chrome/browser/extensions/user_script_master.h

   1 // Copyright (c) 2012 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.
   4
   5 #ifndef CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_
   6 #define CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_
   7
   8 #include <map>
   9 #include <string>
  10
  11 #include "base/compiler_specific.h"
  12 #include "base/files/file_path.h"
  13 #include "base/gtest_prod_util.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/shared_memory.h"
  16 #include "base/strings/string_piece.h"
  17 #include "chrome/browser/extensions/extension_info_map.h"
  18 #include "chrome/common/extensions/extension_messages.h"
  19 #include "chrome/common/extensions/extension_set.h"
  20 #include "chrome/common/extensions/user_script.h"
  21 #include "content/public/browser/browser_thread.h"
  22 #include "content/public/browser/notification_observer.h"
  23 #include "content/public/browser/notification_registrar.h"
  24
  25 namespace content {
  26 class RenderProcessHost;
  27 }
  28
  29 class Profile;
  30
  31 typedef std::map<std::string, ExtensionSet::ExtensionPathAndDefaultLocale>
  32     ExtensionsInfo;
  33
  34 namespace extensions {
  35
  36 // Manages a segment of shared memory that contains the user scripts the user
  37 // has installed.  Lives on the UI thread.
  38 class UserScriptMaster : public base::RefCountedThreadSafe<UserScriptMaster>,
  39                          public content::NotificationObserver {
  40  public:
  41   explicit UserScriptMaster(Profile* profile);
  42
  43   // Kicks off a process on the file thread to reload scripts from disk
  44   // into a new chunk of shared memory and notify renderers.
  45   virtual void StartLoad();
  46
  47   // Gets the segment of shared memory for the scripts.
  48   base::SharedMemory* GetSharedMemory() const {
  49     return shared_memory_.get();
  50   }
  51
  52   // Called by the script reloader when new scripts have been loaded.
  53   void NewScriptsAvailable(base::SharedMemory* handle);
  54
  55   // Return true if we have any scripts ready.
  56   bool ScriptsReady() const { return shared_memory_.get() != NULL; }
  57
  58  protected:
  59   friend class base::RefCountedThreadSafe<UserScriptMaster>;
  60
  61   virtual ~UserScriptMaster();
  62
  63  public:
  64   // We reload user scripts on the file thread to prevent blocking the UI.
  65   // ScriptReloader lives on the file thread and does the reload
  66   // work, and then sends a message back to its master with a new SharedMemory*.
  67   // ScriptReloader is the worker that manages running the script load
  68   // on the file thread. It must be created on, and its public API must only be
  69   // called from, the master's thread.
  70   class ScriptReloader
  71       : public base::RefCountedThreadSafe<UserScriptMaster::ScriptReloader> {
  72    public:
  73     // Parses the includes out of |script| and returns them in |includes|.
  74     static bool ParseMetadataHeader(const base::StringPiece& script_text,
  75                                     UserScript* script);
  76
  77     explicit ScriptReloader(UserScriptMaster* master);
  78
  79     // Start loading of scripts.
  80     // Will always send a message to the master upon completion.
  81     void StartLoad(const UserScriptList& external_scripts,
  82                    const ExtensionsInfo& extension_info_);
  83
  84     // The master is going away; don't call it back.
  85     void DisownMaster() {
  86       master_ = NULL;
  87     }
  88
  89    private:
  90     FRIEND_TEST_ALL_PREFIXES(UserScriptMasterTest, SkipBOMAtTheBeginning);
  91     FRIEND_TEST_ALL_PREFIXES(UserScriptMasterTest, LeaveBOMNotAtTheBeginning);
  92     friend class base::RefCountedThreadSafe<UserScriptMaster::ScriptReloader>;
  93
  94     ~ScriptReloader();
  95
  96     // Where functions are run:
  97     //    master          file
  98     //   StartLoad   ->  RunLoad
  99     //                     LoadUserScripts()
 100     // NotifyMaster  <-  RunLoad
 101
 102     // Runs on the master thread.
 103     // Notify the master that new scripts are available.
 104     void NotifyMaster(base::SharedMemory* memory);
 105
 106     // Runs on the File thread.
 107     // Load the specified user scripts, calling NotifyMaster when done.
 108     // |user_scripts| is intentionally passed by value so its lifetime isn't
 109     // tied to the caller.
 110     void RunLoad(const UserScriptList& user_scripts);
 111
 112     void LoadUserScripts(UserScriptList* user_scripts);
 113
 114     // Uses extensions_info_ to build a map of localization messages.
 115     // Returns NULL if |extension_id| is invalid.
 116     SubstitutionMap* GetLocalizationMessages(std::string extension_id);
 117
 118     // A pointer back to our master.
 119     // May be NULL if DisownMaster() is called.
 120     UserScriptMaster* master_;
 121
 122     // Maps extension info needed for localization to an extension ID.
 123     ExtensionsInfo extensions_info_;
 124
 125     // The message loop to call our master back on.
 126     // Expected to always outlive us.
 127     content::BrowserThread::ID master_thread_id_;
 128
 129     DISALLOW_COPY_AND_ASSIGN(ScriptReloader);
 130   };
 131
 132  private:
 133   // content::NotificationObserver implementation.
 134   virtual void Observe(int type,
 135                        const content::NotificationSource& source,
 136                        const content::NotificationDetails& details) OVERRIDE;
 137
 138   // Sends the renderer process a new set of user scripts.
 139   void SendUpdate(content::RenderProcessHost* process,
 140                   base::SharedMemory* shared_memory);
 141
 142   // Manages our notification registrations.
 143   content::NotificationRegistrar registrar_;
 144
 145   // We hang on to our pointer to know if we've already got one running.
 146   scoped_refptr<ScriptReloader> script_reloader_;
 147
 148   // Contains the scripts that were found the last time scripts were updated.
 149   scoped_ptr<base::SharedMemory> shared_memory_;
 150
 151   // List of scripts from currently-installed extensions we should load.
 152   UserScriptList user_scripts_;
 153
 154   // Maps extension info needed for localization to an extension ID.
 155   ExtensionsInfo extensions_info_;
 156
 157   // If the extensions service has finished loading its initial set of
 158   // extensions.
 159   bool extensions_service_ready_;
 160
 161   // If list of user scripts is modified while we're loading it, we note
 162   // that we're currently mid-load and then start over again once the load
 163   // finishes.  This boolean tracks whether another load is pending.
 164   bool pending_load_;
 165
 166   // The profile for which the scripts managed here are installed.
 167   Profile* profile_;
 168
 169   DISALLOW_COPY_AND_ASSIGN(UserScriptMaster);
 170 };
 171
 172 }  // namespace extensions
 173
 174 #endif  // CHROME_BROWSER_EXTENSIONS_USER_SCRIPT_MASTER_H_