     "github.com/status-im/go-ethereum/common/hexutil",
     "github.com/status-im/migrate",
+    "github.com/status-im/migrate/database/postgres",
     "github.com/status-im/migrate/database/sqlcipher",
     "github.com/status-im/migrate/source/go_bindata",
     "github.com/status-im/rendezvous",

Makefile

@@ -191,7 +191,7 @@ setup-build: dep-install lint-install release-install gomobile-install ##@other
 setup: setup-build setup-dev ##@other Prepare project for development and building
 
 generate: ##@other Regenerate assets and other auto-generated stuff
-	go generate ./static ./static/migrations
+	go generate ./static ./static/encryption_migrations ./static/mailserver_db_migrations
 	$(shell cd ./services/shhext/chat && exec protoc --go_out=. ./*.proto)
 
 prepare-release: clean-release

VERSION

@@ -1 +1 @@
-0.25.0-beta.1
+0.25.0-beta.2

config/README.md

@@ -67,6 +67,26 @@ If you want your node to relay Whisper(SHH) protocol messages you'll want to inc
 ```
 The `MailServerPassword` is used for symmetric encryption of history requests.
 
+By default it will use `leveldb` embedded database. To use postgres instead you need to 
+pass a config of this kind:
+
+```json
+{
+    "WhisperConfig": {
+        "Enabled": true,
+        "EnableMailServer": true,
+        "LightClient": false,
+        "MailServerPassword": "status-offline-inbox"
+        "DatabaseConfig": {
+          "PGConfig": {
+            "Enabled": true,
+            "URI": "postgres://user:password@host:port?options"
+          }
+        }
+    }
+}
+```
+
 __NOTE:__ The default password used by Status App and [our mailservers](https://fleets.status.im/) is `status-offline-inbox`.
 
 ## `ClusterConfig`

mailserver/cleaner.go

@@ -16,7 +16,7 @@ const (
 type dbCleaner struct {
 	sync.RWMutex
 
-	db        dbImpl
+	db        DB
 	batchSize int
 	retention time.Duration
 
@@ -25,7 +25,7 @@ type dbCleaner struct {
 }
 
 // newDBCleaner returns a new cleaner for db.
-func newDBCleaner(db dbImpl, retention time.Duration) *dbCleaner {
+func newDBCleaner(db DB, retention time.Duration) *dbCleaner {
 	return &dbCleaner{
 		db:        db,
 		retention: retention,

mailserver/cleaner_test.go

@@ -90,7 +90,7 @@ func setupTestServer(t *testing.T) *WMailServer {
 	var s WMailServer
 	db, _ := leveldb.Open(storage.NewMemStorage(), nil)
 
-	s.db = &LevelDBImpl{ldb: db}
+	s.db = &LevelDB{ldb: db}
 	s.pow = powRequirement
 	return &s
 }
@@ -114,7 +114,7 @@ func testMessagesCount(t *testing.T, expected int, s *WMailServer) {
 	require.Equal(t, expected, count, fmt.Sprintf("expected %d message, got: %d", expected, count))
 }
 
-func countMessages(t *testing.T, db dbImpl) int {
+func countMessages(t *testing.T, db DB) int {
 	var (
 		count      int
 		zero       common.Hash
@@ -130,12 +130,17 @@ func countMessages(t *testing.T, db dbImpl) int {
 		end:   ku.raw,
 	}
 
-	i := db.BuildIterator(query)
+	i, _ := db.BuildIterator(query)
 	defer i.Release()
 
 	for i.Next() {
 		var env whisper.Envelope
-		err := rlp.DecodeBytes(i.Value(), &env)
+		value, err := i.GetEnvelope(query.bloom)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		err = rlp.DecodeBytes(value, &env)
 		if err != nil {
 			t.Fatal(err)
 		}

mailserver/mailserver.go

@@ -55,7 +55,7 @@ const (
 
 // WMailServer whisper mailserver.
 type WMailServer struct {
-	db         dbImpl
+	db         DB
 	w          *whisper.Whisper
 	pow        float64
 	symFilter  *whisper.Filter
@@ -69,8 +69,6 @@ type WMailServer struct {
 
 // Init initializes mailServer.
 func (s *WMailServer) Init(shh *whisper.Whisper, config *params.WhisperConfig) error {
-	var err error
-
 	if len(config.DataDir) == 0 {
 		return errDirectoryNotProvided
 	}
@@ -92,11 +90,22 @@ func (s *WMailServer) Init(shh *whisper.Whisper, config *params.WhisperConfig) e
 
 	// Open database in the last step in order not to init with error
 	// and leave the database open by accident.
-	database, err := NewLevelDBImpl(config)
+	if config.DatabaseConfig.PGConfig.Enabled {
-	if err != nil {
+		log.Info("Connecting to postgres database")
-		return fmt.Errorf("open DB: %s", err)
+		database, err := NewPostgresDB(config)
+		if err != nil {
+			return fmt.Errorf("open DB: %s", err)
+		}
+		s.db = database
+		log.Info("Connected to postgres database")
+	} else {
+		// Defaults to LevelDB
+		database, err := NewLevelDB(config)
+		if err != nil {
+			return fmt.Errorf("open DB: %s", err)
+		}
+		s.db = database
 	}
-	s.db = database
 
 	if config.MailServerDataRetention > 0 {
 		// MailServerDataRetention is a number of days.
@@ -253,7 +262,15 @@ func (s *WMailServer) DeliverMail(peer *whisper.Peer, request *whisper.Envelope)
 		requestsBatchedCounter.Inc(1)
 	}
 
-	iter := s.createIterator(lower, upper, cursor, bloom, limit)
+	iter, err := s.createIterator(lower, upper, cursor, bloom, limit)
+	if err != nil {
+		log.Error("[mailserver:DeliverMail] request failed",
+			"peerID", peerID,
+			"requestID", requestID)
+
+		return
+	}
+
 	defer iter.Release()
 
 	bundles := make(chan []rlp.RawValue, 5)
@@ -347,7 +364,10 @@ func (s *WMailServer) SyncMail(peer *whisper.Peer, request whisper.SyncMailReque
 		return fmt.Errorf("request is invalid: %v", err)
 	}
 
-	iter := s.createIterator(request.Lower, request.Upper, request.Cursor, nil, 0)
+	iter, err := s.createIterator(request.Lower, request.Upper, request.Cursor, nil, 0)
+	if err != nil {
+		return err
+	}
 	defer iter.Release()
 
 	bundles := make(chan []rlp.RawValue, 5)
@@ -393,7 +413,7 @@ func (s *WMailServer) SyncMail(peer *whisper.Peer, request whisper.SyncMailReque
 			peer,
 			whisper.SyncResponse{Error: "failed to process all envelopes"},
 		)
-		return fmt.Errorf("levelDB iterator failed: %v", err)
+		return fmt.Errorf("LevelDB iterator failed: %v", err)
 	}
 
 	log.Info("Finished syncing envelopes", "peer", peerIDString(peer))
@@ -428,7 +448,7 @@ func (s *WMailServer) exceedsPeerRequests(peer []byte) bool {
 	return true
 }
 
-func (s *WMailServer) createIterator(lower, upper uint32, cursor []byte, bloom []byte, limit uint32) Iterator {
+func (s *WMailServer) createIterator(lower, upper uint32, cursor []byte, bloom []byte, limit uint32) (Iterator, error) {
 	var (
 		emptyHash  common.Hash
 		emptyTopic whisper.TopicType
@@ -495,7 +515,13 @@ func (s *WMailServer) processRequestInBundles(
 			continue
 		}
 
-		key := iter.DBKey()
+		key, err := iter.DBKey()
+		if err != nil {
+			log.Error("[mailserver:processRequestInBundles] failed getting key",
+				"requestID", requestID)
+			break
+
+		}
 
 		lastEnvelopeHash = key.EnvelopeHash()
 		processedEnvelopes++

mailserver/mailserver_db.go

@@ -5,9 +5,9 @@ import (
 	"time"
 )
 
-// dbImpl is an interface to abstract interactions with the db so that the mailserver
+// DB is an interface to abstract interactions with the db so that the mailserver
 // is agnostic to the underlaying technology used
-type dbImpl interface {
+type DB interface {
 	Close() error
 	// SaveEnvelope stores an envelope
 	SaveEnvelope(*whisper.Envelope) error
@@ -16,14 +16,12 @@ type dbImpl interface {
 	// Prune removes envelopes older than time
 	Prune(time.Time, int) (int, error)
 	// BuildIterator returns an iterator over envelopes
-	BuildIterator(query CursorQuery) Iterator
+	BuildIterator(query CursorQuery) (Iterator, error)
 }
 
 type Iterator interface {
 	Next() bool
-	Prev() bool
+	DBKey() (*DBKey, error)
-	DBKey() *DBKey
-	Value() []byte
 	Release()
 	Error() error
 	GetEnvelope(bloom []byte) ([]byte, error)

mailserver/mailserver_db_leveldb.go

@@ -14,7 +14,7 @@ import (
 	"time"
 )
 
-type LevelDBImpl struct {
+type LevelDB struct {
 	// We can't embed as there are some state problems with go-routines
 	ldb *leveldb.DB
 }
@@ -23,10 +23,10 @@ type LevelDBIterator struct {
 	iterator.Iterator
 }
 
-func (i *LevelDBIterator) DBKey() *DBKey {
+func (i *LevelDBIterator) DBKey() (*DBKey, error) {
 	return &DBKey{
 		raw: i.Key(),
-	}
+	}, nil
 }
 
 func (i *LevelDBIterator) GetEnvelope(bloom []byte) ([]byte, error) {
@@ -34,7 +34,11 @@ func (i *LevelDBIterator) GetEnvelope(bloom []byte) ([]byte, error) {
 	rawValue := make([]byte, len(i.Value()))
 	copy(rawValue, i.Value())
 
-	key := i.DBKey()
+	key, err := i.DBKey()
+	if err != nil {
+		return nil, err
+	}
+
 	if len(key.Bytes()) != DBKeyLength {
 		var err error
 		envelopeBloom, err = extractBloomFromEncodedEnvelope(rawValue)
@@ -51,18 +55,18 @@ func (i *LevelDBIterator) GetEnvelope(bloom []byte) ([]byte, error) {
 
 }
 
-func NewLevelDBImpl(config *params.WhisperConfig) (*LevelDBImpl, error) {
+func NewLevelDB(config *params.WhisperConfig) (*LevelDB, error) {
 	// Open opens an existing leveldb database
 	db, err := leveldb.OpenFile(config.DataDir, nil)
 	if _, iscorrupted := err.(*errors.ErrCorrupted); iscorrupted {
 		log.Info("database is corrupted trying to recover", "path", config.DataDir)
 		db, err = leveldb.RecoverFile(config.DataDir, nil)
 	}
-	return &LevelDBImpl{ldb: db}, err
+	return &LevelDB{ldb: db}, err
 }
 
 // Build iterator returns an iterator given a start/end and a cursor
-func (db *LevelDBImpl) BuildIterator(query CursorQuery) Iterator {
+func (db *LevelDB) BuildIterator(query CursorQuery) (Iterator, error) {
 	defer recoverLevelDBPanics("BuildIterator")
 
 	i := db.ldb.NewIterator(&util.Range{Start: query.start, Limit: query.end}, nil)
@@ -70,18 +74,18 @@ func (db *LevelDBImpl) BuildIterator(query CursorQuery) Iterator {
 	if len(query.cursor) == CursorLength {
 		i.Seek(query.cursor)
 	}
-	return &LevelDBIterator{i}
+	return &LevelDBIterator{i}, nil
 }
 
 // GetEnvelope get an envelope by its key
-func (db *LevelDBImpl) GetEnvelope(key *DBKey) ([]byte, error) {
+func (db *LevelDB) GetEnvelope(key *DBKey) ([]byte, error) {
 	defer recoverLevelDBPanics("GetEnvelope")
 
 	return db.ldb.Get(key.Bytes(), nil)
 }
 
 // Prune removes envelopes older than time
-func (db *LevelDBImpl) Prune(t time.Time, batchSize int) (int, error) {
+func (db *LevelDB) Prune(t time.Time, batchSize int) (int, error) {
 	defer recoverLevelDBPanics("Prune")
 
 	var zero common.Hash
@@ -92,14 +96,22 @@ func (db *LevelDBImpl) Prune(t time.Time, batchSize int) (int, error) {
 		start: kl.Bytes(),
 		end:   ku.Bytes(),
 	}
-	i := db.BuildIterator(query)
+	i, err := db.BuildIterator(query)
+	if err != nil {
+		return 0, err
+	}
 	defer i.Release()
 
 	batch := leveldb.Batch{}
 	removed := 0
 
 	for i.Next() {
-		batch.Delete(i.DBKey().Bytes())
+		dbKey, err := i.DBKey()
+		if err != nil {
+			return 0, err
+		}
+
+		batch.Delete(dbKey.Bytes())
 
 		if batch.Len() == batchSize {
 			if err := db.ldb.Write(&batch, nil); err != nil {
@@ -123,7 +135,7 @@ func (db *LevelDBImpl) Prune(t time.Time, batchSize int) (int, error) {
 }
 
 // SaveEnvelope stores an envelope in leveldb and increments the metrics
-func (db *LevelDBImpl) SaveEnvelope(env *whisper.Envelope) error {
+func (db *LevelDB) SaveEnvelope(env *whisper.Envelope) error {
 	defer recoverLevelDBPanics("SaveEnvelope")
 
 	key := NewDBKey(env.Expiry-env.TTL, env.Topic, env.Hash())
@@ -143,7 +155,7 @@ func (db *LevelDBImpl) SaveEnvelope(env *whisper.Envelope) error {
 	return err
 }
 
-func (db *LevelDBImpl) Close() error {
+func (db *LevelDB) Close() error {
 	return db.ldb.Close()
 }
 

mailserver/mailserver_db_postgres.go

@@ -0,0 +1,225 @@
+package mailserver
+
+import (
+	"database/sql"
+	"fmt"
+	"time"
+
+	// Import postgres driver
+	_ "github.com/lib/pq"
+	"github.com/status-im/migrate"
+	"github.com/status-im/migrate/database/postgres"
+	"github.com/status-im/migrate/source/go_bindata"
+	"github.com/status-im/status-go/mailserver/migrations"
+	"github.com/status-im/status-go/params"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rlp"
+	whisper "github.com/status-im/whisper/whisperv6"
+)
+
+func NewPostgresDB(config *params.WhisperConfig) (*PostgresDB, error) {
+	db, err := sql.Open("postgres", config.DatabaseConfig.PGConfig.URI)
+	if err != nil {
+		return nil, err
+	}
+
+	instance := &PostgresDB{db: db}
+	if err := instance.setup(); err != nil {
+		return nil, err
+	}
+
+	return instance, nil
+}
+
+type PostgresDB struct {
+	db *sql.DB
+}
+
+type postgresIterator struct {
+	*sql.Rows
+}
+
+func (i *postgresIterator) DBKey() (*DBKey, error) {
+	var value []byte
+	var id []byte
+	if err := i.Scan(&id, &value); err != nil {
+		return nil, err
+	}
+	return &DBKey{raw: id}, nil
+}
+
+func (i *postgresIterator) Error() error {
+	return nil
+}
+
+func (i *postgresIterator) Release() {
+	i.Close()
+}
+
+func (i *postgresIterator) GetEnvelope(bloom []byte) ([]byte, error) {
+	var value []byte
+	var id []byte
+	if err := i.Scan(&id, &value); err != nil {
+		return nil, err
+	}
+
+	return value, nil
+}
+
+func (i *PostgresDB) BuildIterator(query CursorQuery) (Iterator, error) {
+	var upperLimit []byte
+	var stmtString string
+	if len(query.cursor) > 0 {
+		// If we have a cursor, we don't want to include that envelope in the result set
+		upperLimit = query.cursor
+
+		// We disable security checks as we need to use string interpolation
+		// for this, but it's converted to 0s and 1s so no injection should be possible
+		/* #nosec */
+		stmtString = fmt.Sprintf("SELECT id, data FROM envelopes where id >= $1 AND id < $2 AND bloom & b'%s'::bit(512) = bloom ORDER BY ID DESC LIMIT $3", toBitString(query.bloom))
+	} else {
+		upperLimit = query.end
+		// We disable security checks as we need to use string interpolation
+		// for this, but it's converted to 0s and 1s so no injection should be possible
+		/* #nosec */
+		stmtString = fmt.Sprintf("SELECT id, data FROM envelopes where id >= $1 AND id <= $2 AND bloom & b'%s'::bit(512) = bloom ORDER BY ID DESC LIMIT $3", toBitString(query.bloom))
+	}
+
+	stmt, err := i.db.Prepare(stmtString)
+	if err != nil {
+		return nil, err
+	}
+
+	rows, err := stmt.Query(query.start, upperLimit, query.limit)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &postgresIterator{rows}, nil
+}
+
+func (i *PostgresDB) setup() error {
+	resources := bindata.Resource(
+		migrations.AssetNames(),
+		func(name string) ([]byte, error) {
+			return migrations.Asset(name)
+		},
+	)
+
+	source, err := bindata.WithInstance(resources)
+	if err != nil {
+		return err
+	}
+
+	driver, err := postgres.WithInstance(i.db, &postgres.Config{})
+	if err != nil {
+		return err
+	}
+
+	m, err := migrate.NewWithInstance(
+		"go-bindata",
+		source,
+		"postgres",
+		driver)
+	if err != nil {
+		return err
+	}
+
+	if err = m.Up(); err != migrate.ErrNoChange {
+		return err
+	}
+
+	return nil
+}
+
+func (i *PostgresDB) Close() error {
+	return i.db.Close()
+}
+
+func (i *PostgresDB) GetEnvelope(key *DBKey) ([]byte, error) {
+	statement := `SELECT data FROM envelopes WHERE id = $1`
+
+	stmt, err := i.db.Prepare(statement)
+	if err != nil {
+		return nil, err
+	}
+	defer stmt.Close()
+
+	var envelope []byte
+
+	if err = stmt.QueryRow(key.Bytes()).Scan(&envelope); err != nil {
+		return nil, err
+	}
+
+	return envelope, nil
+}
+
+func (i *PostgresDB) Prune(t time.Time, batch int) (int, error) {
+	var zero common.Hash
+	var emptyTopic whisper.TopicType
+	kl := NewDBKey(0, emptyTopic, zero)
+	ku := NewDBKey(uint32(t.Unix()), emptyTopic, zero)
+	statement := "DELETE FROM envelopes WHERE id BETWEEN $1 AND $2"
+
+	stmt, err := i.db.Prepare(statement)
+	if err != nil {
+		return 0, err
+	}
+	defer stmt.Close()
+
+	if _, err = stmt.Exec(kl.Bytes(), ku.Bytes()); err != nil {
+		return 0, err
+	}
+
+	return 0, nil
+}
+
+func (i *PostgresDB) SaveEnvelope(env *whisper.Envelope) error {
+	key := NewDBKey(env.Expiry-env.TTL, env.Topic, env.Hash())
+	rawEnvelope, err := rlp.EncodeToBytes(env)
+	if err != nil {
+		log.Error(fmt.Sprintf("rlp.EncodeToBytes failed: %s", err))
+		archivedErrorsCounter.Inc(1)
+		return err
+	}
+
+	statement := "INSERT INTO envelopes (id, data, topic, bloom) VALUES ($1, $2, $3, B'"
+	statement += toBitString(env.Bloom())
+	statement += "'::bit(512)) ON CONFLICT (id) DO NOTHING;"
+	stmt, err := i.db.Prepare(statement)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	_, err = stmt.Exec(
+		key.Bytes(),
+		rawEnvelope,
+		topicToByte(env.Topic),
+	)
+
+	if err != nil {
+		archivedErrorsCounter.Inc(1)
+		return err
+	}
+
+	archivedMeter.Mark(1)
+	archivedSizeMeter.Mark(int64(whisper.EnvelopeHeaderLength + len(env.Data)))
+
+	return nil
+}
+
+func topicToByte(t whisper.TopicType) []byte {
+	return []byte{t[0], t[1], t[2], t[3]}
+}
+
+func toBitString(bloom []byte) string {
+	val := ""
+	for _, n := range bloom {
+		val += fmt.Sprintf("%08b", n)
+	}
+	return val
+}

mailserver/mailserver_test.go

@@ -577,7 +577,9 @@ func (s *MailserverSuite) TestProcessRequestDeadlockHandling() {
 
 	for _, tc := range testCases {
 		s.T().Run(tc.Name, func(t *testing.T) {
-			iter := s.server.createIterator(lower, upper, cursor, nil, 0)
+			iter, err := s.server.createIterator(lower, upper, cursor, nil, 0)
+			s.Require().NoError(err)
+
 			defer iter.Release()
 
 			// Nothing reads from this unbuffered channel which simulates a situation
@@ -776,7 +778,7 @@ func generateEnvelope(sentTime time.Time) (*whisper.Envelope, error) {
 func processRequestAndCollectHashes(
 	server *WMailServer, lower, upper uint32, cursor []byte, bloom []byte, limit int,
 ) ([]common.Hash, []byte, common.Hash) {
-	iter := server.createIterator(lower, upper, cursor, nil, 0)
+	iter, _ := server.createIterator(lower, upper, cursor, nil, 0)
 	defer iter.Release()
 	bundles := make(chan []rlp.RawValue, 10)
 	done := make(chan struct{})

mailserver/migrations/bindata.go

@@ -0,0 +1,281 @@
+// Code generated by go-bindata.
