chrome/browser/media_galleries/win/mtp_device_delegate_impl_win.cc

   1 // Copyright (c) 2013 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 // MTPDeviceDelegateImplWin implementation.
   6
   7 #include "chrome/browser/media_galleries/win/mtp_device_delegate_impl_win.h"
   8
   9 #include <portabledevice.h>
  10
  11 #include <vector>
  12
  13 #include "base/bind.h"
  14 #include "base/files/file_path.h"
  15 #include "base/logging.h"
  16 #include "base/memory/ref_counted.h"
  17 #include "base/sequenced_task_runner.h"
  18 #include "base/stl_util.h"
  19 #include "base/strings/string_split.h"
  20 #include "base/strings/string_util.h"
  21 #include "base/strings/utf_string_conversions.h"
  22 #include "base/task_runner_util.h"
  23 #include "base/threading/thread_restrictions.h"
  24 #include "chrome/browser/media_galleries/fileapi/media_file_system_backend.h"
  25 #include "chrome/browser/media_galleries/win/mtp_device_object_entry.h"
  26 #include "chrome/browser/media_galleries/win/mtp_device_object_enumerator.h"
  27 #include "chrome/browser/media_galleries/win/mtp_device_operations_util.h"
  28 #include "chrome/browser/media_galleries/win/portable_device_map_service.h"
  29 #include "chrome/browser/media_galleries/win/snapshot_file_details.h"
  30 #include "chrome/browser/storage_monitor/storage_monitor.h"
  31 #include "content/public/browser/browser_thread.h"
  32 #include "webkit/common/fileapi/file_system_util.h"
  33
  34 namespace {
  35
  36 // Gets the details of the MTP partition storage specified by the
  37 // |storage_path| on the UI thread. Returns true if the storage details are
  38 // valid and returns false otherwise.
  39 bool GetStorageInfoOnUIThread(const base::string16& storage_path,
  40                               base::string16* pnp_device_id,
  41                               base::string16* storage_object_id) {
  42   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  43   DCHECK(!storage_path.empty());
  44   DCHECK(pnp_device_id);
  45   DCHECK(storage_object_id);
  46   base::string16 storage_device_id;
  47   base::RemoveChars(storage_path, L"\\\\", &storage_device_id);
  48   DCHECK(!storage_device_id.empty());
  49   // TODO(gbillock): Take the StorageMonitor as an argument.
  50   StorageMonitor* monitor = StorageMonitor::GetInstance();
  51   DCHECK(monitor);
  52   return monitor->GetMTPStorageInfoFromDeviceId(
  53       base::UTF16ToUTF8(storage_device_id), pnp_device_id, storage_object_id);
  54 }
  55
  56 // Returns the object id of the file object specified by the |file_path|,
  57 // e.g. if the |file_path| is "\\MTP:StorageSerial:SID-{1001,,192}:125\DCIM"
  58 // and |device_info.registered_device_path_| is
  59 // "\\MTP:StorageSerial:SID-{1001,,192}:125", this function returns the
  60 // identifier of the "DCIM" folder object.
  61 //
  62 // Returns an empty string if the device is detached while the request is in
  63 // progress or when the |file_path| is invalid.
  64 base::string16 GetFileObjectIdFromPathOnBlockingPoolThread(
  65     const MTPDeviceDelegateImplWin::StorageDeviceInfo& device_info,
  66     const base::FilePath& file_path) {
  67   base::ThreadRestrictions::AssertIOAllowed();
  68   DCHECK(!file_path.empty());
  69   IPortableDevice* device =
  70       PortableDeviceMapService::GetInstance()->GetPortableDevice(
  71           device_info.registered_device_path);
  72   if (!device)
  73     return base::string16();
  74
  75   if (device_info.registered_device_path == file_path.value())
  76     return device_info.storage_object_id;
  77
  78   base::FilePath relative_path;
  79   if (!base::FilePath(device_info.registered_device_path).AppendRelativePath(
  80           file_path, &relative_path))
  81     return base::string16();
  82
  83   std::vector<base::string16> path_components;
  84   relative_path.GetComponents(&path_components);
  85   DCHECK(!path_components.empty());
  86   base::string16 parent_id(device_info.storage_object_id);
  87   base::string16 file_object_id;
  88   for (size_t i = 0; i < path_components.size(); ++i) {
  89     file_object_id =
  90         media_transfer_protocol::GetObjectIdFromName(device, parent_id,
  91                                                      path_components[i]);
  92     if (file_object_id.empty())
  93       break;
  94     parent_id = file_object_id;
  95   }
  96   return file_object_id;
  97 }
  98
  99 // Returns a pointer to a new instance of AbstractFileEnumerator for the given
 100 // |root| directory. Called on a blocking pool thread.
