allow retry if incomplete

client/file/sync.go

@@ -98,12 +98,13 @@ func Sync(versionDB *tmdb.Store, remoteGrpcUrl, remoteUrl, remoteWsUrl, rootDir
 				fmt.Printf("mm-pairs: %+v, %+v\n", len(pairs), err)
 				if err != nil {
 					fmt.Println("invalid decode")
-					panic(err)
 				}
 				if err = versionDB.PutAtVersion(int64(data.BlockNum), pairs); err != nil {
 					fmt.Println("mm-put-at-version-panic")
 					panic(err)
 				}
+				data.ChResult <- err
+
 			case err := <-chErr:
 				// fail read
 				fmt.Println("mm-fail-read-panic")

client/file/watcher.go

@@ -56,6 +56,7 @@ func (d *httpFileDownloader) GetData(path string) ([]byte, error) {
 type BlockData struct {
 	BlockNum int
 	Data     []byte
+	ChResult chan<- error
 }
 
 type BlockFileWatcher struct {
@@ -131,11 +132,14 @@ func (w *BlockFileWatcher) fetch(blockNum int) error {
 		}
 		return err
 	}
+
+	chResult := make(chan error)
 	w.chData <- &BlockData{
 		BlockNum: blockNum,
 		Data:     data,
+		ChResult: chResult,
 	}
-	return nil
+	return <-chResult
 }
 
 func (w *BlockFileWatcher) Start(