+// sources:
+// 1557732988_initialize_db.down.sql
+// 1557732988_initialize_db.up.sql
+// static.go
+// DO NOT EDIT!
+
+package migrations
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+func bindataRead(data []byte, name string) ([]byte, error) {
+	gz, err := gzip.NewReader(bytes.NewBuffer(data))
+	if err != nil {
+		return nil, fmt.Errorf("Read %q: %v", name, err)
+	}
+
+	var buf bytes.Buffer
+	_, err = io.Copy(&buf, gz)
+	clErr := gz.Close()
+
+	if err != nil {
+		return nil, fmt.Errorf("Read %q: %v", name, err)
+	}
+	if clErr != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
+}
+
+type asset struct {
+	bytes []byte
+	info  os.FileInfo
+}
+
+type bindataFileInfo struct {
+	name    string
+	size    int64
+	mode    os.FileMode
+	modTime time.Time
+}
+
+func (fi bindataFileInfo) Name() string {
+	return fi.name
+}
+func (fi bindataFileInfo) Size() int64 {
+	return fi.size
+}
+func (fi bindataFileInfo) Mode() os.FileMode {
+	return fi.mode
+}
+func (fi bindataFileInfo) ModTime() time.Time {
+	return fi.modTime
+}
+func (fi bindataFileInfo) IsDir() bool {
+	return false
+}
+func (fi bindataFileInfo) Sys() interface{} {
+	return nil
+}
+
+var __1557732988_initialize_dbDownSql = []byte("\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff\x72\x09\xf2\x0f\x50\xf0\xf4\x73\x71\x8d\x50\xc8\x4c\x89\x4f\xca\xc9\xcf\xcf\x8d\xcf\x4c\xa9\xb0\xe6\x42\x95\x28\xc9\x2f\xc8\x4c\x46\x92\x08\x71\x74\xf2\x71\x55\x48\xcd\x2b\x4b\xcd\xc9\x2f\x48\x2d\xb6\xe6\x02\x04\x00\x00\xff\xff\x6b\x93\xaa\x08\x48\x00\x00\x00")
+
+func _1557732988_initialize_dbDownSqlBytes() ([]byte, error) {
+	return bindataRead(
+		__1557732988_initialize_dbDownSql,
+		"1557732988_initialize_db.down.sql",
+	)
+}
+
+func _1557732988_initialize_dbDownSql() (*asset, error) {
+	bytes, err := _1557732988_initialize_dbDownSqlBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	info := bindataFileInfo{name: "1557732988_initialize_db.down.sql", size: 72, mode: os.FileMode(420), modTime: time.Unix(1557741108, 0)}
+	a := &asset{bytes: bytes, info: info}
+	return a, nil
+}
+
+var __1557732988_initialize_dbUpSql = []byte("\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff\x72\x0e\x72\x75\x0c\x71\x55\x08\x71\x74\xf2\x71\x55\x48\xcd\x2b\x4b\xcd\xc9\x2f\x48\x2d\x56\xd0\xc8\x4c\x51\x70\x8a\x0c\x71\x75\x54\xf0\xf3\x0f\x51\xf0\x0b\xf5\xf1\x51\x08\xf5\xf3\x0c\x0c\x75\xd5\x51\x48\x49\x2c\x49\x44\x93\xd3\x51\x28\xc9\x2f\xc8\x4c\xc6\x10\x4d\xca\xc9\xcf\xcf\x55\x70\xf2\x0c\xd1\x30\x35\x34\xd2\x84\x4b\x68\x5a\x73\x71\x41\xed\xf5\xf4\x73\x71\x8d\x50\xc8\x4c\x89\x07\x2b\x8d\xcf\x4c\xa9\x50\xf0\xf7\x43\x73\x87\x8b\x6b\xb0\x33\xd4\x2c\x4d\x6b\x0c\x8d\x60\x9b\xf1\x69\x04\x2b\xd0\xb4\xe6\x02\x04\x00\x00\xff\xff\xe2\x06\x6b\x16\xea\x00\x00\x00")
+
+func _1557732988_initialize_dbUpSqlBytes() ([]byte, error) {
+	return bindataRead(
+		__1557732988_initialize_dbUpSql,
+		"1557732988_initialize_db.up.sql",
+	)
+}
+
+func _1557732988_initialize_dbUpSql() (*asset, error) {
+	bytes, err := _1557732988_initialize_dbUpSqlBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	info := bindataFileInfo{name: "1557732988_initialize_db.up.sql", size: 234, mode: os.FileMode(420), modTime: time.Unix(1557742866, 0)}
+	a := &asset{bytes: bytes, info: info}
+	return a, nil
+}
+
+var _staticGo = []byte("\x1f\x8b\x08\x00\x00\x00\x00\x00\x00\xff\x54\x8c\x41\x6a\xc3\x40\x0c\x45\xf7\x73\x8a\xbf\x6c\xa1\x1e\xed\x7b\x82\x52\x12\x08\x24\x17\x90\x6d\x21\x0b\xc7\x33\x46\x52\x72\xfe\x6c\x12\x42\x96\x8f\xc7\x7b\x44\x38\xf1\xb4\xb2\x0a\x22\x39\x6d\x82\x6c\xa3\xcc\xf1\xa2\xaf\xff\xf3\x0f\xfe\x2e\xc7\xc3\x37\x5c\xa2\xdf\x7c\x92\x80\x9b\x2e\x09\x6b\xd9\x91\x8b\x60\xb4\xc6\x6e\x12\x65\xff\x38\x95\x42\xa4\xfd\x57\xa5\x89\x73\x0a\xb4\x0f\xa3\xb5\x99\x93\x31\xec\xab\x62\x33\x75\x4e\xeb\x2d\x30\x74\xd4\x4a\xb5\xd2\xc6\x76\x0d\xf1\xbb\x38\xbd\x35\x3d\xb3\xaa\x1d\xb5\x3c\x02\x00\x00\xff\xff\xf4\xe4\x35\xe2\xb2\x00\x00\x00")
+
+func staticGoBytes() ([]byte, error) {
+	return bindataRead(
+		_staticGo,
+		"static.go",
+	)
+}
+
+func staticGo() (*asset, error) {
+	bytes, err := staticGoBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	info := bindataFileInfo{name: "static.go", size: 178, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
+	a := &asset{bytes: bytes, info: info}
+	return a, nil
+}
+
+// Asset loads and returns the asset for the given name.
+// It returns an error if the asset could not be found or
+// could not be loaded.
+func Asset(name string) ([]byte, error) {
+	cannonicalName := strings.Replace(name, "\\", "/", -1)
+	if f, ok := _bindata[cannonicalName]; ok {
+		a, err := f()
+		if err != nil {
+			return nil, fmt.Errorf("Asset %s can't read by error: %v", name, err)
+		}
+		return a.bytes, nil
+	}
+	return nil, fmt.Errorf("Asset %s not found", name)
+}
+
+// MustAsset is like Asset but panics when Asset would return an error.
+// It simplifies safe initialization of global variables.
+func MustAsset(name string) []byte {
+	a, err := Asset(name)
+	if err != nil {
+		panic("asset: Asset(" + name + "): " + err.Error())
+	}
+
+	return a
+}
+
+// AssetInfo loads and returns the asset info for the given name.
+// It returns an error if the asset could not be found or
+// could not be loaded.
+func AssetInfo(name string) (os.FileInfo, error) {
+	cannonicalName := strings.Replace(name, "\\", "/", -1)
+	if f, ok := _bindata[cannonicalName]; ok {
+		a, err := f()
+		if err != nil {
+			return nil, fmt.Errorf("AssetInfo %s can't read by error: %v", name, err)
+		}
+		return a.info, nil
+	}
+	return nil, fmt.Errorf("AssetInfo %s not found", name)
+}
+
+// AssetNames returns the names of the assets.
+func AssetNames() []string {
+	names := make([]string, 0, len(_bindata))
+	for name := range _bindata {
+		names = append(names, name)
+	}
+	return names
+}
+
+// _bindata is a table, holding each asset generator, mapped to its name.
+var _bindata = map[string]func() (*asset, error){
+	"1557732988_initialize_db.down.sql": _1557732988_initialize_dbDownSql,
+	"1557732988_initialize_db.up.sql": _1557732988_initialize_dbUpSql,
+	"static.go": staticGo,
+}
+
+// AssetDir returns the file names below a certain
+// directory embedded in the file by go-bindata.
+// For example if you run go-bindata on data/... and data contains the
+// following hierarchy:
+//     data/
+//       foo.txt
+//       img/
+//         a.png
+//         b.png
+// then AssetDir("data") would return []string{"foo.txt", "img"}
+// AssetDir("data/img") would return []string{"a.png", "b.png"}
+// AssetDir("foo.txt") and AssetDir("notexist") would return an error
+// AssetDir("") will return []string{"data"}.
+func AssetDir(name string) ([]string, error) {
+	node := _bintree
+	if len(name) != 0 {
+		cannonicalName := strings.Replace(name, "\\", "/", -1)
+		pathList := strings.Split(cannonicalName, "/")
+		for _, p := range pathList {
+			node = node.Children[p]
+			if node == nil {
+				return nil, fmt.Errorf("Asset %s not found", name)
+			}
+		}
+	}
+	if node.Func != nil {
+		return nil, fmt.Errorf("Asset %s not found", name)
+	}
+	rv := make([]string, 0, len(node.Children))
+	for childName := range node.Children {
+		rv = append(rv, childName)
+	}
+	return rv, nil
+}
+
+type bintree struct {
+	Func     func() (*asset, error)
+	Children map[string]*bintree
+}
+var _bintree = &bintree{nil, map[string]*bintree{
+	"1557732988_initialize_db.down.sql": &bintree{_1557732988_initialize_dbDownSql, map[string]*bintree{}},
+	"1557732988_initialize_db.up.sql": &bintree{_1557732988_initialize_dbUpSql, map[string]*bintree{}},
+	"static.go": &bintree{staticGo, map[string]*bintree{}},
+}}
+
+// RestoreAsset restores an asset under the given directory
+func RestoreAsset(dir, name string) error {
+	data, err := Asset(name)
+	if err != nil {
+		return err
+	}
+	info, err := AssetInfo(name)
+	if err != nil {
+		return err
+	}
+	err = os.MkdirAll(_filePath(dir, filepath.Dir(name)), os.FileMode(0755))
+	if err != nil {
+		return err
+	}
+	err = ioutil.WriteFile(_filePath(dir, name), data, info.Mode())
+	if err != nil {
+		return err
+	}
+	err = os.Chtimes(_filePath(dir, name), info.ModTime(), info.ModTime())
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// RestoreAssets restores an asset under the given directory recursively
+func RestoreAssets(dir, name string) error {
+	children, err := AssetDir(name)
+	// File
+	if err != nil {
+		return RestoreAsset(dir, name)
+	}
+	// Dir
+	for _, child := range children {
+		err = RestoreAssets(dir, filepath.Join(name, child))
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func _filePath(dir, name string) string {
+	cannonicalName := strings.Replace(name, "\\", "/", -1)
+	return filepath.Join(append([]string{dir}, strings.Split(cannonicalName, "/")...)...)
+}
+

params/config.go

@@ -85,6 +85,20 @@ type WhisperConfig struct {
 	// MaxMessageSize is a maximum size of a devp2p packet handled by the Whisper protocol,
 	// not only the size of envelopes sent in that packet.
 	MaxMessageSize uint32
+
+	// DatabaseConfig is configuration for which datastore we use
+	DatabaseConfig DatabaseConfig
+}
+
+type DatabaseConfig struct {
+	PGConfig PGConfig
+}
+
+type PGConfig struct {
+	// Enabled whether we should use a posgres instance
+	Enabled bool
+	// The URI of the server
+	URI string
 }
 
 // String dumps config object as nicely indented JSON

services/shhext/chat/migrations/bindata.go

@@ -91,7 +91,7 @@ func _1536754952_initial_schemaDownSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1536754952_initial_schema.down.sql", size: 83, mode: os.FileMode(420), modTime: time.Unix(1541418081, 0)}
+	info := bindataFileInfo{name: "1536754952_initial_schema.down.sql", size: 83, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -111,7 +111,7 @@ func _1536754952_initial_schemaUpSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1536754952_initial_schema.up.sql", size: 962, mode: os.FileMode(420), modTime: time.Unix(1541418081, 0)}
+	info := bindataFileInfo{name: "1536754952_initial_schema.up.sql", size: 962, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -131,7 +131,7 @@ func _1539249977_update_ratchet_infoDownSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1539249977_update_ratchet_info.down.sql", size: 311, mode: os.FileMode(420), modTime: time.Unix(1543402727, 0)}
+	info := bindataFileInfo{name: "1539249977_update_ratchet_info.down.sql", size: 311, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -151,7 +151,7 @@ func _1539249977_update_ratchet_infoUpSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1539249977_update_ratchet_info.up.sql", size: 368, mode: os.FileMode(420), modTime: time.Unix(1543402727, 0)}
+	info := bindataFileInfo{name: "1539249977_update_ratchet_info.up.sql", size: 368, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -171,7 +171,7 @@ func _1540715431_add_versionDownSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1540715431_add_version.down.sql", size: 127, mode: os.FileMode(420), modTime: time.Unix(1543402867, 0)}
+	info := bindataFileInfo{name: "1540715431_add_version.down.sql", size: 127, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -191,7 +191,7 @@ func _1540715431_add_versionUpSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1540715431_add_version.up.sql", size: 265, mode: os.FileMode(420), modTime: time.Unix(1543402867, 0)}
+	info := bindataFileInfo{name: "1540715431_add_version.up.sql", size: 265, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -211,7 +211,7 @@ func _1541164797_add_installationsDownSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1541164797_add_installations.down.sql", size: 26, mode: os.FileMode(420), modTime: time.Unix(1543402888, 0)}
+	info := bindataFileInfo{name: "1541164797_add_installations.down.sql", size: 26, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -231,7 +231,7 @@ func _1541164797_add_installationsUpSql() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "1541164797_add_installations.up.sql", size: 216, mode: os.FileMode(420), modTime: time.Unix(1543402888, 0)}
+	info := bindataFileInfo{name: "1541164797_add_installations.up.sql", size: 216, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }
@@ -251,7 +251,7 @@ func staticGo() (*asset, error) {
 		return nil, err
 	}
 
-	info := bindataFileInfo{name: "static.go", size: 188, mode: os.FileMode(420), modTime: time.Unix(1541418081, 0)}
+	info := bindataFileInfo{name: "static.go", size: 188, mode: os.FileMode(420), modTime: time.Unix(1557739557, 0)}
 	a := &asset{bytes: bytes, info: info}
 	return a, nil
 }

static/mailserver_db_migrations/1557732988_initialize_db.down.sql

@@ -0,0 +1,3 @@
+DROP INDEX id_bloom_idx;
+DROP INDEX id_topic_idx;
+DROP TABLE envelopes;

static/mailserver_db_migrations/1557732988_initialize_db.up.sql

@@ -0,0 +1,4 @@
+CREATE TABLE envelopes (id BYTEA NOT NULL UNIQUE, data BYTEA NOT NULL, topic BYTEA NOT NULL, bloom BIT(512) NOT NULL);
+
+CREATE INDEX id_bloom_idx ON envelopes (id DESC, bloom);
+CREATE INDEX id_topic_idx ON envelopes (id DESC, topic);

static/mailserver_db_migrations/static.go

@@ -0,0 +1,4 @@
+// Package static embeds static (JS, HTML) resources right into the binaries
+package static
+
+//go:generate go-bindata -pkg migrations -o ../../mailserver/migrations/bindata.go .

vendor/github.com/lib/pq/LICENSE.md

@@ -0,0 +1,8 @@
+Copyright (c) 2011-2013, 'pq' Contributors
+Portions Copyright (C) 2011 Blake Mizerany
+
+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/lib/pq/array.go

@@ -0,0 +1,756 @@
+package pq
+
+import (
+	"bytes"
+	"database/sql"
+	"database/sql/driver"
+	"encoding/hex"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+var typeByteSlice = reflect.TypeOf([]byte{})
+var typeDriverValuer = reflect.TypeOf((*driver.Valuer)(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.
+//
+// For example:
+//  db.Query(`SELECT * FROM t WHERE id = ANY($1)`, pq.Array([]int{235, 401}))
+//
+//  var x []sql.NullInt64
+//  db.QueryRow('SELECT ARRAY[235, 401]').Scan(pq.Array(&x))
+//
+// Scanning multi-dimensional arrays is not supported.  Arrays where the lower
+// bound is not one (such as `[0:0]={1}') are not supported.
+func Array(a interface{}) interface {
+	driver.Valuer
+	sql.Scanner
+} {
+	switch a := a.(type) {
+	case []bool:
+		return (*BoolArray)(&a)
+	case []float64:
+		return (*Float64Array)(&a)
+	case []int64:
+		return (*Int64Array)(&a)
+	case []string:
+		return (*StringArray)(&a)
+
+	case *[]bool:
+		return (*BoolArray)(a)
+	case *[]float64:
+		return (*Float64Array)(a)
+	case *[]int64:
+		return (*Int64Array)(a)
+	case *[]string:
+		return (*StringArray)(a)
+	}
+
+	return GenericArray{a}
+}
+
+// ArrayDelimiter may be optionally implemented by driver.Valuer or sql.Scanner
+// to override the array delimiter used by GenericArray.
+type ArrayDelimiter interface {
+	// ArrayDelimiter returns the delimiter character(s) for this element's type.
+	ArrayDelimiter() string
+}
+
+// BoolArray represents a one-dimensional array of the PostgreSQL boolean type.
+type BoolArray []bool
+
+// Scan implements the sql.Scanner interface.
+func (a *BoolArray) Scan(src interface{}) error {
+	switch src := src.(type) {
+	case []byte:
+		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)
+}
+
+func (a *BoolArray) scanBytes(src []byte) error {
+	elems, err := scanLinearArray(src, []byte{','}, "BoolArray")
+	if err != nil {
+		return err
+	}
+	if *a != nil && len(elems) == 0 {
+		*a = (*a)[:0]
+	} else {
+		b := make(BoolArray, len(elems))
+		for i, v := range elems {
+			if len(v) != 1 {
+				return fmt.Errorf("pq: could not parse boolean array index %d: invalid boolean %q", i, v)
+			}
+			switch v[0] {
+			case 't':
+				b[i] = true
+			case 'f':
+				b[i] = false
+			default:
+				return fmt.Errorf("pq: could not parse boolean array index %d: invalid boolean %q", i, v)
+			}
+		}
+		*a = b
+	}
+	return nil
+}
+
+// Value implements the driver.Valuer interface.
+func (a BoolArray) Value() (driver.Value, error) {
+	if a == nil {
+		return nil, nil
+	}
+
+	if n := len(a); n > 0 {
+		// There will be exactly two curly brackets, N bytes of values,
+		// and N-1 bytes of delimiters.
+		b := make([]byte, 1+2*n)
+
+		for i := 0; i < n; i++ {
+			b[2*i] = ','
+			if a[i] {
+				b[1+2*i] = 't'
+			} else {
+				b[1+2*i] = 'f'
+			}
+		}
+
+		b[0] = '{'
+		b[2*n] = '}'
+
+		return string(b), nil
+	}
+
+	return "{}", nil
+}
+
+// ByteaArray represents a one-dimensional array of the PostgreSQL bytea type.