 101 scoped_ptr<MTPDeviceObjectEnumerator>
 102 CreateFileEnumeratorOnBlockingPoolThread(
 103     const MTPDeviceDelegateImplWin::StorageDeviceInfo& device_info,
 104     const base::FilePath& root) {
 105   base::ThreadRestrictions::AssertIOAllowed();
 106   DCHECK(!device_info.registered_device_path.empty());
 107   DCHECK(!root.empty());
 108   IPortableDevice* device =
 109       PortableDeviceMapService::GetInstance()->GetPortableDevice(
 110           device_info.registered_device_path);
 111   if (!device)
 112     return scoped_ptr<MTPDeviceObjectEnumerator>();
 113
 114   base::string16 object_id =
 115       GetFileObjectIdFromPathOnBlockingPoolThread(device_info, root);
 116   if (object_id.empty())
 117     return scoped_ptr<MTPDeviceObjectEnumerator>();
 118
 119   MTPDeviceObjectEntries entries;
 120   if (!media_transfer_protocol::GetDirectoryEntries(device, object_id,
 121                                                     &entries) ||
 122       entries.empty())
 123     return scoped_ptr<MTPDeviceObjectEnumerator>();
 124
 125   return scoped_ptr<MTPDeviceObjectEnumerator>(
 126       new MTPDeviceObjectEnumerator(entries));
 127 }
 128
 129 // Opens the device for communication on a blocking pool thread.
 130 // |pnp_device_id| specifies the PnP device id.
 131 // |registered_device_path| specifies the registered file system root path for
 132 // the given device.
 133 bool OpenDeviceOnBlockingPoolThread(
 134     const base::string16& pnp_device_id,
 135     const base::string16& registered_device_path) {
 136   base::ThreadRestrictions::AssertIOAllowed();
 137   DCHECK(!pnp_device_id.empty());
 138   DCHECK(!registered_device_path.empty());
 139   base::win::ScopedComPtr<IPortableDevice> device =
 140       media_transfer_protocol::OpenDevice(pnp_device_id);
 141   bool init_succeeded = device.get() != NULL;
 142   if (init_succeeded) {
 143     PortableDeviceMapService::GetInstance()->AddPortableDevice(
 144         registered_device_path, device.get());
 145   }
 146   return init_succeeded;
 147 }
 148
 149 // Gets the |file_path| details from the MTP device specified by the
 150 // |device_info.registered_device_path|. On success, |error| is set to
 151 // base::PLATFORM_FILE_OK and fills in |file_info|. On failure, |error| is set
 152 // to corresponding platform file error and |file_info| is not set.
