go: doltcore/env/actions: remotes: Only use clone on the backup path if the src TableFileStore does not include a chunk journal.

go/libraries/doltcore/doltdb/doltdb.go

@@ -1487,6 +1487,29 @@ func (ddb *DoltDB) Clone(ctx context.Context, destDB *DoltDB, eventCh chan<- pul
 	return pull.Clone(ctx, datas.ChunkStoreFromDatabase(ddb.db), datas.ChunkStoreFromDatabase(destDB.db), eventCh)
 }
 
+// Returns |true| if the underlying ChunkStore for this DoltDB implements |chunks.TableFileStore|.
+func (ddb *DoltDB) IsTableFileStore() bool {
+	_, ok := datas.ChunkStoreFromDatabase(ddb.db).(chunks.TableFileStore)
+	return ok
+}
+
+func (ddb *DoltDB) TableFileStoreHasJournal(ctx context.Context) (bool, error) {
+	tableFileStore, ok := datas.ChunkStoreFromDatabase(ddb.db).(chunks.TableFileStore)
+	if !ok {
+		return false, errors.New("unsupported operation, DoltDB.TableFileStoreHasManifest on non-TableFileStore")
+	}
+	_, tableFiles, _, err := tableFileStore.Sources(ctx)
+	if err != nil {
+		return false, err
+	}
+	for _, tableFile := range tableFiles {
+		if tableFile.FileID() == chunks.JournalFileID {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
 func (ddb *DoltDB) SetCommitHooks(ctx context.Context, postHooks []CommitHook) *DoltDB {
 	ddb.db = ddb.db.SetCommitHooks(ctx, postHooks)
 	return ddb

go/libraries/doltcore/env/actions/remotes.go

@@ -455,6 +455,35 @@ func FetchRefSpecs(ctx context.Context, dbData env.DbData, srcDB *doltdb.DoltDB,
 	return nil
 }
 
+// SyncRoots is going to copy the root hash of the database from srcDb to destDb.
+// We can do this |Clone| if (1) destDb is empty, (2) destDb and srcDb are both
+// |TableFileStore|s, and (3) srcDb does *not* have a journal file. The most
+// common scenario where this occurs is when we are restoring a backup.
+//
+// The journal's interaction with TableFileStore is not great currently ---
+// when accessing a journal file through TableFileStore, the Reader() should in
+// reality return something which is going to result in reading an actual table
+// file. For now, we avoid the |Clone| path when the journal file is present.
+func canSyncRootsWithClone(ctx context.Context, srcDb, destDb *doltdb.DoltDB, destDbRoot hash.Hash) (bool, error) {
+	if !destDbRoot.IsEmpty() {
+		return false, nil
+	}
+	if !srcDb.IsTableFileStore() {
+		return false, nil
+	}
+	if !destDb.IsTableFileStore() {
+		return false, nil
+	}
+	srcHasJournal, err := srcDb.TableFileStoreHasJournal(ctx)
+	if err != nil {
+		return false, err
+	}
+	if srcHasJournal {
+		return false, nil
+	}
+	return true, nil
+}
+
 // SyncRoots copies the entire chunkstore from srcDb to destDb and rewrites the remote manifest. Used to
 // streamline database backup and restores.
 // TODO: this should read/write a backup lock file specific to the client who created the backup
@@ -484,10 +513,12 @@ func SyncRoots(ctx context.Context, srcDb, destDb *doltdb.DoltDB, tempTableDir s
 		}
 	}()
 
-	if destRoot.IsEmpty() {
-		// In this case, we can clone into the dest root, if both src and destination support it.
-		// We will try to translate the stats from the table file events to the statsCh.
+	canClone, err := canSyncRootsWithClone(ctx, srcDb, destDb, destRoot)
+	if err != nil {
+		return err
+	}
 
+	if canClone {
 		tfCh := make(chan pull.TableFileEvent)
 		go func() {
 			start := time.Now()

go/store/chunks/tablefilestore.go

@@ -21,6 +21,8 @@ import (
 	"github.com/dolthub/dolt/go/store/hash"
 )
 
+const JournalFileID = "vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv"
+
 // TableFile is an interface for working with an existing table file
 type TableFile interface {
 	// FileID gets the id of the file

go/store/nbs/journal_writer.go

@@ -26,6 +26,7 @@ import (
 	"github.com/dolthub/swiss"
 	"golang.org/x/sync/errgroup"
 
+	"github.com/dolthub/dolt/go/store/chunks"
 	"github.com/dolthub/dolt/go/store/hash"
 )
 
@@ -36,7 +37,7 @@ const (
 	//   but we don't have a hard limit on record size right now
 	journalWriterBuffSize = 1024 * 1024
 
-	chunkJournalAddr = "vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv"
+	chunkJournalAddr = chunks.JournalFileID
 
 	journalIndexFileName = "journal.idx"