media/filters/file_data_source.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 #ifndef MEDIA_FILTERS_FILE_DATA_SOURCE_H_
   6 #define MEDIA_FILTERS_FILE_DATA_SOURCE_H_
   7
   8 #include <string>
   9
  10 #include "base/gtest_prod_util.h"
  11 #include "base/synchronization/lock.h"
  12 #include "media/base/filters.h"
  13
  14 namespace media {
  15
  16 // Basic data source that treats the URL as a file path, and uses the file
  17 // system to read data for a media pipeline.
  18 class FileDataSource : public DataSource {
  19  public:
  20   FileDataSource();
  21   virtual ~FileDataSource();
  22
  23   PipelineStatus Initialize(const std::string& url);
  24
  25   // Implementation of Filter.
  26   virtual void set_host(FilterHost* filter_host);
  27   virtual void Stop(FilterCallback* callback);
  28
  29   // Implementation of DataSource.
  30   virtual void Read(int64 position, size_t size, uint8* data,
  31                     ReadCallback* read_callback);
  32   virtual bool GetSize(int64* size_out);
  33   virtual bool IsStreaming();
  34   virtual void SetPreload(Preload preload);
  35
  36  private:
  37   // Only allow factories and tests to create this object.
  38   //
  39   // TODO(scherkus): I'm getting tired of these factories getting in the way
  40   // of my tests!!!
  41   FRIEND_TEST_ALL_PREFIXES(FileDataSourceTest, OpenFile);
  42   FRIEND_TEST_ALL_PREFIXES(FileDataSourceTest, ReadData);
  43   FRIEND_TEST_ALL_PREFIXES(FileDataSourceTest, Seek);
  44
  45   // File handle.  NULL if not initialized or an error occurs.
  46   FILE* file_;
  47
  48   // Size of the file in bytes.
  49   int64 file_size_;
  50
  51   // Critical section that protects all of the DataSource methods to prevent
  52   // a Stop from happening while in the middle of a file I/O operation.
  53   // TODO(ralphl): Ideally this would use asynchronous I/O or we will know
  54   // that we will block for a short period of time in reads.  Otherwise, we can
  55   // hang the pipeline Stop.
  56   base::Lock lock_;
  57
  58   DISALLOW_COPY_AND_ASSIGN(FileDataSource);
  59 };
  60
  61 }  // namespace media
  62
  63 #endif  // MEDIA_FILTERS_FILE_DATA_SOURCE_H_