 153 base::PlatformFileError GetFileInfoOnBlockingPoolThread(
 154     const MTPDeviceDelegateImplWin::StorageDeviceInfo& device_info,
 155     const base::FilePath& file_path,
 156     base::PlatformFileInfo* file_info) {
 157   base::ThreadRestrictions::AssertIOAllowed();
 158   DCHECK(!device_info.registered_device_path.empty());
 159   DCHECK(!file_path.empty());
 160   DCHECK(file_info);
 161   IPortableDevice* device =
 162       PortableDeviceMapService::GetInstance()->GetPortableDevice(
 163           device_info.registered_device_path);
 164   if (!device)
 165     return base::PLATFORM_FILE_ERROR_FAILED;
 166
 167   base::string16 object_id =
 168       GetFileObjectIdFromPathOnBlockingPoolThread(device_info, file_path);
 169   if (object_id.empty())
 170     return base::PLATFORM_FILE_ERROR_FAILED;
 171   return media_transfer_protocol::GetFileEntryInfo(device, object_id,
 172                                                    file_info);
 173 }
 174
 175 // Reads the |root| directory file entries on a blocking pool thread. On
 176 // success, |error| is set to base::PLATFORM_FILE_OK and |entries| contains the
 177 // directory file entries. On failure, |error| is set to platform file error
 178 // and |entries| is not set.
 179 base::PlatformFileError ReadDirectoryOnBlockingPoolThread(
 180     const MTPDeviceDelegateImplWin::StorageDeviceInfo& device_info,
 181     const base::FilePath& root,
 182     fileapi::AsyncFileUtil::EntryList* entries) {
 183   base::ThreadRestrictions::AssertIOAllowed();
 184   DCHECK(!root.empty());
 185   DCHECK(entries);
 186   base::PlatformFileInfo file_info;
 187   base::PlatformFileError error = GetFileInfoOnBlockingPoolThread(device_info,
 188                                                                   root,
 189                                                                   &file_info);
 190   if (error != base::PLATFORM_FILE_OK)
 191     return error;
 192
 193   if (!file_info.is_directory)
 194     return base::PLATFORM_FILE_ERROR_NOT_A_DIRECTORY;
 195
 196   base::FilePath current;
 197   scoped_ptr<MTPDeviceObjectEnumerator> file_enum =
 198       CreateFileEnumeratorOnBlockingPoolThread(device_info, root);
 199   if (!file_enum)
 200     return error;
 201
 202   while (!(current = file_enum->Next()).empty()) {
 203     fileapi::DirectoryEntry entry;
 204     entry.is_directory = file_enum->IsDirectory();
 205     entry.name = fileapi::VirtualPath::BaseName(current).value();
 206     entry.size = file_enum->Size();
 207     entry.last_modified_time = file_enum->LastModifiedTime();
 208     entries->push_back(entry);
 209   }
 210   return error;
 211 }
 212
 213 // Gets the device file stream object on a blocking pool thread.
 214 // |device_info| contains the device storage partition details.
 215 // On success, returns base::PLATFORM_FILE_OK and file stream details are set in
 216 // |file_details|. On failure, returns a platform file error and file stream
 217 // details are not set in |file_details|.
 218 base::PlatformFileError GetFileStreamOnBlockingPoolThread(
 219     const MTPDeviceDelegateImplWin::StorageDeviceInfo& device_info,
 220     SnapshotFileDetails* file_details) {
 221   base::ThreadRestrictions::AssertIOAllowed();
 222   DCHECK(file_details);
 223   DCHECK(!file_details->request_info().device_file_path.empty());
 224   DCHECK(!file_details->request_info().snapshot_file_path.empty());
 225   IPortableDevice* device =
 226       PortableDeviceMapService::GetInstance()->GetPortableDevice(
 227           device_info.registered_device_path);
 228   if (!device)
 229     return base::PLATFORM_FILE_ERROR_FAILED;
 230
 231   base::string16 file_object_id =
 232       GetFileObjectIdFromPathOnBlockingPoolThread(
 233           device_info, file_details->request_info().device_file_path);
 234   if (file_object_id.empty())
 235     return base::PLATFORM_FILE_ERROR_FAILED;
 236
 237   base::PlatformFileInfo file_info;
 238   base::PlatformFileError error =
 239       GetFileInfoOnBlockingPoolThread(
 240           device_info,
 241           file_details->request_info().device_file_path,
 242           &file_info);
 243   if (error != base::PLATFORM_FILE_OK)
 244     return error;
 245
 246   DWORD optimal_transfer_size = 0;
 247   base::win::ScopedComPtr<IStream> file_stream;
 248   if (file_info.size > 0) {
 249     HRESULT hr = media_transfer_protocol::GetFileStreamForObject(
 250         device,
 251         file_object_id,
 252         file_stream.Receive(),
 253         &optimal_transfer_size);
 254     if (hr != S_OK)
 255       return base::PLATFORM_FILE_ERROR_FAILED;
 256   }
 257
 258   // LocalFileStreamReader is used to read the contents of the snapshot file.
