add vendor

vendor/github.com/siddontang/rdb/loader.go

@@ -0,0 +1,112 @@
+// Copyright 2014 Wandoujia Inc. All Rights Reserved.
+// Licensed under the MIT (MIT-LICENSE.txt) license.
+
+package rdb
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"hash"
+	"io"
+	"strconv"
+)
+
+type Loader struct {
+	*rdbReader
+	crc hash.Hash64
+	db  uint32
+}
+
+func NewLoader(r io.Reader) *Loader {
+	l := &Loader{}
+	l.crc = newDigest()
+	l.rdbReader = newRdbReader(io.TeeReader(r, l.crc))
+	return l
+}
+
+func (l *Loader) LoadHeader() error {
+	header := make([]byte, 9)
+	if err := l.readFull(header); err != nil {
+		return err
+	}
+	if !bytes.Equal(header[:5], []byte("REDIS")) {
+		return fmt.Errorf("verify magic string, invalid file format")
+	}
+	if version, err := strconv.ParseInt(string(header[5:]), 10, 64); err != nil {
+		return err
+	} else if version <= 0 || version > Version {
+		return fmt.Errorf("verify version, invalid RDB version number %d", version)
+	}
+	return nil
+}
+
+func (l *Loader) LoadChecksum() error {
+	crc1 := l.crc.Sum64()
+	if crc2, err := l.readUint64(); err != nil {
+		return err
+	} else if crc1 != crc2 {
+		return fmt.Errorf("checksum validation failed")
+	}
+	return nil
+}
+
+type Entry struct {
+	DB       uint32
+	Key      []byte
+	ValDump  []byte
+	ExpireAt uint64
+}
+
+func (l *Loader) LoadEntry() (entry *Entry, err error) {
+	var expireat uint64
+	for {
+		var otype byte
+		if otype, err = l.readByte(); err != nil {
+			return
+		}
+		switch otype {
+		case rdbFlagExpiryMS:
+			if expireat, err = l.readUint64(); err != nil {
+				return
+			}
+		case rdbFlagExpiry:
+			var sec uint32
+			if sec, err = l.readUint32(); err != nil {
+				return
+			}
+			expireat = uint64(sec) * 1000
+		case rdbFlagSelectDB:
+			if l.db, err = l.readLength(); err != nil {
+				return
+			}
+		case rdbFlagEOF:
+			return
+		default:
+			var key, obj []byte
+			if key, err = l.readString(); err != nil {
+				return
+			}
+			if obj, err = l.readObject(otype); err != nil {
+				return
+			}
+			entry = &Entry{}
+			entry.DB = l.db
+			entry.Key = key
+			entry.ValDump = createValDump(otype, obj)
+			entry.ExpireAt = expireat
+			return
+		}
+	}
+}
+
+func createValDump(otype byte, obj []byte) []byte {
+	var b bytes.Buffer
+	c := newDigest()
+	w := io.MultiWriter(&b, c)
+	w.Write([]byte{otype})
+	w.Write(obj)
+	binary.Write(w, binary.LittleEndian, uint16(Version))
+	binary.Write(w, binary.LittleEndian, c.Sum64())
+	return b.Bytes()
+}