+type ByteaArray [][]byte
+
+// Scan implements the sql.Scanner interface.
+func (a *ByteaArray) Scan(src interface{}) error {
+	switch src := src.(type) {
+	case []byte:
+		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)
+}
+
+func (a *ByteaArray) scanBytes(src []byte) error {
+	elems, err := scanLinearArray(src, []byte{','}, "ByteaArray")
+	if err != nil {
+		return err
+	}
+	if *a != nil && len(elems) == 0 {
+		*a = (*a)[:0]
+	} else {
+		b := make(ByteaArray, len(elems))
+		for i, v := range elems {
+			b[i], err = parseBytea(v)
+			if err != nil {
+				return fmt.Errorf("could not parse bytea array index %d: %s", i, err.Error())
+			}
+		}
+		*a = b
+	}
+	return nil
+}
+
+// Value implements the driver.Valuer interface. It uses the "hex" format which
+// is only supported on PostgreSQL 9.0 or newer.
+func (a ByteaArray) Value() (driver.Value, error) {
+	if a == nil {
+		return nil, nil
+	}
+
+	if n := len(a); n > 0 {
+		// There will be at least two curly brackets, 2*N bytes of quotes,
+		// 3*N bytes of hex formatting, and N-1 bytes of delimiters.
+		size := 1 + 6*n
+		for _, x := range a {
+			size += hex.EncodedLen(len(x))
+		}
+
+		b := make([]byte, size)
+
+		for i, s := 0, b; i < n; i++ {
+			o := copy(s, `,"\\x`)
+			o += hex.Encode(s[o:], a[i])
+			s[o] = '"'
+			s = s[o+1:]
+		}
+
+		b[0] = '{'
+		b[size-1] = '}'
+
+		return string(b), nil
+	}
+
+	return "{}", nil
+}
+
+// Float64Array represents a one-dimensional array of the PostgreSQL double
+// precision type.
+type Float64Array []float64
+
+// Scan implements the sql.Scanner interface.
+func (a *Float64Array) Scan(src interface{}) error {
+	switch src := src.(type) {
+	case []byte:
+		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)
+}
+
+func (a *Float64Array) scanBytes(src []byte) error {
+	elems, err := scanLinearArray(src, []byte{','}, "Float64Array")
+	if err != nil {
+		return err
+	}
+	if *a != nil && len(elems) == 0 {
+		*a = (*a)[:0]
+	} else {
+		b := make(Float64Array, len(elems))
+		for i, v := range elems {
+			if b[i], err = strconv.ParseFloat(string(v), 64); err != nil {
+				return fmt.Errorf("pq: parsing array element index %d: %v", i, err)
+			}
+		}
+		*a = b
+	}
+	return nil
+}
+
+// Value implements the driver.Valuer interface.
+func (a Float64Array) Value() (driver.Value, error) {
+	if a == nil {
+		return nil, nil
+	}
+
+	if n := len(a); n > 0 {
+		// There will be at least two curly brackets, N bytes of values,
+		// and N-1 bytes of delimiters.
+		b := make([]byte, 1, 1+2*n)
+		b[0] = '{'
+
+		b = strconv.AppendFloat(b, a[0], 'f', -1, 64)
+		for i := 1; i < n; i++ {
+			b = append(b, ',')
+			b = strconv.AppendFloat(b, a[i], 'f', -1, 64)
+		}
+
+		return string(append(b, '}')), nil
+	}
+
+	return "{}", nil
+}
+
+// GenericArray implements the driver.Valuer and sql.Scanner interfaces for
+// an array or slice of any dimension.
+type GenericArray struct{ A interface{} }
+
+func (GenericArray) evaluateDestination(rt reflect.Type) (reflect.Type, func([]byte, reflect.Value) error, string) {
+	var assign func([]byte, reflect.Value) error
+	var del = ","
+
+	// 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) {
+			// 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)
+				if src == nil {
+					err = ss.Scan(nil)
+				} else {
+					err = ss.Scan(src)
+				}
+				return
+			}
+			goto FoundType
+		}
+
+		assign = func([]byte, reflect.Value) error {
+			return fmt.Errorf("pq: scanning to %s is not implemented; only sql.Scanner", rt)
+		}
+	}
+
+FoundType:
+
+	if ad, ok := reflect.Zero(rt).Interface().(ArrayDelimiter); ok {
+		del = ad.ArrayDelimiter()
+	}
+
+	return rt, assign, del
+}
+
+// Scan implements the sql.Scanner interface.
+func (a GenericArray) Scan(src interface{}) error {
+	dpv := reflect.ValueOf(a.A)
+	switch {
+	case dpv.Kind() != reflect.Ptr:
+		return fmt.Errorf("pq: destination %T is not a pointer to array or slice", a.A)
+	case dpv.IsNil():
+		return fmt.Errorf("pq: destination %T is nil", a.A)
+	}
+
+	dv := dpv.Elem()
+	switch dv.Kind() {
+	case reflect.Slice:
+	case reflect.Array:
+	default:
+		return fmt.Errorf("pq: destination %T is not a pointer to array or slice", a.A)
+	}
+
+	switch src := src.(type) {
+	case []byte:
+		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())
+}
+
+func (a GenericArray) scanBytes(src []byte, dv reflect.Value) error {
+	dtype, assign, del := a.evaluateDestination(dv.Type().Elem())
+	dims, elems, err := parseArray(src, []byte(del))
+	if err != nil {
+		return err
+	}
+
+	// TODO allow multidimensional
+
+	if len(dims) > 1 {
+		return fmt.Errorf("pq: scanning from multidimensional ARRAY%s is not implemented",
+			strings.Replace(fmt.Sprint(dims), " ", "][", -1))
+	}
+
+	// Treat a zero-dimensional array like an array with a single dimension of zero.
+	if len(dims) == 0 {
+		dims = append(dims, 0)
+	}
+
+	for i, rt := 0, dv.Type(); i < len(dims); i, rt = i+1, rt.Elem() {
+		switch rt.Kind() {
+		case reflect.Slice:
+		case reflect.Array:
+			if rt.Len() != dims[i] {
+				return fmt.Errorf("pq: cannot convert ARRAY%s to %s",
+					strings.Replace(fmt.Sprint(dims), " ", "][", -1), dv.Type())
+			}
+		default:
+			// TODO handle multidimensional
+		}
+	}
+
+	values := reflect.MakeSlice(reflect.SliceOf(dtype), len(elems), len(elems))
+	for i, e := range elems {
+		if err := assign(e, values.Index(i)); err != nil {
+			return fmt.Errorf("pq: parsing array element index %d: %v", i, err)
+		}
+	}
+
+	// TODO handle multidimensional
+
+	switch dv.Kind() {
+	case reflect.Slice:
+		dv.Set(values.Slice(0, dims[0]))
+	case reflect.Array:
+		for i := 0; i < dims[0]; i++ {
+			dv.Index(i).Set(values.Index(i))
+		}
+	}
+
+	return nil
+}
+
+// Value implements the driver.Valuer interface.
+func (a GenericArray) Value() (driver.Value, error) {
+	if a.A == nil {
+		return nil, nil
+	}
+
+	rv := reflect.ValueOf(a.A)
+
+	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)
+	}
+
+	if n := rv.Len(); n > 0 {
+		// There will be at least two curly brackets, N bytes of values,
+		// and N-1 bytes of delimiters.
+		b := make([]byte, 0, 1+2*n)
+
+		b, _, err := appendArray(b, rv, n)
+		return string(b), err
+	}
+
+	return "{}", nil
+}
+
+// Int64Array represents a one-dimensional array of the PostgreSQL integer types.
+type Int64Array []int64
+
+// Scan implements the sql.Scanner interface.
+func (a *Int64Array) Scan(src interface{}) error {
+	switch src := src.(type) {
+	case []byte:
+		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)
+}
+
+func (a *Int64Array) scanBytes(src []byte) error {
+	elems, err := scanLinearArray(src, []byte{','}, "Int64Array")
+	if err != nil {
+		return err
+	}
+	if *a != nil && len(elems) == 0 {
+		*a = (*a)[:0]
+	} else {
+		b := make(Int64Array, len(elems))
+		for i, v := range elems {
+			if b[i], err = strconv.ParseInt(string(v), 10, 64); err != nil {
+				return fmt.Errorf("pq: parsing array element index %d: %v", i, err)
+			}
+		}
+		*a = b
+	}
+	return nil
+}
+
+// Value implements the driver.Valuer interface.
+func (a Int64Array) Value() (driver.Value, error) {
+	if a == nil {
+		return nil, nil
+	}
+
+	if n := len(a); n > 0 {
+		// There will be at least two curly brackets, N bytes of values,
+		// and N-1 bytes of delimiters.
+		b := make([]byte, 1, 1+2*n)
+		b[0] = '{'
+
+		b = strconv.AppendInt(b, a[0], 10)
+		for i := 1; i < n; i++ {
+			b = append(b, ',')
+			b = strconv.AppendInt(b, a[i], 10)
+		}
+
+		return string(append(b, '}')), nil
+	}
+
+	return "{}", nil
+}
+
+// StringArray represents a one-dimensional array of the PostgreSQL character types.
+type StringArray []string
+
+// Scan implements the sql.Scanner interface.
+func (a *StringArray) Scan(src interface{}) error {
+	switch src := src.(type) {
+	case []byte:
+		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)
+}
+
+func (a *StringArray) scanBytes(src []byte) error {
+	elems, err := scanLinearArray(src, []byte{','}, "StringArray")
+	if err != nil {
+		return err
+	}
+	if *a != nil && len(elems) == 0 {
+		*a = (*a)[:0]
+	} else {
+		b := make(StringArray, len(elems))
+		for i, v := range elems {
+			if b[i] = string(v); v == nil {
+				return fmt.Errorf("pq: parsing array element index %d: cannot convert nil to string", i)
+			}
+		}
+		*a = b
+	}
+	return nil
+}
+
+// Value implements the driver.Valuer interface.
+func (a StringArray) Value() (driver.Value, error) {
+	if a == nil {
+		return nil, nil
+	}
+
+	if n := len(a); n > 0 {
+		// There will be at least two curly brackets, 2*N bytes of quotes,
+		// and N-1 bytes of delimiters.
+		b := make([]byte, 1, 1+3*n)
+		b[0] = '{'
+
+		b = appendArrayQuotedBytes(b, []byte(a[0]))
+		for i := 1; i < n; i++ {
+			b = append(b, ',')
+			b = appendArrayQuotedBytes(b, []byte(a[i]))
+		}
+
+		return string(append(b, '}')), nil
+	}
+
+	return "{}", nil
+}
+
+// appendArray appends rv to the buffer, returning the extended buffer and
+// the delimiter used between elements.
+//
+// It panics when n <= 0 or rv's Kind is not reflect.Array nor reflect.Slice.
+func appendArray(b []byte, rv reflect.Value, n int) ([]byte, string, error) {
+	var del string
+	var err error
+
+	b = append(b, '{')
+
+	if b, del, err = appendArrayElement(b, rv.Index(0)); err != nil {
+		return b, del, err
+	}
+
+	for i := 1; i < n; i++ {
+		b = append(b, del...)
+		if b, del, err = appendArrayElement(b, rv.Index(i)); err != nil {
+			return b, del, err
+		}
+	}
+
+	return append(b, '}'), del, nil
+}
+
+// appendArrayElement appends rv to the buffer, returning the extended buffer
+// and the delimiter to use before the next element.
+//
+// When rv's Kind is neither reflect.Array nor reflect.Slice, it is converted
+// using driver.DefaultParameterConverter and the resulting []byte or string
+// is double-quoted.
+//
+// See http://www.postgresql.org/docs/current/static/arrays.html#ARRAYS-IO
+func appendArrayElement(b []byte, rv reflect.Value) ([]byte, string, error) {
+	if k := rv.Kind(); k == reflect.Array || k == reflect.Slice {
+		if t := rv.Type(); t != typeByteSlice && !t.Implements(typeDriverValuer) {
+			if n := rv.Len(); n > 0 {
+				return appendArray(b, rv, n)
+			}
+
+			return b, "", nil
+		}
+	}
+
+	var del = ","
+	var err error
+	var iv interface{} = rv.Interface()
+
+	if ad, ok := iv.(ArrayDelimiter); ok {
+		del = ad.ArrayDelimiter()
+	}
+
+	if iv, err = driver.DefaultParameterConverter.ConvertValue(iv); err != nil {
+		return b, del, err
+	}
+
+	switch v := iv.(type) {
+	case nil:
+		return append(b, "NULL"...), del, nil
+	case []byte:
+		return appendArrayQuotedBytes(b, v), del, nil
+	case string:
+		return appendArrayQuotedBytes(b, []byte(v)), del, nil
+	}
+
+	b, err = appendValue(b, iv)
+	return b, del, err
+}
+
+func appendArrayQuotedBytes(b, v []byte) []byte {
+	b = append(b, '"')
+	for {
+		i := bytes.IndexAny(v, `"\`)
+		if i < 0 {
+			b = append(b, v...)
+			break
+		}
+		if i > 0 {
+			b = append(b, v[:i]...)
+		}
+		b = append(b, '\\', v[i])
+		v = v[i+1:]
+	}
+	return append(b, '"')
+}
+
+func appendValue(b []byte, v driver.Value) ([]byte, error) {
+	return append(b, encode(nil, v, 0)...), nil
+}
+
+// parseArray extracts the dimensions and elements of an array represented in
+// text format. Only representations emitted by the backend are supported.
+// Notably, whitespace around brackets and delimiters is significant, and NULL
+// is case-sensitive.
+//
+// See http://www.postgresql.org/docs/current/static/arrays.html#ARRAYS-IO
+func parseArray(src, del []byte) (dims []int, elems [][]byte, err error) {
+	var depth, i int
+
+	if len(src) < 1 || src[0] != '{' {
+		return nil, nil, fmt.Errorf("pq: unable to parse array; expected %q at offset %d", '{', 0)
+	}
+
+Open:
+	for i < len(src) {
+		switch src[i] {
+		case '{':
+			depth++
+			i++
+		case '}':
+			elems = make([][]byte, 0)
+			goto Close
+		default:
+			break Open
+		}
+	}
+	dims = make([]int, i)
+
+Element:
+	for i < len(src) {
+		switch src[i] {
+		case '{':
+			if depth == len(dims) {
+				break Element
+			}
+			depth++
+			dims[depth-1] = 0
+			i++
+		case '"':
+			var elem = []byte{}
+			var escape bool
+			for i++; i < len(src); i++ {
+				if escape {
+					elem = append(elem, src[i])
+					escape = false
+				} else {
+					switch src[i] {
+					default:
+						elem = append(elem, src[i])
+					case '\\':
+						escape = true
+					case '"':
+						elems = append(elems, elem)
+						i++
+						break Element
+					}
+				}
+			}
+		default:
+			for start := i; i < len(src); i++ {
+				if bytes.HasPrefix(src[i:], del) || src[i] == '}' {
+					elem := src[start:i]
+					if len(elem) == 0 {
+						return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i)
+					}
+					if bytes.Equal(elem, []byte("NULL")) {
+						elem = nil
+					}
+					elems = append(elems, elem)
+					break Element
+				}
+			}
+		}
+	}
+
+	for i < len(src) {
+		if bytes.HasPrefix(src[i:], del) && depth > 0 {
+			dims[depth-1]++
+			i += len(del)
+			goto Element
+		} else if src[i] == '}' && depth > 0 {
+			dims[depth-1]++
+			depth--
+			i++
+		} else {
+			return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i)
+		}
+	}
+
+Close:
+	for i < len(src) {
+		if src[i] == '}' && depth > 0 {
+			depth--
+			i++
+		} else {
+			return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i)
+		}
+	}
+	if depth > 0 {
+		err = fmt.Errorf("pq: unable to parse array; expected %q at offset %d", '}', i)
+	}
+	if err == nil {
+		for _, d := range dims {
+			if (len(elems) % d) != 0 {
+				err = fmt.Errorf("pq: multidimensional arrays must have elements with matching dimensions")
+			}
+		}
+	}
+	return
+}
+
+func scanLinearArray(src, del []byte, typ string) (elems [][]byte, err error) {
+	dims, elems, err := parseArray(src, del)
+	if err != nil {
+		return nil, err
+	}
+	if len(dims) > 1 {
+		return nil, fmt.Errorf("pq: cannot convert ARRAY%s to %s", strings.Replace(fmt.Sprint(dims), " ", "][", -1), typ)
+	}
+	return elems, err
+}

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

@@ -0,0 +1,91 @@
+package pq
+
+import (
+	"bytes"
+	"encoding/binary"
+
+	"github.com/lib/pq/oid"
+)
+
+type readBuf []byte
+
+func (b *readBuf) int32() (n int) {
+	n = int(int32(binary.BigEndian.Uint32(*b)))
+	*b = (*b)[4:]
+	return
+}
+
+func (b *readBuf) oid() (n oid.Oid) {
+	n = oid.Oid(binary.BigEndian.Uint32(*b))
+	*b = (*b)[4:]
+	return
+}
+
+// N.B: this is actually an unsigned 16-bit integer, unlike int32
+func (b *readBuf) int16() (n int) {
+	n = int(binary.BigEndian.Uint16(*b))
+	*b = (*b)[2:]
+	return
+}
+
+func (b *readBuf) string() string {
+	i := bytes.IndexByte(*b, 0)
+	if i < 0 {
+		errorf("invalid message format; expected string terminator")
+	}
+	s := (*b)[:i]
+	*b = (*b)[i+1:]
+	return string(s)
+}
+
+func (b *readBuf) next(n int) (v []byte) {
+	v = (*b)[:n]
+	*b = (*b)[n:]
+	return
+}
+
+func (b *readBuf) byte() byte {
+	return b.next(1)[0]
+}
+
+type writeBuf struct {
+	buf []byte
+	pos int
+}
+
+func (b *writeBuf) int32(n int) {
+	x := make([]byte, 4)
+	binary.BigEndian.PutUint32(x, uint32(n))
+	b.buf = append(b.buf, x...)
+}
+
+func (b *writeBuf) int16(n int) {
+	x := make([]byte, 2)
+	binary.BigEndian.PutUint16(x, uint16(n))
+	b.buf = append(b.buf, x...)
+}
+
+func (b *writeBuf) string(s string) {
+	b.buf = append(b.buf, (s + "\000")...)
+}
+
+func (b *writeBuf) byte(c byte) {
+	b.buf = append(b.buf, c)
+}
+
+func (b *writeBuf) bytes(v []byte) {
+	b.buf = append(b.buf, v...)
+}
+
+func (b *writeBuf) wrap() []byte {
+	p := b.buf[b.pos:]
+	binary.BigEndian.PutUint32(p, uint32(len(p)))
+	return b.buf
+}
+
+func (b *writeBuf) next(c byte) {
+	p := b.buf[b.pos:]
+	binary.BigEndian.PutUint32(p, uint32(len(p)))
+	b.pos = len(b.buf) + 1
+	b.buf = append(b.buf, c, 0, 0, 0, 0)
+}

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

@@ -0,0 +1,149 @@
+package pq
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"time"
+)
+
+// 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) Ping(ctx context.Context) error {
+	if finish := cn.watchCancel(ctx); finish != nil {
+		defer finish()
+	}
+	rows, err := cn.simpleQuery("SELECT 'lib/pq ping test';")
+	if err != nil {
+		return driver.ErrBadConn // https://golang.org/pkg/database/sql/driver/#Pinger
+	}
+	rows.Close()
+	return nil
+}
+
+func (cn *conn) watchCancel(ctx context.Context) func() {
+	if done := ctx.Done(); done != nil {
+		finished := make(chan struct{})
+		go func() {
+			select {
+			case <-done:
+				// At this point the function level context is canceled,
+				// so it must not be used for the additional network
+				// request to cancel the query.
+				// Create a new context to pass into the dial.
+				ctxCancel, cancel := context.WithTimeout(context.Background(), time.Second*10)
+				defer cancel()
+
+				_ = cn.cancel(ctxCancel)
+				finished <- struct{}{}
+			case <-finished:
+			}
+		}()
+		return func() {
+			select {
+			case <-finished:
+			case finished <- struct{}{}:
+			}
+		}
+	}
+	return nil
+}
+
+func (cn *conn) cancel(ctx context.Context) error {
+	c, err := dial(ctx, 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 +1,110 @@
+package pq
+
+import (
+	"context"
+	"database/sql/driver"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// 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 {
+	opts   values
+	dialer Dialer
+}
+
+// Connect returns a connection to the database using the fixed configuration
+// of this Connector. Context is not used.
