Update dependencies (#5574)

Update vendor

vendor/go.etcd.io/etcd/client/v3/watch.go

@@ -37,6 +37,13 @@ const (
 	EventTypePut    = mvccpb.PUT
 
 	closeSendErrTimeout = 250 * time.Millisecond
+
+	// AutoWatchID is the watcher ID passed in WatchStream.Watch when no
+	// user-provided ID is available. If pass, an ID will automatically be assigned.
+	AutoWatchID = 0
+
+	// InvalidWatchID represents an invalid watch ID and prevents duplication with an existing watch.
+	InvalidWatchID = -1
 )
 
 type Event mvccpb.Event
@@ -450,7 +457,7 @@ func (w *watcher) closeStream(wgs *watchGrpcStream) {
 
 func (w *watchGrpcStream) addSubstream(resp *pb.WatchResponse, ws *watcherStream) {
 	// check watch ID for backward compatibility (<= v3.3)
-	if resp.WatchId == -1 || (resp.Canceled && resp.CancelReason != "") {
+	if resp.WatchId == InvalidWatchID || (resp.Canceled && resp.CancelReason != "") {
 		w.closeErr = v3rpc.Error(errors.New(resp.CancelReason))
 		// failed; no channel
 		close(ws.recvc)
@@ -481,7 +488,7 @@ func (w *watchGrpcStream) closeSubstream(ws *watcherStream) {
 	} else if ws.outc != nil {
 		close(ws.outc)
 	}
-	if ws.id != -1 {
+	if ws.id != InvalidWatchID {
 		delete(w.substreams, ws.id)
 		return
 	}
@@ -533,6 +540,7 @@ func (w *watchGrpcStream) run() {
 	cancelSet := make(map[int64]struct{})
 
 	var cur *pb.WatchResponse
+	backoff := time.Millisecond
 	for {
 		select {
 		// Watch() requested
@@ -543,7 +551,7 @@ func (w *watchGrpcStream) run() {
 				// TODO: pass custom watch ID?
 				ws := &watcherStream{
 					initReq: *wreq,
-					id:      -1,
+					id:      InvalidWatchID,
 					outc:    outc,
 					// unbuffered so resumes won't cause repeat events
 					recvc: make(chan *WatchResponse),
@@ -649,6 +657,7 @@ func (w *watchGrpcStream) run() {
 				closeErr = err
 				return
 			}
+			backoff = w.backoffIfUnavailable(backoff, err)
 			if wc, closeErr = w.newWatchClient(); closeErr != nil {
 				return
 			}
@@ -669,7 +678,7 @@ func (w *watchGrpcStream) run() {
 			if len(w.substreams)+len(w.resuming) == 0 {
 				return
 			}
-			if ws.id != -1 {
+			if ws.id != InvalidWatchID {
 				// client is closing an established watch; close it on the server proactively instead of waiting
 				// to close when the next message arrives
 				cancelSet[ws.id] = struct{}{}
@@ -716,9 +725,9 @@ func (w *watchGrpcStream) dispatchEvent(pbresp *pb.WatchResponse) bool {
 		cancelReason:    pbresp.CancelReason,
 	}
 
-	// watch IDs are zero indexed, so request notify watch responses are assigned a watch ID of -1 to
+	// watch IDs are zero indexed, so request notify watch responses are assigned a watch ID of InvalidWatchID to
 	// indicate they should be broadcast.
-	if wr.IsProgressNotify() && pbresp.WatchId == -1 {
+	if wr.IsProgressNotify() && pbresp.WatchId == InvalidWatchID {
 		return w.broadcastResponse(wr)
 	}
 
@@ -873,7 +882,7 @@ func (w *watchGrpcStream) newWatchClient() (pb.Watch_WatchClient, error) {
 	w.resumec = make(chan struct{})
 	w.joinSubstreams()
 	for _, ws := range w.substreams {
-		ws.id = -1
+		ws.id = InvalidWatchID
 		w.resuming = append(w.resuming, ws)
 	}
 	// strip out nils, if any
@@ -963,6 +972,21 @@ func (w *watchGrpcStream) joinSubstreams() {
 
 var maxBackoff = 100 * time.Millisecond
 
+func (w *watchGrpcStream) backoffIfUnavailable(backoff time.Duration, err error) time.Duration {
+	if isUnavailableErr(w.ctx, err) {
+		// retry, but backoff
+		if backoff < maxBackoff {
+			// 25% backoff factor
+			backoff = backoff + backoff/4
+			if backoff > maxBackoff {
+				backoff = maxBackoff
+			}
+		}
+		time.Sleep(backoff)
+	}
+	return backoff
+}
+
 // openWatchClient retries opening a watch client until success or halt.
 // manually retry in case "ws==nil && err==nil"
 // TODO: remove FailFast=false
@@ -983,17 +1007,7 @@ func (w *watchGrpcStream) openWatchClient() (ws pb.Watch_WatchClient, err error)
 		if isHaltErr(w.ctx, err) {
 			return nil, v3rpc.Error(err)
 		}
-		if isUnavailableErr(w.ctx, err) {
-			// retry, but backoff
-			if backoff < maxBackoff {
-				// 25% backoff factor
-				backoff = backoff + backoff/4
-				if backoff > maxBackoff {
-					backoff = maxBackoff
-				}
-			}
-			time.Sleep(backoff)
-		}
+		backoff = w.backoffIfUnavailable(backoff, err)
 	}
 	return ws, nil
 }