downloader: added set log prefix grpc method (#11731)

To print the current download progress, we currently call the GRPC
method RecalcStats for every log entry. However, given the frequent
updates to the downloader in recent days, we may need to add more
information to the logs. This would require updating the Go interfaces,
which can be painful.

To streamline this process, I've added a log prefix to move the
responsibility of logging the download progress directly to the
downloader. This change also allows us to print a proper prefix
(currently "OtterSync"). As a result, we may soon be able to remove
StatsReply, since Erigon is primarily concerned with whether the
download is complete or not.

erigon-lib/direct/downloader_client.go

@@ -48,3 +48,6 @@ func (c *DownloaderClient) Verify(ctx context.Context, in *proto_downloader.Veri
 func (c *DownloaderClient) Stats(ctx context.Context, in *proto_downloader.StatsRequest, opts ...grpc.CallOption) (*proto_downloader.StatsReply, error) {
 	return c.server.Stats(ctx, in)
 }
+func (c *DownloaderClient) SetLogPrefix(ctx context.Context, in *proto_downloader.SetLogPrefixRequest, opts ...grpc.CallOption) (*emptypb.Empty, error) {
+	return c.server.SetLogPrefix(ctx, in)
+}

erigon-lib/downloader/downloader.go

@@ -96,6 +96,8 @@ type Downloader struct {
 	downloadLimit   *rate.Limit
 
 	stuckFileDetailedLogs bool
+
+	logPrefix string
 }
 
 type downloadInfo struct {
@@ -341,6 +343,7 @@ func New(ctx context.Context, cfg *downloadercfg.Cfg, logger log.Logger, verbosi
 		webDownloadSessions: map[string]*RCloneSession{},
 		downloading:         map[string]*downloadInfo{},
 		webseedsDiscover:    discover,
+		logPrefix:           "",
 	}
 	d.webseeds.SetTorrent(d.torrentFS, snapLock.Downloads, cfg.DownloadTorrentFilesFromWebseed)
 
@@ -2174,8 +2177,13 @@ func (d *Downloader) ReCalcStats(interval time.Duration) {
 		stats.Completed = false
 	}
 
+	prefix := d.logPrefix
+	if d.logPrefix == "" {
+		prefix = "[snapshots]"
+	}
+
 	if !stats.Completed {
-		logger.Debug("[snapshots] download info",
+		logger.Debug(fmt.Sprintf("[%s]", prefix),
 			"len", len(torrents),
 			"webTransfers", webTransfers,
 			"torrent", torrentInfo,
@@ -2861,3 +2869,7 @@ func openClient(ctx context.Context, dbDir, snapDir string, cfg *torrent.ClientC
 
 	return db, c, m, torrentClient, nil
 }
+
+func (d *Downloader) SetLogPrefix(prefix string) {
+	d.logPrefix = prefix
+}

erigon-lib/downloader/downloader_grpc_server.go

@@ -146,3 +146,9 @@ func (s *GrpcServer) Stats(ctx context.Context, request *proto_downloader.StatsR
 func Proto2InfoHash(in *prototypes.H160) metainfo.Hash {
 	return gointerfaces.ConvertH160toAddress(in)
 }
+
+func (s *GrpcServer) SetLogPrefix(ctx context.Context, request *proto_downloader.SetLogPrefixRequest) (*emptypb.Empty, error) {
+	s.d.SetLogPrefix(request.Prefix)
+
+	return &emptypb.Empty{}, nil
+}

eth/stagedsync/stage_snapshots.go

@@ -600,7 +600,7 @@ func SnapshotsPrune(s *PruneState, cfg SnapshotsCfg, ctx context.Context, tx kv.
 
 		cfg.blockRetire.RetireBlocksInBackground(ctx, minBlockNumber, s.ForwardProgress, log.LvlDebug, func(downloadRequest []services.DownloadRequest) error {
 			if cfg.snapshotDownloader != nil && !reflect.ValueOf(cfg.snapshotDownloader).IsNil() {
-				if err := snapshotsync.RequestSnapshotsDownload(ctx, downloadRequest, cfg.snapshotDownloader); err != nil {
+				if err := snapshotsync.RequestSnapshotsDownload(ctx, downloadRequest, cfg.snapshotDownloader, ""); err != nil {
 					return err
 				}
 			}