 259   // Snapshot file modification time does not match the last modified time
 260   // of the original media file. Therefore, set the last modified time to null
 261   // in order to avoid the verification in LocalFileStreamReader.
 262   //
 263   // Users will use HTML5 FileSystem Entry getMetadata() interface to get the
 264   // actual last modified time of the media file.
 265   file_info.last_modified = base::Time();
 266
 267   DCHECK(file_info.size == 0 || optimal_transfer_size > 0U);
 268   file_details->set_file_info(file_info);
 269   file_details->set_device_file_stream(file_stream);
 270   file_details->set_optimal_transfer_size(optimal_transfer_size);
 271   return error;
 272 }
 273
 274 // Copies the data chunk from device file to the snapshot file based on the
 275 // parameters specified by |file_details|.
 276 // Returns the total number of bytes written to the snapshot file for non-empty
 277 // files, or 0 on failure. For empty files, just return 0.
 278 DWORD WriteDataChunkIntoSnapshotFileOnBlockingPoolThread(
 279     const SnapshotFileDetails& file_details) {
 280   base::ThreadRestrictions::AssertIOAllowed();
 281   if (file_details.file_info().size == 0)
 282     return 0;
 283   return media_transfer_protocol::CopyDataChunkToLocalFile(
 284       file_details.device_file_stream(),
 285       file_details.request_info().snapshot_file_path,
 286       file_details.optimal_transfer_size());
 287 }
 288
 289 void DeletePortableDeviceOnBlockingPoolThread(
 290     const base::string16& registered_device_path) {
 291   base::ThreadRestrictions::AssertIOAllowed();
 292   PortableDeviceMapService::GetInstance()->RemovePortableDevice(
 293       registered_device_path);
 294 }
 295
 296 }  // namespace
 297
 298 // Used by CreateMTPDeviceAsyncDelegate() to create the MTP device
 299 // delegate on the IO thread.
 300 void OnGetStorageInfoCreateDelegate(
 301     const base::string16& device_location,
 302     const CreateMTPDeviceAsyncDelegateCallback& callback,
 303     base::string16* pnp_device_id,
 304     base::string16* storage_object_id,
 305     bool succeeded) {
 306   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 307   DCHECK(pnp_device_id);
 308   DCHECK(storage_object_id);
 309   if (!succeeded)
 310     return;
 311   callback.Run(new MTPDeviceDelegateImplWin(device_location,
 312                                             *pnp_device_id,
 313                                             *storage_object_id));
 314 }
 315
 316 void CreateMTPDeviceAsyncDelegate(
 317     const base::string16& device_location,
 318     const CreateMTPDeviceAsyncDelegateCallback& callback) {
 319   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 320   DCHECK(!device_location.empty());
 321   base::string16* pnp_device_id = new base::string16;
 322   base::string16* storage_object_id = new base::string16;
 323   content::BrowserThread::PostTaskAndReplyWithResult<bool>(
 324       content::BrowserThread::UI,
 325       FROM_HERE,
 326       base::Bind(&GetStorageInfoOnUIThread,
 327                  device_location,
 328                  base::Unretained(pnp_device_id),
 329                  base::Unretained(storage_object_id)),
 330       base::Bind(&OnGetStorageInfoCreateDelegate,
 331                  device_location,
 332                  callback,
 333                  base::Owned(pnp_device_id),
 334                  base::Owned(storage_object_id)));
 335 }
 336
 337 // MTPDeviceDelegateImplWin ---------------------------------------------------
 338
 339 MTPDeviceDelegateImplWin::StorageDeviceInfo::StorageDeviceInfo(
 340     const base::string16& pnp_device_id,
 341     const base::string16& registered_device_path,
 342     const base::string16& storage_object_id)
 343     : pnp_device_id(pnp_device_id),
 344       registered_device_path(registered_device_path),
 345       storage_object_id(storage_object_id) {
 346   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 347 }
 348
 349 MTPDeviceDelegateImplWin::PendingTaskInfo::PendingTaskInfo(
 350     const tracked_objects::Location& location,
