add 'FlusbDB' api, which used to clear all data on the specific db

ledis/ledis_test.go

@@ -62,3 +62,40 @@ func TestSelect(t *testing.T) {
 		t.Fatal(string(v))
 	}
 }
+
+func TestFlush(t *testing.T) {
+	db0, _ := testLedis.Select(0)
+	db1, _ := testLedis.Select(1)
+
+	db0.Set([]byte("a"), []byte("1"))
+	db0.ZAdd([]byte("zset_0"), ScorePair{int64(1), []byte("ma")})
+	db0.ZAdd([]byte("zset_0"), ScorePair{int64(2), []byte("mb")})
+
+	db1.Set([]byte("b"), []byte("2"))
+	db1.LPush([]byte("lst"), []byte("a1"), []byte("b2"))
+	db1.ZAdd([]byte("zset_0"), ScorePair{int64(3), []byte("mc")})
+
+	db1.Flush()
+
+	//	0 - existing
+	if exists, _ := db0.Exists([]byte("a")); exists <= 0 {
+		t.Fatal(false)
+	}
+
+	if zcnt, _ := db0.ZCard([]byte("zset_0")); zcnt != 2 {
+		t.Fatal(zcnt)
+	}
+
+	//	1 - deleted
+	if exists, _ := db1.Exists([]byte("b")); exists > 0 {
+		t.Fatal(false)
+	}
+
+	if llen, _ := db1.LLen([]byte("lst")); llen > 0 {
+		t.Fatal(llen)
+	}
+
+	if zcnt, _ := db1.ZCard([]byte("zset_1")); zcnt > 0 {
+		t.Fatal(zcnt)
+	}
+}

ledis/t_hash.go

@@ -396,3 +396,26 @@ func (db *DB) HClear(key []byte) (int64, error) {
 	err := t.Commit()
 	return num, err
 }
+
+func (db *DB) HFlush() (drop int64, err error) {
+	t := db.kvTx
+	t.Lock()
+	defer t.Unlock()
+
+	minKey := make([]byte, 2)
+	minKey[0] = db.index
+	minKey[1] = hashType
+
+	maxKey := make([]byte, 2)
+	maxKey[0] = db.index
+	maxKey[1] = hSizeType + 1
+
+	it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, 0, -1)
+	for ; it.Valid(); it.Next() {
+		t.Delete(it.Key())
+		drop++
+	}
+
+	err = t.Commit()
+	return
+}

ledis/t_kv.go

@@ -2,6 +2,7 @@ package ledis
 
 import (
 	"errors"
+	"github.com/siddontang/go-leveldb/leveldb"
 )
 
 type KVPair struct {
@@ -258,3 +259,26 @@ func (db *DB) SetNX(key []byte, value []byte) (int64, error) {
 
 	return n, err
 }
+
+func (db *DB) KvFlush() (drop int64, err error) {
+	t := db.kvTx
+	t.Lock()
+	defer t.Unlock()
+
+	minKey := make([]byte, 2)
+	minKey[0] = db.index
+	minKey[1] = kvType
+
+	maxKey := make([]byte, 2)
+	maxKey[0] = db.index
+	maxKey[1] = kvType + 1
+
+	it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, 0, -1)
+	for ; it.Valid(); it.Next() {
+		t.Delete(it.Key())
+		drop++
+	}
+
+	err = t.Commit()
+	return
+}

ledis/t_list.go

@@ -380,3 +380,26 @@ func (db *DB) LClear(key []byte) (int64, error) {
 	err = t.Commit()
 	return num, err
 }
+
+func (db *DB) LFlush() (drop int64, err error) {
+	t := db.listTx
+	t.Lock()
+	defer t.Unlock()
+
+	minKey := make([]byte, 2)
+	minKey[0] = db.index
+	minKey[1] = listType
+
+	maxKey := make([]byte, 2)
+	maxKey[0] = db.index
+	maxKey[1] = lMetaType + 1
+
+	it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, 0, -1)
+	for ; it.Valid(); it.Next() {
+		t.Delete(it.Key())
+		drop++
+	}
+
+	err = t.Commit()
+	return
+}

ledis/t_zset.go

@@ -660,3 +660,27 @@ func (db *DB) ZRangeByScoreGeneric(key []byte, min int64, max int64,
 
 	return db.zRange(key, min, max, withScores, offset, count, reverse)
 }
+
+func (db *DB) ZFlush() (drop int64, err error) {
+	t := db.zsetTx
+	t.Lock()
+	defer t.Unlock()
+
+	minKey := make([]byte, 2)
+	minKey[0] = db.index
+	minKey[1] = zsetType
+
+	maxKey := make([]byte, 2)
+	maxKey[0] = db.index
+	maxKey[1] = zScoreType + 1
+
+	it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, 0, -1)
+	for ; it.Valid(); it.Next() {
+		t.Delete(it.Key())
+		drop++
+	}
+
+	err = t.Commit()
+	// to do : binlog
+	return
+}