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

chrome/browser/extensions/user_script_master_manager.h

+// Copyright (c) 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 CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_MANAGER_H_
+#define CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_MANAGER_H_
+
+#include "base/containers/scoped_ptr_hash_map.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/scoped_observer.h"
+#include "chrome/browser/extensions/declarative_user_script_master.h"
+#include "chrome/browser/extensions/user_script_master.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/browser/extension_registry_observer.h"
+#include "extensions/common/extension.h"
+#include "extensions/common/user_script.h"
+
+namespace content {
+
+class BrowserContext;
+
+}  // namespace content
+
+class Profile;
+
+namespace extensions {
+
+class UserScriptMasterManager : public ExtensionRegistryObserver {
+ public:
+  explicit UserScriptMasterManager(Profile* profile);
+  virtual ~UserScriptMasterManager();
+
+  UserScriptMaster* shared_master() { return shared_master_.get(); }
+
+  DeclarativeUserScriptMaster* GetDeclarativeMasterByExtension(
+      const ExtensionId& extension_id) {
+    if (!declarative_masters_.get(extension_id)) {
+      declarative_masters_.set(extension_id,
+                               make_scoped_ptr(new DeclarativeUserScriptMaster(
+                                   profile_, extension_id)));
+    }
+    return declarative_masters_.get(extension_id);
+  }
+
+  // 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;
+
+ private:
+  Profile* profile_;
+
+  // Shared memory region manager for scripts statically declared in extension
+  // manifests. This region is shared between all extensions.
+  scoped_ptr<UserScriptMaster> shared_master_;
+
+  // Shared memory region manager for programmatically declared scripts, one per
+  // extension. Managers are instantiated the first time the declarative API is
+  // used by an extension to request content scripts.
+  base::ScopedPtrHashMap<ExtensionId, DeclarativeUserScriptMaster>
+      declarative_masters_;
+
+  // Listen to extension load, unloaded notifications.
+  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserScriptMasterManager);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_MANAGER_H_