src/storage/browser/fileapi/local_file_stream_writer.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 "storage/browser/fileapi/local_file_stream_writer.h"
   6
   7 #include "base/callback.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "base/profiler/scoped_tracker.h"
  10 #include "net/base/file_stream.h"
  11 #include "net/base/io_buffer.h"
  12 #include "net/base/net_errors.h"
  13
  14 namespace storage {
  15
  16 namespace {
  17
  18 const int kOpenFlagsForWrite = base::File::FLAG_OPEN |
  19                                base::File::FLAG_WRITE |
  20                                base::File::FLAG_ASYNC;
  21 const int kCreateFlagsForWrite = base::File::FLAG_CREATE |
  22                                  base::File::FLAG_WRITE |
  23                                  base::File::FLAG_ASYNC;
  24
  25 }  // namespace
  26
  27 FileStreamWriter* FileStreamWriter::CreateForLocalFile(
  28     base::TaskRunner* task_runner,
  29     const base::FilePath& file_path,
  30     int64 initial_offset,
  31     OpenOrCreate open_or_create) {
  32   return new LocalFileStreamWriter(
  33       task_runner, file_path, initial_offset, open_or_create);
  34 }
  35
  36 LocalFileStreamWriter::~LocalFileStreamWriter() {
  37   // Invalidate weak pointers so that we won't receive any callbacks from
  38   // in-flight stream operations, which might be triggered during the file close
  39   // in the FileStream destructor.
  40   weak_factory_.InvalidateWeakPtrs();
  41
  42   // FileStream's destructor closes the file safely, since we opened the file
  43   // by its Open() method.
  44 }
  45
  46 int LocalFileStreamWriter::Write(net::IOBuffer* buf, int buf_len,
  47                                  const net::CompletionCallback& callback) {
  48   DCHECK(!has_pending_operation_);
  49   DCHECK(cancel_callback_.is_null());
  50
  51   has_pending_operation_ = true;
  52   if (stream_impl_) {
  53     int result = InitiateWrite(buf, buf_len, callback);
  54     if (result != net::ERR_IO_PENDING)
  55       has_pending_operation_ = false;
  56     return result;
  57   }
  58   return InitiateOpen(callback,
  59                       base::Bind(&LocalFileStreamWriter::ReadyToWrite,
  60                                  weak_factory_.GetWeakPtr(),
  61                                  make_scoped_refptr(buf), buf_len, callback));
  62 }
  63
  64 int LocalFileStreamWriter::Cancel(const net::CompletionCallback& callback) {
  65   if (!has_pending_operation_)
  66     return net::ERR_UNEXPECTED;
  67
  68   DCHECK(!callback.is_null());
  69   cancel_callback_ = callback;
  70   return net::ERR_IO_PENDING;
  71 }
  72
  73 int LocalFileStreamWriter::Flush(const net::CompletionCallback& callback) {
  74   DCHECK(!has_pending_operation_);
  75   DCHECK(cancel_callback_.is_null());
  76
  77   // Write() is not called yet, so there's nothing to flush.
  78   if (!stream_impl_)
  79     return net::OK;
  80
  81   has_pending_operation_ = true;
  82   int result = InitiateFlush(callback);
  83   if (result != net::ERR_IO_PENDING)
  84     has_pending_operation_ = false;
  85   return result;
  86 }
  87
  88 LocalFileStreamWriter::LocalFileStreamWriter(base::TaskRunner* task_runner,
  89                                              const base::FilePath& file_path,
  90                                              int64 initial_offset,
  91                                              OpenOrCreate open_or_create)
  92     : file_path_(file_path),
  93       open_or_create_(open_or_create),
  94       initial_offset_(initial_offset),
  95       task_runner_(task_runner),
  96       has_pending_operation_(false),
  97       weak_factory_(this) {}
  98
  99 int LocalFileStreamWriter::InitiateOpen(
 100     const net::CompletionCallback& error_callback,
 101     const base::Closure& main_operation) {
 102   DCHECK(has_pending_operation_);
 103   DCHECK(!stream_impl_.get());
 104
 105   stream_impl_.reset(new net::FileStream(task_runner_));
 106
 107   int open_flags = 0;
 108   switch (open_or_create_) {
 109   case OPEN_EXISTING_FILE:
 110     open_flags = kOpenFlagsForWrite;
 111     break;
 112   case CREATE_NEW_FILE:
 113     open_flags = kCreateFlagsForWrite;
 114     break;
 115   }
 116
 117   return stream_impl_->Open(file_path_,
 118                             open_flags,
 119                             base::Bind(&LocalFileStreamWriter::DidOpen,
 120                                        weak_factory_.GetWeakPtr(),
 121                                        error_callback,
 122                                        main_operation));
 123 }
 124
 125 void LocalFileStreamWriter::DidOpen(
 126     const net::CompletionCallback& error_callback,
 127     const base::Closure& main_operation,
 128     int result) {
 129   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 130   tracked_objects::ScopedTracker tracking_profile(
 131       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 132           "423948 LocalFileStreamWriter::DidOpen"));
 133
 134   DCHECK(has_pending_operation_);
 135   DCHECK(stream_impl_.get());
 136
 137   if (CancelIfRequested())
 138     return;
 139
 140   if (result != net::OK) {
 141     has_pending_operation_ = false;
 142     stream_impl_.reset(NULL);
 143     error_callback.Run(result);
 144     return;
 145   }
 146
 147   InitiateSeek(error_callback, main_operation);
 148 }
 149
 150 void LocalFileStreamWriter::InitiateSeek(
 151     const net::CompletionCallback& error_callback,
 152     const base::Closure& main_operation) {
 153   DCHECK(has_pending_operation_);
 154   DCHECK(stream_impl_.get());
 155
 156   if (initial_offset_ == 0) {
 157     // No need to seek.
