Implement Asynchronous Module Definition API for Mojo

gin/modules/module_registry.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef GIN_MODULES_MODULE_REGISTRY_H_
+#define GIN_MODULES_MODULE_REGISTRY_H_
+
+#include <list>
+#include <string>
+#include "base/compiler_specific.h"
+#include "gin/per_context_data.h"
+
+namespace gin {
+
+struct PendingModule;
+
+// This class implements the Asynchronous Module Definition (AMD) API.
+// https://github.com/amdjs/amdjs-api/wiki/AMD
+//
+// Our implementation isn't complete yet. Missing features:
+//   1) Built-in support for require, exports, and module.
+//   2) Path resoltuion in module names.
+//
+// For these reasons, we don't have an "amd" property on the "define"
+// function. The spec says we should only add that property once our
+// implementation complies with the specification.
+//
+class ModuleRegistry : public ContextSupplement {
+ public:
+  static ModuleRegistry* From(v8::Handle<v8::Context> context);
+
+  static void RegisterGlobals(v8::Isolate* isolate,
+                              v8::Handle<v8::ObjectTemplate> templ);
+
+  // The caller must have already entered our context.
+  void AddBuiltinModule(v8::Isolate* isolate,
+                        const std::string& id,
+                        v8::Handle<v8::ObjectTemplate> templ);
+
+  // Takes ownership of |pending|. The caller must have already entered
+  // our context.
+  void AddPendingModule(v8::Isolate* isolate, PendingModule* pending);

[Aaron Boodman, 2013/11/15 18:56:06]

What is the rationale for not relying upon base? It's a bummer to continually
work around not having its utilities, such as scoped_ptr.

[abarth-chromium, 2013/11/15 19:13:37]

Yeah, I agree that it's awkward not to have base.

The Mojo C++ bindings don't pull in base because we want folks to be able to
write Mojo apps that don't use base.  Maybe that's less of a concern for this
code because we'll already pulling in v8?

If you want to add a base dependency, that's ok with me.

[Aaron Boodman, 2013/11/15 19:54:30]

In the bravo case, at least, the developer provides javascript, so the presence
of base in the process isn't going to bother him :).

+
+ private:
+  typedef std::list<PendingModule*> PendingModuleList;  // Owning reference.
+
+  explicit ModuleRegistry(v8::Isolate* isolate);
+  virtual ~ModuleRegistry();
+
+  static v8::Handle<v8::String> Key(v8::Isolate* isolate);
+
+  // From ContextSupplement:
+  virtual void Detach(v8::Handle<v8::Context> context) OVERRIDE;
+
+  // Takes ownership of |pending|.
+  bool AttemptToLoad(v8::Isolate* isolate, PendingModule* pending);
+  void AttemptToLoadPendingModules(v8::Isolate* isolate);
+
+  v8::Persistent<v8::Object> modules_;
+  PendingModuleList pending_modules_;
+
+  DISALLOW_COPY_AND_ASSIGN(ModuleRegistry);
+};
+
+}  // namespace gin
+
+#endif  // GIN_MODULES_MODULE_REGISTRY_H_