add other session providers (#5963)

1 files changed, 922 insertions, 0 deletions

diff --git a/vendor/github.com/lunny/nodb/t_bit.go b/vendor/github.com/lunny/nodb/t_bit.go
new file mode 100644
index 0000000000..930d4ba568
--- /dev/null
+++ b/vendor/github.com/lunny/nodb/t_bit.go
@@ -0,0 +1,922 @@
+package nodb
+
+import (
+	"encoding/binary"
+	"errors"
+	"sort"
+	"time"
+
+	"github.com/lunny/nodb/store"
+)
+
+const (
+	OPand uint8 = iota + 1
+	OPor
+	OPxor
+	OPnot
+)
+
+type BitPair struct {
+	Pos int32
+	Val uint8
+}
+
+type segBitInfo struct {
+	Seq uint32
+	Off uint32
+	Val uint8
+}
+
+type segBitInfoArray []segBitInfo
+
+const (
+	// byte
+	segByteWidth uint32 = 9
+	segByteSize  uint32 = 1 << segByteWidth
+
+	// bit
+	segBitWidth uint32 = segByteWidth + 3
+	segBitSize  uint32 = segByteSize << 3
+
+	maxByteSize uint32 = 8 << 20
+	maxSegCount uint32 = maxByteSize / segByteSize
+
+	minSeq uint32 = 0
+	maxSeq uint32 = uint32((maxByteSize << 3) - 1)
+)
+
+var bitsInByte = [256]int32{0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3,
+	4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3,
+	3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4,
+	5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4,
+	3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4,
+	5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 1, 2,
+	2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3,
+	4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
+	3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4,
+	5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6,
+	6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5,
+	6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8}
+
+var fillBits = [...]uint8{1, 3, 7, 15, 31, 63, 127, 255}
+
+var emptySegment []byte = make([]byte, segByteSize, segByteSize)
+
+var fillSegment []byte = func() []byte {
+	data := make([]byte, segByteSize, segByteSize)
+	for i := uint32(0); i < segByteSize; i++ {
+		data[i] = 0xff
+	}
+	return data
+}()
+
+var errBinKey = errors.New("invalid bin key")
+var errOffset = errors.New("invalid offset")
+var errDuplicatePos = errors.New("duplicate bit pos")
+
+func getBit(sz []byte, offset uint32) uint8 {
+	index := offset >> 3
+	if index >= uint32(len(sz)) {
+		return 0 // error("overflow")
+	}
+
+	offset -= index << 3
+	return sz[index] >> offset & 1
+}
+
+func setBit(sz []byte, offset uint32, val uint8) bool {
+	if val != 1 && val != 0 {
+		return false // error("invalid val")
+	}
+
+	index := offset >> 3
+	if index >= uint32(len(sz)) {
+		return false // error("overflow")
+	}
+
+	offset -= index << 3
+	if sz[index]>>offset&1 != val {
+		sz[index] ^= (1 << offset)
+	}
+	return true
+}
+
+func (datas segBitInfoArray) Len() int {
+	return len(datas)
+}
+
+func (datas segBitInfoArray) Less(i, j int) bool {
+	res := (datas)[i].Seq < (datas)[j].Seq
+	if !res && (datas)[i].Seq == (datas)[j].Seq {
