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

chrome/browser/extensions/user_script_master.h

-// Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_
-#define CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_
-
-#include <map>
-#include <string>
-
-#include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/scoped_observer.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "extensions/browser/extension_registry_observer.h"
-#include "extensions/common/extension_messages.h"
-#include "extensions/common/extension_set.h"
-#include "extensions/common/user_script.h"
-
-namespace base {
-class SharedMemory;
-}
-
-namespace content {
-class RenderProcessHost;
-}
-
-class Profile;
-
-namespace extensions {
-
-class ContentVerifier;
-class ExtensionRegistry;
-
-typedef std::map<std::string, ExtensionSet::ExtensionPathAndDefaultLocale>
-    ExtensionsInfo;
-
-// Manages a segment of shared memory that contains the user scripts the user
-// has installed.  Lives on the UI thread.
-class UserScriptMaster : public content::NotificationObserver,
-                         public ExtensionRegistryObserver {
- public:
-  // Parses the includes out of |script| and returns them in |includes|.
-  static bool ParseMetadataHeader(const base::StringPiece& script_text,
-                                  UserScript* script);
-
-  // A wrapper around the method to load user scripts, which is normally run on
-  // the file thread. Exposed only for tests.
-  static void LoadScriptsForTest(UserScriptList* user_scripts);
-
-  explicit UserScriptMaster(Profile* profile);
-  virtual ~UserScriptMaster();
-
-  // Kicks off a process on the file thread to reload scripts from disk
-  // into a new chunk of shared memory and notify renderers.
-  virtual void StartLoad();
-
-  // Gets the segment of shared memory for the scripts.
-  base::SharedMemory* GetSharedMemory() const {
-    return shared_memory_.get();
-  }
-
-  // Return true if we have any scripts ready.
-  bool ScriptsReady() const { return shared_memory_.get() != NULL; }
-
- private:
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  // ExtensionRegistryObserver implementation.
-  virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
-                                 const Extension* extension) OVERRIDE;
-  virtual void OnExtensionUnloaded(
-      content::BrowserContext* browser_context,
-      const Extension* extension,
-      UnloadedExtensionInfo::Reason reason) OVERRIDE;
-
-  // Called when ExtensionSystem is ready.
-  void OnExtensionsReady();
-
-  // Called once we have finished loading the scripts on the file thread.
-  void OnScriptsLoaded(scoped_ptr<UserScriptList> user_scripts,
-                       scoped_ptr<base::SharedMemory> shared_memory);
-
-  // Sends the renderer process a new set of user scripts. If
-  // |changed_extensions| is not empty, this signals that only the scripts from
-  // those extensions should be updated. Otherwise, all extensions will be
-  // updated.
-  void SendUpdate(content::RenderProcessHost* process,
-                  base::SharedMemory* shared_memory,
-                  const std::set<std::string>& changed_extensions);
-
-  bool is_loading() const {
-    // Ownership of |user_scripts_| is passed to the file thread when loading.
-    return user_scripts_.get() == NULL;
-  }
-
-  // Manages our notification registrations.
-  content::NotificationRegistrar registrar_;
-
-  // Contains the scripts that were found the last time scripts were updated.
-  scoped_ptr<base::SharedMemory> shared_memory_;
-
-  // List of scripts from currently-installed extensions we should load.
-  scoped_ptr<UserScriptList> user_scripts_;
-
-  // Maps extension info needed for localization to an extension ID.
-  ExtensionsInfo extensions_info_;
-
-  // The IDs of the extensions which have changed since the last update sent to
-  // the renderer.
-  std::set<std::string> changed_extensions_;
-
-  // The mutually-exclusive sets of extensions that were added or removed since
-  // the last script load.
-  std::set<std::string> added_extensions_;
-  std::set<std::string> removed_extensions_;
-
-  // If the extensions service has finished loading its initial set of
-  // extensions.
-  bool extensions_service_ready_;
-
-  // If list of user scripts is modified while we're loading it, we note
-  // that we're currently mid-load and then start over again once the load
-  // finishes.  This boolean tracks whether another load is pending.
-  bool pending_load_;
-
-  // Whether or not we are currently loading.
-  bool is_loading_;
-
-  // The profile for which the scripts managed here are installed.
-  Profile* profile_;
-
-  // Listen to extension load, unloaded notifications.
-  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
-      extension_registry_observer_;
-
-  base::WeakPtrFactory<UserScriptMaster> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(UserScriptMaster);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_