Golang WriteBatch.Delete方法代码示例

func Srem(args [][]byte, wb *levigo.WriteBatch) interface{} {
	mk := metaKey(args[0])
	card, err := scard(mk, nil)
	if err != nil {
		return err
	}
	if card == 0 {
		return card
	}
	var deleted uint32
	key := NewKeyBuffer(SetKey, args[0], len(args[1]))
	for _, member := range args[1:] {
		key.SetSuffix(member)
		res, err := DB.Get(ReadWithoutCacheFill, key.Key())
		if err != nil {
			return err
		}
		if res == nil {
			continue
		}
		wb.Delete(key.Key())
		deleted++
	}
	if deleted == card {
		wb.Delete(mk)
	} else if deleted > 0 { // decrement the cardinality
		setCard(mk, card-deleted, wb)
	}
	return deleted
}

func Hdel(args [][]byte, wb *levigo.WriteBatch) interface{} {
	mk := metaKey(args[0])
	length, err := hlen(mk, nil)
	if err != nil {
		return err
	}
	if length == 0 {
		return 0
	}

	var deleted uint32
	key := NewKeyBuffer(HashKey, args[0], len(args[1]))
	for _, field := range args[1:] {
		key.SetSuffix(field)
		res, err := DB.Get(ReadWithoutCacheFill, key.Key())
		if err != nil {
			return err
		}
		if res == nil {
			continue
		}
		wb.Delete(key.Key())
		deleted++
	}
	if deleted == length {
		wb.Delete(mk)
	} else if deleted > 0 {
		setHlen(mk, length-deleted, wb)
	}
	return deleted
}

func DelHash(key []byte, wb *levigo.WriteBatch) {
	it := DB.NewIterator(ReadWithoutCacheFill)
	defer it.Close()
	iterKey := NewKeyBuffer(HashKey, key, 0)
	for it.Seek(iterKey.Key()); it.Valid(); it.Next() {
		k := it.Key()
		if !iterKey.IsPrefixOf(k) {
			break
		}
		wb.Delete(k)
	}
}

func DelSet(key []byte, wb *levigo.WriteBatch) {
	it := DB.NewIterator(ReadWithoutCacheFill)
	defer it.Close()
	iterKey := NewKeyBuffer(SetKey, key, 0)
	for it.Seek(iterKey.Key()); it.Valid(); it.Next() {
		k := it.Key()
		// If the prefix of the current key doesn't match the iteration key,
		// we have reached the end of the set
		if !iterKey.IsPrefixOf(k) {
			break
		}
		wb.Delete(k)
	}
}

// TODO: refactor with above.
func RemoveIndex(index [2]string, key []byte, indexDb *levigo.DB, wb *levigo.WriteBatch) error {
	searchKey := []byte(index[0] + "~" + index[1])
	keys, err := indexDb.Get(LReadOptions, searchKey)
	if err != nil {
		return err
	}
	keys = removeDataKey(keys, key)
	if len(keys) > 0 {
		wb.Put(searchKey, keys)
	} else {
		wb.Delete(searchKey)
	}
	return nil
}

func delKey(key []byte, wb *levigo.WriteBatch) (deleted bool, err error) {
	res, err := DB.Get(ReadWithoutCacheFill, key)
	if err != nil {
		return
	}
	if res == nil {
		return
	}
	if len(res) < 1 {
		return false, InvalidDataError
	}
	del(key[1:], res[0], wb)
	wb.Delete(key)
	return true, nil
}

func lpop(key []byte, left bool, wb *levigo.WriteBatch) (interface{}, error) {
	mk := metaKey(key)
	l, err := llen(mk, nil)
	if err != nil {
		return nil, err
	}
	if l.length == 0 {
		return nil, nil
	}

	iterKey := NewKeyBuffer(ListKey, key, 0)
	it := DB.NewIterator(ReadWithoutCacheFill)
	defer it.Close()
	if !left {
		iterKey.ReverseIterKey()
	}
	it.Seek(iterKey.Key())
	if !left {
		it.Prev()
	}
	if !it.Valid() {
		return nil, nil
	}
	k := it.Key()
	if !iterKey.IsPrefixOf(k) {
		return nil, nil
	}
	res := it.Value()

