chrome/browser/chromeos/drive/fileapi/webkit_file_stream_reader_impl.h

   1 // Copyright 2014 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_CHROMEOS_DRIVE_FILEAPI_WEBKIT_FILE_STREAM_READER_IMPL_H_
   6 #define CHROME_BROWSER_CHROMEOS_DRIVE_FILEAPI_WEBKIT_FILE_STREAM_READER_IMPL_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/files/file_path.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/time/time.h"
  14 #include "chrome/browser/chromeos/drive/drive_file_stream_reader.h"
  15 #include "net/base/completion_callback.h"
  16 #include "storage/browser/fileapi/file_stream_reader.h"
  17
  18 namespace base {
  19 class SequencedTaskRunner;
  20 }  // namespace base
  21
  22 namespace drive {
  23
  24 class ResourceEntry;
  25
  26 namespace internal {
  27
  28 // The implementation of storage::FileStreamReader for drive file system.
  29 // storage::FileStreamReader does not provide a way for explicit
  30 // initialization, hence the initialization of this class will be done lazily.
  31 // Note that when crbug.com/225339 is resolved, this class will be also
  32 // initialized explicitly.
  33 class WebkitFileStreamReaderImpl : public storage::FileStreamReader {
  34  public:
  35   WebkitFileStreamReaderImpl(
  36       const DriveFileStreamReader::FileSystemGetter& file_system_getter,
  37       base::SequencedTaskRunner* file_task_runner,
  38       const base::FilePath& drive_file_path,
  39       int64 offset,
  40       const base::Time& expected_modification_time);
  41   ~WebkitFileStreamReaderImpl() override;
  42
  43   // storage::FileStreamReader override.
  44   int Read(net::IOBuffer* buffer,
  45            int buffer_length,
  46            const net::CompletionCallback& callback) override;
  47   int64 GetLength(const net::Int64CompletionCallback& callback) override;
  48
  49  private:
  50   // Called upon the initialization completion of |stream_reader_|.
  51   // Processes the result of the initialization with checking last
  52   // modified time, and calls |callback| with net::Error code as its result.
  53   void OnStreamReaderInitialized(
  54       const net::CompletionCallback& callback,
  55       int error,
  56       scoped_ptr<ResourceEntry> entry);
  57
  58   // Part of Read(). Called after all the initialization process is completed.
  59   void ReadAfterStreamReaderInitialized(
  60       scoped_refptr<net::IOBuffer> buffer,
  61       int buffer_length,
  62       const net::CompletionCallback& callback,
  63       int initialization_result);
  64
  65   // Part of GetLength(). Called after all the initialization process is
  66   // completed.
  67   void GetLengthAfterStreamReaderInitialized(
  68       const net::Int64CompletionCallback& callback,
  69       int initialization_result);
  70
  71   scoped_ptr<DriveFileStreamReader> stream_reader_;
  72   const base::FilePath drive_file_path_;
  73   const int64 offset_;
  74   const base::Time expected_modification_time_;
  75
  76   // This is available only after initialize is done.
  77   int64 file_size_;
  78
  79   // This should remain the last member so it'll be destroyed first and
  80   // invalidate its weak pointers before other members are destroyed.
  81   base::WeakPtrFactory<WebkitFileStreamReaderImpl> weak_ptr_factory_;
  82   DISALLOW_COPY_AND_ASSIGN(WebkitFileStreamReaderImpl);
  83 };
  84
  85 }  // namespace internal
  86 }  // namespace drive
  87
  88 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILEAPI_WEBKIT_FILE_STREAM_READER_IMPL_H_