chrome/browser/media_galleries/fileapi/safe_audio_video_checker.h

   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_MEDIA_GALLERIES_FILEAPI_SAFE_AUDIO_VIDEO_CHECKER_H_
   6 #define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_SAFE_AUDIO_VIDEO_CHECKER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback_forward.h"
  10 #include "base/files/scoped_platform_file_closer.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/platform_file.h"
  13 #include "content/public/browser/utility_process_host_client.h"
  14 #include "webkit/browser/fileapi/copy_or_move_file_validator.h"
  15
  16 namespace content {
  17 class UtilityProcessHost;
  18 }
  19
  20 // Uses a utility process to validate a media file.  If the callback returns
  21 // PLATFORM_FILE_OK, then the file appears to be a valid media file. This does
  22 // not attempt to decode the entire file, which may take a considerable amount
  23 // of time.  This class may be constructed on any thread, but should run on the
  24 // IO thread.
  25 class SafeAudioVideoChecker : public content::UtilityProcessHostClient {
  26  public:
  27   // Takes responsibility for closing |file|.
  28   SafeAudioVideoChecker(
  29       const base::PlatformFile& file,
  30       const fileapi::CopyOrMoveFileValidator::ResultCallback& callback);
  31
  32   // Must be called on the IO thread.
  33   void Start();
  34
  35  private:
  36   enum State {
  37     INITIAL_STATE,
  38     PINGED_STATE,
  39     STARTED_STATE,
  40     FINISHED_STATE
  41   };
  42
  43   virtual ~SafeAudioVideoChecker();
  44
  45   // Starts validation once the utility process has been started.
  46   virtual void OnProcessStarted();
  47
  48   // Notification of the result from the utility process.
  49   void OnCheckingFinished(bool valid);
  50
  51   // UtilityProcessHostClient implementation.
  52   virtual void OnProcessCrashed(int exit_code) OVERRIDE;
  53   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
  54
  55   State state_;
  56
  57   // This should be accessed through |file_closer_| to ensure it hasn't already
  58   // been closed.
  59   base::PlatformFile file_;
  60
  61   // Ensures that |file_| is closed if the utility process is not started for
  62   // some reason.
  63   base::ScopedPlatformFileCloser file_closer_;
  64
  65   const fileapi::CopyOrMoveFileValidator::ResultCallback callback_;
  66
  67   base::WeakPtr<content::UtilityProcessHost> utility_process_host_;
  68
  69   DISALLOW_COPY_AND_ASSIGN(SafeAudioVideoChecker);
  70 };
  71
  72 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_SAFE_AUDIO_VIDEO_CHECKER_H_