content/browser/download/download_file_manager.h

   1 // Copyright (c) 2011 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 // The DownloadFileManager owns a set of DownloadFile objects, each of which
   6 // represent one in progress download and performs the disk IO for that
   7 // download. The DownloadFileManager itself is a singleton object owned by the
   8 // ResourceDispatcherHost.
   9 //
  10 // The DownloadFileManager uses the file_thread for performing file write
  11 // operations, in order to avoid disk activity on either the IO (network) thread
  12 // and the UI thread. It coordinates the notifications from the network and UI.
  13 //
  14 // A typical download operation involves multiple threads:
  15 //
  16 // Updating an in progress download
  17 // io_thread
  18 //      |----> data ---->|
  19 //                     file_thread (writes to disk)
  20 //                              |----> stats ---->|
  21 //                                              ui_thread (feedback for user and
  22 //                                                         updates to history)
  23 //
  24 // Cancel operations perform the inverse order when triggered by a user action:
  25 // ui_thread (user click)
  26 //    |----> cancel command ---->|
  27 //                          file_thread (close file)
  28 //                                 |----> cancel command ---->|
  29 //                                                    io_thread (stops net IO
  30 //                                                               for download)
  31 //
  32 // The DownloadFileManager tracks download requests, mapping from a download
  33 // ID (unique integer created in the IO thread) to the DownloadManager for the
  34 // tab (profile) where the download was initiated. In the event of a tab closure
  35 // during a download, the DownloadFileManager will continue to route data to the
  36 // appropriate DownloadManager. In progress downloads are cancelled for a
  37 // DownloadManager that exits (such as when closing a profile).
  38
  39 #ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_
  40 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_
  41 #pragma once
  42
  43 #include <map>
  44
  45 #include "base/atomic_sequence_num.h"
  46 #include "base/basictypes.h"
  47 #include "base/gtest_prod_util.h"
  48 #include "base/hash_tables.h"
  49 #include "base/memory/ref_counted.h"
  50 #include "base/timer.h"
  51 #include "content/browser/download/download_request_handle.h"
  52 #include "net/base/net_errors.h"
  53 #include "ui/gfx/native_widget_types.h"
  54
  55 struct DownloadBuffer;
  56 struct DownloadCreateInfo;
  57 struct DownloadSaveInfo;
  58 class DownloadFile;
  59 class DownloadManager;
  60 class FilePath;
  61 class GURL;
  62 class ResourceDispatcherHost;
  63
  64 namespace net {
  65 class URLRequestContextGetter;
  66 }
  67
  68 // Manages all in progress downloads.
  69 class DownloadFileManager
  70     : public base::RefCountedThreadSafe<DownloadFileManager> {
  71  public:
  72   explicit DownloadFileManager(ResourceDispatcherHost* rdh);
  73
  74   // Called on shutdown on the UI thread.
  75   void Shutdown();
  76
  77   // Called on the IO or UI threads.
  78   int GetNextId();
  79
  80   // Called on UI thread to make DownloadFileManager start the download.
  81   void StartDownload(DownloadCreateInfo* info);
  82
  83   // Handlers for notifications sent from the IO thread and run on the
  84   // FILE thread.
  85   void UpdateDownload(int id, DownloadBuffer* buffer);
  86   // |net_error| is 0 for normal completions, and non-0 for errors.
  87   // |security_info| contains SSL information (cert_id, cert_status,
  88   // security_bits, ssl_connection_status), which can be used to
  89   // fine-tune the error message.  It is empty if the transaction
  90   // was not performed securely.
  91   void OnResponseCompleted(int id,
  92                            DownloadBuffer* buffer,
  93                            net::Error net_error,
  94                            const std::string& security_info);
  95
  96   // Handlers for notifications sent from the UI thread and run on the
  97   // FILE thread.  These are both terminal actions with respect to the
  98   // download file, as far as the DownloadFileManager is concerned -- if
  99   // anything happens to the download file after they are called, it will
 100   // be ignored.
 101   void CancelDownload(int id);
 102   void CompleteDownload(int id);
 103
 104   // Called on FILE thread by DownloadManager at the beginning of its shutdown.
 105   void OnDownloadManagerShutdown(DownloadManager* manager);
 106
 107   // The DownloadManager in the UI thread has provided an intermediate
 108   // .crdownload name for the download specified by |id|.
 109   void RenameInProgressDownloadFile(int id, const FilePath& full_path);
 110
 111   // The DownloadManager in the UI thread has provided a final name for the
 112   // download specified by |id|.
 113   // |overwrite_existing_file| prevents uniquification, and is used for SAFE
 114   // downloads, as the user may have decided to overwrite the file.
 115   // Sent from the UI thread and run on the FILE thread.
 116   void RenameCompletingDownloadFile(int id,
 117                                     const FilePath& full_path,
 118                                     bool overwrite_existing_file);
 119
 120   // The number of downloads currently active on the DownloadFileManager.
 121   // Primarily for testing.
 122   int NumberOfActiveDownloads() const {
 123     return downloads_.size();
 124   }
 125
 126  private:
 127   friend class base::RefCountedThreadSafe<DownloadFileManager>;
 128   friend class DownloadManagerTest;
 129   FRIEND_TEST_ALL_PREFIXES(DownloadManagerTest, StartDownload);
 130
 131   ~DownloadFileManager();
 132
 133   // Timer helpers for updating the UI about the current progress of a download.
 134   void StartUpdateTimer();
 135   void StopUpdateTimer();
 136   void UpdateInProgressDownloads();
 137
 138   // Clean up helper that runs on the download thread.
 139   void OnShutdown();
 140
 141   // Creates DownloadFile on FILE thread and continues starting the download
 142   // process.
 143   void CreateDownloadFile(DownloadCreateInfo* info,
 144                           DownloadManager* download_manager,
 145                           bool hash_needed);
 146
 147   // Called only on the download thread.
 148   DownloadFile* GetDownloadFile(int id);
 149
 150   // Called only from RenameInProgressDownloadFile and
 151   // RenameCompletingDownloadFile on the FILE thread.
 152   // |rename_error| indicates what error caused the cancel.
 153   void CancelDownloadOnRename(int id, net::Error rename_error);
 154
 155   // Erases the download file with the given the download |id| and removes
 156   // it from the maps.
 157   void EraseDownload(int id);
 158
 159   // Unique ID for each DownloadItem.
 160   base::AtomicSequenceNumber next_id_;
 161
 162   typedef base::hash_map<int, DownloadFile*> DownloadFileMap;
 163
 164   // A map of all in progress downloads.  It owns the download files.
 165   DownloadFileMap downloads_;
 166
 167   // Schedule periodic updates of the download progress. This timer
 168   // is controlled from the FILE thread, and posts updates to the UI thread.
 169   base::RepeatingTimer<DownloadFileManager> update_timer_;
 170
 171   ResourceDispatcherHost* resource_dispatcher_host_;
 172
 173   DISALLOW_COPY_AND_ASSIGN(DownloadFileManager);
 174 };
 175
 176 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_