+func (c *Connector) Connect(ctx context.Context) (driver.Conn, error) {
+	return c.open(ctx)
+}
+
+// Driver returnst the underlying driver of this Connector.
+func (c *Connector) Driver() driver.Driver {
+	return &Driver{}
+}
+
+// NewConnector returns a connector for the pq driver in a fixed configuration
+// with the given dsn. 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(dsn string) (*Connector, error) {
+	var err error
+	o := make(values)
+
+	// A number of defaults are applied here, in this order:
+	//
+	// * Very low precedence defaults applied in every situation
+	// * Environment variables
+	// * Explicitly passed connection information
+	o["host"] = "localhost"
+	o["port"] = "5432"
+	// N.B.: Extra float digits should be set to 3, but that breaks
+	// Postgres 8.4 and older, where the max is 2.
+	o["extra_float_digits"] = "2"
+	for k, v := range parseEnviron(os.Environ()) {
+		o[k] = v
+	}
+
+	if strings.HasPrefix(dsn, "postgres://") || strings.HasPrefix(dsn, "postgresql://") {
+		dsn, err = ParseURL(dsn)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if err := parseOpts(dsn, o); err != nil {
+		return nil, err
+	}
+
+	// Use the "fallback" application name if necessary
+	if fallback, ok := o["fallback_application_name"]; ok {
+		if _, ok := o["application_name"]; !ok {
+			o["application_name"] = fallback
+		}
+	}
+
+	// We can't work with any client_encoding other than UTF-8 currently.
+	// However, we have historically allowed the user to set it to UTF-8
+	// explicitly, and there's no reason to break such programs, so allow that.
+	// Note that the "options" setting could also set client_encoding, but
+	// parsing its value is not worth it.  Instead, we always explicitly send
+	// client_encoding as a separate run-time parameter, which should override
+	// anything set in options.
+	if enc, ok := o["client_encoding"]; ok && !isUTF8(enc) {
+		return nil, errors.New("client_encoding must be absent or 'UTF8'")
+	}
+	o["client_encoding"] = "UTF8"
+	// DateStyle needs a similar treatment.
+	if datestyle, ok := o["datestyle"]; ok {
+		if datestyle != "ISO, MDY" {
+			return nil, fmt.Errorf("setting datestyle must be absent or %v; got %v", "ISO, MDY", datestyle)
+		}
+	} else {
+		o["datestyle"] = "ISO, MDY"
+	}
+
+	// If a user is not provided by any other means, the last
+	// resort is to use the current operating system provided user
+	// name.
+	if _, ok := o["user"]; !ok {
+		u, err := userCurrent()
+		if err != nil {
+			return nil, err
+		}
+		o["user"] = u
+	}
+
+	return &Connector{opts: o, dialer: defaultDialer{}}, nil
+}

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

@@ -0,0 +1,282 @@
+package pq
+
+import (
+	"database/sql/driver"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"sync"
+)
+
+var (
+	errCopyInClosed               = errors.New("pq: copyin statement has already been closed")
+	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
+// Tx.Prepare().  The target table should be visible in search_path.
+func CopyIn(table string, columns ...string) string {
+	stmt := "COPY " + QuoteIdentifier(table) + " ("
+	for i, col := range columns {
+		if i != 0 {
+			stmt += ", "
+		}
+		stmt += QuoteIdentifier(col)
+	}
+	stmt += ") FROM STDIN"
+	return stmt
+}
+
+// CopyInSchema creates a COPY FROM statement which can be prepared with
+// Tx.Prepare().
+func CopyInSchema(schema, table string, columns ...string) string {
+	stmt := "COPY " + QuoteIdentifier(schema) + "." + QuoteIdentifier(table) + " ("
+	for i, col := range columns {
+		if i != 0 {
+			stmt += ", "
+		}
+		stmt += QuoteIdentifier(col)
+	}
+	stmt += ") FROM STDIN"
+	return stmt
+}
+
+type copyin struct {
+	cn      *conn
+	buffer  []byte
+	rowData chan []byte
+	done    chan bool
+
+	closed bool
+
+	sync.Mutex // guards err
+	err        error
+}
+
+const ciBufferSize = 64 * 1024
+
+// flush buffer before the buffer is filled up and needs reallocation
+const ciBufferFlushSize = 63 * 1024
+
+func (cn *conn) prepareCopyIn(q string) (_ driver.Stmt, err error) {
+	if !cn.isInTransaction() {
+		return nil, errCopyNotSupportedOutsideTxn
+	}
+
+	ci := &copyin{
+		cn:      cn,
+		buffer:  make([]byte, 0, ciBufferSize),
+		rowData: make(chan []byte),
+		done:    make(chan bool, 1),
+	}
+	// add CopyData identifier + 4 bytes for message length
+	ci.buffer = append(ci.buffer, 'd', 0, 0, 0, 0)
+
+	b := cn.writeBuf('Q')
+	b.string(q)
+	cn.send(b)
+
+awaitCopyInResponse:
+	for {
+		t, r := cn.recv1()
+		switch t {
+		case 'G':
+			if r.byte() != 0 {
+				err = errBinaryCopyNotSupported
+				break awaitCopyInResponse
+			}
+			go ci.resploop()
+			return ci, nil
+		case 'H':
+			err = errCopyToNotSupported
+			break awaitCopyInResponse
+		case 'E':
+			err = parseError(r)
+		case 'Z':
+			if err == nil {
+				ci.setBad()
+				errorf("unexpected ReadyForQuery in response to COPY")
+			}
+			cn.processReadyForQuery(r)
+			return nil, err
+		default:
+			ci.setBad()
+			errorf("unknown response for copy query: %q", t)
+		}
+	}
+
+	// something went wrong, abort COPY before we return
+	b = cn.writeBuf('f')
+	b.string(err.Error())
+	cn.send(b)
+
+	for {
+		t, r := cn.recv1()
+		switch t {
+		case 'c', 'C', 'E':
+		case 'Z':
+			// correctly aborted, we're done
+			cn.processReadyForQuery(r)
+			return nil, err
+		default:
+			ci.setBad()
+			errorf("unknown response for CopyFail: %q", t)
+		}
+	}
+}
+
+func (ci *copyin) flush(buf []byte) {
+	// set message length (without message identifier)
+	binary.BigEndian.PutUint32(buf[1:], uint32(len(buf)-1))
+
+	_, err := ci.cn.c.Write(buf)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func (ci *copyin) resploop() {
+	for {
+		var r readBuf
+		t, err := ci.cn.recvMessage(&r)
+		if err != nil {
+			ci.setBad()
+			ci.setError(err)
+			ci.done <- true
+			return
+		}
+		switch t {
+		case 'C':
+			// complete
+		case 'N':
+			// NoticeResponse
+		case 'Z':
+			ci.cn.processReadyForQuery(&r)
+			ci.done <- true
+			return
+		case 'E':
+			err := parseError(&r)
+			ci.setError(err)
+		default:
+			ci.setBad()
+			ci.setError(fmt.Errorf("unknown response during CopyIn: %q", t))
+			ci.done <- true
+			return
+		}
+	}
+}
+
+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)
+	ci.Unlock()
+	return isSet
+}
+
+// setError() sets ci.err if one has not been set already.  Caller must not be
+// holding ci.Mutex.
+func (ci *copyin) setError(err error) {
+	ci.Lock()
+	if ci.err == nil {
+		ci.err = err
+	}
+	ci.Unlock()
+}
+
+func (ci *copyin) NumInput() int {
+	return -1
+}
+
+func (ci *copyin) Query(v []driver.Value) (r driver.Rows, err error) {
+	return nil, ErrNotSupported
+}
+
+// Exec inserts values into the COPY stream. The insert is asynchronous
+// and Exec can return errors from previous Exec calls to the same
+// COPY stmt.
+//
+// You need to call Exec(nil) to sync the COPY stream and to get any
+// errors from pending data, since Stmt.Close() doesn't return errors
+// to the user.
+func (ci *copyin) Exec(v []driver.Value) (r driver.Result, err error) {
+	if ci.closed {
+		return nil, errCopyInClosed
+	}
+
+	if ci.isBad() {
+		return nil, driver.ErrBadConn
+	}
+	defer ci.cn.errRecover(&err)
+
+	if ci.isErrorSet() {
+		return nil, ci.err
+	}
+
+	if len(v) == 0 {
+		return nil, ci.Close()
+	}
+
+	numValues := len(v)
+	for i, value := range v {
+		ci.buffer = appendEncodedText(&ci.cn.parameterStatus, ci.buffer, value)
+		if i < numValues-1 {
+			ci.buffer = append(ci.buffer, '\t')
+		}
+	}
+
+	ci.buffer = append(ci.buffer, '\n')
+
+	if len(ci.buffer) > ciBufferFlushSize {
+		ci.flush(ci.buffer)
+		// reset buffer, keep bytes for message identifier and length
+		ci.buffer = ci.buffer[:5]
+	}
+
+	return driver.RowsAffected(0), nil
+}
+
+func (ci *copyin) Close() (err error) {
+	if ci.closed { // Don't do anything, we're already closed
+		return nil
+	}
+	ci.closed = true
+
+	if ci.isBad() {
+		return driver.ErrBadConn
+	}
+	defer ci.cn.errRecover(&err)
+
+	if len(ci.buffer) > 0 {
+		ci.flush(ci.buffer)
+	}
+	// Avoid touching the scratch buffer as resploop could be using it.
+	err = ci.cn.sendSimpleMessage('c')
+	if err != nil {
+		return err
+	}
+
+	<-ci.done
+	ci.cn.inCopy = false
+
+	if ci.isErrorSet() {
+		err = ci.err
+		return err
+	}
+	return nil
+}

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

@@ -0,0 +1,245 @@
+/*
+Package pq is a pure Go Postgres driver for the database/sql package.
+
+In most cases clients will use the database/sql package instead of
+using this package directly. For example:
+
+	import (
+		"database/sql"
+
+		_ "github.com/lib/pq"
+	)
+
+	func main() {
+		connStr := "user=pqgotest dbname=pqgotest sslmode=verify-full"
+		db, err := sql.Open("postgres", connStr)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		age := 21
+		rows, err := db.Query("SELECT name FROM users WHERE age = $1", age)
+		…
+	}
+
+You can also connect to a database using a URL. For example:
+
+	connStr := "postgres://pqgotest:password@localhost/pqgotest?sslmode=verify-full"
+	db, err := sql.Open("postgres", connStr)
+
+
+Connection String Parameters
+
+
+Similarly to libpq, when establishing a connection using pq you are expected to
+supply a connection string containing zero or more parameters.
+A subset of the connection parameters supported by libpq are also supported by pq.
+Additionally, pq also lets you specify run-time parameters (such as search_path or work_mem)
+directly in the connection string.  This is different from libpq, which does not allow
+run-time parameters in the connection string, instead requiring you to supply
+them in the options parameter.
+
+For compatibility with libpq, the following special connection parameters are
+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)
+	* 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)
+	* 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.
+	* 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.
+
+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-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.
+
+Use single quotes for values that contain whitespace:
+
+    "user=pqgotest password='with spaces'"
+
+A backslash will escape the next character in values:
+
+    "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",
+matching with the same rules as Postgres. It is an error to provide
+any other value.
+
+In addition to the parameters listed above, any run-time parameter that can be
+set at backend start time can be set in the connection string.  For more
+information, see
+http://www.postgresql.org/docs/current/static/runtime-config.html.
+
+Most environment variables as specified at http://www.postgresql.org/docs/current/static/libpq-envars.html
+supported by libpq are also supported by pq.  If any of the environment
+variables not supported by pq are set, pq will panic during connection
+establishment.  Environment variables have a lower precedence than explicitly
+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:
+
+	rows, err := db.Query(`SELECT name FROM users WHERE favorite_fruit = $1
+		OR age BETWEEN $2 AND $2 + 3`, "orange", 64)
+
+pq does not support the LastInsertId() method of the Result type in database/sql.
+To return the identifier of an INSERT (or UPDATE or DELETE), use the Postgres
+RETURNING clause with a standard Query or QueryRow call:
+
+	var userid int
+	err := db.QueryRow(`INSERT INTO users(name, favorite_fruit, age)
+		VALUES('beatrice', 'starfruit', 93) RETURNING id`).Scan(&userid)
+
+For more details on RETURNING, see the Postgres documentation:
+
+	http://www.postgresql.org/docs/current/static/sql-insert.html
+	http://www.postgresql.org/docs/current/static/sql-update.html
+	http://www.postgresql.org/docs/current/static/sql-delete.html
+
+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 {
+            fmt.Println("pq error:", err.Code.Name())
+        }
+
+See the pq.Error type for details.
+
+
+Bulk imports
+
+You can perform bulk imports by preparing a statement returned by pq.CopyIn (or
+pq.CopyInSchema) in an explicit transaction (sql.Tx). The returned statement
+handle can then be repeatedly "executed" to copy data into the target table.
+After all data has been processed you should call Exec() once with no arguments
+to flush all buffered data. Any call to Exec() might return an error which
+should be handled appropriately, but because of the internal buffering an error
+returned by Exec() might not be related to the data passed in the call that
+failed.
+
+CopyIn uses COPY FROM internally. It is not possible to COPY outside of an
+explicit transaction in pq.
+
+Usage example:
+
+	txn, err := db.Begin()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	stmt, err := txn.Prepare(pq.CopyIn("users", "name", "age"))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for _, user := range users {
+		_, err = stmt.Exec(user.Name, int64(user.Age))
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	_, err = stmt.Exec()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = stmt.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = txn.Commit()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+
+Notifications
+
+
+PostgreSQL supports a simple publish/subscribe model over database
+connections.  See http://www.postgresql.org/docs/current/static/sql-notify.html
+for more information about the general mechanism.
+
+To start listening for notifications, you first have to open a new connection
+to the database by calling NewListener.  This connection can not be used for
+anything other than LISTEN / NOTIFY.  Calling Listen will open a "notification
+channel"; once a notification channel is open, a notification generated on that
+channel will effect a send on the Listener.Notify channel.  A notification
+channel will remain open until Unlisten is called, though connection loss might
+result in some notifications being lost.  To solve this problem, Listener sends
+a nil pointer over the Notify channel any time the connection is re-established
+following a connection loss.  The application can get information about the
+state of the underlying connection by setting an event callback in the call to
+NewListener.
+
+A single Listener can safely be used from concurrent goroutines, which means
+that there is often no need to create more than one Listener in your
+application.  However, a Listener is always connected to a single database, so
+you will need to create a new Listener instance for every database you want to
+receive notifications in.
+
+The channel name in both Listen and Unlisten is case sensitive, and can contain
+any characters legal in an identifier (see
+http://www.postgresql.org/docs/current/static/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
+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
+https://godoc.org/github.com/lib/pq/example/listen.
+
+*/
+package pq

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

@@ -0,0 +1,602 @@
+package pq
+
+import (
+	"bytes"
+	"database/sql/driver"
+	"encoding/binary"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/lib/pq/oid"
+)
+
+func binaryEncode(parameterStatus *parameterStatus, x interface{}) []byte {
+	switch v := x.(type) {
+	case []byte:
+		return v
+	default:
+		return encode(parameterStatus, x, oid.T_unknown)
+	}
+}
+
+func encode(parameterStatus *parameterStatus, x interface{}, pgtypOid oid.Oid) []byte {
+	switch v := x.(type) {
+	case int64:
+		return strconv.AppendInt(nil, v, 10)
+	case float64:
+		return strconv.AppendFloat(nil, v, 'f', -1, 64)
+	case []byte:
+		if pgtypOid == oid.T_bytea {
+			return encodeBytea(parameterStatus.serverVersion, v)
+		}
+
+		return v
+	case string:
+		if pgtypOid == oid.T_bytea {
+			return encodeBytea(parameterStatus.serverVersion, []byte(v))
+		}
+
+		return []byte(v)
+	case bool:
+		return strconv.AppendBool(nil, v)
+	case time.Time:
+		return formatTs(v)
+
+	default:
+		errorf("encode: unknown type for %T", v)
+	}
+
+	panic("not reached")
+}
+
+func decode(parameterStatus *parameterStatus, s []byte, typ oid.Oid, f format) interface{} {
+	switch f {
+	case formatBinary:
+		return binaryDecode(parameterStatus, s, typ)
+	case formatText:
+		return textDecode(parameterStatus, s, typ)
+	default:
+		panic("not reached")
+	}
+}
+
+func binaryDecode(parameterStatus *parameterStatus, s []byte, typ oid.Oid) interface{} {
+	switch typ {
+	case oid.T_bytea:
+		return s
+	case oid.T_int8:
+		return int64(binary.BigEndian.Uint64(s))
+	case oid.T_int4:
+		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))
+	}
+
+	panic("not reached")
+}
+
+func textDecode(parameterStatus *parameterStatus, s []byte, typ oid.Oid) interface{} {
+	switch typ {
+	case oid.T_char, oid.T_varchar, oid.T_text:
+		return string(s)
+	case oid.T_bytea:
+		b, err := parseBytea(s)
+		if err != nil {
+			errorf("%s", err)
+		}
+		return b
+	case oid.T_timestamptz:
+		return parseTs(parameterStatus.currentLocation, string(s))
+	case oid.T_timestamp, oid.T_date:
+		return parseTs(nil, string(s))
+	case oid.T_time:
+		return mustParse("15:04:05", typ, s)
+	case oid.T_timetz:
+		return mustParse("15:04:05-07", typ, s)
+	case oid.T_bool:
+		return s[0] == 't'
+	case oid.T_int8, oid.T_int4, oid.T_int2:
+		i, err := strconv.ParseInt(string(s), 10, 64)
+		if err != nil {
+			errorf("%s", err)
+		}
+		return i
+	case oid.T_float4, oid.T_float8:
+		// We always use 64 bit parsing, regardless of whether the input text is for
+		// a float4 or float8, because clients expect float64s for all float datatypes
+		// and returning a 32-bit parsed float64 produces lossy results.
+		f, err := strconv.ParseFloat(string(s), 64)
+		if err != nil {
+			errorf("%s", err)
+		}
+		return f
+	}
+
+	return s
+}
+
+// appendEncodedText encodes item in text format as required by COPY
+// and appends to buf
+func appendEncodedText(parameterStatus *parameterStatus, buf []byte, x interface{}) []byte {
+	switch v := x.(type) {
+	case int64:
+		return strconv.AppendInt(buf, v, 10)
+	case float64:
+		return strconv.AppendFloat(buf, v, 'f', -1, 64)
+	case []byte:
+		encodedBytea := encodeBytea(parameterStatus.serverVersion, v)
+		return appendEscapedText(buf, string(encodedBytea))
+	case string:
+		return appendEscapedText(buf, v)
+	case bool:
+		return strconv.AppendBool(buf, v)
+	case time.Time:
+		return append(buf, formatTs(v)...)
+	case nil:
+		return append(buf, "\\N"...)
+	default:
+		errorf("encode: unknown type for %T", v)
+	}
+
+	panic("not reached")
+}
+
+func appendEscapedText(buf []byte, text string) []byte {
+	escapeNeeded := false
+	startPos := 0
+	var c byte
+
+	// check if we need to escape
+	for i := 0; i < len(text); i++ {
+		c = text[i]
+		if c == '\\' || c == '\n' || c == '\r' || c == '\t' {
+			escapeNeeded = true
+			startPos = i
+			break
+		}
+	}
+	if !escapeNeeded {
+		return append(buf, text...)
+	}
+
+	// copy till first char to escape, iterate the rest
+	result := append(buf, text[:startPos]...)