	wb.Delete(k)
	l.length--
	if l.length == 0 {
		wb.Delete(mk)
	} else {
		// decode the sequence number from the list item key
		seq := int64(binary.BigEndian.Uint64(k[len(key)+5:])) + math.MinInt64
		if left {
			l.left = seq
		} else {
			l.right = seq
		}
		setLlen(mk, l, wb)
	}

	return res, nil
}

func DelZset(key []byte, wb *levigo.WriteBatch) {
	// TODO: count keys to verify everything works as expected?
	it := DB.NewIterator(ReadWithoutCacheFill)
	defer it.Close()
	iterKey := NewKeyBuffer(ZSetKey, key, 0)
	scoreKey := NewKeyBuffer(ZScoreKey, key, 0)

	for it.Seek(iterKey.Key()); it.Valid(); it.Next() {
		k := it.Key()
		// If the prefix of the current key doesn't match the iteration key,
		// we have reached the end of the zset
		if !iterKey.IsPrefixOf(k) {
			break
		}
		wb.Delete(k)
		setZScoreKeyMember(scoreKey, k[len(iterKey.Key()):])
		setZScoreKeyScore(scoreKey, btof(it.Value()))
		wb.Delete(scoreKey.Key())
	}
}

func Spop(args [][]byte, wb *levigo.WriteBatch) interface{} {
	mk := metaKey(args[0])
	card, err := scard(mk, nil)
	if err != nil {
		return err
	}
	if card == 0 {
		return nil
	}
	key := NewKeyBuffer(SetKey, args[0], 1)
	member := srand(key)
	if member == nil {
		return nil
	}
	key.SetSuffix(member)
	wb.Delete(key.Key())
	if card == 1 { // we're removing the last remaining member
		wb.Delete(mk)
	} else {
		setCard(mk, card-1, wb)
	}
	return member
}

func Zrem(args [][]byte, wb *levigo.WriteBatch) interface{} {
	mk := metaKey(args[0])
	card, err := zcard(mk, nil)
	if err != nil {
		return err
	}
	if card == 0 {
		return 0
	}

	var deleted uint32
	setKey := NewKeyBuffer(ZSetKey, args[0], len(args[1]))
	scoreKey := NewKeyBuffer(ZScoreKey, args[0], 8+len(args[1]))
	// Delete each of the members
	for _, member := range args[1:] {
		setKey.SetSuffix(member)
		res, err := DB.Get(ReadWithoutCacheFill, setKey.Key())
		if err != nil {
			return nil
		}
		if res == nil {
			continue
		}
		if len(res) != 8 {
			return InvalidDataError
		}

		score := btof(res)
		setZScoreKeyMember(scoreKey, member)
		setZScoreKeyScore(scoreKey, score)
		wb.Delete(setKey.Key())
		wb.Delete(scoreKey.Key())
		deleted++
	}
	if deleted == card { // We deleted all of the members, so delete the meta key
		wb.Delete(mk)
	} else if deleted > 0 { // Decrement the cardinality
		setZcard(mk, card-deleted, wb)
	}

	return deleted
}

func zrangebyscore(args [][]byte, flag zrangeFlag, wb *levigo.WriteBatch) interface{} {
	// use a snapshot for this read so that the zcard is consistent
	snapshot := DB.NewSnapshot()
	opts := levigo.NewReadOptions()
	opts.SetSnapshot(snapshot)
	defer opts.Close()
	defer DB.ReleaseSnapshot(snapshot)

	mk := metaKey(args[0])
	card, err := zcard(mk, opts)
	if err != nil {
		return err
	}

	var minExclusive, maxExclusive bool
	if args[1][0] == '(' {
		minExclusive = true
		args[1] = args[1][1:]
	}
	if args[2][0] == '(' {
		maxExclusive = true
		args[2] = args[2][1:]
	}
	min, err := bconv.ParseFloat(args[1], 64)
	max, err2 := bconv.ParseFloat(args[2], 64)
	if err != nil || err2 != nil {
		return fmt.Errorf("min or max is not a float")
	}
	if flag == zrangeReverse {
		min, max = max, min
		minExclusive, maxExclusive = maxExclusive, minExclusive
	}

	if card == 0 || min > max {
		if flag <= zrangeReverse {
			return []interface{}{}
		} else {
			return 0
		}
	}