+		res = (datas)[i].Off < (datas)[j].Off
+	}
+	return res
+}
+
+func (datas segBitInfoArray) Swap(i, j int) {
+	datas[i], datas[j] = datas[j], datas[i]
+}
+
+func (db *DB) bEncodeMetaKey(key []byte) []byte {
+	mk := make([]byte, len(key)+2)
+	mk[0] = db.index
+	mk[1] = BitMetaType
+
+	copy(mk[2:], key)
+	return mk
+}
+
+func (db *DB) bDecodeMetaKey(bkey []byte) ([]byte, error) {
+	if len(bkey) < 2 || bkey[0] != db.index || bkey[1] != BitMetaType {
+		return nil, errBinKey
+	}
+
+	return bkey[2:], nil
+}
+
+func (db *DB) bEncodeBinKey(key []byte, seq uint32) []byte {
+	bk := make([]byte, len(key)+8)
+
+	pos := 0
+	bk[pos] = db.index
+	pos++
+	bk[pos] = BitType
+	pos++
+
+	binary.BigEndian.PutUint16(bk[pos:], uint16(len(key)))
+	pos += 2
+
+	copy(bk[pos:], key)
+	pos += len(key)
+
+	binary.BigEndian.PutUint32(bk[pos:], seq)
+
+	return bk
+}
+
+func (db *DB) bDecodeBinKey(bkey []byte) (key []byte, seq uint32, err error) {
+	if len(bkey) < 8 || bkey[0] != db.index {
+		err = errBinKey
+		return
+	}
+
+	keyLen := binary.BigEndian.Uint16(bkey[2:4])
+	if int(keyLen+8) != len(bkey) {
+		err = errBinKey
+		return
+	}
+
+	key = bkey[4 : 4+keyLen]
+	seq = uint32(binary.BigEndian.Uint32(bkey[4+keyLen:]))
+	return
+}
+
+func (db *DB) bCapByteSize(seq uint32, off uint32) uint32 {
+	var offByteSize uint32 = (off >> 3) + 1
+	if offByteSize > segByteSize {
+		offByteSize = segByteSize
+	}
+
+	return seq<<segByteWidth + offByteSize
+}
+
+func (db *DB) bParseOffset(key []byte, offset int32) (seq uint32, off uint32, err error) {
+	if offset < 0 {
+		if tailSeq, tailOff, e := db.bGetMeta(key); e != nil {
+			err = e
+			return
+		} else if tailSeq >= 0 {
+			offset += int32((uint32(tailSeq)<<segBitWidth | uint32(tailOff)) + 1)
+			if offset < 0 {
+				err = errOffset
+				return
+			}
+		}
+	}
+
+	off = uint32(offset)
+
+	seq = off >> segBitWidth
+	off &= (segBitSize - 1)
+	return
+}
+
+func (db *DB) bGetMeta(key []byte) (tailSeq int32, tailOff int32, err error) {
+	var v []byte
+
+	mk := db.bEncodeMetaKey(key)
+	v, err = db.bucket.Get(mk)
+	if err != nil {
+		return
+	}
+
+	if v != nil {
+		tailSeq = int32(binary.LittleEndian.Uint32(v[0:4]))
+		tailOff = int32(binary.LittleEndian.Uint32(v[4:8]))
+	} else {
+		tailSeq = -1
+		tailOff = -1
+	}
+	return
+}
+
+func (db *DB) bSetMeta(t *batch, key []byte, tailSeq uint32, tailOff uint32) {
+	ek := db.bEncodeMetaKey(key)
+
+	buf := make([]byte, 8)
+	binary.LittleEndian.PutUint32(buf[0:4], tailSeq)
+	binary.LittleEndian.PutUint32(buf[4:8], tailOff)
+
+	t.Put(ek, buf)
+	return
+}
+
+func (db *DB) bUpdateMeta(t *batch, key []byte, seq uint32, off uint32) (tailSeq uint32, tailOff uint32, err error) {
+	var tseq, toff int32
+	var update bool = false
+
+	if tseq, toff, err = db.bGetMeta(key); err != nil {
+		return
+	} else if tseq < 0 {
+		update = true
+	} else {
+		tailSeq = uint32(MaxInt32(tseq, 0))
+		tailOff = uint32(MaxInt32(toff, 0))
