1 files changed, 305 insertions, 0 deletions
diff --git a/toolkit/jetpack/sdk/content/content-worker.js b/toolkit/jetpack/sdk/content/content-worker.js
new file mode 100644
index 000000000..0a8225733
--- /dev/null
+++ b/toolkit/jetpack/sdk/content/content-worker.js
@@ -0,0 +1,305 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+Object.freeze({
+  // TODO: Bug 727854 Use same implementation than common JS modules,
+  // i.e. EventEmitter module
+
+  /**
+   * Create an EventEmitter instance.
+   */
+  createEventEmitter: function createEventEmitter(emit) {
+    let listeners = Object.create(null);
+    let eventEmitter = Object.freeze({
+      emit: emit,
+      on: function on(name, callback) {
+        if (typeof callback !== "function")
+          return this;
+        if (!(name in listeners))
+          listeners[name] = [];
+        listeners[name].push(callback);
+        return this;
+      },
+      once: function once(name, callback) {
+        eventEmitter.on(name, function onceCallback() {
+          eventEmitter.removeListener(name, onceCallback);
+          callback.apply(callback, arguments);
+        });
+      },
+      removeListener: function removeListener(name, callback) {
+        if (!(name in listeners))
+          return;
+        let index = listeners[name].indexOf(callback);
+        if (index == -1)
+          return;
+        listeners[name].splice(index, 1);
+      }
+    });
+    function onEvent(name) {
+      if (!(name in listeners))
+        return [];
+      let args = Array.slice(arguments, 1);
+      let results = [];
+      for (let callback of listeners[name]) {
+        results.push(callback.apply(null, args));
+      }
+      return results;
+    }
+    return {
+      eventEmitter: eventEmitter,
+      emit: onEvent
+    };
+  },
+
+  /**
+   * Create an EventEmitter instance to communicate with chrome module
+   * by passing only strings between compartments.
+   * This function expects `emitToChrome` function, that allows to send
+   * events to the chrome module. It returns the EventEmitter as `pipe`
+   * attribute, and, `onChromeEvent` a function that allows chrome module
+   * to send event into the EventEmitter.
+   *
+   *                  pipe.emit --> emitToChrome
+   *              onChromeEvent --> callback registered through pipe.on
+   */
+  createPipe: function createPipe(emitToChrome) {
+    let ContentWorker = this;
+    function onEvent(type, ...args) {
+      // JSON.stringify is buggy with cross-sandbox values,
+      // it may return "{}" on functions. Use a replacer to match them correctly.
+      let replacer = (k, v) =>
+        typeof(v) === "function"
+          ? (type === "console" ? Function.toString.call(v) : void(0))
+          : v;
+
+      let str = JSON.stringify([type, ...args], replacer);
+      emitToChrome(str);
+    }
+
+    let { eventEmitter, emit } =
+      ContentWorker.createEventEmitter(onEvent);
+
+    return {
+      pipe: eventEmitter,
+      onChromeEvent: function onChromeEvent(array) {
+        // We either receive a stringified array, or a real array.
+        // We still allow to pass an array of objects, in WorkerSandbox.emitSync
+        // in order to allow sending DOM node reference between content script
+        // and modules (only used for context-menu API)
+        let args = typeof array == "string" ? JSON.parse(array) : array;
+        return emit.apply(null, args);
+      }
+    };
+  },
+
+  injectConsole: function injectConsole(exports, pipe) {
+    exports.console = Object.freeze({
+      log: pipe.emit.bind(null, "console", "log"),
+      info: pipe.emit.bind(null, "console", "info"),
+      warn: pipe.emit.bind(null, "console", "warn"),
+      error: pipe.emit.bind(null, "console", "error"),
+      debug: pipe.emit.bind(null, "console", "debug"),
+      exception: pipe.emit.bind(null, "console", "exception"),
+      trace: pipe.emit.bind(null, "console", "trace"),
+      time: pipe.emit.bind(null, "console", "time"),
+      timeEnd: pipe.emit.bind(null, "console", "timeEnd")
+    });
+  },
+
+  injectTimers: function injectTimers(exports, chromeAPI, pipe, console) {
+    // wrapped functions from `'timer'` module.
+    // Wrapper adds `try catch` blocks to the callbacks in order to
+    // emit `error` event if exception is thrown in
+    // the Worker global scope.
+    // @see http://www.w3.org/TR/workers/#workerutils
+
+    // List of all living timeouts/intervals
+    let _timers = Object.create(null);
+
+    // Keep a reference to original timeout functions
+    let {
+      setTimeout: chromeSetTimeout,
+      setInterval: chromeSetInterval,
+      clearTimeout: chromeClearTimeout,
+      clearInterval: chromeClearInterval
+    } = chromeAPI.timers;
+
+    function registerTimer(timer) {
+      let registerMethod = null;
+      if (timer.kind == "timeout")
+        registerMethod = chromeSetTimeout;
+      else if (timer.kind == "interval")
+        registerMethod = chromeSetInterval;
+      else
+        throw new Error("Unknown timer kind: " + timer.kind);
+
+      if (typeof timer.fun == 'string') {
+        let code = timer.fun;
+        timer.fun = () => chromeAPI.sandbox.evaluate(exports, code);
+      } else if (typeof timer.fun != 'function') {
+        throw new Error('Unsupported callback type' + typeof timer.fun);
+      }
+
+      let id = registerMethod(onFire, timer.delay);
+      function onFire() {
+        try {
+          if (timer.kind == "timeout")
+            delete _timers[id];
+          timer.fun.apply(null, timer.args);
+        } catch(e) {
+          console.exception(e);
+          let wrapper = {
+            instanceOfError: instanceOf(e, Error),
+            value: e,
+          };
+          if (wrapper.instanceOfError) {
+            wrapper.value = {
+              message: e.message,
+              fileName: e.fileName,
+              lineNumber: e.lineNumber,
+              stack: e.stack,
+              name: e.name,
+            };
+          }
+          pipe.emit('error', wrapper);
+        }
+      }
+      _timers[id] = timer;
+      return id;
+    }
+
+    // copied from sdk/lang/type.js since modules are not available here
+    function instanceOf(value, Type) {
+      var isConstructorNameSame;
+      var isConstructorSourceSame;
+
+      // If `instanceof` returned `true` we know result right away.
