src/net/base/file_stream_context.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 "net/base/file_stream_context.h"
   6
   7 #include "base/files/file_path.h"
   8 #include "base/location.h"
   9 #include "base/message_loop/message_loop_proxy.h"
  10 #include "base/task_runner.h"
  11 #include "base/task_runner_util.h"
  12 #include "base/threading/thread_restrictions.h"
  13 #include "base/values.h"
  14 #include "net/base/net_errors.h"
  15
  16 #if defined(OS_ANDROID)
  17 #include "base/android/content_uri_utils.h"
  18 #endif
  19
  20 namespace net {
  21
  22 namespace {
  23
  24 void CallInt64ToInt(const CompletionCallback& callback, int64 result) {
  25   callback.Run(static_cast<int>(result));
  26 }
  27
  28 }  // namespace
  29
  30 FileStream::Context::IOResult::IOResult()
  31     : result(OK),
  32       os_error(0) {
  33 }
  34
  35 FileStream::Context::IOResult::IOResult(int64 result, int os_error)
  36     : result(result),
  37       os_error(os_error) {
  38 }
  39
  40 // static
  41 FileStream::Context::IOResult FileStream::Context::IOResult::FromOSError(
  42     int64 os_error) {
  43   return IOResult(MapSystemError(os_error), os_error);
  44 }
  45
  46 // ---------------------------------------------------------------------
  47
  48 FileStream::Context::OpenResult::OpenResult() {
  49 }
  50
  51 FileStream::Context::OpenResult::OpenResult(base::File file,
  52                                             IOResult error_code)
  53     : file(file.Pass()),
  54       error_code(error_code) {
  55 }
  56
  57 FileStream::Context::OpenResult::OpenResult(RValue other)
  58     : file(other.object->file.Pass()),
  59       error_code(other.object->error_code) {
  60 }
  61
  62 FileStream::Context::OpenResult& FileStream::Context::OpenResult::operator=(
  63     RValue other) {
  64   if (this != other.object) {
  65     file = other.object->file.Pass();
  66     error_code = other.object->error_code;
  67   }
  68   return *this;
  69 }
  70
  71 // ---------------------------------------------------------------------
  72
  73 void FileStream::Context::Orphan() {
  74   DCHECK(!orphaned_);
  75
  76   orphaned_ = true;
  77
  78   if (!async_in_progress_) {
  79     CloseAndDelete();
  80   } else if (file_.IsValid()) {
  81 #if defined(OS_WIN)
  82     CancelIo(file_.GetPlatformFile());
  83 #endif
  84   }
  85 }
  86
  87 void FileStream::Context::Open(const base::FilePath& path,
  88                                int open_flags,
  89                                const CompletionCallback& callback) {
  90   DCHECK(!async_in_progress_);
  91
  92   bool posted = base::PostTaskAndReplyWithResult(
  93       task_runner_.get(),
  94       FROM_HERE,
  95       base::Bind(
  96           &Context::OpenFileImpl, base::Unretained(this), path, open_flags),
  97       base::Bind(&Context::OnOpenCompleted, base::Unretained(this), callback));
  98   DCHECK(posted);
  99
 100   async_in_progress_ = true;
 101 }
 102
 103 void FileStream::Context::Close(const CompletionCallback& callback) {
 104   DCHECK(!async_in_progress_);
 105   bool posted = base::PostTaskAndReplyWithResult(
 106       task_runner_.get(),
 107       FROM_HERE,
 108       base::Bind(&Context::CloseFileImpl, base::Unretained(this)),
 109       base::Bind(&Context::OnAsyncCompleted,
 110                  base::Unretained(this),
 111                  IntToInt64(callback)));
 112   DCHECK(posted);
 113
 114   async_in_progress_ = true;
 115 }
 116
 117 void FileStream::Context::Seek(base::File::Whence whence,
 118                                int64 offset,
 119                                const Int64CompletionCallback& callback) {
 120   DCHECK(!async_in_progress_);
 121
 122   bool posted = base::PostTaskAndReplyWithResult(
 123       task_runner_.get(),
 124       FROM_HERE,
 125       base::Bind(
 126           &Context::SeekFileImpl, base::Unretained(this), whence, offset),
 127       base::Bind(&Context::OnAsyncCompleted,
 128                  base::Unretained(this),
 129                  callback));
 130   DCHECK(posted);
 131
 132   async_in_progress_ = true;
 133 }
 134
 135 void FileStream::Context::Flush(const CompletionCallback& callback) {
 136   DCHECK(!async_in_progress_);
 137
 138   bool posted = base::PostTaskAndReplyWithResult(
 139       task_runner_.get(),
 140       FROM_HERE,
 141       base::Bind(&Context::FlushFileImpl, base::Unretained(this)),
 142       base::Bind(&Context::OnAsyncCompleted,
 143                  base::Unretained(this),
 144                  IntToInt64(callback)));
 145   DCHECK(posted);
 146
 147   async_in_progress_ = true;
 148 }
 149
 150 FileStream::Context::OpenResult FileStream::Context::OpenFileImpl(
 151     const base::FilePath& path, int open_flags) {
 152 #if defined(OS_POSIX)
 153   // Always use blocking IO.