	// shortcut for zcount of -Inf to +Inf
	if flag == zrangeCount && math.IsInf(min, -1) && math.IsInf(max, 1) {
		return card
	}

	var withscores bool
	var offset, total int64 = 0, -1
	if flag <= zrangeReverse && len(args) > 3 {
		if len(args) == 4 || len(args) == 7 {
			if EqualIgnoreCase(args[3], []byte("withscores")) {
				withscores = true
			}
		} else if len(args) != 6 {
			return SyntaxError
		}
		if len(args) >= 6 {
			if EqualIgnoreCase(args[len(args)-3], []byte("limit")) {
				offset, err = bconv.ParseInt(args[len(args)-2], 10, 64)
				total, err2 = bconv.ParseInt(args[len(args)-1], 10, 64)
				if err != nil || err2 != nil {
					return InvalidIntError
				}
				if offset < 0 || total < 1 {
					return []interface{}{}
				}
			} else {
				return SyntaxError
			}
		}
	}

	it := DB.NewIterator(opts)
	defer it.Close()

	var deleted, count uint32
	var deleteKey *KeyBuffer
	if flag == zrangeDelete {
		deleteKey = NewKeyBuffer(ZSetKey, args[0], 0)
	}

	res := []interface{}{}
	iterKey := NewKeyBuffer(ZScoreKey, args[0], 8)
	if flag != zrangeReverse {
		setZScoreKeyScore(iterKey, min)
	} else {
		setZScoreKeyScore(iterKey, max)
		iterKey.ReverseIterKey()
	}
	it.Seek(iterKey.Key())
	for i := int64(0); it.Valid(); i++ {
		if flag == zrangeReverse {
			it.Prev()
		}
		if i >= offset {
			if total > -1 && i-offset >= total {
				break
			}
			k := it.Key()
			if !iterKey.IsPrefixOf(k) {
//.........这里部分代码省略.........

func zadd(args [][]byte, wb *levigo.WriteBatch, incr bool) interface{} {
	var newMembers uint32
	var score float64
	scoreBytes := make([]byte, 8)
	setKey := NewKeyBuffer(ZSetKey, args[0], len(args[2]))
	scoreKey := NewKeyBuffer(ZScoreKey, args[0], 8+len(args[2]))

	mk := metaKey(args[0])
	card, err := zcard(mk, nil)
	if err != nil {
		return err
	}

	// Iterate through each of the score/member pairs
	for i := 1; i < len(args); i += 2 {
		var err error
		score, err = bconv.ParseFloat(args[i], 64)
		if err != nil {
			return fmt.Errorf("'%s' is not a valid float", string(args[1]))
		}

		// Check if the member exists
		setKey.SetSuffix(args[i+1])
		var res []byte
		if card > 0 {
			res, err = DB.Get(DefaultReadOptions, setKey.Key())
			if err != nil {
				return err
			}
		}

		// set the score key with 8 empty bytes before the member for the score
		setZScoreKeyMember(scoreKey, args[i+1])
		if res != nil { // We got a score from the db, so the member already exists
			if len(res) != 8 {
				return InvalidDataError
			}
			actualScore := math.Float64frombits(binary.BigEndian.Uint64(res))
			if incr { // this is a ZINCRBY, so increment the score
				score += actualScore
			}
			if score == actualScore { // Member already exists with the same score, do nothing
				continue
			}

			// Delete score key for member
			setZScoreKeyScore(scoreKey, actualScore)
			wb.Delete(scoreKey.Key())
		} else { // No score found, we're adding a new member
			newMembers++
		}

		// Store the set and score keys
		binary.BigEndian.PutUint64(scoreBytes, math.Float64bits(score))
		setZScoreKeyScore(scoreKey, score)
		wb.Put(setKey.Key(), scoreBytes)
		wb.Put(scoreKey.Key(), []byte{}) // The score key is only used for sorting, the value is empty
	}

	// Update the set metadata with the new cardinality
	if newMembers > 0 {
		setZcard(mk, card+newMembers, wb)
	}

	if incr { // This is a ZINCRBY, return the new score
		return ftoa(score)
	}
	return newMembers
}

func DelString(key []byte, wb *levigo.WriteBatch) {
	wb.Delete(stringKey(key))
}