+      var isInstanceOf = value instanceof Type;
+
+      // If `instanceof` returned `false` we do ducktype check since `Type` may be
+      // from a different sandbox. If a constructor of the `value` or a constructor
+      // of the value's prototype has same name and source we assume that it's an
+      // instance of the Type.
+      if (!isInstanceOf && value) {
+        isConstructorNameSame = value.constructor.name === Type.name;
+        isConstructorSourceSame = String(value.constructor) == String(Type);
+        isInstanceOf = (isConstructorNameSame && isConstructorSourceSame) ||
+                        instanceOf(Object.getPrototypeOf(value), Type);
+      }
+      return isInstanceOf;
+    }
+
+    function unregisterTimer(id) {
+      if (!(id in _timers))
+        return;
+      let { kind } = _timers[id];
+      delete _timers[id];
+      if (kind == "timeout")
+        chromeClearTimeout(id);
+      else if (kind == "interval")
+        chromeClearInterval(id);
+      else
+        throw new Error("Unknown timer kind: " + kind);
+    }
+
+    function disableAllTimers() {
+      Object.keys(_timers).forEach(unregisterTimer);
+    }
+
+    exports.setTimeout = function ContentScriptSetTimeout(callback, delay) {
+      return registerTimer({
+        kind: "timeout",
+        fun: callback,
+        delay: delay,
+        args: Array.slice(arguments, 2)
+      });
+    };
+    exports.clearTimeout = function ContentScriptClearTimeout(id) {
+      unregisterTimer(id);
+    };
+
+    exports.setInterval = function ContentScriptSetInterval(callback, delay) {
+      return registerTimer({
+        kind: "interval",
+        fun: callback,
+        delay: delay,
+        args: Array.slice(arguments, 2)
+      });
+    };
+    exports.clearInterval = function ContentScriptClearInterval(id) {
+      unregisterTimer(id);
+    };
+
+    // On page-hide, save a list of all existing timers before disabling them,
+    // in order to be able to restore them on page-show.
+    // These events are fired when the page goes in/out of bfcache.
+    // https://developer.mozilla.org/En/Working_with_BFCache
+    let frozenTimers = [];
+    pipe.on("pageshow", function onPageShow() {
+      frozenTimers.forEach(registerTimer);
+    });
+    pipe.on("pagehide", function onPageHide() {
+      frozenTimers = [];
+      for (let id in _timers)
+        frozenTimers.push(_timers[id]);
+      disableAllTimers();
+      // Some other pagehide listeners may register some timers that won't be
+      // frozen as this particular pagehide listener is called first.
+      // So freeze these timers on next cycle.
+      chromeSetTimeout(function () {
+        for (let id in _timers)
+          frozenTimers.push(_timers[id]);
+        disableAllTimers();
+      }, 0);
+    });
+
+    // Unregister all timers when the page is destroyed
+    // (i.e. when it is removed from bfcache)
+    pipe.on("detach", function clearTimeouts() {
+      disableAllTimers();
+      _timers = {};
+      frozenTimers = [];
+    });
+  },
+
+  injectMessageAPI: function injectMessageAPI(exports, pipe, console) {
+
+    let ContentWorker = this;
+    let { eventEmitter: port, emit : portEmit } =
+      ContentWorker.createEventEmitter(pipe.emit.bind(null, "event"));
+    pipe.on("event", portEmit);
+
+    let self = {
+      port: port,
+      postMessage: pipe.emit.bind(null, "message"),
+      on: pipe.on.bind(null),
+      once: pipe.once.bind(null),
+      removeListener: pipe.removeListener.bind(null),
+    };
+    Object.defineProperty(exports, "self", {
+      value: self
+    });
+  },
+
+  injectOptions: function (exports, options) {
+    Object.defineProperty( exports.self, "options", { value: JSON.parse( options ) });
+  },
+
+  inject: function (exports, chromeAPI, emitToChrome, options) {
+    let ContentWorker = this;
+    let { pipe, onChromeEvent } =
+      ContentWorker.createPipe(emitToChrome);
+
+    ContentWorker.injectConsole(exports, pipe);
+    ContentWorker.injectTimers(exports, chromeAPI, pipe, exports.console);
+    ContentWorker.injectMessageAPI(exports, pipe, exports.console);
+    if ( options !== undefined ) {
+      ContentWorker.injectOptions(exports, options);
+    }
+
+    Object.freeze( exports.self );
+
+    return onChromeEvent;
+  }
+});