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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 CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_
40 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_
41 #pragma once
42 
43 #include <map>
44 
45 #include "base/basictypes.h"
46 #include "base/gtest_prod_util.h"
47 #include "base/hash_tables.h"
48 #include "base/memory/ref_counted.h"
49 #include "base/timer.h"
50 #include "ui/gfx/native_widget_types.h"
51 
52 struct DownloadBuffer;
53 struct DownloadCreateInfo;
54 struct DownloadSaveInfo;
55 class DownloadFile;
56 class DownloadManager;
57 class FilePath;
58 class GURL;
59 class ResourceDispatcherHost;
60 
61 namespace net {
62 class URLRequestContextGetter;
63 }
64 
65 // Manages all in progress downloads.
66 class DownloadFileManager
67     : public base::RefCountedThreadSafe<DownloadFileManager> {
68  public:
69   explicit DownloadFileManager(ResourceDispatcherHost* rdh);
70 
71   // Called on shutdown on the UI thread.
72   void Shutdown();
73 
74   // Called on the IO thread
75   int GetNextId();
76 
77   // Called on UI thread to make DownloadFileManager start the download.
78   void StartDownload(DownloadCreateInfo* info);
79 
80   // Handlers for notifications sent from the IO thread and run on the
81   // FILE thread.
82   void UpdateDownload(int id, DownloadBuffer* buffer);
83   // |os_error| is 0 for normal completions, and non-0 for errors.
84   // |security_info| contains SSL information (cert_id, cert_status,
85   // security_bits, ssl_connection_status), which can be used to
86   // fine-tune the error message.  It is empty if the transaction
87   // was not performed securely.
88   void OnResponseCompleted(int id,
89                            DownloadBuffer* buffer,
90                            int os_error,
91                            const std::string& security_info);
92 
93   // Handlers for notifications sent from the UI thread and run on the
94   // FILE thread.  These are both terminal actions with respect to the
95   // download file, as far as the DownloadFileManager is concerned -- if
96   // anything happens to the download file after they are called, it will
97   // be ignored.
98   void CancelDownload(int id);
99   void CompleteDownload(int id);
100 
101   // Called on FILE thread by DownloadManager at the beginning of its shutdown.
102   void OnDownloadManagerShutdown(DownloadManager* manager);
103 
104   // The DownloadManager in the UI thread has provided an intermediate
105   // .crdownload name for the download specified by |id|.
106   void RenameInProgressDownloadFile(int id, const FilePath& full_path);
107 
108   // The DownloadManager in the UI thread has provided a final name for the
109   // download specified by |id|.
110   // |overwrite_existing_file| prevents uniquification, and is used for SAFE
111   // downloads, as the user may have decided to overwrite the file.
112   // Sent from the UI thread and run on the FILE thread.
113   void RenameCompletingDownloadFile(int id,
114                                     const FilePath& full_path,
115                                     bool overwrite_existing_file);
116 
117   // The number of downloads currently active on the DownloadFileManager.
118   // Primarily for testing.
NumberOfActiveDownloads()119   int NumberOfActiveDownloads() const {
120     return downloads_.size();
121   }
122 
123  private:
124   friend class base::RefCountedThreadSafe<DownloadFileManager>;
125   friend class DownloadManagerTest;
126   FRIEND_TEST_ALL_PREFIXES(DownloadManagerTest, StartDownload);
127 
128   ~DownloadFileManager();
129 
130   // Timer helpers for updating the UI about the current progress of a download.
131   void StartUpdateTimer();
132   void StopUpdateTimer();
133   void UpdateInProgressDownloads();
134 
135   // Clean up helper that runs on the download thread.
136   void OnShutdown();
137 
138   // Creates DownloadFile on FILE thread and continues starting the download
139   // process.
140   void CreateDownloadFile(DownloadCreateInfo* info,
141                           DownloadManager* download_manager,
142                           bool hash_needed);
143 
144   // Tells the ResourceDispatcherHost to resume a download request
145   // that was paused to wait for the on-disk file to be created.
146   void ResumeDownloadRequest(int child_id, int request_id);
147 
148   // Called only on the download thread.
149   DownloadFile* GetDownloadFile(int id);
150 
151   // Called only from RenameInProgressDownloadFile and
152   // RenameCompletingDownloadFile on the FILE thread.
153   void CancelDownloadOnRename(int id);
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 DownloadFile.
160   int 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  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_MANAGER_H_
177