add some base set function

ledis/const.go

@@ -16,6 +16,8 @@ const (
 	ZScoreType  byte = 8
 	BitType     byte = 9
 	BitMetaType byte = 10
+	SetType     byte = 11
+	SSizeType   byte = 12
 
 	maxDataType byte = 100
 
@@ -35,6 +37,8 @@ var (
 		ZScoreType:  "zscore",
 		BitType:     "bit",
 		BitMetaType: "bitmeta",
+		SetType:     "set",
+		SSizeType:   "ssize",
 		ExpTimeType: "exptime",
 		ExpMetaType: "expmeta",
 	}
@@ -48,6 +52,7 @@ var (
 	errKeySize        = errors.New("invalid key size")
 	errValueSize      = errors.New("invalid value size")
 	errHashFieldSize  = errors.New("invalid hash field size")
+	errSetMemberSize  = errors.New("invalid set member size")
 	errZSetMemberSize = errors.New("invalid zset member size")
 	errExpireValue    = errors.New("invalid expire value")
 )
@@ -65,6 +70,9 @@ const (
 	//max zset member size
 	MaxZSetMemberSize int = 1024
 
+	//max set member size
+	MaxSetMemberSize int = 1024
+
 	//max value size
 	MaxValueSize int = 10 * 1024 * 1024
 )

ledis/t_set.go

@@ -0,0 +1,100 @@
+package ledis
+
+import (
+	"encoding/binary"
+	"errors"
+)
+
+var errSetKey = errors.New("invalid set key")
+var errSSizeKey = errors.New("invalid ssize key")
+
+const (
+	setStartSep byte = ':'
+	setStopSep  byte = setStartSep + 1
+)
+
+func checkSetKeyMember(key []byte, member []byte) error {
+	if len(key) > MaxKeySize || len(key) == 0 {
+		return errKeySize
+	} else if len(member) > MaxSetMemberSize || len(member) == 0 {
+		return errSetMemberSize
+	}
+	return nil
+}
+
+func (db *DB) sEncodeSizeKey(key []byte) []byte {
+	buf := make([]byte, len(key)+2)
+
+	buf[0] = db.index
+	buf[1] = SSizeType
+
+	copy(buf[2:], key)
+	return buf
+}
+
+func (db *DB) sDecodeSizeKey(ek []byte) ([]byte, error) {
+	if len(ek) < 2 || ek[0] != db.index || ek[1] != SSizeType {
+		return nil, errSSizeKey
+	}
+
+	return ek[2:], nil
+}
+
+func (db *DB) sEncodeSetKey(key []byte, member []byte) []byte {
+	buf := make([]byte, len(key)+len(member)+1+1+2+1)
+
+	pos := 0
+	buf[pos] = db.index
+	pos++
+	buf[pos] = SetType
+	pos++
+
+	binary.BigEndian.PutUint16(buf[pos:], uint16(len(key)))
+	pos += 2
+
+	copy(buf[pos:], key)
+	pos += len(key)
+
+	buf[pos] = setStartSep
+	pos++
+	copy(buf[pos:], member)
+
+	return buf
+}
+
+func (db *DB) sDecodeSetKey(ek []byte) ([]byte, []byte, error) {
+	if len(ek) < 5 || ek[0] != db.index || ek[1] != SetType {
+		return nil, nil, errSetKey
+	}
+
+	pos := 2
+	keyLen := int(binary.BigEndian.Uint16(ek[pos:]))
+	pos += 2
+
+	if keyLen+5 > len(ek) {
+		return nil, nil, errSetKey
+	}
+
+	key := ek[pos : pos+keyLen]
+	pos += keyLen
+
+	if ek[pos] != hashStartSep {
+		return nil, nil, errSetKey
+	}
+
+	pos++
+	member := ek[pos:]
+	return key, member, nil
+}
+
+func (db *DB) sEncodeStartKey(key []byte) []byte {
+	return db.sEncodeSetKey(key, nil)
+}
+
+func (db *DB) sEncodeStopKey(key []byte) []byte {
+	k := db.sEncodeSetKey(key, nil)
+
+	k[len(k)-1] = setStopSep
+
+	return k
+}