Receive binary Brackets-Node command responses

src/utils/NodeConnection.js

@@ -24,7 +24,7 @@
 
 /*jslint vars: true, plusplus: true, devel: true, nomen: true, indent: 4,
 maxerr: 50, browser: true */
-/*global $, define, brackets, WebSocket */
+/*global $, define, brackets, WebSocket, ArrayBuffer, Uint32Array */
 
 define(function (require, exports, module) {
     "use strict";
@@ -46,6 +46,9 @@ define(function (require, exports, module) {
     /** @define{number} Milliseconds to wait before retrying connecting */
     var RETRY_DELAY         = 500;   // 1/2 second
 
+    /** @define {number} Maximum value of the command ID counter */
+    var MAX_COUNTER_VALUE = 4294967295; // 2^32 - 1
+
     /**
      * @private
      * Helper function to auto-reject a deferred after a given amount of time.
@@ -74,6 +77,10 @@ define(function (require, exports, module) {
                 port = nodePort;
                 ws = new WebSocket("ws://localhost:" + port);
 
+                // Expect ArrayBuffer objects from Node when receiving binary
+                // data instead of DOM Blobs, which are the default.
+                ws.binaryType = "arraybuffer";
+
                 // If the server port isn't open, we get a close event
                 // at some point in the future (and will not get an onopen 
                 // event)
@@ -174,6 +181,23 @@ define(function (require, exports, module) {
      */
     NodeConnection.prototype._pendingCommandDeferreds = null;
 
+    /**
+     * @private
+     * @return {number} The next command ID to use. Always representable as an
+     * unsigned 32-bit integer.
+     */
+    NodeConnection.prototype._getNextCommandID = function () {
+        var nextID;
+
+        if (this._commandCount > MAX_COUNTER_VALUE) {
+            nextID = this._commandCount = 0;
+        } else {
+            nextID = this._commandCount++;
+        }
+
+        return nextID;
+    };
+
     /**
      * @private
      * Helper function to do cleanup work when a connection fails
@@ -402,12 +426,36 @@ define(function (require, exports, module) {
      */
     NodeConnection.prototype._receive = function (message) {
         var responseDeferred = null;
+        var data = message.data;
         var m;
-        try {
-            m = JSON.parse(message.data);
-        } catch (e) {
-            console.error("[NodeConnection] received malformed message", message, e.message);
-            return;
+
+        if (message.data instanceof ArrayBuffer) {
+            // The first four bytes encode the command ID as an unsigned 32-bit integer
+            if (data.byteLength < 4) {
+                console.error("[NodeConnection] received malformed binary message");
+                return;
+            }
+
+            var header = data.slice(0, 4),
+                body = data.slice(4),
+                headerView = new Uint32Array(header),
+                id = headerView[0];
+
+            // Unpack the binary message into a commandResponse
+            m = {
+                type: "commandResponse",
+                message: {
+                    id: id,
+                    response: body
+                }
+            };
+        } else {
+            try {
+                m = JSON.parse(data);
+            } catch (e) {
+                console.error("[NodeConnection] received malformed message", message, e.message);
+                return;
+            }
         }
 
         switch (m.type) {
@@ -467,7 +515,7 @@ define(function (require, exports, module) {
                 return function () {
                     var deferred = $.Deferred();
                     var parameters = Array.prototype.slice.call(arguments, 0);
-                    var id = self._commandCount++;
+                    var id = self._getNextCommandID();
                     self._pendingCommandDeferreds[id] = deferred;
                     self._send({id: id,
                                domain: domainName,