+		update = (seq > tailSeq || (seq == tailSeq && off > tailOff))
+	}
+
+	if update {
+		db.bSetMeta(t, key, seq, off)
+		tailSeq = seq
+		tailOff = off
+	}
+	return
+}
+
+func (db *DB) bDelete(t *batch, key []byte) (drop int64) {
+	mk := db.bEncodeMetaKey(key)
+	t.Delete(mk)
+
+	minKey := db.bEncodeBinKey(key, minSeq)
+	maxKey := db.bEncodeBinKey(key, maxSeq)
+	it := db.bucket.RangeIterator(minKey, maxKey, store.RangeClose)
+	for ; it.Valid(); it.Next() {
+		t.Delete(it.RawKey())
+		drop++
+	}
+	it.Close()
+
+	return drop
+}
+
+func (db *DB) bGetSegment(key []byte, seq uint32) ([]byte, []byte, error) {
+	bk := db.bEncodeBinKey(key, seq)
+	segment, err := db.bucket.Get(bk)
+	if err != nil {
+		return bk, nil, err
+	}
+	return bk, segment, nil
+}
+
+func (db *DB) bAllocateSegment(key []byte, seq uint32) ([]byte, []byte, error) {
+	bk, segment, err := db.bGetSegment(key, seq)
+	if err == nil && segment == nil {
+		segment = make([]byte, segByteSize, segByteSize)
+	}
+	return bk, segment, err
+}
+
+func (db *DB) bIterator(key []byte) *store.RangeLimitIterator {
+	sk := db.bEncodeBinKey(key, minSeq)
+	ek := db.bEncodeBinKey(key, maxSeq)
+	return db.bucket.RangeIterator(sk, ek, store.RangeClose)
+}
+
+func (db *DB) bSegAnd(a []byte, b []byte, res *[]byte) {
+	if a == nil || b == nil {
+		*res = nil
+		return
+	}
+
+	data := *res
+	if data == nil {
+		data = make([]byte, segByteSize, segByteSize)
+		*res = data
+	}
+
+	for i := uint32(0); i < segByteSize; i++ {
+		data[i] = a[i] & b[i]
+	}
+	return
+}
+
+func (db *DB) bSegOr(a []byte, b []byte, res *[]byte) {
+	if a == nil || b == nil {
+		if a == nil && b == nil {
+			*res = nil
+		} else if a == nil {
+			*res = b
+		} else {
+			*res = a
+		}
+		return
+	}
+
+	data := *res
+	if data == nil {
+		data = make([]byte, segByteSize, segByteSize)
+		*res = data
+	}
+
+	for i := uint32(0); i < segByteSize; i++ {
+		data[i] = a[i] | b[i]
+	}
+	return
+}
+
+func (db *DB) bSegXor(a []byte, b []byte, res *[]byte) {
+	if a == nil && b == nil {
+		*res = fillSegment
+		return
+	}
+
+	if a == nil {
+		a = emptySegment
+	}
+
+	if b == nil {
+		b = emptySegment
+	}
+
+	data := *res
+	if data == nil {
+		data = make([]byte, segByteSize, segByteSize)
+		*res = data
+	}
+
+	for i := uint32(0); i < segByteSize; i++ {
+		data[i] = a[i] ^ b[i]
+	}
+
+	return
+}
+
+func (db *DB) bExpireAt(key []byte, when int64) (int64, error) {
+	t := db.binBatch
+	t.Lock()
+	defer t.Unlock()
+
+	if seq, _, err := db.bGetMeta(key); err != nil || seq < 0 {
+		return 0, err
+	} else {
+		db.expireAt(t, BitType, key, when)
+		if err := t.Commit(); err != nil {
+			return 0, err
+		}
+	}
+	return 1, nil
+}
+
+func (db *DB) bCountByte(val byte, soff uint32, eoff uint32) int32 {
+	if soff > eoff {
+		soff, eoff = eoff, soff
+	}
+
+	mask := uint8(0)
+	if soff > 0 {
+		mask |= fillBits[soff-1]
+	}
+	if eoff < 7 {
+		mask |= (fillBits[7] ^ fillBits[eoff])