+	for i := startPos; i < len(text); i++ {
+		c = text[i]
+		switch c {
+		case '\\':
+			result = append(result, '\\', '\\')
+		case '\n':
+			result = append(result, '\\', 'n')
+		case '\r':
+			result = append(result, '\\', 'r')
+		case '\t':
+			result = append(result, '\\', 't')
+		default:
+			result = append(result, c)
+		}
+	}
+	return result
+}
+
+func mustParse(f string, typ oid.Oid, s []byte) time.Time {
+	str := string(s)
+
+	// check for a 30-minute-offset timezone
+	if (typ == oid.T_timestamptz || typ == oid.T_timetz) &&
+		str[len(str)-3] == ':' {
+		f += ":00"
+	}
+	t, err := time.Parse(f, str)
+	if err != nil {
+		errorf("decode: %s", err)
+	}
+	return t
+}
+
+var errInvalidTimestamp = errors.New("invalid timestamp")
+
+type timestampParser struct {
+	err error
+}
+
+func (p *timestampParser) expect(str string, char byte, pos int) {
+	if p.err != nil {
+		return
+	}
+	if pos+1 > len(str) {
+		p.err = errInvalidTimestamp
+		return
+	}
+	if c := str[pos]; c != char && p.err == nil {
+		p.err = fmt.Errorf("expected '%v' at position %v; got '%v'", char, pos, c)
+	}
+}
+
+func (p *timestampParser) mustAtoi(str string, begin int, end int) int {
+	if p.err != nil {
+		return 0
+	}
+	if begin < 0 || end < 0 || begin > end || end > len(str) {
+		p.err = errInvalidTimestamp
+		return 0
+	}
+	result, err := strconv.Atoi(str[begin:end])
+	if err != nil {
+		if p.err == nil {
+			p.err = fmt.Errorf("expected number; got '%v'", str)
+		}
+		return 0
+	}
+	return result
+}
+
+// The location cache caches the time zones typically used by the client.
+type locationCache struct {
+	cache map[int]*time.Location
+	lock  sync.Mutex
+}
+
+// All connections share the same list of timezones. Benchmarking shows that
+// about 5% speed could be gained by putting the cache in the connection and
+// losing the mutex, at the cost of a small amount of memory and a somewhat
+// significant increase in code complexity.
+var globalLocationCache = newLocationCache()
+
+func newLocationCache() *locationCache {
+	return &locationCache{cache: make(map[int]*time.Location)}
+}
+
+// Returns the cached timezone for the specified offset, creating and caching
+// it if necessary.
+func (c *locationCache) getLocation(offset int) *time.Location {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	location, ok := c.cache[offset]
+	if !ok {
+		location = time.FixedZone("", offset)
+		c.cache[offset] = location
+	}
+
+	return location
+}
+
+var infinityTsEnabled = false
+var infinityTsNegative time.Time
+var infinityTsPositive time.Time
+
+const (
+	infinityTsEnabledAlready        = "pq: infinity timestamp enabled already"
+	infinityTsNegativeMustBeSmaller = "pq: infinity timestamp: negative value must be smaller (before) than positive"
+)
+
+// EnableInfinityTs controls the handling of Postgres' "-infinity" and
+// "infinity" "timestamp"s.
+//
+// If EnableInfinityTs is not called, "-infinity" and "infinity" will return
+// []byte("-infinity") and []byte("infinity") respectively, and potentially
+// cause error "sql: Scan error on column index 0: unsupported driver -> Scan
+// pair: []uint8 -> *time.Time", when scanning into a time.Time value.
+//
+// Once EnableInfinityTs has been called, all connections created using this
+// driver will decode Postgres' "-infinity" and "infinity" for "timestamp",
+// "timestamp with time zone" and "date" types to the predefined minimum and
+// maximum times, respectively.  When encoding time.Time values, any time which
+// equals or precedes the predefined minimum time will be encoded to
+// "-infinity".  Any values at or past the maximum time will similarly be
+// encoded to "infinity".
+//
+// If EnableInfinityTs is called with negative >= positive, it will panic.
+// Calling EnableInfinityTs after a connection has been established results in
+// undefined behavior.  If EnableInfinityTs is called more than once, it will
+// panic.
+func EnableInfinityTs(negative time.Time, positive time.Time) {
+	if infinityTsEnabled {
+		panic(infinityTsEnabledAlready)
+	}
+	if !negative.Before(positive) {
+		panic(infinityTsNegativeMustBeSmaller)
+	}
+	infinityTsEnabled = true
+	infinityTsNegative = negative
+	infinityTsPositive = positive
+}
+
+/*
+ * Testing might want to toggle infinityTsEnabled
+ */
+func disableInfinityTs() {
+	infinityTsEnabled = false
+}
+
+// This is a time function specific to the Postgres default DateStyle
+// setting ("ISO, MDY"), the only one we currently support. This
+// accounts for the discrepancies between the parsing available with
+// time.Parse and the Postgres date formatting quirks.
+func parseTs(currentLocation *time.Location, str string) interface{} {
+	switch str {
+	case "-infinity":
+		if infinityTsEnabled {
+			return infinityTsNegative
+		}
+		return []byte(str)
+	case "infinity":
+		if infinityTsEnabled {
+			return infinityTsPositive
+		}
+		return []byte(str)
+	}
+	t, err := ParseTimestamp(currentLocation, str)
+	if err != nil {
+		panic(err)
+	}
+	return t
+}
+
+// ParseTimestamp parses Postgres' text format. It returns a time.Time in
+// currentLocation iff that time's offset agrees with the offset sent from the
+// Postgres server. Otherwise, ParseTimestamp returns a time.Time with the
+// fixed offset offset provided by the Postgres server.
+func ParseTimestamp(currentLocation *time.Location, str string) (time.Time, error) {
+	p := timestampParser{}
+
+	monSep := strings.IndexRune(str, '-')
+	// this is Gregorian year, not ISO Year
+	// In Gregorian system, the year 1 BC is followed by AD 1
+	year := p.mustAtoi(str, 0, monSep)
+	daySep := monSep + 3
+	month := p.mustAtoi(str, monSep+1, daySep)
+	p.expect(str, '-', daySep)
+	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) > minLen {
+		p.expect(str, ' ', timeSep)
+		minSep := timeSep + 3
+		p.expect(str, ':', minSep)
+		hour = p.mustAtoi(str, timeSep+1, minSep)
+		secSep := minSep + 3
+		p.expect(str, ':', secSep)
+		minute = p.mustAtoi(str, minSep+1, secSep)
+		secEnd := secSep + 3
+		second = p.mustAtoi(str, secSep+1, secEnd)
+	}
+	remainderIdx := monSep + len("01-01 00:00:00") + 1
+	// Three optional (but ordered) sections follow: the
+	// fractional seconds, the time zone offset, and the BC
+	// designation. We set them up here and adjust the other
+	// offsets if the preceding sections exist.
+
+	nanoSec := 0
+	tzOff := 0
+
+	if remainderIdx < len(str) && str[remainderIdx] == '.' {
+		fracStart := remainderIdx + 1
+		fracOff := strings.IndexAny(str[fracStart:], "-+ ")
+		if fracOff < 0 {
+			fracOff = len(str) - fracStart
+		}
+		fracSec := p.mustAtoi(str, fracStart, fracStart+fracOff)
+		nanoSec = fracSec * (1000000000 / int(math.Pow(10, float64(fracOff))))
+
+		remainderIdx += fracOff + 1
+	}
+	if tzStart := remainderIdx; tzStart < len(str) && (str[tzStart] == '-' || str[tzStart] == '+') {
+		// time zone separator is always '-' or '+' (UTC is +00)
+		var tzSign int
+		switch c := str[tzStart]; c {
+		case '-':
+			tzSign = -1
+		case '+':
+			tzSign = +1
+		default:
+			return time.Time{}, fmt.Errorf("expected '-' or '+' at position %v; got %v", tzStart, c)
+		}
+		tzHours := p.mustAtoi(str, tzStart+1, tzStart+3)
+		remainderIdx += 3
+		var tzMin, tzSec int
+		if remainderIdx < len(str) && str[remainderIdx] == ':' {
+			tzMin = p.mustAtoi(str, remainderIdx+1, remainderIdx+3)
+			remainderIdx += 3
+		}
+		if remainderIdx < len(str) && str[remainderIdx] == ':' {
+			tzSec = p.mustAtoi(str, remainderIdx+1, remainderIdx+3)
+			remainderIdx += 3
+		}
+		tzOff = tzSign * ((tzHours * 60 * 60) + (tzMin * 60) + tzSec)
+	}
+	var isoYear int
+
+	if isBC {
+		isoYear = 1 - year
+		remainderIdx += 3
+	} else {
+		isoYear = year
+	}
+	if remainderIdx < len(str) {
+		return time.Time{}, fmt.Errorf("expected end of input, got %v", str[remainderIdx:])
+	}
+	t := time.Date(isoYear, time.Month(month), day,
+		hour, minute, second, nanoSec,
+		globalLocationCache.getLocation(tzOff))
+
+	if currentLocation != nil {
+		// Set the location of the returned Time based on the session's
+		// TimeZone value, but only if the local time zone database agrees with
+		// the remote database on the offset.
+		lt := t.In(currentLocation)
+		_, newOff := lt.Zone()
+		if newOff == tzOff {
+			t = lt
+		}
+	}
+
+	return t, p.err
+}
+
+// formatTs formats t into a format postgres understands.
+func formatTs(t time.Time) []byte {
+	if infinityTsEnabled {
+		// t <= -infinity : ! (t > -infinity)
+		if !t.After(infinityTsNegative) {
+			return []byte("-infinity")
+		}
+		// t >= infinity : ! (!t < infinity)
+		if !t.Before(infinityTsPositive) {
+			return []byte("infinity")
+		}
+	}
+	return FormatTimestamp(t)
+}
+
+// FormatTimestamp formats t into Postgres' text format for timestamps.
+func FormatTimestamp(t time.Time) []byte {
+	// Need to send dates before 0001 A.D. with " BC" suffix, instead of the
+	// minus sign preferred by Go.
+	// Beware, "0000" in ISO is "1 BC", "-0001" is "2 BC" and so on
+	bc := false
+	if t.Year() <= 0 {
+		// flip year sign, and add 1, e.g: "0" will be "1", and "-10" will be "11"
+		t = t.AddDate((-t.Year())*2+1, 0, 0)
+		bc = true
+	}
+	b := []byte(t.Format("2006-01-02 15:04:05.999999999Z07:00"))
+
+	_, offset := t.Zone()
+	offset = offset % 60
+	if offset != 0 {
+		// RFC3339Nano already printed the minus sign
+		if offset < 0 {
+			offset = -offset
+		}
+
+		b = append(b, ':')
+		if offset < 10 {
+			b = append(b, '0')
+		}
+		b = strconv.AppendInt(b, int64(offset), 10)
+	}
+
+	if bc {
+		b = append(b, " BC"...)
+	}
+	return b
+}
+
+// Parse a bytea value received from the server.  Both "hex" and the legacy
+// "escape" format are supported.
+func parseBytea(s []byte) (result []byte, err error) {
+	if len(s) >= 2 && bytes.Equal(s[:2], []byte("\\x")) {
+		// bytea_output = hex
+		s = s[2:] // trim off leading "\\x"
+		result = make([]byte, hex.DecodedLen(len(s)))
+		_, err := hex.Decode(result, s)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		// bytea_output = escape
+		for len(s) > 0 {
+			if s[0] == '\\' {
+				// escaped '\\'
+				if len(s) >= 2 && s[1] == '\\' {
+					result = append(result, '\\')
+					s = s[2:]
+					continue
+				}
+
+				// '\\' followed by an octal number
+				if len(s) < 4 {
+					return nil, fmt.Errorf("invalid bytea sequence %v", s)
+				}
+				r, err := strconv.ParseInt(string(s[1:4]), 8, 9)
+				if err != nil {
+					return nil, fmt.Errorf("could not parse bytea value: %s", err.Error())
+				}
+				result = append(result, byte(r))
+				s = s[4:]
+			} else {
+				// We hit an unescaped, raw byte.  Try to read in as many as
+				// possible in one go.
+				i := bytes.IndexByte(s, '\\')
+				if i == -1 {
+					result = append(result, s...)
+					break
+				}
+				result = append(result, s[:i]...)
+				s = s[i:]
+			}
+		}
+	}
+
+	return result, nil
+}
+
+func encodeBytea(serverVersion int, v []byte) (result []byte) {
+	if serverVersion >= 90000 {
+		// Use the hex format if we know that the server supports it
+		result = make([]byte, 2+hex.EncodedLen(len(v)))
+		result[0] = '\\'
+		result[1] = 'x'
+		hex.Encode(result[2:], v)
+	} else {
+		// .. or resort to "escape"
+		for _, b := range v {
+			if b == '\\' {
+				result = append(result, '\\', '\\')
+			} else if b < 0x20 || b > 0x7e {
+				result = append(result, []byte(fmt.Sprintf("\\%03o", b))...)
+			} else {
+				result = append(result, b)
+			}
+		}
+	}
+
+	return result
+}
+
+// NullTime represents a time.Time that may be null. NullTime implements the
+// sql.Scanner interface so it can be used as a scan destination, similar to
+// sql.NullString.
+type NullTime struct {
+	Time  time.Time
+	Valid bool // Valid is true if Time is not NULL
+}
+
+// Scan implements the Scanner interface.
+func (nt *NullTime) Scan(value interface{}) error {
+	nt.Time, nt.Valid = value.(time.Time)
+	return nil
+}
+
+// Value implements the driver Valuer interface.
+func (nt NullTime) Value() (driver.Value, error) {
+	if !nt.Valid {
+		return nil, nil
+	}
+	return nt.Time, nil
+}

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

@@ -0,0 +1,515 @@
+package pq
+
+import (
+	"database/sql/driver"
+	"fmt"
+	"io"
+	"net"
+	"runtime"
+)
+
+// Error severities
+const (
+	Efatal   = "FATAL"
+	Epanic   = "PANIC"
+	Ewarning = "WARNING"
+	Enotice  = "NOTICE"
+	Edebug   = "DEBUG"
+	Einfo    = "INFO"
+	Elog     = "LOG"
+)
+
+// Error represents an error communicating with the server.
+//
+// See http://www.postgresql.org/docs/current/static/protocol-error-fields.html for details of the fields
+type Error struct {
+	Severity         string
+	Code             ErrorCode
+	Message          string
+	Detail           string
+	Hint             string
+	Position         string
+	InternalPosition string
+	InternalQuery    string
+	Where            string
+	Schema           string
+	Table            string
+	Column           string
+	DataTypeName     string
+	Constraint       string
+	File             string
+	Line             string
+	Routine          string
+}
+
+// ErrorCode is a five-character error code.
+type ErrorCode string
+
+// Name returns a more human friendly rendering of the error code, namely the
+// "condition name".
+//
+// See http://www.postgresql.org/docs/9.3/static/errcodes-appendix.html for
+// details.
+func (ec ErrorCode) Name() string {
+	return errorCodeNames[ec]
+}
+
+// ErrorClass is only the class part of an error code.
+type ErrorClass string
+
+// Name returns the condition name of an error class.  It is equivalent to the
+// condition name of the "standard" error code (i.e. the one having the last
+// three characters "000").
+func (ec ErrorClass) Name() string {
+	return errorCodeNames[ErrorCode(ec+"000")]
+}
+
+// Class returns the error class, e.g. "28".
+//
+// See http://www.postgresql.org/docs/9.3/static/errcodes-appendix.html for
+// details.
