improved throttle of connections based on websocket speed

wsclient.js

@@ -52,7 +52,7 @@ function run(copts) {
         // stuff waiting for all other connections to finish because it tried writing near the border.
         var bufSize = wsHandlers.sendMessage(Packer.pack(opts, chunk));
         if (pausedClients.length || bufSize > 1024*1024) {
-          console.log('paused connection', cid, 'to allow websocket to catch up');
+          // console.log('[onLocalData] paused connection', cid, 'to allow websocket to catch up');
           conn.pause();
           pausedClients.push(conn);
         }
@@ -97,15 +97,19 @@ function run(copts) {
       }
 
       conn.write(opts.data);
-      if (conn.bufferSize > 1024*1024) {
-        wsHandlers.sendMessage(Packer.pack(opts, null, 'pause'));
-        conn.once('drain', function () {
-          wsHandlers.sendMessage(Packer.pack(opts, null, 'resume'));
-        });
-      }
       // It might seem weird to increase the "read" value in a function named `write`, but this
       // is bytes read from the tunnel and written to the local connection.
       conn.tunnelRead += opts.data.byteLength;
+
+      if (!conn.remotePaused && conn.bufferSize > 1024*1024) {
+        wsHandlers.sendMessage(Packer.pack(opts, conn.tunnelRead, 'pause'));
+        conn.remotePaused = true;
+
+        conn.once('drain', function () {
+          wsHandlers.sendMessage(Packer.pack(opts, conn.tunnelRead, 'resume'));
+          conn.remotePaused = false;
+        });
+      }
       return true;
     }
 
@@ -416,9 +420,18 @@ function run(copts) {
       timeoutId = setTimeout(wsHandlers.checkTimeout, activityTimeout);
 
       wstunneler._socket.on('drain', function () {
+        // the websocket library has it's own buffer apart from node's socket buffer, but that one
+        // is much more difficult to watch, so we watch for the lower level buffer to drain and
+        // then check to see if the upper level buffer is still too full to write to. Note that
+        // the websocket library buffer has something to do with compression, so I'm not requiring
+        // that to be 0 before we start up again.
+        if (wstunneler.bufferedAmount > 128*1024) {
+          return;
+        }
+
         pausedClients.forEach(function (conn) {
           if (!conn.manualPause) {
-            console.log('resuming connection', conn.tunnelCid, 'now the websocket has caught up');
+            // console.log('resuming connection', conn.tunnelCid, 'now the websocket has caught up');
             conn.resume();
           }
         });
@@ -458,7 +471,7 @@ function run(copts) {
       if (wstunneler) {
         try {
           wstunneler.send(msg, {binary: true});
-          return wstunneler._socket.bufferSize;
+          return wstunneler.bufferedAmount;
         } catch (err) {
           // There is a chance that this occurred after the websocket was told to close
           // and before it finished, in which case we don't need to log the error.