+	}
+	mask = fillBits[7] ^ mask
+
+	return bitsInByte[val&mask]
+}
+
+func (db *DB) bCountSeg(key []byte, seq uint32, soff uint32, eoff uint32) (cnt int32, err error) {
+	if soff >= segBitSize || soff < 0 ||
+		eoff >= segBitSize || eoff < 0 {
+		return
+	}
+
+	var segment []byte
+	if _, segment, err = db.bGetSegment(key, seq); err != nil {
+		return
+	}
+
+	if segment == nil {
+		return
+	}
+
+	if soff > eoff {
+		soff, eoff = eoff, soff
+	}
+
+	headIdx := int(soff >> 3)
+	endIdx := int(eoff >> 3)
+	sByteOff := soff - ((soff >> 3) << 3)
+	eByteOff := eoff - ((eoff >> 3) << 3)
+
+	if headIdx == endIdx {
+		cnt = db.bCountByte(segment[headIdx], sByteOff, eByteOff)
+	} else {
+		cnt = db.bCountByte(segment[headIdx], sByteOff, 7) +
+			db.bCountByte(segment[endIdx], 0, eByteOff)
+	}
+
+	// sum up following bytes
+	for idx, end := headIdx+1, endIdx-1; idx <= end; idx += 1 {
+		cnt += bitsInByte[segment[idx]]
+		if idx == end {
+			break
+		}
+	}
+
+	return
+}
+
+func (db *DB) BGet(key []byte) (data []byte, err error) {
+	if err = checkKeySize(key); err != nil {
+		return
+	}
+
+	var ts, to int32
+	if ts, to, err = db.bGetMeta(key); err != nil || ts < 0 {
+		return
+	}
+
+	var tailSeq, tailOff = uint32(ts), uint32(to)
+	var capByteSize uint32 = db.bCapByteSize(tailSeq, tailOff)
+	data = make([]byte, capByteSize, capByteSize)
+
+	minKey := db.bEncodeBinKey(key, minSeq)
+	maxKey := db.bEncodeBinKey(key, tailSeq)
+	it := db.bucket.RangeIterator(minKey, maxKey, store.RangeClose)
+
+	var seq, s, e uint32
+	for ; it.Valid(); it.Next() {
+		if _, seq, err = db.bDecodeBinKey(it.RawKey()); err != nil {
+			data = nil
+			break
+		}
+
+		s = seq << segByteWidth
+		e = MinUInt32(s+segByteSize, capByteSize)
+		copy(data[s:e], it.RawValue())
+	}
+	it.Close()
+
+	return
+}
+
+func (db *DB) BDelete(key []byte) (drop int64, err error) {
+	if err = checkKeySize(key); err != nil {
+		return
+	}
+
+	t := db.binBatch
+	t.Lock()
+	defer t.Unlock()
+
+	drop = db.bDelete(t, key)
+	db.rmExpire(t, BitType, key)
+
+	err = t.Commit()
+	return
+}
+
+func (db *DB) BSetBit(key []byte, offset int32, val uint8) (ori uint8, err error) {
+	if err = checkKeySize(key); err != nil {
+		return
+	}
+
+	//	todo : check offset
+	var seq, off uint32
+	if seq, off, err = db.bParseOffset(key, offset); err != nil {
+		return 0, err
+	}
+
+	var bk, segment []byte
+	if bk, segment, err = db.bAllocateSegment(key, seq); err != nil {
+		return 0, err
+	}
+
+	if segment != nil {
+		ori = getBit(segment, off)
+		if setBit(segment, off, val) {
+			t := db.binBatch
+			t.Lock()
+			defer t.Unlock()
+
+			t.Put(bk, segment)
+			if _, _, e := db.bUpdateMeta(t, key, seq, off); e != nil {
+				err = e
+				return
+			}
+
+			err = t.Commit()
+		}
+	}
+
+	return
+}
+
+func (db *DB) BMSetBit(key []byte, args ...BitPair) (place int64, err error) {
+	if err = checkKeySize(key); err != nil {
+		return
+	}
+
