feat: add the snapshot sync for v2 store

store/v2/root/snapshot.go

@@ -46,7 +46,7 @@ func (rs *Store) Restore(height uint64, format uint32, chunks <-chan io.ReadClos
 	}
 
 	// Set up a restore stream pipeline
-	// chan io.ReadCloser -> chunkReader -> zlib -> delimited Protobuf -> ExportNode
+	// chan io.ReadCloser -> chunkReader -> zlib -> delimited Protobuf -> Exported KV Item
 	chunkReader := snapshots.NewChunkReader(chunks)
 	defer chunkReader.Close()
 	zReader, err := zlib.NewReader(chunkReader)
@@ -71,6 +71,10 @@ func (rs *Store) Restore(height uint64, format uint32, chunks <-chan io.ReadClos
 
 		switch item := item.Item.(type) {
 		case *storetypes.SnapshotItem_Schema:
+			if len(rs.schema) != 0 {
+				return sdkerrors.Wrap(sdkerrors.ErrLogic, "store schema is not empty")
+			}
+
 			storeSchemaReceived = true
 			schemaWriter := prefixdb.NewPrefixWriter(rs.stateTxn, schemaPrefix)
 			sKeys := item.Schema.GetKeys()
@@ -150,7 +154,7 @@ func (rs *Store) Snapshot(height uint64, format uint32) (<-chan io.ReadCloser, e
 	ch := make(chan io.ReadCloser)
 	go func() {
 		// Set up a stream pipeline to serialize snapshot nodes:
-		// ExportNode -> delimited Protobuf -> zlib -> buffer -> chunkWriter -> chan io.ReadCloser
+		// Export KV Item -> delimited Protobuf -> zlib -> buffer -> chunkWriter -> chan io.ReadCloser
 		chunkWriter := snapshots.NewChunkWriter(ch, snapshotChunkSize)
 		defer chunkWriter.Close()
 		bufWriter := bufio.NewWriterSize(chunkWriter, snapshotBufferSize)

store/v2/root/snapshot_test.go

@@ -170,10 +170,13 @@ func TestMultistoreSnapshot_Checksum(t *testing.T) {
 }
 
 func TestMultistoreSnapshotRestore(t *testing.T) {
-	source := newMultiStoreWithBasicData(t, memdb.NewDB(), 4)
+	source := newMultiStoreWithGeneratedData(t, memdb.NewDB(), 3, 4)
 	target := newMultiStore(t, memdb.NewDB(), 0)
 	require.Equal(t, source.LastCommitID().Version, int64(1))
 	version := uint64(source.LastCommitID().Version)
+	// check for target store restore
+	require.Equal(t, target.LastCommitID().Version, int64(0))
+
 	chunks, err := source.Snapshot(version, snapshottypes.CurrentFormat)
 	require.NoError(t, err)
 	ready := make(chan struct{})
@@ -191,11 +194,19 @@ func TestMultistoreSnapshotRestore(t *testing.T) {
 		require.Equal(t, sourceSubStore, targetSubStore)
 	}
 
-	// restore checking for non-empty store
-	target2 := newMultiStoreWithBasicData(t, memdb.NewDB(), 0)
+	// checking snapshot restore for non-empty store with existed saved version
+	target2 := newMultiStoreWithBasicData(t, memdb.NewDB(), 4)
 	ready2 := make(chan struct{})
 	err = target2.Restore(version, snapshottypes.CurrentFormat, chunks, ready2)
 	require.Error(t, err)
+
+	// checking snapshot restoring for store with existed schema and without existed versions
+	target3 := newMultiStore(t, memdb.NewDB(), 4)
+	ready3 := make(chan struct{})
+	chunks, err = source.Snapshot(version, snapshottypes.CurrentFormat)
+	require.NoError(t, err)
+	err = target3.Restore(version, snapshottypes.CurrentFormat, chunks, ready3)
+	require.Error(t, err)
 }
 
 func BenchmarkMultistoreSnapshot100K(b *testing.B) {