src/webkit/browser/fileapi/file_system_file_stream_reader.cc

   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 #include "webkit/browser/fileapi/file_system_file_stream_reader.h"
   6
   7 #include "base/files/file_util_proxy.h"
   8 #include "base/platform_file.h"
   9 #include "base/single_thread_task_runner.h"
  10 #include "net/base/file_stream.h"
  11 #include "net/base/io_buffer.h"
  12 #include "net/base/net_errors.h"
  13 #include "webkit/browser/blob/file_stream_reader.h"
  14 #include "webkit/browser/fileapi/file_system_context.h"
  15 #include "webkit/browser/fileapi/file_system_operation_runner.h"
  16
  17 using webkit_blob::FileStreamReader;
  18
  19 // TODO(kinuko): Remove this temporary namespace hack after we move both
  20 // blob and fileapi into content namespace.
  21 namespace webkit_blob {
  22
  23 FileStreamReader* FileStreamReader::CreateForFileSystemFile(
  24     fileapi::FileSystemContext* file_system_context,
  25     const fileapi::FileSystemURL& url,
  26     int64 initial_offset,
  27     const base::Time& expected_modification_time) {
  28   return new fileapi::FileSystemFileStreamReader(
  29       file_system_context,
  30       url,
  31       initial_offset,
  32       expected_modification_time);
  33 }
  34
  35 }  // namespace webkit_blob
  36
  37 namespace fileapi {
  38
  39 namespace {
  40
  41 void ReadAdapter(base::WeakPtr<FileSystemFileStreamReader> reader,
  42                  net::IOBuffer* buf, int buf_len,
  43                  const net::CompletionCallback& callback) {
  44   if (!reader.get())
  45     return;
  46   int rv = reader->Read(buf, buf_len, callback);
  47   if (rv != net::ERR_IO_PENDING)
  48     callback.Run(rv);
  49 }
  50
  51 void GetLengthAdapter(base::WeakPtr<FileSystemFileStreamReader> reader,
  52                       const net::Int64CompletionCallback& callback) {
  53   if (!reader.get())
  54     return;
  55   int rv = reader->GetLength(callback);
  56   if (rv != net::ERR_IO_PENDING)
  57     callback.Run(rv);
  58 }
  59
  60 void Int64CallbackAdapter(const net::Int64CompletionCallback& callback,
  61                           int value) {
  62   callback.Run(value);
  63 }
  64
  65 }  // namespace
  66
  67 FileSystemFileStreamReader::~FileSystemFileStreamReader() {
  68 }
  69
  70 int FileSystemFileStreamReader::Read(
  71     net::IOBuffer* buf, int buf_len,
  72     const net::CompletionCallback& callback) {
  73   if (local_file_reader_)
  74     return local_file_reader_->Read(buf, buf_len, callback);
  75   return CreateSnapshot(
  76       base::Bind(&ReadAdapter, weak_factory_.GetWeakPtr(),
  77                  make_scoped_refptr(buf), buf_len, callback),
  78       callback);
  79 }
  80
  81 int64 FileSystemFileStreamReader::GetLength(
  82     const net::Int64CompletionCallback& callback) {
  83   if (local_file_reader_)
  84     return local_file_reader_->GetLength(callback);
  85   return CreateSnapshot(
  86       base::Bind(&GetLengthAdapter, weak_factory_.GetWeakPtr(), callback),
  87       base::Bind(&Int64CallbackAdapter, callback));
  88 }
  89
  90 FileSystemFileStreamReader::FileSystemFileStreamReader(
  91     FileSystemContext* file_system_context,
  92     const FileSystemURL& url,
  93     int64 initial_offset,
  94     const base::Time& expected_modification_time)
  95     : file_system_context_(file_system_context),
  96       url_(url),
  97       initial_offset_(initial_offset),
  98       expected_modification_time_(expected_modification_time),
  99       has_pending_create_snapshot_(false),
 100       weak_factory_(this) {
 101 }
 102
 103 int FileSystemFileStreamReader::CreateSnapshot(
 104     const base::Closure& callback,
 105     const net::CompletionCallback& error_callback) {
 106   DCHECK(!has_pending_create_snapshot_);
 107   has_pending_create_snapshot_ = true;
 108   file_system_context_->operation_runner()->CreateSnapshotFile(
 109       url_,
 110       base::Bind(&FileSystemFileStreamReader::DidCreateSnapshot,
 111                  weak_factory_.GetWeakPtr(),
 112                  callback,
 113                  error_callback));
 114   return net::ERR_IO_PENDING;
 115 }
 116
 117 void FileSystemFileStreamReader::DidCreateSnapshot(
 118     const base::Closure& callback,
 119     const net::CompletionCallback& error_callback,
 120     base::File::Error file_error,
 121     const base::File::Info& file_info,
 122     const base::FilePath& platform_path,
 123     const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
 124   DCHECK(has_pending_create_snapshot_);
 125   DCHECK(!local_file_reader_.get());
 126   has_pending_create_snapshot_ = false;
 127
 128   if (file_error != base::File::FILE_OK) {
 129     error_callback.Run(net::FileErrorToNetError(file_error));
 130     return;
 131   }
 132
 133   // Keep the reference (if it's non-null) so that the file won't go away.
 134   snapshot_ref_ = file_ref;
 135
 136   local_file_reader_.reset(
 137       FileStreamReader::CreateForLocalFile(
 138           file_system_context_->default_file_task_runner(),
 139           platform_path, initial_offset_, expected_modification_time_));
 140
 141   callback.Run();
 142 }
 143
 144 }  // namespace fileapi