 154   open_flags &= ~base::File::FLAG_ASYNC;
 155 #endif
 156   base::File file;
 157 #if defined(OS_ANDROID)
 158   if (path.IsContentUri()) {
 159     // Check that only Read flags are set.
 160     DCHECK_EQ(open_flags & ~base::File::FLAG_ASYNC,
 161               base::File::FLAG_OPEN | base::File::FLAG_READ);
 162     file = base::OpenContentUriForRead(path);
 163   } else {
 164 #endif  // defined(OS_ANDROID)
 165     // FileStream::Context actually closes the file asynchronously,
 166     // independently from FileStream's destructor. It can cause problems for
 167     // users wanting to delete the file right after FileStream deletion. Thus
 168     // we are always adding SHARE_DELETE flag to accommodate such use case.
 169     // TODO(rvargas): This sounds like a bug, as deleting the file would
 170     // presumably happen on the wrong thread. There should be an async delete.
 171     open_flags |= base::File::FLAG_SHARE_DELETE;
 172     file.Initialize(path, open_flags);
 173 #if defined(OS_ANDROID)
 174   }
 175 #endif  // defined(OS_ANDROID)
 176   if (!file.IsValid())
 177     return OpenResult(base::File(),
 178                       IOResult::FromOSError(logging::GetLastSystemErrorCode()));
 179
 180   return OpenResult(file.Pass(), IOResult(OK, 0));
 181 }
 182
 183 FileStream::Context::IOResult FileStream::Context::CloseFileImpl() {
 184   file_.Close();
 185   return IOResult(OK, 0);
 186 }
 187
 188 FileStream::Context::IOResult FileStream::Context::FlushFileImpl() {
 189   if (file_.Flush())
 190     return IOResult(OK, 0);
 191
 192   return IOResult::FromOSError(logging::GetLastSystemErrorCode());
 193 }
 194
 195 void FileStream::Context::OnOpenCompleted(const CompletionCallback& callback,
 196                                           OpenResult open_result) {
 197   file_ = open_result.file.Pass();
 198   if (file_.IsValid() && !orphaned_)
 199     OnFileOpened();
 200
 201   OnAsyncCompleted(IntToInt64(callback), open_result.error_code);
 202 }
 203
 204 void FileStream::Context::CloseAndDelete() {
 205   DCHECK(!async_in_progress_);
 206
 207   if (file_.IsValid()) {
 208     bool posted = task_runner_.get()->PostTask(
 209         FROM_HERE,
 210         base::Bind(base::IgnoreResult(&Context::CloseFileImpl),
 211                    base::Owned(this)));
 212     DCHECK(posted);
 213   } else {
 214     delete this;
 215   }
 216 }
 217
 218 Int64CompletionCallback FileStream::Context::IntToInt64(
 219     const CompletionCallback& callback) {
 220   return base::Bind(&CallInt64ToInt, callback);
 221 }
 222
 223 void FileStream::Context::OnAsyncCompleted(
 224     const Int64CompletionCallback& callback,
 225     const IOResult& result) {
 226   // Reset this before Run() as Run() may issue a new async operation. Also it
 227   // should be reset before Close() because it shouldn't run if any async
 228   // operation is in progress.
 229   async_in_progress_ = false;
 230   if (orphaned_)
 231     CloseAndDelete();
 232   else
 233     callback.Run(result.result);
 234 }
 235
 236 }  // namespace net