1// Copyright 2013 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_COMPONENT_UPDATER_BACKGROUND_DOWNLOADER_WIN_H_
6#define CHROME_BROWSER_COMPONENT_UPDATER_BACKGROUND_DOWNLOADER_WIN_H_
7
8#include <windows.h>
9#include <bits.h>
10
11#include "base/strings/string16.h"
12#include "base/time/time.h"
13#include "base/timer/timer.h"
14#include "base/win/scoped_comptr.h"
15#include "chrome/browser/component_updater/crx_downloader.h"
16
17namespace base {
18class FilePath;
19}
20
21namespace component_updater {
22
23// Implements a downloader in terms of the BITS service. The public interface
24// of this class and the CrxDownloader overrides are expected to be called
25// from the UI thread. The rest of the class code runs on the FILE thread in
26// a single threaded apartment. Instances of this class are created and
27// destroyed in the UI thread. See the implementation of the class destructor
28// for details regarding the clean up of resources acquired in this class.
29class BackgroundDownloader : public CrxDownloader {
30 protected:
31  friend class CrxDownloader;
32  BackgroundDownloader(scoped_ptr<CrxDownloader> successor,
33                       net::URLRequestContextGetter* context_getter,
34                       scoped_refptr<base::SequencedTaskRunner> task_runner);
35  virtual ~BackgroundDownloader();
36
37 private:
38  // Overrides for CrxDownloader.
39  virtual void DoStartDownload(const GURL& url) OVERRIDE;
40
41  // Called asynchronously on the FILE thread at different stages during
42  // the download. |OnDownloading| can be called multiple times.
43  // |EndDownload| switches the execution flow from the FILE to the UI thread.
44  // Accessing any data members of this object on the FILE thread after
45  // calling |EndDownload| is unsafe.
46  void BeginDownload(const GURL& url);
47  void OnDownloading();
48  void EndDownload(HRESULT hr);
49
50  // Handles the job state transitions to a final state.
51  void OnStateTransferred();
52  void OnStateError();
53  void OnStateCancelled();
54  void OnStateAcknowledged();
55
56  // Handles the transition to a transient state where the job is in the
57  // queue but not actively transferring data.
58  void OnStateQueued();
59
60  // Handles the job state transition to a transient, non-final error state.
61  void OnStateTransientError();
62
63  // Handles the job state corresponding to transferring data.
64  void OnStateTransferring();
65
66  HRESULT QueueBitsJob(const GURL& url);
67  HRESULT CreateOrOpenJob(const GURL& url);
68  HRESULT InitializeNewJob(const GURL& url);
69
70  // Returns true if at the time of the call, it appears that the job
71  // has not been making progress toward completion.
72  bool IsStuck();
73
74  // Makes the downloaded file available to the caller by renaming the
75  // temporary file to its destination and removing it from the BITS queue.
76  HRESULT CompleteJob();
77
78  net::URLRequestContextGetter* context_getter_;
79  scoped_refptr<base::SequencedTaskRunner> task_runner_;
80
81  // The timer and the BITS interface pointers have thread affinity. These
82  // members are initialized on the FILE thread and they must be destroyed
83  // on the FILE thread.
84  scoped_ptr<base::RepeatingTimer<BackgroundDownloader> > timer_;
85
86  base::win::ScopedComPtr<IBackgroundCopyManager> bits_manager_;
87  base::win::ScopedComPtr<IBackgroundCopyJob> job_;
88
89  // Contains the time when the download of the current url has started.
90  base::Time download_start_time_;
91
92  // Contains the time when the BITS job is last seen making progress.
93  base::Time job_stuck_begin_time_;
94
95  // True if EndDownload was called.
96  bool is_completed_;
97
98  // Contains the path of the downloaded file if the download was successful.
99  base::FilePath response_;
100
101  DISALLOW_COPY_AND_ASSIGN(BackgroundDownloader);
102};
103
104}  // namespace component_updater
105
106#endif  // CHROME_BROWSER_COMPONENT_UPDATER_BACKGROUND_DOWNLOADER_WIN_H_
107