Separate plugin_metadata from plugin_installer, thread-safe plugin_finder

chrome/browser/plugins/plugin_finder.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_PLUGINS_PLUGIN_FINDER_H_
 #define CHROME_BROWSER_PLUGINS_PLUGIN_FINDER_H_
 
 #include <map>
 #include <string>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
-#include "base/hash_tables.h"
+#include "base/synchronization/lock.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "base/string16.h"
 #include "webkit/plugins/webplugininfo.h"
 
 namespace base {
 class DictionaryValue;
 }
 
 class GURL;
+class PluginMetadata;
+
+#if defined(ENABLE_PLUGIN_INSTALLATION)
 class PluginInstaller;
+#endif
 
+// This class should be created and initialized by calling
+// |GetInstance()| and |Init()| on the UI thread.

[Bernhard Bauer, 2012/09/24 09:14:25]

This comment isn't correct anymore.

[ibraaaa, 2012/09/24 11:01:07]

reverted the custom traits.
On 2012/09/24 09:14:25, Bernhard Bauer wrote:

+// After that it can be safely used on any other thread.
 class PluginFinder {
  public:
-  typedef std::vector<webkit::WebPluginInfo> PluginVector;
-  typedef base::Callback<void(const PluginVector&, PluginFinder*)>
-      CombinedCallback;
-  // Gets PluginFinder and vector of Plugins asynchronously. It then
-  // calls |cb| once both are fetched.
-  static void GetPluginsAndPluginFinder(const CombinedCallback& cb);
+  static PluginFinder* GetInstance();
 
+  // TODO(ibraaaa): DELETE. http://crbug.com/124396
   static void Get(const base::Callback<void(PluginFinder*)>& cb);
 
+#if defined(ENABLE_PLUGIN_INSTALLATION)
   // Finds a plug-in for the given MIME type and language (specified as an IETF
   // language tag, i.e. en-US) and returns the PluginInstaller for the plug-in,
   // or NULL if no plug-in is found.
   PluginInstaller* FindPlugin(const std::string& mime_type,
                               const std::string& language);
 
   // Returns the plug-in with the given identifier.
   PluginInstaller* FindPluginWithIdentifier(const std::string& identifier);
+#endif
 
-  // Gets a plug-in installer using |plugin|.
-  PluginInstaller* GetPluginInstaller(const webkit::WebPluginInfo& plugin);
+  // Returns the plug-in metadata with the given identifier.
+  PluginMetadata* FindPluginMetadataWithIdentifier(
+      const std::string& identifier);
+
+  // Gets plug-in metadata using |plugin|.
+  PluginMetadata* GetPluginMetadata(const webkit::WebPluginInfo& plugin);
 
  private:
+  // Custom traits that calls |Init()| to initialize the singleton object
+  // after creation.
+  struct CustomSingletonTraits;
+
   friend struct DefaultSingletonTraits<PluginFinder>;
   friend class Singleton<PluginFinder>;
   FRIEND_TEST_ALL_PREFIXES(PluginFinderTest, JsonSyntax);
   FRIEND_TEST_ALL_PREFIXES(PluginFinderTest, PluginGroups);
 
-  static PluginFinder* GetInstance();
-
   PluginFinder();
   ~PluginFinder();
 
+  // It should be called on the UI thread.
+  void Init();
+
   // Loads the plug-in information from the browser resources and parses it.
   // Returns NULL if the plug-in list couldn't be parsed.
   static base::DictionaryValue* LoadPluginList();
 
-  PluginInstaller* CreateInstaller(const std::string& identifier,
-                                   const base::DictionaryValue* plugin_dict);
+  PluginMetadata* CreatePluginMetadata(
+      const std::string& identifier,
+      const base::DictionaryValue* plugin_dict);
 
+  // Initialized in |Init()| method and is read-only after that.
+  // No need to be synchronized.
   scoped_ptr<base::DictionaryValue> plugin_list_;
+#if defined(ENABLE_PLUGIN_INSTALLATION)
   std::map<std::string, PluginInstaller*> installers_;
+#endif
 
-  // Note: Don't free memory for |name_insallers_| values
+  std::map<std::string, PluginMetadata*> identifier_plugin_;
+
+  // Note: Don't free memory for |name_plugin_| values
   // since it holds pointers to same instances
-  // in |installers_| (Double De-allocation).
-  base::hash_map<string16, PluginInstaller*> name_installers_;
+  // in |identifier_plugin_| (Double De-allocation).
+  std::map<string16, PluginMetadata*> name_plugin_;
+
+  // Synchronization for |installers_|, |identifier_plugin_| and
+  // |name_plugin_| are required since multiple threads
+  // can be accessing them concurrently.
+  base::Lock mutex_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginFinder);
 };
 
 #endif  // CHROME_BROWSER_PLUGINS_PLUGIN_FINDER_H_