Declarative content scripts: Renderer-side: per-extension shared memory regions (lazily loaded)

extensions/renderer/user_script_set_manager.h

+// Copyright 2014 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 EXTENSIONS_RENDERER_USER_SCRIPT_SET_MANAGER_H_
+#define EXTENSIONS_RENDERER_USER_SCRIPT_SET_MANAGER_H_
+
+#include <map>
+#include <set>
+#include <string>
+
+#include "base/memory/linked_ptr.h"
+#include "base/memory/shared_memory.h"
+#include "base/observer_list.h"
+#include "content/public/renderer/render_process_observer.h"
+#include "extensions/common/extension.h"
+#include "extensions/common/user_script.h"
+#include "extensions/renderer/user_script_set.h"
+
+namespace IPC {
+

[Devlin, 2014/07/28 18:15:28]

nit: we usually make these forward declarations a bit smaller:
namespace IPC {
class Message;
}

(note no "// namespace IPC" and no newlines between brackets.)

[Mark Dittmer, 2014/07/28 22:21:28]

Done.

+class Message;
+
+}  // namespace IPC
+
+namespace blink {
+
+class WebFrame;
+
+}  // namespace blink
+
+namespace extensions {
+
+class ExtensionSet;
+class ScriptInjection;
+
+// Manager for separate UserScriptSets, one for each shared memory region.
+// Regions are organized as follows:
+// static_scripts -- contains all extensions' scripts that are statically
+//                   declared in the extension manifest.
+// programmatic_scripts -- one region per extension containing only
+//                         programmatically declared scripts, instantiated

[Devlin, 2014/07/28 18:15:28]

nit of nits: programmatically-declared

[Mark Dittmer, 2014/07/28 22:21:29]

Done.

+//                         when an extension first creates a declarative rule
+//                         that would, if triggered, request a script injection.
+class UserScriptSetManager : public content::RenderProcessObserver {
+ public:
+  // Like a UserScriptSet::Observer, but automatically subscribes to all sets
+  // associated with the manager.
+  class Observer {
+   public:
+    virtual void OnUserScriptsUpdated(
+        const std::set<std::string>& changed_extensions,
+        const std::vector<UserScript*>& scripts) = 0;
+  };
+
+  UserScriptSetManager(const ExtensionSet* extensions);
+
+  virtual ~UserScriptSetManager();
+
+  // ScopedObserver Source implementation.

[Devlin, 2014/07/28 18:15:28]

nit: Usually "X implementation." refers to a direct superclass.  These are
probably common enough that they don't even need comments, but if you wanted,
I'd just stick with "Adds or removes an observer."

[Mark Dittmer, 2014/07/28 22:21:29]

Done.

+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  // content::RenderProcessObserver implementation.
+  virtual bool OnControlMessageReceived(const IPC::Message& message) OVERRIDE;

[Devlin, 2014/07/28 18:15:28]

Make this private.

[Mark Dittmer, 2014/07/28 22:21:29]

Done.

+
+  const UserScriptSet* static_scripts() const { return &static_scripts_; }
+
+  const UserScriptSet* ProgrammaticScripts(const ExtensionId& extensionId);

[Devlin, 2014/07/28 18:15:28]

If an accessor is "complex" (colloquially, not technically) and is not inlined
and hacker_style, we usually give it a full name.  In this case,
GetProgrammaticScriptsForExtension().

[Mark Dittmer, 2014/07/28 22:21:28]

Done.

+
+  // Put all injections from |static_scripts| and each of |programmatic_scripts|
+  // into |injections| via successive calls to
+  // UserScriptSet::GetInjections(injections, web_frame, tab_id, run_location).

[Devlin, 2014/07/28 18:15:28]

nit: Try not to include implementation details in the comments.  So, in this
case, just saying "Puts all injections from ... into |injections|" is
sufficient.  Note also that this should be "Puts", not "put", as we have a style
to describe methods in an adjectival sense, rather than in a command sense (this
*is* actually in the style guide, but trust me, I have to correct myself on this
one all the time. :))

[Mark Dittmer, 2014/07/28 22:21:28]

It's good to get the details right! Done.

+  void GetAllInjections(ScopedVector<ScriptInjection>* injections,
+                        blink::WebFrame* web_frame,
+                        int tab_id,
+                        UserScript::RunLocation run_location);
+
+  // Get active extension IDs from |static_scripts| and each of
+  // |programmatic_scripts|.
+  void GetAllActiveExtensionIds(std::set<std::string>* ids) const;
+
+ private:
+  // Map for per-extension sets that may be defined programmatically.
+  typedef std::map<ExtensionId, linked_ptr<UserScriptSet> > UserScriptSetMap;
+
+  // Handle the UpdateUserScripts extension message.
+  void OnUpdateUserScripts(base::SharedMemoryHandle shared_memory,
+                           const ExtensionId& extension_id,
+                           const std::set<std::string>& changed_extensions);
+
+  // Scripts statically defined in extension manifests.
+  UserScriptSet static_scripts_;
+
+  // Scripts programmatically defined through API calls (initialized and stored
+  // per-extension).
+  UserScriptSetMap programmatic_scripts_;
+
+  // The set of all known extensions. Owned by the Dispatcher.
+  const ExtensionSet* extensions_;
+
+  // The associated observers.
+  ObserverList<Observer> observers_;

[Devlin, 2014/07/28 18:15:28]

DISALLOW_COPY_AND_ASSIGN()

[Mark Dittmer, 2014/07/28 22:21:28]

Done.

+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_USER_SCRIPT_SET_MANAGER_H_