webkit/fileapi/file_system_file_stream_reader.h

   1 // Copyright (c) 2012 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 WEBKIT_FILEAPI_FILE_SYSTEM_FILE_STREAM_READER_H_
   6 #define WEBKIT_FILEAPI_FILE_SYSTEM_FILE_STREAM_READER_H_
   7
   8 #include "base/bind.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/platform_file.h"
  11 #include "base/time.h"
  12 #include "webkit/blob/file_stream_reader.h"
  13 #include "webkit/blob/shareable_file_reference.h"
  14 #include "webkit/fileapi/file_system_url.h"
  15 #include "webkit/storage/webkit_storage_export.h"
  16
  17 namespace base {
  18 class FilePath;
  19 class SequencedTaskRunner;
  20 }
  21
  22 namespace webkit_blob {
  23 class LocalFileStreamReader;
  24 }
  25
  26 namespace fileapi {
  27
  28 class FileSystemContext;
  29
  30 // TODO(kinaba,satorux): This generic implementation would work for any
  31 // filesystems but remote filesystem should implement its own reader
  32 // rather than relying on FileSystemOperation::GetSnapshotFile() which
  33 // may force downloading the entire contents for remote files.
  34 class WEBKIT_STORAGE_EXPORT_PRIVATE FileSystemFileStreamReader
  35     : public webkit_blob::FileStreamReader {
  36  public:
  37   // Creates a new FileReader for a filesystem URL |url| form |initial_offset|.
  38   // |expected_modification_time| specifies the expected last modification if
  39   // the value is non-null, the reader will check the underlying file's actual
  40   // modification time to see if the file has been modified, and if it does any
  41   // succeeding read operations should fail with ERR_UPLOAD_FILE_CHANGED error.
  42   FileSystemFileStreamReader(FileSystemContext* file_system_context,
  43                              const FileSystemURL& url,
  44                              int64 initial_offset,
  45                              const base::Time& expected_modification_time);
  46   virtual ~FileSystemFileStreamReader();
  47
  48   // FileStreamReader overrides.
  49   virtual int Read(net::IOBuffer* buf, int buf_len,
  50                    const net::CompletionCallback& callback) OVERRIDE;
  51   virtual int64 GetLength(
  52       const net::Int64CompletionCallback& callback) OVERRIDE;
  53
  54  private:
  55   int CreateSnapshot(const base::Closure& callback,
  56                      const net::CompletionCallback& error_callback);
  57   void DidCreateSnapshot(
  58       const base::Closure& callback,
  59       const net::CompletionCallback& error_callback,
  60       base::PlatformFileError file_error,
  61       const base::PlatformFileInfo& file_info,
  62       const base::FilePath& platform_path,
  63       const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref);
  64
  65   scoped_refptr<FileSystemContext> file_system_context_;
  66   FileSystemURL url_;
  67   const int64 initial_offset_;
  68   const base::Time expected_modification_time_;
  69   scoped_ptr<webkit_blob::LocalFileStreamReader> local_file_reader_;
  70   scoped_refptr<webkit_blob::ShareableFileReference> snapshot_ref_;
  71   bool has_pending_create_snapshot_;
  72   base::WeakPtrFactory<FileSystemFileStreamReader> weak_factory_;
  73
  74   DISALLOW_COPY_AND_ASSIGN(FileSystemFileStreamReader);
  75 };
  76
  77 }  // namespace fileapi
  78
  79 #endif  // WEBKIT_FILEAPI_FILE_SYSTEM_FILE_STREAM_READER_H_