+	//	(ps : so as to aviod wasting memory copy while calling db.Get() and batch.Put(),
+	//		  here we sequence the params by pos, so that we can merge the execution of
+	//		  diff pos setting which targets on the same segment respectively. )
+
+	//	#1 : sequence request data
+	var argCnt = len(args)
+	var bitInfos segBitInfoArray = make(segBitInfoArray, argCnt)
+	var seq, off uint32
+
+	for i, info := range args {
+		if seq, off, err = db.bParseOffset(key, info.Pos); err != nil {
+			return
+		}
+
+		bitInfos[i].Seq = seq
+		bitInfos[i].Off = off
+		bitInfos[i].Val = info.Val
+	}
+
+	sort.Sort(bitInfos)
+
+	for i := 1; i < argCnt; i++ {
+		if bitInfos[i].Seq == bitInfos[i-1].Seq && bitInfos[i].Off == bitInfos[i-1].Off {
+			return 0, errDuplicatePos
+		}
+	}
+
+	//	#2 : execute bit set in order
+	t := db.binBatch
+	t.Lock()
+	defer t.Unlock()
+
+	var curBinKey, curSeg []byte
+	var curSeq, maxSeq, maxOff uint32
+
+	for _, info := range bitInfos {
+		if curSeg != nil && info.Seq != curSeq {
+			t.Put(curBinKey, curSeg)
+			curSeg = nil
+		}
+
+		if curSeg == nil {
+			curSeq = info.Seq
+			if curBinKey, curSeg, err = db.bAllocateSegment(key, info.Seq); err != nil {
+				return
+			}
+
+			if curSeg == nil {
+				continue
+			}
+		}
+
+		if setBit(curSeg, info.Off, info.Val) {
+			maxSeq = info.Seq
+			maxOff = info.Off
+			place++
+		}
+	}
+
+	if curSeg != nil {
+		t.Put(curBinKey, curSeg)
+	}
+
+	//	finally, update meta
+	if place > 0 {
+		if _, _, err = db.bUpdateMeta(t, key, maxSeq, maxOff); err != nil {
+			return
+		}
+
+		err = t.Commit()
+	}
+
+	return
+}
+
+func (db *DB) BGetBit(key []byte, offset int32) (uint8, error) {
+	if seq, off, err := db.bParseOffset(key, offset); err != nil {
+		return 0, err
+	} else {
+		_, segment, err := db.bGetSegment(key, seq)
+		if err != nil {
+			return 0, err
+		}
+
+		if segment == nil {
+			return 0, nil
+		} else {
+			return getBit(segment, off), nil
+		}
+	}
+}
+
+// func (db *DB) BGetRange(key []byte, start int32, end int32) ([]byte, error) {
+// 	section := make([]byte)
+
+// 	return
+// }
+
+func (db *DB) BCount(key []byte, start int32, end int32) (cnt int32, err error) {
+	var sseq, soff uint32
+	if sseq, soff, err = db.bParseOffset(key, start); err != nil {
+		return
+	}
+
+	var eseq, eoff uint32
+	if eseq, eoff, err = db.bParseOffset(key, end); err != nil {
+		return
+	}
+
+	if sseq > eseq || (sseq == eseq && soff > eoff) {
+		sseq, eseq = eseq, sseq
+		soff, eoff = eoff, soff
+	}
+
+	var segCnt int32
+	if eseq == sseq {
+		if segCnt, err = db.bCountSeg(key, sseq, soff, eoff); err != nil {
+			return 0, err
+		}
+
+		cnt = segCnt
+
+	} else {
+		if segCnt, err = db.bCountSeg(key, sseq, soff, segBitSize-1); err != nil {
+			return 0, err
+		} else {
+			cnt += segCnt
+		}
+
+		if segCnt, err = db.bCountSeg(key, eseq, 0, eoff); err != nil {
+			return 0, err
+		} else {
+			cnt += segCnt
+		}
+	}
+
+	//	middle segs