+func (ec ErrorCode) Class() ErrorClass {
+	return ErrorClass(ec[0:2])
+}
+
+// errorCodeNames is a mapping between the five-character error codes and the
+// human readable "condition names". It is derived from the list at
+// http://www.postgresql.org/docs/9.3/static/errcodes-appendix.html
+var errorCodeNames = map[ErrorCode]string{
+	// Class 00 - Successful Completion
+	"00000": "successful_completion",
+	// Class 01 - Warning
+	"01000": "warning",
+	"0100C": "dynamic_result_sets_returned",
+	"01008": "implicit_zero_bit_padding",
+	"01003": "null_value_eliminated_in_set_function",
+	"01007": "privilege_not_granted",
+	"01006": "privilege_not_revoked",
+	"01004": "string_data_right_truncation",
+	"01P01": "deprecated_feature",
+	// Class 02 - No Data (this is also a warning class per the SQL standard)
+	"02000": "no_data",
+	"02001": "no_additional_dynamic_result_sets_returned",
+	// Class 03 - SQL Statement Not Yet Complete
+	"03000": "sql_statement_not_yet_complete",
+	// Class 08 - Connection Exception
+	"08000": "connection_exception",
+	"08003": "connection_does_not_exist",
+	"08006": "connection_failure",
+	"08001": "sqlclient_unable_to_establish_sqlconnection",
+	"08004": "sqlserver_rejected_establishment_of_sqlconnection",
+	"08007": "transaction_resolution_unknown",
+	"08P01": "protocol_violation",
+	// Class 09 - Triggered Action Exception
+	"09000": "triggered_action_exception",
+	// Class 0A - Feature Not Supported
+	"0A000": "feature_not_supported",
+	// Class 0B - Invalid Transaction Initiation
+	"0B000": "invalid_transaction_initiation",
+	// Class 0F - Locator Exception
+	"0F000": "locator_exception",
+	"0F001": "invalid_locator_specification",
+	// Class 0L - Invalid Grantor
+	"0L000": "invalid_grantor",
+	"0LP01": "invalid_grant_operation",
+	// Class 0P - Invalid Role Specification
+	"0P000": "invalid_role_specification",
+	// Class 0Z - Diagnostics Exception
+	"0Z000": "diagnostics_exception",
+	"0Z002": "stacked_diagnostics_accessed_without_active_handler",
+	// Class 20 - Case Not Found
+	"20000": "case_not_found",
+	// Class 21 - Cardinality Violation
+	"21000": "cardinality_violation",
+	// Class 22 - Data Exception
+	"22000": "data_exception",
+	"2202E": "array_subscript_error",
+	"22021": "character_not_in_repertoire",
+	"22008": "datetime_field_overflow",
+	"22012": "division_by_zero",
+	"22005": "error_in_assignment",
+	"2200B": "escape_character_conflict",
+	"22022": "indicator_overflow",
+	"22015": "interval_field_overflow",
+	"2201E": "invalid_argument_for_logarithm",
+	"22014": "invalid_argument_for_ntile_function",
+	"22016": "invalid_argument_for_nth_value_function",
+	"2201F": "invalid_argument_for_power_function",
+	"2201G": "invalid_argument_for_width_bucket_function",
+	"22018": "invalid_character_value_for_cast",
+	"22007": "invalid_datetime_format",
+	"22019": "invalid_escape_character",
+	"2200D": "invalid_escape_octet",
+	"22025": "invalid_escape_sequence",
+	"22P06": "nonstandard_use_of_escape_character",
+	"22010": "invalid_indicator_parameter_value",
+	"22023": "invalid_parameter_value",
+	"2201B": "invalid_regular_expression",
+	"2201W": "invalid_row_count_in_limit_clause",
+	"2201X": "invalid_row_count_in_result_offset_clause",
+	"22009": "invalid_time_zone_displacement_value",
+	"2200C": "invalid_use_of_escape_character",
+	"2200G": "most_specific_type_mismatch",
+	"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",
+	"22027": "trim_error",
+	"22024": "unterminated_c_string",
+	"2200F": "zero_length_character_string",
+	"22P01": "floating_point_exception",
+	"22P02": "invalid_text_representation",
+	"22P03": "invalid_binary_representation",
+	"22P04": "bad_copy_file_format",
+	"22P05": "untranslatable_character",
+	"2200L": "not_an_xml_document",
+	"2200M": "invalid_xml_document",
+	"2200N": "invalid_xml_content",
+	"2200S": "invalid_xml_comment",
+	"2200T": "invalid_xml_processing_instruction",
+	// Class 23 - Integrity Constraint Violation
+	"23000": "integrity_constraint_violation",
+	"23001": "restrict_violation",
+	"23502": "not_null_violation",
+	"23503": "foreign_key_violation",
+	"23505": "unique_violation",
+	"23514": "check_violation",
+	"23P01": "exclusion_violation",
+	// Class 24 - Invalid Cursor State
+	"24000": "invalid_cursor_state",
+	// Class 25 - Invalid Transaction State
+	"25000": "invalid_transaction_state",
+	"25001": "active_sql_transaction",
+	"25002": "branch_transaction_already_active",
+	"25008": "held_cursor_requires_same_isolation_level",
+	"25003": "inappropriate_access_mode_for_branch_transaction",
+	"25004": "inappropriate_isolation_level_for_branch_transaction",
+	"25005": "no_active_sql_transaction_for_branch_transaction",
+	"25006": "read_only_sql_transaction",
+	"25007": "schema_and_data_statement_mixing_not_supported",
+	"25P01": "no_active_sql_transaction",
+	"25P02": "in_failed_sql_transaction",
+	// Class 26 - Invalid SQL Statement Name
+	"26000": "invalid_sql_statement_name",
+	// Class 27 - Triggered Data Change Violation
+	"27000": "triggered_data_change_violation",
+	// Class 28 - Invalid Authorization Specification
+	"28000": "invalid_authorization_specification",
+	"28P01": "invalid_password",
+	// Class 2B - Dependent Privilege Descriptors Still Exist
+	"2B000": "dependent_privilege_descriptors_still_exist",
+	"2BP01": "dependent_objects_still_exist",
+	// Class 2D - Invalid Transaction Termination
+	"2D000": "invalid_transaction_termination",
+	// Class 2F - SQL Routine Exception
+	"2F000": "sql_routine_exception",
+	"2F005": "function_executed_no_return_statement",
+	"2F002": "modifying_sql_data_not_permitted",
+	"2F003": "prohibited_sql_statement_attempted",
+	"2F004": "reading_sql_data_not_permitted",
+	// Class 34 - Invalid Cursor Name
+	"34000": "invalid_cursor_name",
+	// Class 38 - External Routine Exception
+	"38000": "external_routine_exception",
+	"38001": "containing_sql_not_permitted",
+	"38002": "modifying_sql_data_not_permitted",
+	"38003": "prohibited_sql_statement_attempted",
+	"38004": "reading_sql_data_not_permitted",
+	// Class 39 - External Routine Invocation Exception
+	"39000": "external_routine_invocation_exception",
+	"39001": "invalid_sqlstate_returned",
+	"39004": "null_value_not_allowed",
+	"39P01": "trigger_protocol_violated",
+	"39P02": "srf_protocol_violated",
+	// Class 3B - Savepoint Exception
+	"3B000": "savepoint_exception",
+	"3B001": "invalid_savepoint_specification",
+	// Class 3D - Invalid Catalog Name
+	"3D000": "invalid_catalog_name",
+	// Class 3F - Invalid Schema Name
+	"3F000": "invalid_schema_name",
+	// Class 40 - Transaction Rollback
+	"40000": "transaction_rollback",
+	"40002": "transaction_integrity_constraint_violation",
+	"40001": "serialization_failure",
+	"40003": "statement_completion_unknown",
+	"40P01": "deadlock_detected",
+	// Class 42 - Syntax Error or Access Rule Violation
+	"42000": "syntax_error_or_access_rule_violation",
+	"42601": "syntax_error",
+	"42501": "insufficient_privilege",
+	"42846": "cannot_coerce",
+	"42803": "grouping_error",
+	"42P20": "windowing_error",
+	"42P19": "invalid_recursion",
+	"42830": "invalid_foreign_key",
+	"42602": "invalid_name",
+	"42622": "name_too_long",
+	"42939": "reserved_name",
+	"42804": "datatype_mismatch",
+	"42P18": "indeterminate_datatype",
+	"42P21": "collation_mismatch",
+	"42P22": "indeterminate_collation",
+	"42809": "wrong_object_type",
+	"42703": "undefined_column",
+	"42883": "undefined_function",
+	"42P01": "undefined_table",
+	"42P02": "undefined_parameter",
+	"42704": "undefined_object",
+	"42701": "duplicate_column",
+	"42P03": "duplicate_cursor",
+	"42P04": "duplicate_database",
+	"42723": "duplicate_function",
+	"42P05": "duplicate_prepared_statement",
+	"42P06": "duplicate_schema",
+	"42P07": "duplicate_table",
+	"42712": "duplicate_alias",
+	"42710": "duplicate_object",
+	"42702": "ambiguous_column",
+	"42725": "ambiguous_function",
+	"42P08": "ambiguous_parameter",
+	"42P09": "ambiguous_alias",
+	"42P10": "invalid_column_reference",
+	"42611": "invalid_column_definition",
+	"42P11": "invalid_cursor_definition",
+	"42P12": "invalid_database_definition",
+	"42P13": "invalid_function_definition",
+	"42P14": "invalid_prepared_statement_definition",
+	"42P15": "invalid_schema_definition",
+	"42P16": "invalid_table_definition",
+	"42P17": "invalid_object_definition",
+	// Class 44 - WITH CHECK OPTION Violation
+	"44000": "with_check_option_violation",
+	// Class 53 - Insufficient Resources
+	"53000": "insufficient_resources",
+	"53100": "disk_full",
+	"53200": "out_of_memory",
+	"53300": "too_many_connections",
+	"53400": "configuration_limit_exceeded",
+	// Class 54 - Program Limit Exceeded
+	"54000": "program_limit_exceeded",
+	"54001": "statement_too_complex",
+	"54011": "too_many_columns",
+	"54023": "too_many_arguments",
+	// Class 55 - Object Not In Prerequisite State
+	"55000": "object_not_in_prerequisite_state",
+	"55006": "object_in_use",
+	"55P02": "cant_change_runtime_param",
+	"55P03": "lock_not_available",
+	// Class 57 - Operator Intervention
+	"57000": "operator_intervention",
+	"57014": "query_canceled",
+	"57P01": "admin_shutdown",
+	"57P02": "crash_shutdown",
+	"57P03": "cannot_connect_now",
+	"57P04": "database_dropped",
+	// Class 58 - System Error (errors external to PostgreSQL itself)
+	"58000": "system_error",
+	"58030": "io_error",
+	"58P01": "undefined_file",
+	"58P02": "duplicate_file",
+	// Class F0 - Configuration File Error
+	"F0000": "config_file_error",
+	"F0001": "lock_file_exists",
+	// Class HV - Foreign Data Wrapper Error (SQL/MED)
+	"HV000": "fdw_error",
+	"HV005": "fdw_column_name_not_found",
+	"HV002": "fdw_dynamic_parameter_value_needed",
+	"HV010": "fdw_function_sequence_error",
+	"HV021": "fdw_inconsistent_descriptor_information",
+	"HV024": "fdw_invalid_attribute_value",
+	"HV007": "fdw_invalid_column_name",
+	"HV008": "fdw_invalid_column_number",
+	"HV004": "fdw_invalid_data_type",
+	"HV006": "fdw_invalid_data_type_descriptors",
+	"HV091": "fdw_invalid_descriptor_field_identifier",
+	"HV00B": "fdw_invalid_handle",
+	"HV00C": "fdw_invalid_option_index",
+	"HV00D": "fdw_invalid_option_name",
+	"HV090": "fdw_invalid_string_length_or_buffer_length",
+	"HV00A": "fdw_invalid_string_format",
+	"HV009": "fdw_invalid_use_of_null_pointer",
+	"HV014": "fdw_too_many_handles",
+	"HV001": "fdw_out_of_memory",
+	"HV00P": "fdw_no_schemas",
+	"HV00J": "fdw_option_name_not_found",
+	"HV00K": "fdw_reply_handle",
+	"HV00Q": "fdw_schema_not_found",
+	"HV00R": "fdw_table_not_found",
+	"HV00L": "fdw_unable_to_create_execution",
+	"HV00M": "fdw_unable_to_create_reply",
+	"HV00N": "fdw_unable_to_establish_connection",
+	// Class P0 - PL/pgSQL Error
+	"P0000": "plpgsql_error",
+	"P0001": "raise_exception",
+	"P0002": "no_data_found",
+	"P0003": "too_many_rows",
+	// Class XX - Internal Error
+	"XX000": "internal_error",
+	"XX001": "data_corrupted",
+	"XX002": "index_corrupted",
+}
+
+func parseError(r *readBuf) *Error {
+	err := new(Error)
+	for t := r.byte(); t != 0; t = r.byte() {
+		msg := r.string()
+		switch t {
+		case 'S':
+			err.Severity = msg
+		case 'C':
+			err.Code = ErrorCode(msg)
+		case 'M':
+			err.Message = msg
+		case 'D':
+			err.Detail = msg
+		case 'H':
+			err.Hint = msg
+		case 'P':
+			err.Position = msg
+		case 'p':
+			err.InternalPosition = msg
+		case 'q':
+			err.InternalQuery = msg
+		case 'W':
+			err.Where = msg
+		case 's':
+			err.Schema = msg
+		case 't':
+			err.Table = msg
+		case 'c':
+			err.Column = msg
+		case 'd':
+			err.DataTypeName = msg
+		case 'n':
+			err.Constraint = msg
+		case 'F':
+			err.File = msg
+		case 'L':
+			err.Line = msg
+		case 'R':
+			err.Routine = msg
+		}
+	}
+	return err
+}
+
+// Fatal returns true if the Error Severity is fatal.
+func (err *Error) Fatal() bool {
+	return err.Severity == Efatal
+}
+
+// Get implements the legacy PGError interface. New code should use the fields
+// of the Error struct directly.
+func (err *Error) Get(k byte) (v string) {
+	switch k {
+	case 'S':
+		return err.Severity
+	case 'C':
+		return string(err.Code)
+	case 'M':
+		return err.Message
+	case 'D':
+		return err.Detail
+	case 'H':
+		return err.Hint
+	case 'P':
+		return err.Position
+	case 'p':
+		return err.InternalPosition
+	case 'q':
+		return err.InternalQuery
+	case 'W':
+		return err.Where
+	case 's':
+		return err.Schema
+	case 't':
+		return err.Table
+	case 'c':
+		return err.Column
+	case 'd':
+		return err.DataTypeName
+	case 'n':
+		return err.Constraint
+	case 'F':
+		return err.File
+	case 'L':
+		return err.Line
+	case 'R':
+		return err.Routine
+	}
+	return ""
+}
+
+func (err Error) Error() string {
+	return "pq: " + err.Message
+}
+
+// PGError is an interface used by previous versions of pq. It is provided
+// only to support legacy code. New code should use the Error type.
+type PGError interface {
+	Error() string
+	Fatal() bool
+	Get(k byte) (v string)
+}
+
+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 {
+		// Do nothing
+		return
+	}
+	var ok bool
+	*err, ok = e.(error)
+	if !ok {
+		*err = fmt.Errorf("pq: unexpected error: %#v", e)
+	}
+}
+
+func (c *conn) errRecover(err *error) {
+	e := recover()
+	switch v := e.(type) {
+	case nil:
+		// Do nothing
+	case runtime.Error:
+		c.bad = true
+		panic(v)
+	case *Error:
+		if v.Fatal() {
+			*err = driver.ErrBadConn
+		} else {
+			*err = v
+		}
+	case *net.OpError:
+		c.bad = true
+		*err = v
+	case error:
+		if v == io.EOF || v.(error).Error() == "remote error: handshake failure" {
+			*err = driver.ErrBadConn
+		} else {
+			*err = v
+		}
+
+	default:
+		c.bad = true
+		panic(fmt.Sprintf("unknown error: %#v", e))
+	}
+
+	// Any time we return ErrBadConn, we need to remember it since *Tx doesn't
+	// mark the connection bad in database/sql.
+	if *err == driver.ErrBadConn {
+		c.bad = true
+	}
+}

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

@@ -0,0 +1,797 @@
+package pq
+
+// Package pq is a pure Go Postgres driver for the database/sql package.
+// This module contains support for Postgres LISTEN/NOTIFY.
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// Notification represents a single notification from the database.
+type Notification struct {
+	// Process ID (PID) of the notifying postgres backend.
+	BePid int
+	// Name of the channel the notification was sent on.
+	Channel string
+	// Payload, or the empty string if unspecified.
+	Extra string
+}
+
+func recvNotification(r *readBuf) *Notification {
+	bePid := r.int32()
+	channel := r.string()
+	extra := r.string()
+
+	return &Notification{bePid, channel, extra}
+}
+
+const (
+	connStateIdle int32 = iota
+	connStateExpectResponse
+	connStateExpectReadyForQuery
+)
+
+type message struct {
+	typ byte
+	err error
+}
+
+var errListenerConnClosed = errors.New("pq: ListenerConn has been closed")
+
+// ListenerConn is a low-level interface for waiting for notifications.  You
+// should use Listener instead.
+type ListenerConn struct {
+	// guards cn and err
+	connectionLock sync.Mutex
+	cn             *conn
+	err            error
+
+	connState int32
+
+	// the sending goroutine will be holding this lock
+	senderLock sync.Mutex
+
+	notificationChan chan<- *Notification
+
+	replyChan chan message
+}
+
+// NewListenerConn creates a new ListenerConn. Use NewListener instead.
+func NewListenerConn(name string, notificationChan chan<- *Notification) (*ListenerConn, error) {
+	return newDialListenerConn(defaultDialer{}, name, notificationChan)
+}
+
+func newDialListenerConn(d Dialer, name string, c chan<- *Notification) (*ListenerConn, error) {
+	cn, err := DialOpen(d, name)
+	if err != nil {
+		return nil, err
+	}
+
+	l := &ListenerConn{
+		cn:               cn.(*conn),
+		notificationChan: c,
+		connState:        connStateIdle,
+		replyChan:        make(chan message, 2),
+	}
+
+	go l.listenerConnMain()
+
+	return l, nil
+}
+
+// We can only allow one goroutine at a time to be running a query on the
+// connection for various reasons, so the goroutine sending on the connection
+// must be holding senderLock.
+//
+// Returns an error if an unrecoverable error has occurred and the ListenerConn
+// should be abandoned.
+func (l *ListenerConn) acquireSenderLock() error {
+	// we must acquire senderLock first to avoid deadlocks; see ExecSimpleQuery
+	l.senderLock.Lock()
+
+	l.connectionLock.Lock()
+	err := l.err
+	l.connectionLock.Unlock()
+	if err != nil {
+		l.senderLock.Unlock()
+		return err
+	}
+	return nil
+}
+
+func (l *ListenerConn) releaseSenderLock() {
+	l.senderLock.Unlock()
+}
+
+// setState advances the protocol state to newState.  Returns false if moving
+// to that state from the current state is not allowed.
+func (l *ListenerConn) setState(newState int32) bool {
+	var expectedState int32
+
+	switch newState {
+	case connStateIdle:
+		expectedState = connStateExpectReadyForQuery
+	case connStateExpectResponse:
+		expectedState = connStateIdle
+	case connStateExpectReadyForQuery:
+		expectedState = connStateExpectResponse
+	default:
+		panic(fmt.Sprintf("unexpected listenerConnState %d", newState))
+	}
+
+	return atomic.CompareAndSwapInt32(&l.connState, expectedState, newState)
+}
+
+// Main logic is here: receive messages from the postgres backend, forward
+// notifications and query replies and keep the internal state in sync with the
+// protocol state.  Returns when the connection has been lost, is about to go
+// away or should be discarded because we couldn't agree on the state with the
+// server backend.
+func (l *ListenerConn) listenerConnLoop() (err error) {
+	defer errRecoverNoErrBadConn(&err)
+
+	r := &readBuf{}
+	for {
+		t, err := l.cn.recvMessage(r)
+		if err != nil {
+			return err
+		}
+
+		switch t {
+		case 'A':
+			// recvNotification copies all the data so we don't need to worry
+			// about the scratch buffer being overwritten.
+			l.notificationChan <- recvNotification(r)
+
+		case 'T', 'D':
+			// only used by tests; ignore
+
+		case 'E':
+			// We might receive an ErrorResponse even when not in a query; it
+			// is expected that the server will close the connection after
+			// that, but we should make sure that the error we display is the
+			// one from the stray ErrorResponse, not io.ErrUnexpectedEOF.
+			if !l.setState(connStateExpectReadyForQuery) {
+				return parseError(r)
+			}
+			l.replyChan <- message{t, parseError(r)}
+
+		case 'C', 'I':
+			if !l.setState(connStateExpectReadyForQuery) {
+				// protocol out of sync
+				return fmt.Errorf("unexpected CommandComplete")
+			}
+			// ExecSimpleQuery doesn't need to know about this message
+
+		case 'Z':
+			if !l.setState(connStateIdle) {
+				// protocol out of sync
+				return fmt.Errorf("unexpected ReadyForQuery")
+			}
+			l.replyChan <- message{t, nil}
+
+		case 'N', 'S':
+			// ignore
+		default:
+			return fmt.Errorf("unexpected message %q from server in listenerConnLoop", t)
+		}
+	}
+}
+
+// This is the main routine for the goroutine receiving on the database
+// connection.  Most of the main logic is in listenerConnLoop.
+func (l *ListenerConn) listenerConnMain() {
+	err := l.listenerConnLoop()
+
+	// listenerConnLoop terminated; we're done, but we still have to clean up.
+	// Make sure nobody tries to start any new queries by making sure the err
+	// pointer is set.  It is important that we do not overwrite its value; a
+	// connection could be closed by either this goroutine or one sending on
+	// the connection -- whoever closes the connection is assumed to have the
+	// more meaningful error message (as the other one will probably get
+	// net.errClosed), so that goroutine sets the error we expose while the
+	// other error is discarded.  If the connection is lost while two
+	// goroutines are operating on the socket, it probably doesn't matter which
+	// error we expose so we don't try to do anything more complex.
+	l.connectionLock.Lock()
+	if l.err == nil {
+		l.err = err
+	}
+	l.cn.Close()
+	l.connectionLock.Unlock()
+
+	// There might be a query in-flight; make sure nobody's waiting for a
+	// response to it, since there's not going to be one.
+	close(l.replyChan)
+
+	// let the listener know we're done
+	close(l.notificationChan)
+
+	// this ListenerConn is done
+}
+
+// Listen sends a LISTEN query to the server. See ExecSimpleQuery.
+func (l *ListenerConn) Listen(channel string) (bool, error) {
+	return l.ExecSimpleQuery("LISTEN " + QuoteIdentifier(channel))
+}
+
+// Unlisten sends an UNLISTEN query to the server. See ExecSimpleQuery.
+func (l *ListenerConn) Unlisten(channel string) (bool, error) {
+	return l.ExecSimpleQuery("UNLISTEN " + QuoteIdentifier(channel))
+}
+
+// UnlistenAll sends an `UNLISTEN *` query to the server. See ExecSimpleQuery.
+func (l *ListenerConn) UnlistenAll() (bool, error) {
+	return l.ExecSimpleQuery("UNLISTEN *")
+}
+
+// Ping the remote server to make sure it's alive.  Non-nil error means the
+// connection has failed and should be abandoned.
+func (l *ListenerConn) Ping() error {
+	sent, err := l.ExecSimpleQuery("")
+	if !sent {
+		return err
+	}
+	if err != nil {
+		// shouldn't happen
+		panic(err)
+	}
+	return nil
+}
+
+// Attempt to send a query on the connection.  Returns an error if sending the
+// query failed, and the caller should initiate closure of this connection.
+// The caller must be holding senderLock (see acquireSenderLock and
+// releaseSenderLock).
+func (l *ListenerConn) sendSimpleQuery(q string) (err error) {
+	defer errRecoverNoErrBadConn(&err)
+
+	// must set connection state before sending the query
+	if !l.setState(connStateExpectResponse) {
+		panic("two queries running at the same time")
+	}
+
+	// Can't use l.cn.writeBuf here because it uses the scratch buffer which
+	// might get overwritten by listenerConnLoop.
+	b := &writeBuf{
+		buf: []byte("Q\x00\x00\x00\x00"),
+		pos: 1,
+	}
+	b.string(q)
+	l.cn.send(b)
+
+	return nil
+}
+
+// ExecSimpleQuery executes a "simple query" (i.e. one with no bindable
+// 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.
+//   2) If "executed" is false, the query could not be executed on the remote
+//      server.  err will be non-nil.
+//
+// After a call to ExecSimpleQuery has returned an executed=false value, the
+// connection has either been closed or will be closed shortly thereafter, and
+// all subsequently executed queries will return an error.
+func (l *ListenerConn) ExecSimpleQuery(q string) (executed bool, err error) {
+	if err = l.acquireSenderLock(); err != nil {
+		return false, err
+	}
+	defer l.releaseSenderLock()
+
+	err = l.sendSimpleQuery(q)
+	if err != nil {
+		// We can't know what state the protocol is in, so we need to abandon
+		// this connection.
+		l.connectionLock.Lock()
+		// Set the error pointer if it hasn't been set already; see
+		// listenerConnMain.
+		if l.err == nil {
+			l.err = err
+		}
+		l.connectionLock.Unlock()
+		l.cn.c.Close()
+		return false, err
+	}
+
+	// now we just wait for a reply..
+	for {
+		m, ok := <-l.replyChan
+		if !ok {
+			// We lost the connection to server, don't bother waiting for a
+			// a response.  err should have been set already.
