Fix rocksmq load with prefix (#7678)

Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

internal/kv/rocksdb/rocksdb_kv.go

@@ -90,6 +90,14 @@ func (kv *RocksdbKV) LoadWithPrefix(key string) ([]string, []string, error) {
 	return keys, values, nil
 }
 
+func (kv *RocksdbKV) ResetPrefixLength(len int) error {
+	kv.DB.Close()
+	kv.Opts.SetPrefixExtractor(gorocksdb.NewFixedPrefixTransform(len))
+	var err error
+	kv.DB, err = gorocksdb.OpenDb(kv.Opts, kv.GetName())
+	return err
+}
+
 func (kv *RocksdbKV) MultiLoad(keys []string) ([]string, error) {
 	values := make([]string, 0, len(keys))
 	for _, key := range keys {

internal/util/rocksmq/server/rocksmq/rocksmq_impl.go

@@ -113,7 +113,7 @@ func NewRocksMQ(name string, idAllocator allocator.GIDAllocator) (*rocksmq, erro
 	opts := gorocksdb.NewDefaultOptions()
 	opts.SetBlockBasedTableFactory(bbto)
 	opts.SetCreateIfMissing(true)
-	opts.SetPrefixExtractor(gorocksdb.NewFixedPrefixTransform(FixedChannelNameLen + 1))
+	opts.SetPrefixExtractor(gorocksdb.NewFixedPrefixTransform(FixedChannelNameLen))
 
 	db, err := gorocksdb.OpenDb(opts, name)
 	if err != nil {

internal/util/rocksmq/server/rocksmq/rocksmq_retention.go

@@ -76,10 +76,10 @@ func prefixLoad(db *gorocksdb.DB, prefix string) ([]string, []string, error) {
 	for ; iter.Valid(); iter.Next() {
 		key := iter.Key()
 		value := iter.Value()
-		defer key.Free()
-		defer value.Free()
 		keys = append(keys, string(key.Data()))
+		key.Free()
 		values = append(values, string(value.Data()))
+		value.Free()
 	}
 	if err := iter.Err(); err != nil {
 		return nil, nil, err
@@ -112,6 +112,7 @@ func initRetentionInfo(kv *rocksdbkv.RocksdbKV, db *gorocksdb.DB) (*retentionInf
 
 func (ri *retentionInfo) startRetentionInfo() error {
 	var wg sync.WaitGroup
+	ri.kv.ResetPrefixLength(FixedChannelNameLen)
 	for _, topic := range ri.topics {
 		log.Debug("Start load retention info", zap.Any("topic", topic))
 		// Load all page infos