test/spec/NodeConnection-test-files/BinaryTestCommands.js

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2013 Adobe Systems Incorporated. All rights reserved.
+ *  
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"), 
+ * to deal in the Software without restriction, including without limitation 
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+ * and/or sell copies of the Software, and to permit persons to whom the 
+ * Software is furnished to do so, subject to the following conditions:
+ *  
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *  
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+ * DEALINGS IN THE SOFTWARE.
+ * 
+ */
+
+/*jslint vars: true, plusplus: true, devel: true, nomen: true, indent: 4, maxerr: 50, node: true */
+/*global */
+
+(function () {
+    "use strict";
+
+    /**
+     * @private
+     * @type {DomainManager}
+     * The DomainManager passed in at init.
+     */
+    var _domainManager = null;
+
+
+    /**
+     * @private
+     * @type {Buffer}
+     */
+    var _buffer = new Buffer(18);
+
+    // write some bytes into the buffer with varied alignments
+    _buffer.writeUInt8(1, 0);
+    _buffer.writeUInt32LE(Math.pow(2, 32) - 1, 1);
+    _buffer.writeFloatBE(3.141592, 5);
+    _buffer.writeDoubleLE(Number.MAX_VALUE, 9);
+    _buffer.writeInt8(-128, 17);
+
+    /**
+     * @private
+     * @return {Buffer}
+     */
+    function _getBufferSync() {
+        return _buffer;
+    }
+
+    /**
+     * @private
+     * @param {function(?string, Buffer=)} callback
+     */
+    function _getBufferAsync(callback) {
+        process.nextTick(function () {
+            callback(null, _buffer);
+        });
+    }
+
+    /**
+     * @param {DomainManager} DomainManager The DomainManager for the server
+     */
+    function init(DomainManager) {
+        _domainManager = DomainManager;
+        if (!_domainManager.hasDomain("test")) {
+            _domainManager.registerDomain("test", {major: 0, minor: 1});
+        }
+        _domainManager.registerCommand(
+            "binaryTest",
+            "getBufferSync",
+            _getBufferSync,
+            false,
+            "Get a byte array synchronously",
+            [],
+            {name: "bytes", type: "Buffer"}
+        );
+        _domainManager.registerCommand(
+            "binaryTest",
+            "getBufferAsync",
+            _getBufferAsync,
+            true,
+            "Get a byte array asynchronously",
+            [],
+            {name: "bytes", type: "Buffer"}
+        );
+    }
+
+    exports.init = init;
+
+}());

test/spec/NodeConnection-test.js

@@ -25,7 +25,7 @@
 /*jslint vars: true, plusplus: true, devel: true, browser: true, nomen: true,
 indent: 4, maxerr: 50 */
 /*global define, describe, it, xit, expect, beforeEach, afterEach, waits,
-waitsFor, runs, $, brackets, waitsForDone */
+waitsFor, runs, $, brackets, waitsForDone, ArrayBuffer, DataView */
 
 define(function (require, exports, module) {
     "use strict";
@@ -399,5 +399,71 @@ define(function (require, exports, module) {
             });
 
         });
+
+        it("should receive synchronous binary command responses", function () {
+            var connection = createConnection();
+            var commandDeferred = null;
+            var result = null;
+            runConnectAndWait(connection, false);
+            runLoadDomainsAndWait(connection, ["BinaryTestCommands"], false);
+            runs(function () {
+                commandDeferred = connection.domains.binaryTest.getBufferSync();
+                commandDeferred.done(function (response) {
+                    result = response;
+                });
+            });
+            waitsFor(
+                function () {
+                    return commandDeferred &&
+                        commandDeferred.state() === "resolved" &&
+                        result;
+                },
+                CONNECTION_TIMEOUT
+            );
+            runs(function () {
+                var view = new DataView(result);
+
+                expect(result instanceof ArrayBuffer).toBe(true);
+                expect(result.byteLength).toBe(18);
+                expect(view.getUint8(0)).toBe(1);
+                expect(view.getUint32(1)).toBe(4294967295);
+                expect(view.getFloat32(5, false)).toBe(3.141592025756836);
+                expect(view.getFloat64(9, true)).toBe(1.7976931348623157e+308);
+                expect(view.getInt8(17)).toBe(-128);
+            });
+        });
+
+        it("should receive asynchronous binary command response", function () {
+            var connection = createConnection();
+            var commandDeferred = null;
+            var result = null;
+            runConnectAndWait(connection, false);
+            runLoadDomainsAndWait(connection, ["BinaryTestCommands"], false);
+            runs(function () {
+                commandDeferred = connection.domains.binaryTest.getBufferAsync();
+                commandDeferred.done(function (response) {
+                    result = response;
+                });
+            });
+            waitsFor(
+                function () {
+                    return commandDeferred &&
+                        commandDeferred.state() === "resolved" &&
+                        result;
+                },
+                CONNECTION_TIMEOUT
+            );
+            runs(function () {
+                var view = new DataView(result);
+
+                expect(result instanceof ArrayBuffer).toBe(true);
+                expect(result.byteLength).toBe(18);
+                expect(view.getUint8(0)).toBe(1);
+                expect(view.getUint32(1)).toBe(4294967295);
+                expect(view.getFloat32(5, false)).toBe(3.141592025756836);
+                expect(view.getFloat64(9, true)).toBe(1.7976931348623157e+308);
+                expect(view.getInt8(17)).toBe(-128);
+            });
+        });
     });
-});
+});