.

wcfs/wcfs.go

@@ -181,6 +181,8 @@
 // files to @<revX>/bigfile/<bigfileX> drops to zero, and automatically
 // destroys @<revX>/bigfile/<bigfileX> after reasonable timeout.
 //
+// XXX document "bye"
+//
 //
 // Protection against slow or faulty clients
 //
@@ -1883,7 +1885,7 @@ func (wlink *WatchLink) _serve() (err error) {
 	// XXX recheck that it is safe to handle multiple simultaneous watch requests.
 
 	for {
-		l, err := r.ReadString('\n')	// XXX limit accepted line len to prevent DOS
+		l, err := r.ReadString('\n') // TODO limit accepted line len to prevent DOS
 		if err != nil {
 			// r.Read is woken up by sk.CloseRead when serve decides to exit
 			if err == io.ErrClosedPipe || err == io.EOF {
@@ -1957,7 +1959,8 @@ func (wlink *WatchLink) _handleWatch(ctx context.Context, msg string) error {
 
 // sendReq sends wcfs-originated request to client and returns client response.
 func (wlink *WatchLink) sendReq(ctx context.Context, req string) (reply string, err error) {
-	// XXX err ctx
+	defer xerr.Context(&err, "sendReq") // wlink is already put into ctx by caller
+
 	var stream uint64
 	for stream == 0 {
 		stream = atomic.AddUint64(&wlink.reqNext, +2)
@@ -1986,16 +1989,20 @@ func (wlink *WatchLink) sendReq(ctx context.Context, req string) (reply string,
 // send sends a message to client over specified stream ID.
 //
 // Multiple send can be called simultaneously; send serializes writes.
-func (wlink *WatchLink) send(ctx context.Context, stream uint64, msg string) error {
-	// XXX err ctx
-	// XXX assert '\n' not in msg
+func (wlink *WatchLink) send(ctx context.Context, stream uint64, msg string) (err error) {
+	defer xerr.Contextf(&err, "send .%d", stream) // wlink is already put into ctx by caller
+
+	// assert '\n' not in msg
+	if strings.ContainsRune(msg, '\n') {
+		panicf("BUG: msg contains \\n  ; msg: %q", msg)
+	}
 
 	wlink.txMu.Lock()
 	defer wlink.txMu.Unlock()
 
 	pkt := []byte(fmt.Sprintf("%d %s\n", stream, msg))
 	traceIso("S: wlink%d: tx: %q\n", wlink.id, pkt)
-	_, err := wlink.sk.Write(ctx, pkt)
+	_, err = wlink.sk.Write(ctx, pkt)
 	if err != nil {
 		return err
 	}