content/browser/webui/url_data_manager.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 CONTENT_BROWSER_WEBUI_URL_DATA_MANAGER_H_
   6 #define CONTENT_BROWSER_WEBUI_URL_DATA_MANAGER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/memory/ref_counted.h"
  12 #include "base/supports_user_data.h"
  13 #include "content/common/content_export.h"
  14
  15 namespace content {
  16 class BrowserContext;
  17 class URLDataSource;
  18 class URLDataSourceImpl;
  19 class WebUIDataSource;
  20
  21 // To serve dynamic data off of chrome: URLs, implement the
  22 // URLDataManager::DataSource interface and register your handler
  23 // with AddDataSource. DataSources must be added on the UI thread (they are also
  24 // deleted on the UI thread). Internally the DataSources are maintained by
  25 // URLDataManagerBackend, see it for details.
  26 class CONTENT_EXPORT URLDataManager : public base::SupportsUserData::Data {
  27  public:
  28   explicit URLDataManager(BrowserContext* browser_context);
  29   ~URLDataManager() override;
  30
  31   // Adds a DataSource to the collection of data sources. This *must* be invoked
  32   // on the UI thread.
  33   //
  34   // If |AddDataSource| is called more than once for a particular name it will
  35   // release the old |DataSource|, most likely resulting in it getting deleted
  36   // as there are no other references to it. |DataSource| uses the
  37   // |DeleteOnUIThread| trait to insure that the destructor is called on the UI
  38   // thread. This is necessary as some |DataSource|s notably |FileIconSource|
  39   // and |FaviconSource|, have members that will DCHECK if they are not
  40   // destructed in the same thread as they are constructed (the UI thread).
  41   void AddDataSource(URLDataSourceImpl* source);
  42
  43   // Deletes any data sources no longer referenced. This is normally invoked
  44   // for you, but can be invoked to force deletion (such as during shutdown).
  45   static void DeleteDataSources();
  46
  47   // Convenience wrapper function to add |source| to |browser_context|'s
  48   // |URLDataManager|. Creates a URLDataSourceImpl to wrap the given
  49   // source.
  50   static void AddDataSource(BrowserContext* browser_context,
  51                             URLDataSource* source);
  52
  53   // Adds a WebUI data source to |browser_context|'s |URLDataManager|.
  54   static void AddWebUIDataSource(BrowserContext* browser_context,
  55                                  WebUIDataSource* source);
  56
  57  private:
  58   friend class URLDataSourceImpl;
  59   friend struct DeleteURLDataSource;
  60   typedef std::vector<const URLDataSourceImpl*> URLDataSources;
  61
  62   // If invoked on the UI thread the DataSource is deleted immediatlye,
  63   // otherwise it is added to |data_sources_| and a task is scheduled to handle
  64   // deletion on the UI thread. See note abouve DeleteDataSource for more info.
  65   static void DeleteDataSource(const URLDataSourceImpl* data_source);
  66
  67   // Returns true if |data_source| is scheduled for deletion (|DeleteDataSource|
  68   // was invoked).
  69   static bool IsScheduledForDeletion(const URLDataSourceImpl* data_source);
  70
  71   BrowserContext* browser_context_;
  72
  73   // |data_sources_| that are no longer referenced and scheduled for deletion.
  74   // Protected by g_delete_lock in the .cc file.
  75   static URLDataSources* data_sources_;
  76
  77   DISALLOW_COPY_AND_ASSIGN(URLDataManager);
  78 };
  79
  80 }  // namespace content
  81
  82 #endif  // CONTENT_BROWSER_WEBUI_URL_DATA_MANAGER_H_