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