forked from mirror/ledisdb
101 lines
1.8 KiB
Go
101 lines
1.8 KiB
Go
package ledis
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import (
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"encoding/binary"
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"errors"
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)
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var errSetKey = errors.New("invalid set key")
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var errSSizeKey = errors.New("invalid ssize key")
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const (
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setStartSep byte = ':'
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setStopSep byte = setStartSep + 1
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)
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func checkSetKeyMember(key []byte, member []byte) error {
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if len(key) > MaxKeySize || len(key) == 0 {
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return errKeySize
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} else if len(member) > MaxSetMemberSize || len(member) == 0 {
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return errSetMemberSize
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}
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return nil
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}
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func (db *DB) sEncodeSizeKey(key []byte) []byte {
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buf := make([]byte, len(key)+2)
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buf[0] = db.index
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buf[1] = SSizeType
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copy(buf[2:], key)
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return buf
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}
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func (db *DB) sDecodeSizeKey(ek []byte) ([]byte, error) {
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if len(ek) < 2 || ek[0] != db.index || ek[1] != SSizeType {
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return nil, errSSizeKey
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}
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return ek[2:], nil
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}
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func (db *DB) sEncodeSetKey(key []byte, member []byte) []byte {
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buf := make([]byte, len(key)+len(member)+1+1+2+1)
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pos := 0
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buf[pos] = db.index
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pos++
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buf[pos] = SetType
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pos++
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binary.BigEndian.PutUint16(buf[pos:], uint16(len(key)))
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pos += 2
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copy(buf[pos:], key)
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pos += len(key)
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buf[pos] = setStartSep
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pos++
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copy(buf[pos:], member)
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return buf
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}
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func (db *DB) sDecodeSetKey(ek []byte) ([]byte, []byte, error) {
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if len(ek) < 5 || ek[0] != db.index || ek[1] != SetType {
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return nil, nil, errSetKey
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}
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pos := 2
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keyLen := int(binary.BigEndian.Uint16(ek[pos:]))
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pos += 2
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if keyLen+5 > len(ek) {
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return nil, nil, errSetKey
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}
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key := ek[pos : pos+keyLen]
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pos += keyLen
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if ek[pos] != hashStartSep {
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return nil, nil, errSetKey
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}
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pos++
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member := ek[pos:]
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return key, member, nil
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}
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func (db *DB) sEncodeStartKey(key []byte) []byte {
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return db.sEncodeSetKey(key, nil)
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}
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func (db *DB) sEncodeStopKey(key []byte) []byte {
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k := db.sEncodeSetKey(key, nil)
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k[len(k)-1] = setStopSep
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return k
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}
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