 351     const base::Callback<base::PlatformFileError(void)>& task,
 352     const base::Callback<void(base::PlatformFileError)>& reply)
 353     : location(location),
 354       task(task),
 355       reply(reply) {
 356 }
 357
 358 MTPDeviceDelegateImplWin::MTPDeviceDelegateImplWin(
 359     const base::string16& registered_device_path,
 360     const base::string16& pnp_device_id,
 361     const base::string16& storage_object_id)
 362     : storage_device_info_(pnp_device_id, registered_device_path,
 363                            storage_object_id),
 364       init_state_(UNINITIALIZED),
 365       media_task_runner_(MediaFileSystemBackend::MediaTaskRunner()),
 366       task_in_progress_(false),
 367       weak_ptr_factory_(this) {
 368   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 369   DCHECK(!registered_device_path.empty());
 370   DCHECK(!pnp_device_id.empty());
 371   DCHECK(!storage_object_id.empty());
 372   DCHECK(media_task_runner_.get());
 373 }
 374
 375 MTPDeviceDelegateImplWin::~MTPDeviceDelegateImplWin() {
 376   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 377 }
 378
 379 void MTPDeviceDelegateImplWin::GetFileInfo(
 380     const base::FilePath& file_path,
 381     const GetFileInfoSuccessCallback& success_callback,
 382     const ErrorCallback& error_callback) {
 383   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 384   DCHECK(!file_path.empty());
 385   base::PlatformFileInfo* file_info = new base::PlatformFileInfo;
 386   EnsureInitAndRunTask(
 387       PendingTaskInfo(FROM_HERE,
 388                       base::Bind(&GetFileInfoOnBlockingPoolThread,
 389                                  storage_device_info_,
 390                                  file_path,
 391                                  base::Unretained(file_info)),
 392                       base::Bind(&MTPDeviceDelegateImplWin::OnGetFileInfo,
 393                                  weak_ptr_factory_.GetWeakPtr(),
 394                                  success_callback,
 395                                  error_callback,
 396                                  base::Owned(file_info))));
 397 }
 398
 399 void MTPDeviceDelegateImplWin::ReadDirectory(
 400     const base::FilePath& root,
 401     const ReadDirectorySuccessCallback& success_callback,
 402     const ErrorCallback& error_callback) {
 403   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 404   DCHECK(!root.empty());
 405   fileapi::AsyncFileUtil::EntryList* entries =
 406       new fileapi::AsyncFileUtil::EntryList;
 407   EnsureInitAndRunTask(
 408       PendingTaskInfo(FROM_HERE,
 409                       base::Bind(&ReadDirectoryOnBlockingPoolThread,
 410                                  storage_device_info_,
 411                                  root,
 412                                  base::Unretained(entries)),
 413                       base::Bind(&MTPDeviceDelegateImplWin::OnDidReadDirectory,
 414                                  weak_ptr_factory_.GetWeakPtr(),
 415                                  success_callback,
 416                                  error_callback,
 417                                  base::Owned(entries))));
 418 }
 419
 420 void MTPDeviceDelegateImplWin::CreateSnapshotFile(
 421     const base::FilePath& device_file_path,
 422     const base::FilePath& snapshot_file_path,
 423     const CreateSnapshotFileSuccessCallback& success_callback,
 424     const ErrorCallback& error_callback) {
 425   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 426   DCHECK(!device_file_path.empty());
 427   DCHECK(!snapshot_file_path.empty());
 428   scoped_ptr<SnapshotFileDetails> file_details(
 429       new SnapshotFileDetails(SnapshotRequestInfo(device_file_path,
 430                                                   snapshot_file_path,
 431                                                   success_callback,
 432                                                   error_callback)));
 433   // Passing a raw SnapshotFileDetails* to the blocking pool is safe, because
 434   // it is owned by |file_details| in the reply callback.