+	var segment []byte
+	skey := db.bEncodeBinKey(key, sseq)
+	ekey := db.bEncodeBinKey(key, eseq)
+
+	it := db.bucket.RangeIterator(skey, ekey, store.RangeOpen)
+	for ; it.Valid(); it.Next() {
+		segment = it.RawValue()
+		for _, bt := range segment {
+			cnt += bitsInByte[bt]
+		}
+	}
+	it.Close()
+
+	return
+}
+
+func (db *DB) BTail(key []byte) (int32, error) {
+	// effective length of data, the highest bit-pos set in history
+	tailSeq, tailOff, err := db.bGetMeta(key)
+	if err != nil {
+		return 0, err
+	}
+
+	tail := int32(-1)
+	if tailSeq >= 0 {
+		tail = int32(uint32(tailSeq)<<segBitWidth | uint32(tailOff))
+	}
+
+	return tail, nil
+}
+
+func (db *DB) BOperation(op uint8, dstkey []byte, srckeys ...[]byte) (blen int32, err error) {
+	//	blen -
+	//		the total bit size of data stored in destination key,
+	//		that is equal to the size of the longest input string.
+
+	var exeOp func([]byte, []byte, *[]byte)
+	switch op {
+	case OPand:
+		exeOp = db.bSegAnd
+	case OPor:
+		exeOp = db.bSegOr
+	case OPxor, OPnot:
+		exeOp = db.bSegXor
+	default:
+		return
+	}
+
+	if dstkey == nil || srckeys == nil {
+		return
+	}
+
+	t := db.binBatch
+	t.Lock()
+	defer t.Unlock()
+
+	var srcKseq, srcKoff int32
+	var seq, off, maxDstSeq, maxDstOff uint32
+
+	var keyNum int = len(srckeys)
+	var validKeyNum int
+	for i := 0; i < keyNum; i++ {
+		if srcKseq, srcKoff, err = db.bGetMeta(srckeys[i]); err != nil {
+			return
+		} else if srcKseq < 0 {
+			srckeys[i] = nil
+			continue
+		}
+
+		validKeyNum++
+
+		seq = uint32(srcKseq)
+		off = uint32(srcKoff)
+		if seq > maxDstSeq || (seq == maxDstSeq && off > maxDstOff) {
+			maxDstSeq = seq
+			maxDstOff = off
+		}
+	}
+
+	if (op == OPnot && validKeyNum != 1) ||
+		(op != OPnot && validKeyNum < 2) {
+		return // with not enough existing source key
+	}
+
+	var srcIdx int
+	for srcIdx = 0; srcIdx < keyNum; srcIdx++ {
+		if srckeys[srcIdx] != nil {
+			break
+		}
+	}
+
+	// init - data
+	var segments = make([][]byte, maxDstSeq+1)
+
+	if op == OPnot {
+		//	ps :
+		//		( ~num == num ^ 0x11111111 )
+		//		we init the result segments with all bit set,
+		//		then we can calculate through the way of 'xor'.
+
+		//	ahead segments bin format : 1111 ... 1111
+		for i := uint32(0); i < maxDstSeq; i++ {
+			segments[i] = fillSegment
+		}
+
+		//	last segment bin format : 1111..1100..0000
+		var tailSeg = make([]byte, segByteSize, segByteSize)
+		var fillByte = fillBits[7]
+		var tailSegLen = db.bCapByteSize(uint32(0), maxDstOff)
+		for i := uint32(0); i < tailSegLen-1; i++ {
+			tailSeg[i] = fillByte
+		}
+		tailSeg[tailSegLen-1] = fillBits[maxDstOff-(tailSegLen-1)<<3]
+		segments[maxDstSeq] = tailSeg
+
+	} else {
+		// ps : init segments by data corresponding to the 1st valid source key
+		it := db.bIterator(srckeys[srcIdx])
+		for ; it.Valid(); it.Next() {
+			if _, seq, err = db.bDecodeBinKey(it.RawKey()); err != nil {
+				// to do ...