+			l.connectionLock.Lock()
+			err := l.err
+			l.connectionLock.Unlock()
+			return false, err
+		}
+		switch m.typ {
+		case 'Z':
+			// sanity check
+			if m.err != nil {
+				panic("m.err != nil")
+			}
+			// done; err might or might not be set
+			return true, err
+
+		case 'E':
+			// sanity check
+			if m.err == nil {
+				panic("m.err == nil")
+			}
+			// server responded with an error; ReadyForQuery to follow
+			err = m.err
+
+		default:
+			return false, fmt.Errorf("unknown response for simple query: %q", m.typ)
+		}
+	}
+}
+
+// Close closes the connection.
+func (l *ListenerConn) Close() error {
+	l.connectionLock.Lock()
+	if l.err != nil {
+		l.connectionLock.Unlock()
+		return errListenerConnClosed
+	}
+	l.err = errListenerConnClosed
+	l.connectionLock.Unlock()
+	// We can't send anything on the connection without holding senderLock.
+	// Simply close the net.Conn to wake up everyone operating on it.
+	return l.cn.c.Close()
+}
+
+// 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
+}
+
+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 (
+	// ListenerEventConnected is emitted only when the database connection
+	// has been initially initialized. The err argument of the callback
+	// will always be nil.
+	ListenerEventConnected ListenerEventType = iota
+
+	// ListenerEventDisconnected is emitted after a database connection has
+	// been lost, either because of an error or because Close has been
+	// called. The err argument will be set to the reason the database
+	// connection was lost.
+	ListenerEventDisconnected
+
+	// ListenerEventReconnected is emitted after a database connection has
+	// been re-established after connection loss. The err argument of the
+	// callback will always be nil. After this event has been emitted, a
+	// nil pq.Notification is sent on the Listener.Notify channel.
+	ListenerEventReconnected
+
+	// ListenerEventConnectionAttemptFailed is emitted after a connection
+	// to the database was attempted, but failed. The err argument will be
+	// 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
+// PostgreSQL database.  For general usage information, see section
+// "Notifications".
+//
+// Listener can safely be used from concurrently running goroutines.
+type Listener struct {
+	// Channel for receiving notifications from the database.  In some cases a
+	// nil value will be sent.  See section "Notifications" above.
+	Notify chan *Notification
+
+	name                 string
+	minReconnectInterval time.Duration
+	maxReconnectInterval time.Duration
+	dialer               Dialer
+	eventCallback        EventCallbackType
+
+	lock                 sync.Mutex
+	isClosed             bool
+	reconnectCond        *sync.Cond
+	cn                   *ListenerConn
+	connNotificationChan <-chan *Notification
+	channels             map[string]struct{}
+}
+
+// NewListener creates a new database connection dedicated to LISTEN / NOTIFY.
+//
+// name should be set to a connection string to be used to establish the
+// database connection (see section "Connection String Parameters" above).
+//
+// minReconnectInterval controls the duration to wait before trying to
+// re-establish the database connection after connection loss.  After each
+// consecutive failure this interval is doubled, until maxReconnectInterval is
+// reached.  Successfully completing the connection establishment procedure
+// resets the interval back to minReconnectInterval.
+//
+// The last parameter eventCallback can be set to a function which will be
+// called by the Listener when the state of the underlying database connection
+// changes.  This callback will be called by the goroutine which dispatches the
+// notifications over the Notify channel, so you should try to avoid doing
+// potentially time-consuming operations from the callback.
+func NewListener(name string,
+	minReconnectInterval time.Duration,
+	maxReconnectInterval time.Duration,
+	eventCallback EventCallbackType) *Listener {
+	return NewDialListener(defaultDialer{}, name, minReconnectInterval, maxReconnectInterval, eventCallback)
+}
+
+// NewDialListener is like NewListener but it takes a Dialer.
+func NewDialListener(d Dialer,
+	name string,
+	minReconnectInterval time.Duration,
+	maxReconnectInterval time.Duration,
+	eventCallback EventCallbackType) *Listener {
+
+	l := &Listener{
+		name:                 name,
+		minReconnectInterval: minReconnectInterval,
+		maxReconnectInterval: maxReconnectInterval,
+		dialer:               d,
+		eventCallback:        eventCallback,
+
+		channels: make(map[string]struct{}),
+
+		Notify: make(chan *Notification, 32),
+	}
+	l.reconnectCond = sync.NewCond(&l.lock)
+
+	go l.listenerMain()
+
+	return l
+}
+
+// NotificationChannel returns the notification channel for this listener.
+// This is the same channel as Notify, and will not be recreated during the
+// life time of the Listener.
+func (l *Listener) NotificationChannel() <-chan *Notification {
+	return l.Notify
+}
+
+// Listen starts listening for notifications on a channel.  Calls to this
+// function will block until an acknowledgement has been received from the
+// server.  Note that Listener automatically re-establishes the connection
+// after connection loss, so this function may block indefinitely if the
+// connection can not be re-established.
+//
+// Listen will only fail in three conditions:
+//   1) The channel is already open.  The returned error will be
+//      ErrChannelAlreadyOpen.
+//   2) The query was executed on the remote server, but PostgreSQL returned an
+//      error message in response to the query.  The returned error will be a
+//      pq.Error containing the information the server supplied.
+//   3) Close is called on the Listener before the request could be completed.
+//
+// The channel name is case-sensitive.
+func (l *Listener) Listen(channel string) error {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	if l.isClosed {
+		return errListenerClosed
+	}
+
+	// The server allows you to issue a LISTEN on a channel which is already
+	// open, but it seems useful to be able to detect this case to spot for
+	// mistakes in application logic.  If the application genuinely does't
+	// care, it can check the exported error and ignore it.
+	_, exists := l.channels[channel]
+	if exists {
+		return ErrChannelAlreadyOpen
+	}
+
+	if l.cn != nil {
+		// If gotResponse is true but error is set, the query was executed on
+		// the remote server, but resulted in an error.  This should be
+		// relatively rare, so it's fine if we just pass the error to our
+		// caller.  However, if gotResponse is false, we could not complete the
+		// query on the remote server and our underlying connection is about
+		// to go away, so we only add relname to l.channels, and wait for
+		// resync() to take care of the rest.
+		gotResponse, err := l.cn.Listen(channel)
+		if gotResponse && err != nil {
+			return err
+		}
+	}
+
+	l.channels[channel] = struct{}{}
+	for l.cn == nil {
+		l.reconnectCond.Wait()
+		// we let go of the mutex for a while
+		if l.isClosed {
+			return errListenerClosed
+		}
+	}
+
+	return nil
+}
+
+// Unlisten removes a channel from the Listener's channel list.  Returns
+// ErrChannelNotOpen if the Listener is not listening on the specified channel.
+// Returns immediately with no error if there is no connection.  Note that you
+// might still get notifications for this channel even after Unlisten has
+// returned.
+//
+// The channel name is case-sensitive.
+func (l *Listener) Unlisten(channel string) error {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	if l.isClosed {
+		return errListenerClosed
+	}
+
+	// Similarly to LISTEN, this is not an error in Postgres, but it seems
+	// useful to distinguish from the normal conditions.
+	_, exists := l.channels[channel]
+	if !exists {
+		return ErrChannelNotOpen
+	}
+
+	if l.cn != nil {
+		// Similarly to Listen (see comment in that function), the caller
+		// should only be bothered with an error if it came from the backend as
+		// a response to our query.
+		gotResponse, err := l.cn.Unlisten(channel)
+		if gotResponse && err != nil {
+			return err
+		}
+	}
+
+	// Don't bother waiting for resync if there's no connection.
+	delete(l.channels, channel)
+	return nil
+}
+
+// UnlistenAll removes all channels from the Listener's channel list.  Returns
+// immediately with no error if there is no connection.  Note that you might
+// still get notifications for any of the deleted channels even after
+// UnlistenAll has returned.
+func (l *Listener) UnlistenAll() error {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	if l.isClosed {
+		return errListenerClosed
+	}
+
+	if l.cn != nil {
+		// Similarly to Listen (see comment in that function), the caller
+		// should only be bothered with an error if it came from the backend as
+		// a response to our query.
+		gotResponse, err := l.cn.UnlistenAll()
+		if gotResponse && err != nil {
+			return err
+		}
+	}
+
+	// Don't bother waiting for resync if there's no connection.
+	l.channels = make(map[string]struct{})
+	return nil
+}
+
+// Ping the remote server to make sure it's alive.  Non-nil return value means
+// that there is no active connection.
+func (l *Listener) Ping() error {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	if l.isClosed {
+		return errListenerClosed
+	}
+	if l.cn == nil {
+		return errors.New("no connection")
+	}
+
+	return l.cn.Ping()
+}
+
+// Clean up after losing the server connection.  Returns l.cn.Err(), which
+// should have the reason the connection was lost.
+func (l *Listener) disconnectCleanup() error {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	// sanity check; can't look at Err() until the channel has been closed
+	select {
+	case _, ok := <-l.connNotificationChan:
+		if ok {
+			panic("connNotificationChan not closed")
+		}
+	default:
+		panic("connNotificationChan not closed")
+	}
+
+	err := l.cn.Err()
+	l.cn.Close()
+	l.cn = nil
+	return err
+}
+
+// Synchronize the list of channels we want to be listening on with the server
+// after the connection has been established.
+func (l *Listener) resync(cn *ListenerConn, notificationChan <-chan *Notification) error {
+	doneChan := make(chan error)
+	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().
+			gotResponse, err := cn.Listen(channel)
+			if gotResponse && err != nil {
+				doneChan <- err
+				return
+			}
+
+			// If we couldn't reach the server, wait for notificationChan to
+			// close and then return the error message from the connection, as
+			// per ListenerConn's interface.
+			if err != nil {
+				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
+	// we can't possibly know which notifications (if any) were lost while
+	// the connection was down, so there's no reason to try and process
+	// these messages at all.
+	for {
+		select {
+		case _, ok := <-notificationChan:
+			if !ok {
+				notificationChan = nil
+			}
+
+		case err := <-doneChan:
+			return err
+		}
+	}
+}
+
+// caller should NOT be holding l.lock
+func (l *Listener) closed() bool {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	return l.isClosed
+}
+
+func (l *Listener) connect() error {
+	notificationChan := make(chan *Notification, 32)
+	cn, err := newDialListenerConn(l.dialer, l.name, notificationChan)
+	if err != nil {
+		return err
+	}
+
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	err = l.resync(cn, notificationChan)
+	if err != nil {
+		cn.Close()
+		return err
+	}
+
+	l.cn = cn
+	l.connNotificationChan = notificationChan
+	l.reconnectCond.Broadcast()
+
+	return nil
+}
+
+// Close disconnects the Listener from the database and shuts it down.
+// Subsequent calls to its methods will return an error.  Close returns an
+// error if the connection has already been closed.
+func (l *Listener) Close() error {
+	l.lock.Lock()
+	defer l.lock.Unlock()
+
+	if l.isClosed {
+		return errListenerClosed
+	}
+
+	if l.cn != nil {
+		l.cn.Close()
+	}
+	l.isClosed = true
+
+	// Unblock calls to Listen()
+	l.reconnectCond.Broadcast()
+
+	return nil
+}
+
+func (l *Listener) emitEvent(event ListenerEventType, err error) {
+	if l.eventCallback != nil {
+		l.eventCallback(event, err)
+	}
+}
+
+// Main logic here: maintain a connection to the server when possible, wait
+// for notifications and emit events.
+func (l *Listener) listenerConnLoop() {
+	var nextReconnect time.Time
+
+	reconnectInterval := l.minReconnectInterval
+	for {
+		for {
+			err := l.connect()
+			if err == nil {
+				break
+			}
+
+			if l.closed() {
+				return
+			}
+			l.emitEvent(ListenerEventConnectionAttemptFailed, err)
+
+			time.Sleep(reconnectInterval)
+			reconnectInterval *= 2
+			if reconnectInterval > l.maxReconnectInterval {
+				reconnectInterval = l.maxReconnectInterval
+			}
+		}
+
+		if nextReconnect.IsZero() {
+			l.emitEvent(ListenerEventConnected, nil)
+		} else {
+			l.emitEvent(ListenerEventReconnected, nil)
+			l.Notify <- nil
+		}
+
+		reconnectInterval = l.minReconnectInterval
+		nextReconnect = time.Now().Add(reconnectInterval)
+
+		for {
+			notification, ok := <-l.connNotificationChan
+			if !ok {
+				// lost connection, loop again
+				break
+			}
+			l.Notify <- notification
+		}
+
+		err := l.disconnectCleanup()
+		if l.closed() {
+			return
+		}
+		l.emitEvent(ListenerEventDisconnected, err)
+
+		time.Sleep(time.Until(nextReconnect))
+	}
+}
+
+func (l *Listener) listenerMain() {
+	l.listenerConnLoop()
+	close(l.Notify)
+}

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

@@ -0,0 +1,6 @@
+// Package oid contains OID constants
+// as defined by the Postgres server.
+package oid
+
+// Oid is a Postgres Object ID.
+type Oid uint32

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

@@ -0,0 +1,93 @@
+// +build ignore
+
+// Generate the table of OID values
+// Run with 'go run gen.go'.
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"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")
+
+	if datname == "" {
+		os.Setenv("PGDATABASE", "pqgotest")
+	}
+
+	if sslmode == "" {
+		os.Setenv("PGSSLMODE", "disable")
+	}
+
+	db, err := sql.Open("postgres", "")
+	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()
+	if err != nil {
+		log.Fatal(err)
+	}
+	f, err := os.Create("types.go")
+	if err != nil {
+		log.Fatal(err)
+	}
+	cmd.Stdout = f
+	err = cmd.Start()
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Fprintln(w, "// Code generated by gen.go. DO NOT EDIT.")
+	fmt.Fprintln(w, "\npackage oid")
+	fmt.Fprintln(w, "const (")
+	for _, oid := range oids {
+		fmt.Fprintf(w, "T_%s Oid = %d\n", oid.Type, oid.ID)
+	}
+	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

@@ -0,0 +1,343 @@
+// Code generated by gen.go. DO NOT EDIT.
+
+package oid
+
+const (
+	T_bool             Oid = 16
+	T_bytea            Oid = 17
+	T_char             Oid = 18
+	T_name             Oid = 19
+	T_int8             Oid = 20
+	T_int2             Oid = 21
+	T_int2vector       Oid = 22
+	T_int4             Oid = 23
+	T_regproc          Oid = 24
+	T_text             Oid = 25
+	T_oid              Oid = 26
+	T_tid              Oid = 27
+	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
+	T_pg_class         Oid = 83
+	T_json             Oid = 114
+	T_xml              Oid = 142
+	T__xml             Oid = 143
+	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
+	T_box              Oid = 603
+	T_polygon          Oid = 604
+	T_line             Oid = 628
+	T__line            Oid = 629
+	T_cidr             Oid = 650
+	T__cidr            Oid = 651
+	T_float4           Oid = 700
+	T_float8           Oid = 701
+	T_abstime          Oid = 702
+	T_reltime          Oid = 703
+	T_tinterval        Oid = 704
+	T_unknown          Oid = 705
+	T_circle           Oid = 718
+	T__circle          Oid = 719
+	T_money            Oid = 790
+	T__money           Oid = 791
+	T_macaddr          Oid = 829
+	T_inet             Oid = 869
+	T__bool            Oid = 1000
+	T__bytea           Oid = 1001
+	T__char            Oid = 1002
+	T__name            Oid = 1003
+	T__int2            Oid = 1005
+	T__int2vector      Oid = 1006
+	T__int4            Oid = 1007
+	T__regproc         Oid = 1008
+	T__text            Oid = 1009
+	T__tid             Oid = 1010
+	T__xid             Oid = 1011
+	T__cid             Oid = 1012
+	T__oidvector       Oid = 1013
+	T__bpchar          Oid = 1014
+	T__varchar         Oid = 1015
+	T__int8            Oid = 1016
+	T__point           Oid = 1017
+	T__lseg            Oid = 1018
+	T__path            Oid = 1019
+	T__box             Oid = 1020
+	T__float4          Oid = 1021
+	T__float8          Oid = 1022
+	T__abstime         Oid = 1023
+	T__reltime         Oid = 1024
+	T__tinterval       Oid = 1025
+	T__polygon         Oid = 1027
+	T__oid             Oid = 1028
+	T_aclitem          Oid = 1033
+	T__aclitem         Oid = 1034
+	T__macaddr         Oid = 1040
+	T__inet            Oid = 1041
+	T_bpchar           Oid = 1042
+	T_varchar          Oid = 1043
+	T_date             Oid = 1082
+	T_time             Oid = 1083
+	T_timestamp        Oid = 1114
+	T__timestamp       Oid = 1115
+	T__date            Oid = 1182
+	T__time            Oid = 1183
+	T_timestamptz      Oid = 1184
+	T__timestamptz     Oid = 1185
+	T_interval         Oid = 1186
+	T__interval        Oid = 1187
+	T__numeric         Oid = 1231
+	T_pg_database      Oid = 1248
+	T__cstring         Oid = 1263
+	T_timetz           Oid = 1266
+	T__timetz          Oid = 1270
+	T_bit              Oid = 1560
+	T__bit             Oid = 1561
+	T_varbit           Oid = 1562
+	T__varbit          Oid = 1563
+	T_numeric          Oid = 1700
+	T_refcursor        Oid = 1790
+	T__refcursor       Oid = 2201
+	T_regprocedure     Oid = 2202
+	T_regoper          Oid = 2203
+	T_regoperator      Oid = 2204
+	T_regclass         Oid = 2205
+	T_regtype          Oid = 2206
+	T__regprocedure    Oid = 2207
+	T__regoper         Oid = 2208
+	T__regoperator     Oid = 2209
+	T__regclass        Oid = 2210
+	T__regtype         Oid = 2211
+	T_record           Oid = 2249
+	T_cstring          Oid = 2275
+	T_any              Oid = 2276
+	T_anyarray         Oid = 2277
+	T_void             Oid = 2278
+	T_trigger          Oid = 2279
+	T_language_handler Oid = 2280
+	T_internal         Oid = 2281
+	T_opaque           Oid = 2282
+	T_anyelement       Oid = 2283
+	T__record          Oid = 2287
+	T_anynonarray      Oid = 2776
+	T_pg_authid        Oid = 2842
+	T_pg_auth_members  Oid = 2843
+	T__txid_snapshot   Oid = 2949
+	T_uuid             Oid = 2950
+	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
+	T_gtsvector        Oid = 3642
+	T__tsvector        Oid = 3643
+	T__gtsvector       Oid = 3644
+	T__tsquery         Oid = 3645
+	T_regconfig        Oid = 3734
+	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
+	T__int4range       Oid = 3905
+	T_numrange         Oid = 3906
+	T__numrange        Oid = 3907
+	T_tsrange          Oid = 3908
+	T__tsrange         Oid = 3909
+	T_tstzrange        Oid = 3910
+	T__tstzrange       Oid = 3911
+	T_daterange        Oid = 3912
+	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/scram/scram.go

@@ -0,0 +1,264 @@
+// Copyright (c) 2014 - Gustavo Niemeyer <gustavo@niemeyer.net>
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Pacakage scram implements a SCRAM-{SHA-1,etc} client per RFC5802.
+//
+// http://tools.ietf.org/html/rfc5802
+//
+package scram
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"hash"
+	"strconv"
+	"strings"
+)
+
+// Client implements a SCRAM-* client (SCRAM-SHA-1, SCRAM-SHA-256, etc).
+//
+// A Client may be used within a SASL conversation with logic resembling:
+//
+//    var in []byte
+//    var client = scram.NewClient(sha1.New, user, pass)
+//    for client.Step(in) {
+//            out := client.Out()
+//            // send out to server
+//            in := serverOut
+//    }
+//    if client.Err() != nil {
+//            // auth failed
+//    }
+//
+type Client struct {
+	newHash func() hash.Hash
+
+	user string
+	pass string
+	step int
+	out  bytes.Buffer
+	err  error
+
+	clientNonce []byte
+	serverNonce []byte
+	saltedPass  []byte
+	authMsg     bytes.Buffer
+}
+
+// NewClient returns a new SCRAM-* client with the provided hash algorithm.