 158     main_operation.Run();
 159     return;
 160   }
 161
 162   int result = stream_impl_->Seek(base::File::FROM_BEGIN, initial_offset_,
 163                                   base::Bind(&LocalFileStreamWriter::DidSeek,
 164                                              weak_factory_.GetWeakPtr(),
 165                                              error_callback,
 166                                              main_operation));
 167   if (result != net::ERR_IO_PENDING) {
 168     has_pending_operation_ = false;
 169     error_callback.Run(result);
 170   }
 171 }
 172
 173 void LocalFileStreamWriter::DidSeek(
 174     const net::CompletionCallback& error_callback,
 175     const base::Closure& main_operation,
 176     int64 result) {
 177   DCHECK(has_pending_operation_);
 178
 179   if (CancelIfRequested())
 180     return;
 181
 182   if (result != initial_offset_) {
 183     // TODO(kinaba) add a more specific error code.
 184     result = net::ERR_FAILED;
 185   }
 186
 187   if (result < 0) {
 188     has_pending_operation_ = false;
 189     error_callback.Run(static_cast<int>(result));
 190     return;
 191   }
 192
 193   main_operation.Run();
 194 }
 195
 196 void LocalFileStreamWriter::ReadyToWrite(
 197     net::IOBuffer* buf, int buf_len,
 198     const net::CompletionCallback& callback) {
 199   DCHECK(has_pending_operation_);
 200
 201   int result = InitiateWrite(buf, buf_len, callback);
 202   if (result != net::ERR_IO_PENDING) {
 203     has_pending_operation_ = false;
 204     callback.Run(result);
 205   }
 206 }
 207
 208 int LocalFileStreamWriter::InitiateWrite(
 209     net::IOBuffer* buf, int buf_len,
 210     const net::CompletionCallback& callback) {
 211   DCHECK(has_pending_operation_);
 212   DCHECK(stream_impl_.get());
 213
 214   return stream_impl_->Write(buf, buf_len,
 215                              base::Bind(&LocalFileStreamWriter::DidWrite,
 216                                         weak_factory_.GetWeakPtr(),
 217                                         callback));
 218 }
 219
 220 void LocalFileStreamWriter::DidWrite(const net::CompletionCallback& callback,
 221                                      int result) {
 222   DCHECK(has_pending_operation_);
 223
 224   if (CancelIfRequested())
 225     return;
 226   has_pending_operation_ = false;
 227   callback.Run(result);
 228 }
 229
 230 int LocalFileStreamWriter::InitiateFlush(
 231     const net::CompletionCallback& callback) {
 232   DCHECK(has_pending_operation_);
 233   DCHECK(stream_impl_.get());
 234
 235   return stream_impl_->Flush(base::Bind(&LocalFileStreamWriter::DidFlush,
 236                                         weak_factory_.GetWeakPtr(),
 237                                         callback));
 238 }
 239
 240 void LocalFileStreamWriter::DidFlush(const net::CompletionCallback& callback,
 241                                      int result) {
 242   DCHECK(has_pending_operation_);
 243
 244   if (CancelIfRequested())
 245     return;
 246   has_pending_operation_ = false;
 247   callback.Run(result);
 248 }
 249
 250 bool LocalFileStreamWriter::CancelIfRequested() {
 251   DCHECK(has_pending_operation_);
 252
 253   if (cancel_callback_.is_null())
 254     return false;
 255
 256   net::CompletionCallback pending_cancel = cancel_callback_;
 257   has_pending_operation_ = false;
 258   cancel_callback_.Reset();
 259   pending_cancel.Run(net::OK);
 260   return true;
 261 }
 262
 263 }  // namespace storage