+				it.Close()
+				return
+			}
+			segments[seq] = it.Value()
+		}
+		it.Close()
+		srcIdx++
+	}
+
+	//	operation with following keys
+	var res []byte
+	for i := srcIdx; i < keyNum; i++ {
+		if srckeys[i] == nil {
+			continue
+		}
+
+		it := db.bIterator(srckeys[i])
+		for idx, end := uint32(0), false; !end; it.Next() {
+			end = !it.Valid()
+			if !end {
+				if _, seq, err = db.bDecodeBinKey(it.RawKey()); err != nil {
+					// to do ...
+					it.Close()
+					return
+				}
+			} else {
+				seq = maxDstSeq + 1
+			}
+
+			// todo :
+			// 		operation 'and' can be optimize here :
+			//		if seq > max_segments_idx, this loop can be break,
+			//		which can avoid cost from Key() and bDecodeBinKey()
+
+			for ; idx < seq; idx++ {
+				res = nil
+				exeOp(segments[idx], nil, &res)
+				segments[idx] = res
+			}
+
+			if !end {
+				res = it.Value()
+				exeOp(segments[seq], res, &res)
+				segments[seq] = res
+				idx++
+			}
+		}
+		it.Close()
+	}
+
+	// clear the old data in case
+	db.bDelete(t, dstkey)
+	db.rmExpire(t, BitType, dstkey)
+
+	//	set data
+	db.bSetMeta(t, dstkey, maxDstSeq, maxDstOff)
+
+	var bk []byte
+	for seq, segt := range segments {
+		if segt != nil {
+			bk = db.bEncodeBinKey(dstkey, uint32(seq))
+			t.Put(bk, segt)
+		}
+	}
+
+	err = t.Commit()
+	if err == nil {
+		// blen = int32(db.bCapByteSize(maxDstOff, maxDstOff))
+		blen = int32(maxDstSeq<<segBitWidth | maxDstOff + 1)
+	}
+
+	return
+}
+
+func (db *DB) BExpire(key []byte, duration int64) (int64, error) {
+	if duration <= 0 {
+		return 0, errExpireValue
+	}
+
+	if err := checkKeySize(key); err != nil {
+		return -1, err
+	}
+
+	return db.bExpireAt(key, time.Now().Unix()+duration)
+}
+
+func (db *DB) BExpireAt(key []byte, when int64) (int64, error) {
+	if when <= time.Now().Unix() {
+		return 0, errExpireValue
+	}
+
+	if err := checkKeySize(key); err != nil {
+		return -1, err
+	}
+
+	return db.bExpireAt(key, when)
+}
+
+func (db *DB) BTTL(key []byte) (int64, error) {
+	if err := checkKeySize(key); err != nil {
+		return -1, err
+	}
+
+	return db.ttl(BitType, key)
+}
+
+func (db *DB) BPersist(key []byte) (int64, error) {
+	if err := checkKeySize(key); err != nil {
+		return 0, err
+	}
+
+	t := db.binBatch
+	t.Lock()
+	defer t.Unlock()
+
+	n, err := db.rmExpire(t, BitType, key)
+	if err != nil {
+		return 0, err
+	}
+
+	err = t.Commit()
+	return n, err
+}
+
+func (db *DB) BScan(key []byte, count int, inclusive bool, match string) ([][]byte, error) {
+	return db.scan(BitMetaType, key, count, inclusive, match)
+}
+
+func (db *DB) bFlush() (drop int64, err error) {
+	t := db.binBatch
+	t.Lock()
+	defer t.Unlock()
+
+	return db.flushType(t, BitType)
+}