chrome/browser/media_galleries/fileapi/safe_picasa_album_table_reader.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_PICASA_ALBUM_TABLE_READER_H_
   6 #define CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_SAFE_PICASA_ALBUM_TABLE_READER_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "chrome/common/media_galleries/picasa_types.h"
  14 #include "content/public/browser/utility_process_host.h"
  15 #include "content/public/browser/utility_process_host_client.h"
  16
  17 namespace base {
  18 class FilePath;
  19 }
  20
  21 namespace IPC {
  22 class Message;
  23 }
  24
  25 namespace picasa {
  26
  27 // SafePicasaAlbumTableReader parses the given Picasa PMP Album Table safely
  28 // via a utility process. The SafePicasaAlbumTableReader object is ref-counted
  29 // and kept alive after Start() is called until the ParserCallback is called.
  30 // The ParserCallback is guaranteed to be called eventually either when the
  31 // utility process replies or when it dies.
  32 class SafePicasaAlbumTableReader : public content::UtilityProcessHostClient {
  33  public:
  34   typedef base::Callback<void(bool parse_success,
  35                               const std::vector<AlbumInfo>&,
  36                               const std::vector<AlbumInfo>&)>
  37       ParserCallback;
  38
  39   // This class takes ownership of |album_table_files| and will close them.
  40   explicit SafePicasaAlbumTableReader(const AlbumTableFiles& album_table_files);
  41
  42   void Start(const ParserCallback& callback);
  43
  44  private:
  45   enum ParserState {
  46     INITIAL_STATE,
  47     PINGED_UTILITY_PROCESS_STATE,
  48     STARTED_PARSING_STATE,
  49     FINISHED_PARSING_STATE,
  50   };
  51
  52   // Private because content::UtilityProcessHostClient is ref-counted.
  53   virtual ~SafePicasaAlbumTableReader();
  54
  55   // Launches the utility process.  Must run on the IO thread.
  56   void StartWorkOnIOThread();
  57
  58   // Notification that the utility process is running, and we can now get its
  59   // process handle.
  60   // Runs on the IO thread.
  61   void OnProcessStarted();
  62
  63   // Notification from the utility process when it finshes parsing the PMP
  64   // database. This is received even if PMP parsing fails.
  65   // Runs on the IO thread.
  66   void OnParsePicasaPMPDatabaseFinished(bool parse_success,
  67                                         const std::vector<AlbumInfo>& albums,
  68                                         const std::vector<AlbumInfo>& folders);
  69
  70   // UtilityProcessHostClient implementation.
  71   // Runs on the IO thread.
  72   virtual void OnProcessCrashed(int exit_code) OVERRIDE;
  73   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
  74
  75   const AlbumTableFiles album_table_files_;
  76
  77   // Only accessed on the IO thread.
  78   base::WeakPtr<content::UtilityProcessHost> utility_process_host_;
  79
  80   // Only accessed on the Media Task Runner.
  81   ParserCallback callback_;
  82
  83   // Verifies the messages from the utility process came at the right time.
  84   // Initialized on the Media Task Runner, but only accessed on the IO thread.
  85   ParserState parser_state_;
  86
  87   DISALLOW_COPY_AND_ASSIGN(SafePicasaAlbumTableReader);
  88 };
  89
  90 }  // namespace picasa
  91
  92 #endif  // CHROME_BROWSER_MEDIA_GALLERIES_FILEAPI_SAFE_PICASA_ALBUM_TABLE_READER_H_