DevTools: add support for chunked protocol messages.

Source/devtools/front_end/sdk/InspectorBackend.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 593 matching lines @@
 }
 
 /**
  * @constructor
  * @extends {InspectorBackendClass.Connection}
  */
 InspectorBackendClass.MainConnection = function()
 {
     InspectorBackendClass.Connection.call(this);
     InspectorFrontendHost.events.addEventListener(InspectorFrontendHostAPI.Events.DispatchMessage, this._dispatchMessage, this);
+    InspectorFrontendHost.events.addEventListener(InspectorFrontendHostAPI.Events.DispatchMessageChunk, this._dispatchMessageChunk, this);
 }
 
 InspectorBackendClass.MainConnection.prototype = {
 
     /**
      * @param {!Object} messageObject
      */
     sendMessage: function(messageObject)
     {
         var message = JSON.stringify(messageObject);
         InspectorFrontendHost.sendMessageToBackend(message);
     },
 
     /**
      * @param {!WebInspector.Event} event
      */
     _dispatchMessage: function(event)
     {
-        this.dispatch(/** @type {!Object|string} */ (event.data));
+        this.dispatch(/** @type {string} */ (event.data));

[dgozman, 2014/10/15 13:51:38]

event.data could actually be an object (at least in layout tests).

[pfeldman, 2014/10/15 14:06:59]

Which layout tests?

+    },
+
+    /**
+     * @param {!WebInspector.Event} event
+     */
+    _dispatchMessageChunk: function(event)
+    {
+        var messageChunk = /** @type {string} */ (event.data["messageChunk"]);
+        var messageSize = /** @type {number} */ (event.data["messageSize"]);

[alph, 2014/10/15 13:44:58]

Why do you need size? lastChunk boolean should be enough.

[pfeldman, 2014/10/15 14:06:59]

I'm doing it for consistency with the backend. Also total size allows proper
allocation in case we use typed arrays, etc.

+        if (messageSize) {
+            this._messageBuffer = "";
+            this._messageSize = messageSize;
+        }
+        this._messageBuffer += messageChunk;
+        if (this._messageBuffer.length === this._messageSize) {
+            this.dispatch(this._messageBuffer);

[dgozman, 2014/10/15 13:51:38]

It's safer to clear |this._messageBuffer| and |this._messageSize| for the case
of recursive dispatches caused by this call.

[pfeldman, 2014/10/15 14:06:59]

This is an async IPC call, we should not re-enter.

+            this._messageBuffer = "";
+            this._messageSize = 0;
+        }
     },
 
     __proto__: InspectorBackendClass.Connection.prototype
 }
 
 /**
  * @constructor
  * @extends {InspectorBackendClass.Connection}
  * @param {string} url
  * @param {!function(!InspectorBackendClass.Connection)} onConnectionReady
@@ skipping 293 matching lines @@
 
 }
 
 InspectorBackendClass.Options = {
     dumpInspectorTimeStats: false,
     dumpInspectorProtocolMessages: false,
     suppressRequestErrors: false
 }
 
 InspectorBackend = new InspectorBackendClass();