SOCKET_FORCED_MESSAGING option

3 files changed, 41 insertions, 9 deletions

diff --git a/src/library.js b/src/library.js
index 9c011730..fad7b58c 100644
--- a/src/library.js
+++ b/src/library.js
@@ -6835,14 +6835,31 @@ LibraryManager.library = {
 #if SOCKET_DEBUG
       Module.print(['onmessage', data.length, '|', Array.prototype.slice.call(data)]);
 #endif
+#if SOCKET_FORCED_MESSAGING
+      var i32View = new Uint32Array(data.buffer);
+      var start = 0;
+      while (start < data.length) {
+        var currLen = i32View[start>>2];
+        assert(currLen > 0);
+        start += 4;
+        assert(start + currLen <= data.length, [data.length, start, currLen]); // must not receive fractured messages!
+        info.inQueue.push(data.subarray(start, start+currLen));
+#if SOCKET_DEBUG
+      Module.print(['onmessage message', currLen, '|', Array.prototype.slice.call(data.subarray(start, start+currLen))]);
+#endif
+        start += currLen;
+      }
+#else
       info.inQueue.push(data);
+#endif
     }
     function send(data) {
       // TODO: if browser accepts views, can optimize this
 #if SOCKET_DEBUG
       Module.print('sender actually sending ' + Array.prototype.slice.call(data));
 #endif
-      info.socket.send(new Uint8Array(data).buffer);
+      // ok to use the underlying buffer, we created data and know that the buffer starts at the beginning
+      info.socket.send(data.buffer);
     }
     var outQueue = [];
     var intervalling = false, interval;
@@ -6865,7 +6882,15 @@ LibraryManager.library = {
       }
     }
     info.sender = function(data) {
-      outQueue.push(data);
+#if SOCKET_FORCED_MESSAGING
+      var buffer = new Uint8Array(data.length+4);
+      var i32View = new Uint32Array(buffer.buffer);
+      i32View[0] = data.length;
+      buffer.set(data, 4);
+      outQueue.push(buffer);
+#else
+      outQueue.push(new Uint8Array(data));
+#endif
       trySend();
     };
     return 0;
diff --git a/src/settings.js b/src/settings.js
index c530b083..ba37c715 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -147,6 +147,12 @@ var LIBRARY_DEBUG = 0; // Print out when we enter a library call (library*.js).
 var GL_DEBUG = 0; // Print out all calls into WebGL. As with LIBRARY_DEBUG, you can set a runtime
                   // option, in this case GL.debug.
 var SOCKET_DEBUG = 0; // Log out socket/network data transfer.
+var SOCKET_FORCED_MESSAGING = 0; // If 1, we make sure that each socket send ends up a single socket
+                                 // receive, that is, we force proper messaging (otherwise, sending
+                                 // [A] and [B] can show up on the other side as [A, B]). This will
+                                 // only work if both sides have it enabled, obviously, so it only
+                                 // makes sense for p2p or when connecting to a special server - we
+                                 // add some metadata (message size) to messages in this mode
 
 var PROFILE_MAIN_LOOP = 0; // Profile the function called in set_main_loop
 
diff --git a/tests/runner.py b/tests/runner.py
index 1ab5c7af..b26162c0 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -10283,13 +10283,14 @@ elif 'browser' in str(sys.argv):
       return relay_server
 
     def test_zz_websockets_bi(self):
-      try:
-        with self.WebsockHarness(8992, self.make_relay_server(8992, 8994)):
-          with self.WebsockHarness(8994, no_server=True):
-            Popen([PYTHON, EMCC, path_from_root('tests', 'websockets_bi_side.c'), '-o', 'side.html', '-DSOCKK=8995']).communicate()
-            self.btest('websockets_bi.c', expected='2499')
-      finally:
-        self.clean_pids()
+      for fm in [0,1]:
+        try:
+          with self.WebsockHarness(8992, self.make_relay_server(8992, 8994)):
+            with self.WebsockHarness(8994, no_server=True):
+              Popen([PYTHON, EMCC, path_from_root('tests', 'websockets_bi_side.c'), '-o', 'side.html', '-DSOCKK=8995', '-s', 'SOCKET_FORCED_MESSAGING=%d' % fm]).communicate()
+              self.btest('websockets_bi.c', expected='2499', args=['-s', 'SOCKET_FORCED_MESSAGING=%d' % fm])
+        finally:
+          self.clean_pids()
 
     def test_zz_websockets_bi_listen(self):
       try: