src/chrome/browser/chromeos/drive/webkit_file_stream_writer_impl.cc

   1 // Copyright 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 #include "chrome/browser/chromeos/drive/webkit_file_stream_writer_impl.h"
   6
   7 #include "base/bind.h"
   8 #include "base/callback_helpers.h"
   9 #include "chrome/browser/chromeos/drive/file_system_util.h"
  10 #include "chrome/browser/chromeos/drive/fileapi_worker.h"
  11 #include "chrome/browser/google_apis/task_util.h"
  12 #include "content/public/browser/browser_thread.h"
  13 #include "net/base/io_buffer.h"
  14 #include "net/base/net_errors.h"
  15 #include "webkit/browser/fileapi/file_stream_writer.h"
  16
  17 using content::BrowserThread;
  18
  19 namespace drive {
  20 namespace internal {
  21 namespace {
  22
  23 // Creates a writable snapshot file of the |drive_path|.
  24 void CreateWritableSnapshotFile(
  25     const WebkitFileStreamWriterImpl::FileSystemGetter& file_system_getter,
  26     const base::FilePath& drive_path,
  27     const fileapi_internal::CreateWritableSnapshotFileCallback& callback) {
  28   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  29
  30   BrowserThread::PostTask(
  31       BrowserThread::UI,
  32       FROM_HERE,
  33       base::Bind(
  34           &fileapi_internal::RunFileSystemCallback,
  35           file_system_getter,
  36           base::Bind(&fileapi_internal::CreateWritableSnapshotFile,
  37                      drive_path, google_apis::CreateRelayCallback(callback)),
  38           google_apis::CreateRelayCallback(base::Bind(
  39               callback, base::PLATFORM_FILE_ERROR_FAILED, base::FilePath(),
  40               base::Closure()))));
  41 }
  42
  43 }  // namespace
  44
  45 WebkitFileStreamWriterImpl::WebkitFileStreamWriterImpl(
  46     const FileSystemGetter& file_system_getter,
  47     base::TaskRunner* file_task_runner,
  48     const base::FilePath& file_path,
  49     int64 offset)
  50     : file_system_getter_(file_system_getter),
  51       file_task_runner_(file_task_runner),
  52       file_path_(file_path),
  53       offset_(offset),
  54       weak_ptr_factory_(this) {
  55 }
  56
  57 WebkitFileStreamWriterImpl::~WebkitFileStreamWriterImpl() {
  58   if (local_file_writer_) {
  59     // If the file is opened, close it at destructor.
  60     // It is necessary to close the local file in advance.
  61     local_file_writer_.reset();
  62     DCHECK(!close_callback_on_ui_thread_.is_null());
  63     BrowserThread::PostTask(BrowserThread::UI,
  64                             FROM_HERE,
  65                             close_callback_on_ui_thread_);
  66   }
  67 }
  68
  69 int WebkitFileStreamWriterImpl::Write(net::IOBuffer* buf,
  70                                       int buf_len,
  71                                       const net::CompletionCallback& callback) {
  72   DCHECK(pending_write_callback_.is_null());
  73   DCHECK(pending_cancel_callback_.is_null());
  74   DCHECK(!callback.is_null());
  75
  76   // If the local file is already available, just delegate to it.
  77   if (local_file_writer_)
  78     return local_file_writer_->Write(buf, buf_len, callback);
  79
  80   // The local file is not yet ready. Create the writable snapshot.
  81   if (file_path_.empty())
  82     return net::ERR_FILE_NOT_FOUND;
  83
  84   pending_write_callback_ = callback;
  85   CreateWritableSnapshotFile(
  86       file_system_getter_, file_path_,
  87       base::Bind(
  88           &WebkitFileStreamWriterImpl::WriteAfterCreateWritableSnapshotFile,
  89           weak_ptr_factory_.GetWeakPtr(), make_scoped_refptr(buf), buf_len));
  90   return net::ERR_IO_PENDING;
  91 }
  92
  93 int WebkitFileStreamWriterImpl::Cancel(
  94     const net::CompletionCallback& callback) {
  95   DCHECK(pending_cancel_callback_.is_null());
  96   DCHECK(!callback.is_null());
  97
  98   // If LocalFileWriter is already created, just delegate the cancel to it.
  99   if (local_file_writer_)
 100     return local_file_writer_->Cancel(callback);
 101
 102   // If file open operation is in-flight, wait for its completion and cancel
 103   // further write operation in WriteAfterCreateWritableSnapshotFile.
 104   if (!pending_write_callback_.is_null()) {
 105     // Dismiss pending write callback immediately.
 106     pending_write_callback_.Reset();
 107     pending_cancel_callback_ = callback;
 108     return net::ERR_IO_PENDING;
 109   }
 110
 111   // Write() is not called yet.
 112   return net::ERR_UNEXPECTED;
 113 }
 114
 115 int WebkitFileStreamWriterImpl::Flush(const net::CompletionCallback& callback) {
 116   DCHECK(pending_cancel_callback_.is_null());
 117   DCHECK(!callback.is_null());
 118
 119   // If LocalFileWriter is already created, just delegate to it.
 120   if (local_file_writer_)
 121     return local_file_writer_->Flush(callback);
 122
 123   // There shouldn't be in-flight Write operation.
 124   DCHECK(pending_write_callback_.is_null());
 125
 126   // Here is the case Flush() is called before any Write() invocation.
 127   // Do nothing.
 128   // Synchronization to the remote server is not done until the file is closed.
 129   return net::OK;
 130 }
 131
 132 void WebkitFileStreamWriterImpl::WriteAfterCreateWritableSnapshotFile(
 133     net::IOBuffer* buf,
 134     int buf_len,
 135     base::PlatformFileError open_result,
 136     const base::FilePath& local_path,
 137     const base::Closure& close_callback_on_ui_thread) {
 138   DCHECK(!local_file_writer_);
 139
 140   if (!pending_cancel_callback_.is_null()) {
 141     DCHECK(pending_write_callback_.is_null());
 142     // Cancel() is called during the creation of the snapshot file.
 143     // Don't write to the file.
 144     if (open_result == base::PLATFORM_FILE_OK) {
 145       // Here the file is internally created. To revert the operation, close
 146       // the file.
 147       DCHECK(!close_callback_on_ui_thread.is_null());
 148       BrowserThread::PostTask(BrowserThread::UI,
 149                               FROM_HERE,
 150                               close_callback_on_ui_thread);
 151     }
 152
 153     base::ResetAndReturn(&pending_cancel_callback_).Run(net::OK);
 154     return;
 155   }
 156
 157   DCHECK(!pending_write_callback_.is_null());
 158
 159   const net::CompletionCallback callback =
 160       base::ResetAndReturn(&pending_write_callback_);
 161   if (open_result != base::PLATFORM_FILE_OK) {
 162     DCHECK(close_callback_on_ui_thread.is_null());
 163     callback.Run(net::PlatformFileErrorToNetError(open_result));
 164     return;
 165   }
 166
 167   // Keep |close_callback| to close the file when the stream is destructed.
 168   DCHECK(!close_callback_on_ui_thread.is_null());
 169   close_callback_on_ui_thread_ = close_callback_on_ui_thread;
 170   local_file_writer_.reset(fileapi::FileStreamWriter::CreateForLocalFile(
 171       file_task_runner_.get(), local_path, offset_));
 172   int result = local_file_writer_->Write(buf, buf_len, callback);
 173   if (result != net::ERR_IO_PENDING)
 174     callback.Run(result);
 175 }
 176
 177 }  // namespace internal
 178 }  // namespace drive