 435   EnsureInitAndRunTask(
 436       PendingTaskInfo(FROM_HERE,
 437                       base::Bind(&GetFileStreamOnBlockingPoolThread,
 438                                  storage_device_info_,
 439                                  file_details.get()),
 440                       base::Bind(&MTPDeviceDelegateImplWin::OnGetFileStream,
 441                                  weak_ptr_factory_.GetWeakPtr(),
 442                                  base::Passed(&file_details))));
 443 }
 444
 445 void MTPDeviceDelegateImplWin::CancelPendingTasksAndDeleteDelegate() {
 446   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 447   PortableDeviceMapService::GetInstance()->MarkPortableDeviceForDeletion(
 448       storage_device_info_.registered_device_path);
 449   media_task_runner_->PostTask(
 450       FROM_HERE,
 451       base::Bind(&DeletePortableDeviceOnBlockingPoolThread,
 452                  storage_device_info_.registered_device_path));
 453   while (!pending_tasks_.empty())
 454     pending_tasks_.pop();
 455   delete this;
 456 }
 457
 458 void MTPDeviceDelegateImplWin::EnsureInitAndRunTask(
 459     const PendingTaskInfo& task_info) {
 460   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 461   if ((init_state_ == INITIALIZED) && !task_in_progress_) {
 462     DCHECK(pending_tasks_.empty());
 463     DCHECK(!current_snapshot_details_.get());
 464     base::PostTaskAndReplyWithResult(media_task_runner_,
 465                                      task_info.location,
 466                                      task_info.task,
 467                                      task_info.reply);
 468     task_in_progress_ = true;
 469     return;
 470   }
 471
 472   pending_tasks_.push(task_info);
 473   if (init_state_ == UNINITIALIZED) {
 474     init_state_ = PENDING_INIT;
 475     base::PostTaskAndReplyWithResult(
 476         media_task_runner_,
 477         FROM_HERE,
 478         base::Bind(&OpenDeviceOnBlockingPoolThread,
 479                    storage_device_info_.pnp_device_id,
 480                    storage_device_info_.registered_device_path),
 481         base::Bind(&MTPDeviceDelegateImplWin::OnInitCompleted,
 482                    weak_ptr_factory_.GetWeakPtr()));
 483     task_in_progress_ = true;
 484   }
 485 }
 486
 487 void MTPDeviceDelegateImplWin::WriteDataChunkIntoSnapshotFile() {
 488   DCHECK(current_snapshot_details_.get());
 489   base::PostTaskAndReplyWithResult(
 490       media_task_runner_,
 491       FROM_HERE,
 492       base::Bind(&WriteDataChunkIntoSnapshotFileOnBlockingPoolThread,
 493                  *current_snapshot_details_),
 494       base::Bind(&MTPDeviceDelegateImplWin::OnWroteDataChunkIntoSnapshotFile,
 495                  weak_ptr_factory_.GetWeakPtr(),
 496                  current_snapshot_details_->request_info().snapshot_file_path));
 497 }
 498
 499 void MTPDeviceDelegateImplWin::ProcessNextPendingRequest() {
 500   DCHECK(!task_in_progress_);
 501   if (pending_tasks_.empty())
 502     return;
 503   const PendingTaskInfo& task_info = pending_tasks_.front();
 504   task_in_progress_ = true;
 505   base::PostTaskAndReplyWithResult(media_task_runner_,
 506                                    task_info.location,
 507                                    task_info.task,
 508                                    task_info.reply);
 509   pending_tasks_.pop();
 510 }
 511
 512 void MTPDeviceDelegateImplWin::OnInitCompleted(bool succeeded) {
 513   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 514   init_state_ = succeeded ? INITIALIZED : UNINITIALIZED;
 515   task_in_progress_ = false;
