separete read from iteration

Author: HuangYi

versiondb/tsrocksdb/store.go

@@ -247,46 +247,37 @@ func (s Store) FixData(storeNames []string, dryRun bool) error {
 
 // fixDataStore iterate the wrong data at version 0, parse the timestamp from the key and write it again.
 func (s Store) fixDataStore(storeName string, dryRun bool) error {
-	var version int64
-	iter, err := s.IteratorAtVersion(storeName, nil, nil, &version)
+	pairs, err := s.loadWrongData(storeName)
 	if err != nil {
 		return err
 	}
-	defer iter.Close()
 
 	batch := grocksdb.NewWriteBatch()
 	defer batch.Destroy()
 
 	prefix := storePrefix(storeName)
-	for ; iter.Valid(); iter.Next() {
-		key := iter.Key()
-		if len(key) < TimestampSize {
-			return fmt.Errorf("invalid key length: %X, store: %s", key, storeName)
-		}
-
-		ts := key[len(key)-TimestampSize:]
-		key = key[:len(key)-TimestampSize]
-		realKey := cloneAppend(prefix, key)
+	readOpts := grocksdb.NewDefaultReadOptions()
+	defer readOpts.Destroy()
+	for _, pair := range pairs {
+		realKey := cloneAppend(prefix, pair.Key)
 
-		readOpts := grocksdb.NewDefaultReadOptions()
-		readOpts.SetTimestamp(ts)
+		readOpts.SetTimestamp(pair.Timestamp)
 		oldValue, err := s.db.GetCF(readOpts, s.cfHandle, realKey)
 		if err != nil {
 			return err
 		}
-		readOpts.Destroy()
 
-		clean := bytes.Equal(oldValue.Data(), iter.Value())
+		clean := bytes.Equal(oldValue.Data(), pair.Value)
 		oldValue.Free()
 
 		if clean {
 			continue
 		}
 
 		if dryRun {
-			fmt.Printf("fix data: %s, key: %X, ts: %X\n", storeName, key, ts)
+			fmt.Printf("fix data: %s, key: %X, ts: %X\n", storeName, pair.Key, pair.Timestamp)
 		} else {
-			batch.PutCFWithTS(s.cfHandle, realKey, ts, iter.Value())
+			batch.PutCFWithTS(s.cfHandle, realKey, pair.Timestamp, pair.Value)
 		}
 	}
 
@@ -297,6 +288,39 @@ func (s Store) fixDataStore(storeName string, dryRun bool) error {
 	return nil
 }
 
+type KVPairWithTS struct {
+	Key       []byte
+	Value     []byte
+	Timestamp []byte
+}
+
+func (s Store) loadWrongData(storeName string) ([]KVPairWithTS, error) {
+	var version int64
+	iter, err := s.IteratorAtVersion(storeName, nil, nil, &version)
+	if err != nil {
+		return nil, err
+	}
+	defer iter.Close()
+
+	var pairs []KVPairWithTS
+	for ; iter.Valid(); iter.Next() {
+		key := iter.Key()
+		if len(key) < TimestampSize {
+			return nil, fmt.Errorf("invalid key length: %X, store: %s", key, storeName)
+		}
+
+		ts := key[len(key)-TimestampSize:]
+		key = key[:len(key)-TimestampSize]
+		pairs = append(pairs, KVPairWithTS{
+			Key:       key,
+			Value:     iter.Value(),
+			Timestamp: ts,
+		})
+	}
+
+	return pairs, nil
+}
+
 func newTSReadOptions(version *int64) *grocksdb.ReadOptions {
 	var ver uint64
 	if version == nil {