+//
+// For SCRAM-SHA-256, for example, use:
+//
+//    client := scram.NewClient(sha256.New, user, pass)
+//
+func NewClient(newHash func() hash.Hash, user, pass string) *Client {
+	c := &Client{
+		newHash: newHash,
+		user:    user,
+		pass:    pass,
+	}
+	c.out.Grow(256)
+	c.authMsg.Grow(256)
+	return c
+}
+
+// Out returns the data to be sent to the server in the current step.
+func (c *Client) Out() []byte {
+	if c.out.Len() == 0 {
+		return nil
+	}
+	return c.out.Bytes()
+}
+
+// Err returns the error that ocurred, or nil if there were no errors.
+func (c *Client) Err() error {
+	return c.err
+}
+
+// SetNonce sets the client nonce to the provided value.
+// If not set, the nonce is generated automatically out of crypto/rand on the first step.
+func (c *Client) SetNonce(nonce []byte) {
+	c.clientNonce = nonce
+}
+
+var escaper = strings.NewReplacer("=", "=3D", ",", "=2C")
+
+// Step processes the incoming data from the server and makes the
+// next round of data for the server available via Client.Out.
+// Step returns false if there are no errors and more data is
+// still expected.
+func (c *Client) Step(in []byte) bool {
+	c.out.Reset()
+	if c.step > 2 || c.err != nil {
+		return false
+	}
+	c.step++
+	switch c.step {
+	case 1:
+		c.err = c.step1(in)
+	case 2:
+		c.err = c.step2(in)
+	case 3:
+		c.err = c.step3(in)
+	}
+	return c.step > 2 || c.err != nil
+}
+
+func (c *Client) step1(in []byte) error {
+	if len(c.clientNonce) == 0 {
+		const nonceLen = 16
+		buf := make([]byte, nonceLen+b64.EncodedLen(nonceLen))
+		if _, err := rand.Read(buf[:nonceLen]); err != nil {
+			return fmt.Errorf("cannot read random SCRAM-SHA-256 nonce from operating system: %v", err)
+		}
+		c.clientNonce = buf[nonceLen:]
+		b64.Encode(c.clientNonce, buf[:nonceLen])
+	}
+	c.authMsg.WriteString("n=")
+	escaper.WriteString(&c.authMsg, c.user)
+	c.authMsg.WriteString(",r=")
+	c.authMsg.Write(c.clientNonce)
+
+	c.out.WriteString("n,,")
+	c.out.Write(c.authMsg.Bytes())
+	return nil
+}
+
+var b64 = base64.StdEncoding
+
+func (c *Client) step2(in []byte) error {
+	c.authMsg.WriteByte(',')
+	c.authMsg.Write(in)
+
+	fields := bytes.Split(in, []byte(","))
+	if len(fields) != 3 {
+		return fmt.Errorf("expected 3 fields in first SCRAM-SHA-256 server message, got %d: %q", len(fields), in)
+	}
+	if !bytes.HasPrefix(fields[0], []byte("r=")) || len(fields[0]) < 2 {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 nonce: %q", fields[0])
+	}
+	if !bytes.HasPrefix(fields[1], []byte("s=")) || len(fields[1]) < 6 {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 salt: %q", fields[1])
+	}
+	if !bytes.HasPrefix(fields[2], []byte("i=")) || len(fields[2]) < 6 {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 iteration count: %q", fields[2])
+	}
+
+	c.serverNonce = fields[0][2:]
+	if !bytes.HasPrefix(c.serverNonce, c.clientNonce) {
+		return fmt.Errorf("server SCRAM-SHA-256 nonce is not prefixed by client nonce: got %q, want %q+\"...\"", c.serverNonce, c.clientNonce)
+	}
+
+	salt := make([]byte, b64.DecodedLen(len(fields[1][2:])))
+	n, err := b64.Decode(salt, fields[1][2:])
+	if err != nil {
+		return fmt.Errorf("cannot decode SCRAM-SHA-256 salt sent by server: %q", fields[1])
+	}
+	salt = salt[:n]
+	iterCount, err := strconv.Atoi(string(fields[2][2:]))
+	if err != nil {
+		return fmt.Errorf("server sent an invalid SCRAM-SHA-256 iteration count: %q", fields[2])
+	}
+	c.saltPassword(salt, iterCount)
+
+	c.authMsg.WriteString(",c=biws,r=")
+	c.authMsg.Write(c.serverNonce)
+
+	c.out.WriteString("c=biws,r=")
+	c.out.Write(c.serverNonce)
+	c.out.WriteString(",p=")
+	c.out.Write(c.clientProof())
+	return nil
+}
+
+func (c *Client) step3(in []byte) error {
+	var isv, ise bool
+	var fields = bytes.Split(in, []byte(","))
+	if len(fields) == 1 {
+		isv = bytes.HasPrefix(fields[0], []byte("v="))
+		ise = bytes.HasPrefix(fields[0], []byte("e="))
+	}
+	if ise {
+		return fmt.Errorf("SCRAM-SHA-256 authentication error: %s", fields[0][2:])
+	} else if !isv {
+		return fmt.Errorf("unsupported SCRAM-SHA-256 final message from server: %q", in)
+	}
+	if !bytes.Equal(c.serverSignature(), fields[0][2:]) {
+		return fmt.Errorf("cannot authenticate SCRAM-SHA-256 server signature: %q", fields[0][2:])
+	}
+	return nil
+}
+
+func (c *Client) saltPassword(salt []byte, iterCount int) {
+	mac := hmac.New(c.newHash, []byte(c.pass))
+	mac.Write(salt)
+	mac.Write([]byte{0, 0, 0, 1})
+	ui := mac.Sum(nil)
+	hi := make([]byte, len(ui))
+	copy(hi, ui)
+	for i := 1; i < iterCount; i++ {
+		mac.Reset()
+		mac.Write(ui)
+		mac.Sum(ui[:0])
+		for j, b := range ui {
+			hi[j] ^= b
+		}
+	}
+	c.saltedPass = hi
+}
+
+func (c *Client) clientProof() []byte {
+	mac := hmac.New(c.newHash, c.saltedPass)
+	mac.Write([]byte("Client Key"))
+	clientKey := mac.Sum(nil)
+	hash := c.newHash()
+	hash.Write(clientKey)
+	storedKey := hash.Sum(nil)
+	mac = hmac.New(c.newHash, storedKey)
+	mac.Write(c.authMsg.Bytes())
+	clientProof := mac.Sum(nil)
+	for i, b := range clientKey {
+		clientProof[i] ^= b
+	}
+	clientProof64 := make([]byte, b64.EncodedLen(len(clientProof)))
+	b64.Encode(clientProof64, clientProof)
+	return clientProof64
+}
+
+func (c *Client) serverSignature() []byte {
+	mac := hmac.New(c.newHash, c.saltedPass)
+	mac.Write([]byte("Server Key"))
+	serverKey := mac.Sum(nil)
+
+	mac = hmac.New(c.newHash, serverKey)
+	mac.Write(c.authMsg.Bytes())
+	serverSignature := mac.Sum(nil)
+
+	encoded := make([]byte, b64.EncodedLen(len(serverSignature)))
+	b64.Encode(encoded, serverSignature)
+	return encoded
+}

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/url.go

@@ -0,0 +1,76 @@
+package pq
+
+import (
+	"fmt"
+	"net"
+	nurl "net/url"
+	"sort"
+	"strings"
+)
+
+// ParseURL no longer needs to be used by clients of this library since supplying a URL as a
+// connection string to sql.Open() is now supported:
+//
+//	sql.Open("postgres", "postgres://bob:secret@1.2.3.4:5432/mydb?sslmode=verify-full")
+//
+// It remains exported here for backwards-compatibility.
+//
+// ParseURL converts a url to a connection string for driver.Open.
+// Example:
+//
+//	"postgres://bob:secret@1.2.3.4:5432/mydb?sslmode=verify-full"
+//
+// converts to:
+//
+//	"user=bob password=secret host=1.2.3.4 port=5432 dbname=mydb sslmode=verify-full"
+//
+// A minimal example:
+//
+//	"postgres://"
+//
+// This will be blank, causing driver.Open to use all of the defaults
+func ParseURL(url string) (string, error) {
+	u, err := nurl.Parse(url)
+	if err != nil {
+		return "", err
+	}
+
+	if u.Scheme != "postgres" && u.Scheme != "postgresql" {
+		return "", fmt.Errorf("invalid connection protocol: %s", u.Scheme)
+	}
+
+	var kvs []string
+	escaper := strings.NewReplacer(` `, `\ `, `'`, `\'`, `\`, `\\`)
+	accrue := func(k, v string) {
+		if v != "" {
+			kvs = append(kvs, k+"="+escaper.Replace(v))
+		}
+	}
+
+	if u.User != nil {
+		v := u.User.Username()
+		accrue("user", v)
+
+		v, _ = u.User.Password()
+		accrue("password", v)
+	}
+
+	if host, port, err := net.SplitHostPort(u.Host); err != nil {
+		accrue("host", u.Host)
+	} else {
+		accrue("host", host)
+		accrue("port", port)
+	}
+
+	if u.Path != "" {
+		accrue("dbname", u.Path[1:])
+	}
+
+	q := u.Query()
+	for k := range q {
+		accrue(k, q.Get(k))
+	}
+
+	sort.Strings(kvs) // Makes testing easier (not a performance concern)
+	return strings.Join(kvs, " "), nil
+}

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

@@ -0,0 +1,24 @@
+// Package pq is a pure Go Postgres driver for the database/sql package.
+
+// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris rumprun
+
+package pq
+
+import (
+	"os"
+	"os/user"
+)
+
+func userCurrent() (string, error) {
+	u, err := user.Current()
+	if err == nil {
+		return u.Username, nil
+	}
+
+	name := os.Getenv("USER")
+	if name != "" {
+		return name, nil
+	}
+
+	return "", ErrCouldNotDetectUsername
+}

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

@@ -0,0 +1,27 @@
+// Package pq is a pure Go Postgres driver for the database/sql package.
+package pq
+
+import (
+	"path/filepath"
+	"syscall"
+)
+
+// Perform Windows user name lookup identically to libpq.
+//
+// The PostgreSQL code makes use of the legacy Win32 function
+// GetUserName, and that function has not been imported into stock Go.
+// GetUserNameEx is available though, the difference being that a
+// wider range of names are available.  To get the output to be the
+// same as GetUserName, only the base (or last) component of the
+// result is returned.
+func userCurrent() (string, error) {
+	pw_name := make([]uint16, 128)
+	pwname_size := uint32(len(pw_name)) - 1
+	err := syscall.GetUserNameEx(syscall.NameSamCompatible, &pw_name[0], &pwname_size)
+	if err != nil {
+		return "", ErrCouldNotDetectUsername
+	}
+	s := syscall.UTF16ToString(pw_name)
+	u := filepath.Base(s)
+	return u, 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
+}

vendor/github.com/status-im/migrate/database/postgres/postgres.go

@@ -0,0 +1,339 @@
+// +build go1.9
+
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"io"
+	"io/ioutil"
+	nurl "net/url"
+	"strconv"
+	"strings"
+
+	"github.com/golang-migrate/migrate"
+	"github.com/golang-migrate/migrate/database"
+	"github.com/lib/pq"
+)
+
+func init() {
+	db := Postgres{}
+	database.Register("postgres", &db)
+	database.Register("postgresql", &db)
+}
+
+var DefaultMigrationsTable = "schema_migrations"
+
+var (
+	ErrNilConfig      = fmt.Errorf("no config")
+	ErrNoDatabaseName = fmt.Errorf("no database name")
+	ErrNoSchema       = fmt.Errorf("no schema")
+	ErrDatabaseDirty  = fmt.Errorf("database is dirty")
+)
+
+type Config struct {
+	MigrationsTable string
+	DatabaseName    string
+}
+
+type Postgres struct {
+	// Locking and unlocking need to use the same connection
+	conn     *sql.Conn
+	db       *sql.DB
+	isLocked bool
+
+	// Open and WithInstance need to garantuee that config is never nil
+	config *Config
+}
+
+func WithInstance(instance *sql.DB, config *Config) (database.Driver, error) {
+	if config == nil {
+		return nil, ErrNilConfig
+	}
+
+	if err := instance.Ping(); err != nil {
+		return nil, err
+	}
+
+	query := `SELECT CURRENT_DATABASE()`
+	var databaseName string
+	if err := instance.QueryRow(query).Scan(&databaseName); err != nil {
+		return nil, &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+
+	if len(databaseName) == 0 {
+		return nil, ErrNoDatabaseName
+	}
+
+	config.DatabaseName = databaseName
+
+	if len(config.MigrationsTable) == 0 {
+		config.MigrationsTable = DefaultMigrationsTable
+	}
+
+	conn, err := instance.Conn(context.Background())
+
+	if err != nil {
+		return nil, err
+	}
+
+	px := &Postgres{
+		conn:   conn,
+		db:     instance,
+		config: config,
+	}
+
+	if err := px.ensureVersionTable(); err != nil {
+		return nil, err
+	}
+
+	return px, nil
+}
+
+func (p *Postgres) Open(url string) (database.Driver, error) {
+	purl, err := nurl.Parse(url)
+	if err != nil {
+		return nil, err
+	}
+
+	db, err := sql.Open("postgres", migrate.FilterCustomQuery(purl).String())
+	if err != nil {
+		return nil, err
+	}
+
+	migrationsTable := purl.Query().Get("x-migrations-table")
+	if len(migrationsTable) == 0 {
+		migrationsTable = DefaultMigrationsTable
+	}
+
+	px, err := WithInstance(db, &Config{
+		DatabaseName:    purl.Path,
+		MigrationsTable: migrationsTable,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return px, nil
+}
+
+func (p *Postgres) Close() error {
+	connErr := p.conn.Close()
+	dbErr := p.db.Close()
+	if connErr != nil || dbErr != nil {
+		return fmt.Errorf("conn: %v, db: %v", connErr, dbErr)
+	}
+	return nil
+}
+
+// https://www.postgresql.org/docs/9.6/static/explicit-locking.html#ADVISORY-LOCKS
+func (p *Postgres) Lock() error {
+	if p.isLocked {
+		return database.ErrLocked
+	}
+
+	aid, err := database.GenerateAdvisoryLockId(p.config.DatabaseName)
+	if err != nil {
+		return err
+	}
+
+	// This will either obtain the lock immediately and return true,
+	// or return false if the lock cannot be acquired immediately.
+	query := `SELECT pg_advisory_lock($1)`
+	if _, err := p.conn.ExecContext(context.Background(), query, aid); err != nil {
+		return &database.Error{OrigErr: err, Err: "try lock failed", Query: []byte(query)}
+	}
+
+	p.isLocked = true
+	return nil
+}
+
+func (p *Postgres) Unlock() error {
+	if !p.isLocked {
+		return nil
+	}
+
+	aid, err := database.GenerateAdvisoryLockId(p.config.DatabaseName)
+	if err != nil {
+		return err
+	}
+
+	query := `SELECT pg_advisory_unlock($1)`
+	if _, err := p.conn.ExecContext(context.Background(), query, aid); err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+	p.isLocked = false
+	return nil
+}
+
+func (p *Postgres) Run(migration io.Reader) error {
+	migr, err := ioutil.ReadAll(migration)
+	if err != nil {
+		return err
+	}
+
+	// run migration
+	query := string(migr[:])
+	if _, err := p.conn.ExecContext(context.Background(), query); err != nil {
+		if pgErr, ok := err.(*pq.Error); ok {
+			var line uint
+			var col uint
+			var lineColOK bool
+			if pgErr.Position != "" {
+				if pos, err := strconv.ParseUint(pgErr.Position, 10, 64); err == nil {
+					line, col, lineColOK = computeLineFromPos(query, int(pos))
+				}
+			}
+			message := fmt.Sprintf("migration failed: %s", pgErr.Message)
+			if lineColOK {
+				message = fmt.Sprintf("%s (column %d)", message, col)
+			}
+			if pgErr.Detail != "" {
+				message = fmt.Sprintf("%s, %s", message, pgErr.Detail)
+			}
+			return database.Error{OrigErr: err, Err: message, Query: migr, Line: line}
+		}
+		return database.Error{OrigErr: err, Err: "migration failed", Query: migr}
+	}
+
+	return nil
+}
+
+func computeLineFromPos(s string, pos int) (line uint, col uint, ok bool) {
+	// replace crlf with lf
+	s = strings.Replace(s, "\r\n", "\n", -1)
+	// pg docs: pos uses index 1 for the first character, and positions are measured in characters not bytes
+	runes := []rune(s)
+	if pos > len(runes) {
+		return 0, 0, false
+	}
+	sel := runes[:pos]
+	line = uint(runesCount(sel, newLine) + 1)
+	col = uint(pos - 1 - runesLastIndex(sel, newLine))
+	return line, col, true
+}
+
+const newLine = '\n'
+
+func runesCount(input []rune, target rune) int {
+	var count int
+	for _, r := range input {
+		if r == target {
+			count++
+		}
+	}
+	return count
+}
+
+func runesLastIndex(input []rune, target rune) int {
+	for i := len(input) - 1; i >= 0; i-- {
+		if input[i] == target {
+			return i
+		}
+	}
+	return -1
+}
+
+func (p *Postgres) SetVersion(version int, dirty bool) error {
+	tx, err := p.conn.BeginTx(context.Background(), &sql.TxOptions{})
+	if err != nil {
+		return &database.Error{OrigErr: err, Err: "transaction start failed"}
+	}
+
+	query := `TRUNCATE "` + p.config.MigrationsTable + `"`
+	if _, err := tx.Exec(query); err != nil {
+		tx.Rollback()
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+
+	if version >= 0 {
+		query = `INSERT INTO "` + p.config.MigrationsTable + `" (version, dirty) VALUES ($1, $2)`
+		if _, err := tx.Exec(query, version, dirty); err != nil {
+			tx.Rollback()
+			return &database.Error{OrigErr: err, Query: []byte(query)}
+		}
+	}
+
+	if err := tx.Commit(); err != nil {
+		return &database.Error{OrigErr: err, Err: "transaction commit failed"}
+	}
+
+	return nil
+}
+
+func (p *Postgres) Version() (version int, dirty bool, err error) {
+	query := `SELECT version, dirty FROM "` + p.config.MigrationsTable + `" LIMIT 1`
+	err = p.conn.QueryRowContext(context.Background(), query).Scan(&version, &dirty)
+	switch {
+	case err == sql.ErrNoRows:
+		return database.NilVersion, false, nil
+
+	case err != nil:
+		if e, ok := err.(*pq.Error); ok {
+			if e.Code.Name() == "undefined_table" {
+				return database.NilVersion, false, nil
+			}
+		}
+		return 0, false, &database.Error{OrigErr: err, Query: []byte(query)}
+
+	default:
+		return version, dirty, nil
+	}
+}
+
+func (p *Postgres) Drop() error {
+	// select all tables in current schema
+	query := `SELECT table_name FROM information_schema.tables WHERE table_schema=(SELECT current_schema())`
+	tables, err := p.conn.QueryContext(context.Background(), query)
+	if err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+	defer tables.Close()
+
+	// delete one table after another
+	tableNames := make([]string, 0)
+	for tables.Next() {
+		var tableName string
+		if err := tables.Scan(&tableName); err != nil {
+			return err
+		}
+		if len(tableName) > 0 {
+			tableNames = append(tableNames, tableName)
+		}
+	}
+
+	if len(tableNames) > 0 {
+		// delete one by one ...
+		for _, t := range tableNames {
+			query = `DROP TABLE IF EXISTS ` + t + ` CASCADE`
+			if _, err := p.conn.ExecContext(context.Background(), query); err != nil {
+				return &database.Error{OrigErr: err, Query: []byte(query)}
+			}
+		}
+		if err := p.ensureVersionTable(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (p *Postgres) ensureVersionTable() error {
+	// check if migration table exists
+	var count int
+	query := `SELECT COUNT(1) FROM information_schema.tables WHERE table_name = $1 AND table_schema = (SELECT current_schema()) LIMIT 1`
+	if err := p.conn.QueryRowContext(context.Background(), query, p.config.MigrationsTable).Scan(&count); err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+	if count == 1 {
+		return nil
+	}
+
+	// if not, create the empty migration table
+	query = `CREATE TABLE "` + p.config.MigrationsTable + `" (version bigint not null primary key, dirty boolean not null)`
+	if _, err := p.conn.ExecContext(context.Background(), query); err != nil {
+		return &database.Error{OrigErr: err, Query: []byte(query)}
+	}
+	return nil
+}