Issue 3108 - Inject our about: module into all processes

lib/child/bootstrap.js

+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2015 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+(function()
+{
+  const Cc = Components.classes;
+  const Ci = Components.interfaces;
+  const Cr = Components.results;
+  const Cu = Components.utils;
+
+  let {Loader, main, unload} = Cu.import("resource://gre/modules/commonjs/toolkit/loader.js", {});
+
+  let loader = null;
+
+  let shutdownHandlers = [];
+  let onShutdown =
+  {
+    done: false,
+    add: function(handler)
+    {
+      if (shutdownHandlers.indexOf(handler) < 0)
+        shutdownHandlers.push(handler);
+    },
+    remove: function(handler)
+    {
+      let index = shutdownHandlers.indexOf(handler);
+      if (index >= 0)
+        shutdownHandlers.splice(index, 1);
+    }
+  };
+
+  addMessageListener("AdblockPlus:Info", init);
+  addMessageListener("AdblockPlus:Shutdown", shutdown);
+
+  function init(message)
+  {
+    removeMessageListener("AdblockPlus:Info", init);
+
+    let info = message.data;
+    loader = Loader({
+      paths: {
+        "": info.addonRoot + "lib/"
+      },
+      globals: {
+        Components, Cc, Ci, Cu, Cr, atob, btoa, onShutdown,

[Wladimir Palant, 2015/10/16 12:15:10]

bootstrap.js from buildtools also exposes File and XMLHttpRequest but I think
that we better remove both from the global scope there as well. We don't use
File, and XMLHttpRequest is better accessed via XPCOM explicitly.

The other difference is the Components property - SDK loader will
unconditionally mask it by a getter throwing an exception (see hack in
elemHideHitRegistration.js). So far I couldn't find a better solution than
removing the getter explicitly in the modules that need to access Components.

[Thomas Greiner, 2015/10/16 15:40:25]

I couldn't find a better one either. We could implement our own module resolver
but that would end up being even more effort.

[Wladimir Palant, 2015/10/16 17:52:03]

The alternative is exposing this property as components rather than Components
(the SDK does that) but I'd rather keep it consistent with the current
bootstrap.js in buildtools. We could use the SDK loader there as well, but
currently I have doubts that this would make sense (requires significant effort,
e.g. testing the performance impact, yet doesn't give us anything other than
being consistent with the SDK which seems to be doomed as well).

+        addMessageListener, removeMessageListener, sendAsyncMessage, sendSyncMessage
+      },
+      modules: {"info": info},
+      id: info.addonID
+    });
+    onShutdown.add(() => unload(loader, "disable"))
+
+    main(loader, "child/main");
+  }
+
+  function shutdown(message)
+  {
+    if (message.data == Components.stack.filename)
+    {
+      removeMessageListener("AdblockPlus:Shutdown", shutdown);
+
+      onShutdown.done = true;
+      for (let i = shutdownHandlers.length - 1; i >= 0; i --)
+      {
+        try
+        {
+          shutdownHandlers[i]();
+        }
+        catch (e)
+        {
+          Cu.reportError(e);
+        }
+      }
+      shutdownHandlers = null;
+    }
+  }
+})();
+