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