1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_LOADER_H_
6 #define CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_LOADER_H_
11 #include "base/compiler_specific.h"
12 #include "base/memory/scoped_ptr.h"
13 #include "base/memory/weak_ptr.h"
14 #include "base/scoped_observer.h"
15 #include "content/public/browser/notification_observer.h"
16 #include "content/public/browser/notification_registrar.h"
17 #include "extensions/browser/extension_registry_observer.h"
18 #include "extensions/common/extension.h"
19 #include "extensions/common/extension_set.h"
20 #include "extensions/common/user_script.h"
28 class RenderProcessHost;
33 namespace extensions {
35 class ContentVerifier;
36 class ExtensionRegistry;
38 typedef std::map<ExtensionId, ExtensionSet::ExtensionPathAndDefaultLocale>
41 // Manages one "logical unit" of user scripts in shared memory by constructing a
42 // new shared memory region when the set of scripts changes. Also notifies
43 // renderers of new shared memory region when new renderers appear, or when
44 // script reloading completes. Script loading lives on the UI thread. Instances
45 // of this class are embedded within classes with names ending in
46 // UserScriptMaster. These "master" classes implement the strategy for which
47 // scripts to load/unload on this logical unit of scripts.
48 class UserScriptLoader : public content::NotificationObserver,
49 public ExtensionRegistryObserver {
51 // Parses the includes out of |script| and returns them in |includes|.
52 static bool ParseMetadataHeader(const base::StringPiece& script_text,
55 // A wrapper around the method to load user scripts, which is normally run on
56 // the file thread. Exposed only for tests.
57 static void LoadScriptsForTest(UserScriptList* user_scripts);
59 UserScriptLoader(Profile* profile,
60 const ExtensionId& owner_extension_id,
61 bool listen_for_extension_system_loaded);
62 ~UserScriptLoader() override;
64 // Add |scripts| to the set of scripts managed by this loader.
65 void AddScripts(const std::set<UserScript>& scripts);
67 // Remove |scripts| from the set of scripts managed by this loader.
68 void RemoveScripts(const std::set<UserScript>& scripts);
70 // Clears the set of scripts managed by this loader.
73 // Initiates procedure to start loading scripts on the file thread.
76 // Return true if we have any scripts ready.
77 bool scripts_ready() const { return shared_memory_.get() != NULL; }
80 // content::NotificationObserver implementation.
81 void Observe(int type,
82 const content::NotificationSource& source,
83 const content::NotificationDetails& details) override;
85 // ExtensionRegistryObserver implementation.
86 void OnExtensionUnloaded(content::BrowserContext* browser_context,
87 const Extension* extension,
88 UnloadedExtensionInfo::Reason reason) override;
90 // Initiates script load when we have been waiting for the extension system
92 void OnExtensionSystemReady();
94 // Returns whether or not it is possible that calls to AddScripts(),
95 // RemoveScripts(), and/or ClearScripts() have caused any real change in the
96 // set of scripts to be loaded.
97 bool ScriptsMayHaveChanged() const;
99 // Attempt to initiate a load.
102 // Called once we have finished loading the scripts on the file thread.
103 void OnScriptsLoaded(scoped_ptr<UserScriptList> user_scripts,
104 scoped_ptr<base::SharedMemory> shared_memory);
106 // Sends the renderer process a new set of user scripts. If
107 // |changed_extensions| is not empty, this signals that only the scripts from
108 // those extensions should be updated. Otherwise, all extensions will be
110 void SendUpdate(content::RenderProcessHost* process,
111 base::SharedMemory* shared_memory,
112 const std::set<ExtensionId>& changed_extensions);
114 // Add to |changed_extensions_| those extensions referred to by |scripts|.
115 void ExpandChangedExtensions(const std::set<UserScript>& scripts);
117 // Update |extensions_info_| to contain info for each element of
118 // |changed_extensions_|.
119 void UpdateExtensionsInfo();
121 bool is_loading() const {
122 // Ownership of |user_scripts_| is passed to the file thread when loading.
123 return user_scripts_.get() == NULL;
126 // Manages our notification registrations.
127 content::NotificationRegistrar registrar_;
129 // Contains the scripts that were found the last time scripts were updated.
130 scoped_ptr<base::SharedMemory> shared_memory_;
132 // List of scripts from currently-installed extensions we should load.
133 scoped_ptr<UserScriptList> user_scripts_;
135 // Maps extension info needed for localization to an extension ID.
136 ExtensionsInfo extensions_info_;
138 // The mutually-exclusive sets of scripts that were added or removed since the
140 std::set<UserScript> added_scripts_;
141 std::set<UserScript> removed_scripts_;
143 // Indicates whether the the collection of scripts should be cleared before
144 // additions and removals on the next script load.
147 // The IDs of the extensions which changed in the last update sent to the
149 ExtensionIdSet changed_extensions_;
151 // If the extensions service has finished loading its initial set of
153 bool extension_system_ready_;
155 // If list of user scripts is modified while we're loading it, we note
156 // that we're currently mid-load and then start over again once the load
157 // finishes. This boolean tracks whether another load is pending.
160 // Whether or not we are currently loading.
163 // The profile for which the scripts managed here are installed.
166 // ID of the extension that owns these scripts, if any. This is only set to a
167 // non-empty value for declarative user script shared memory regions.
168 ExtensionId owner_extension_id_;
170 ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
171 extension_registry_observer_;
173 base::WeakPtrFactory<UserScriptLoader> weak_factory_;
175 DISALLOW_COPY_AND_ASSIGN(UserScriptLoader);
178 } // namespace extensions
180 #endif // CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_LOADER_H_