 516   ProcessNextPendingRequest();
 517 }
 518
 519 void MTPDeviceDelegateImplWin::OnGetFileInfo(
 520     const GetFileInfoSuccessCallback& success_callback,
 521     const ErrorCallback& error_callback,
 522     base::PlatformFileInfo* file_info,
 523     base::PlatformFileError error) {
 524   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 525   DCHECK(file_info);
 526   if (error == base::PLATFORM_FILE_OK)
 527     success_callback.Run(*file_info);
 528   else
 529     error_callback.Run(error);
 530   task_in_progress_ = false;
 531   ProcessNextPendingRequest();
 532 }
 533
 534 void MTPDeviceDelegateImplWin::OnDidReadDirectory(
 535     const ReadDirectorySuccessCallback& success_callback,
 536     const ErrorCallback& error_callback,
 537     fileapi::AsyncFileUtil::EntryList* file_list,
 538     base::PlatformFileError error) {
 539   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 540   DCHECK(file_list);
 541   if (error == base::PLATFORM_FILE_OK)
 542     success_callback.Run(*file_list, false /*no more entries*/);
 543   else
 544     error_callback.Run(error);
 545   task_in_progress_ = false;
 546   ProcessNextPendingRequest();
 547 }
 548
 549 void MTPDeviceDelegateImplWin::OnGetFileStream(
 550     scoped_ptr<SnapshotFileDetails> file_details,
 551     base::PlatformFileError error) {
 552   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 553   DCHECK(file_details);
 554   DCHECK(!file_details->request_info().device_file_path.empty());
 555   DCHECK(!file_details->request_info().snapshot_file_path.empty());
 556   DCHECK(!current_snapshot_details_.get());
 557   if (error != base::PLATFORM_FILE_OK) {
 558     file_details->request_info().error_callback.Run(error);
 559     task_in_progress_ = false;
 560     ProcessNextPendingRequest();
 561     return;
 562   }
 563   DCHECK(file_details->file_info().size == 0 ||
 564          file_details->device_file_stream());
 565   current_snapshot_details_.reset(file_details.release());
 566   WriteDataChunkIntoSnapshotFile();
 567 }
 568
 569 void MTPDeviceDelegateImplWin::OnWroteDataChunkIntoSnapshotFile(
 570     const base::FilePath& snapshot_file_path,
 571     DWORD bytes_written) {
 572   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 573   DCHECK(!snapshot_file_path.empty());
 574   if (!current_snapshot_details_.get())
 575     return;
 576   DCHECK_EQ(
 577       current_snapshot_details_->request_info().snapshot_file_path.value(),
 578       snapshot_file_path.value());
 579
 580   bool succeeded = false;
 581   bool should_continue = false;
 582   if (current_snapshot_details_->file_info().size > 0) {
 583     if (current_snapshot_details_->AddBytesWritten(bytes_written)) {
 584       if (current_snapshot_details_->IsSnapshotFileWriteComplete()) {
 585         succeeded = true;
 586       } else {
 587         should_continue = true;
 588       }
 589     }
 590   } else {
 591     // Handle empty files.
 592     DCHECK_EQ(0U, bytes_written);
 593     succeeded = true;
 594   }
 595
 596   if (should_continue) {
 597     WriteDataChunkIntoSnapshotFile();
 598     return;
 599   }
 600   if (succeeded) {
 601     current_snapshot_details_->request_info().success_callback.Run(
 602         current_snapshot_details_->file_info(),
 603         current_snapshot_details_->request_info().snapshot_file_path);
 604   } else {
 605     current_snapshot_details_->request_info().error_callback.Run(
 606         base::PLATFORM_FILE_ERROR_FAILED);
 607   }
 608   task_in_progress_ = false;
 609   current_snapshot_details_.reset();
 610   ProcessNextPendingRequest();
 611 }