net/base/upload_file_element_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 "net/base/upload_file_element_reader.h"
   6
   7 #include "base/bind.h"
   8 #include "base/file_util.h"
   9 #include "base/location.h"
  10 #include "base/task_runner_util.h"
  11 #include "net/base/file_stream.h"
  12 #include "net/base/io_buffer.h"
  13 #include "net/base/net_errors.h"
  14
  15 namespace net {
  16
  17 namespace {
  18
  19 // In tests, this value is used to override the return value of
  20 // UploadFileElementReader::GetContentLength() when set to non-zero.
  21 uint64 overriding_content_length = 0;
  22
  23 // This function is used to implement Init().
  24 template<typename FileStreamDeleter>
  25 int InitInternal(const base::FilePath& path,
  26                  uint64 range_offset,
  27                  uint64 range_length,
  28                  const base::Time& expected_modification_time,
  29                  scoped_ptr<FileStream, FileStreamDeleter>* out_file_stream,
  30                  uint64* out_content_length) {
  31   scoped_ptr<FileStream> file_stream(new FileStream(NULL));
  32   int64 rv = file_stream->OpenSync(
  33       path, base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_READ);
  34   if (rv != OK) {
  35     // If the file can't be opened, we'll just upload an empty file.
  36     DLOG(WARNING) << "Failed to open \"" << path.value()
  37                   << "\" for reading: " << rv;
  38     file_stream.reset();
  39   } else if (range_offset) {
  40     rv = file_stream->SeekSync(FROM_BEGIN, range_offset);
  41     if (rv < 0) {
  42       DLOG(WARNING) << "Failed to seek \"" << path.value()
  43                     << "\" to offset: " << range_offset << " (" << rv << ")";
  44       file_stream.reset();
  45     }
  46   }
  47
  48   int64 length = 0;
  49   if (file_stream.get() &&
  50       file_util::GetFileSize(path, &length) &&
  51       range_offset < static_cast<uint64>(length)) {
  52     // Compensate for the offset.
  53     length = std::min(length - range_offset, range_length);
  54   }
  55   *out_content_length = length;
  56   out_file_stream->reset(file_stream.release());
  57
  58   // If the underlying file has been changed and the expected file modification
  59   // time is set, treat it as error. Note that the expected modification time
  60   // from WebKit is based on time_t precision. So we have to convert both to
  61   // time_t to compare. This check is used for sliced files.
  62   if (!expected_modification_time.is_null()) {
  63     base::PlatformFileInfo info;
  64     if (file_util::GetFileInfo(path, &info) &&
  65         expected_modification_time.ToTimeT() != info.last_modified.ToTimeT()) {
  66       return ERR_UPLOAD_FILE_CHANGED;
  67     }
  68   }
  69
  70   return OK;
  71 }
  72
  73 // This function is used to implement Read().
  74 int ReadInternal(scoped_refptr<IOBuffer> buf,
  75                  int buf_length,
  76                  uint64 bytes_remaining,
  77                  FileStream* file_stream) {
  78   DCHECK_LT(0, buf_length);
  79
  80   const uint64 num_bytes_to_read =
  81       std::min(bytes_remaining, static_cast<uint64>(buf_length));
  82
  83   int result = 0;
  84   if (num_bytes_to_read > 0) {
  85     DCHECK(file_stream);  // file_stream is non-null if content_length_ > 0.
  86     result = file_stream->ReadSync(buf->data(), num_bytes_to_read);
  87     if (result == 0)  // Reached end-of-file earlier than expected.
  88       result = ERR_UPLOAD_FILE_CHANGED;
  89   }
  90   return result;
  91 }
  92
  93 }  // namespace
  94
  95 UploadFileElementReader::FileStreamDeleter::FileStreamDeleter(
  96     base::TaskRunner* task_runner) : task_runner_(task_runner) {
  97   DCHECK(task_runner_.get());
  98 }
  99
 100 UploadFileElementReader::FileStreamDeleter::~FileStreamDeleter() {}
 101
 102 void UploadFileElementReader::FileStreamDeleter::operator() (
 103     FileStream* file_stream) const {
 104   if (file_stream) {
 105     task_runner_->PostTask(FROM_HERE,
 106                            base::Bind(&base::DeletePointer<FileStream>,
 107                                       file_stream));
 108   }
 109 }
 110
 111 UploadFileElementReader::UploadFileElementReader(
 112     base::TaskRunner* task_runner,
 113     const base::FilePath& path,
 114     uint64 range_offset,
 115     uint64 range_length,
 116     const base::Time& expected_modification_time)
 117     : task_runner_(task_runner),
 118       path_(path),
 119       range_offset_(range_offset),
 120       range_length_(range_length),
 121       expected_modification_time_(expected_modification_time),
 122       file_stream_(NULL, FileStreamDeleter(task_runner_.get())),
 123       content_length_(0),
 124       bytes_remaining_(0),
 125       weak_ptr_factory_(this) {
 126   DCHECK(task_runner_.get());
 127 }
 128
 129 UploadFileElementReader::~UploadFileElementReader() {
 130 }
 131
 132 const UploadFileElementReader* UploadFileElementReader::AsFileReader() const {
 133   return this;
 134 }
 135
 136 int UploadFileElementReader::Init(const CompletionCallback& callback) {
 137   DCHECK(!callback.is_null());
 138   Reset();
 139
 140   ScopedFileStreamPtr* file_stream =
 141       new ScopedFileStreamPtr(NULL, FileStreamDeleter(task_runner_.get()));
 142   uint64* content_length = new uint64;
 143   const bool posted = base::PostTaskAndReplyWithResult(
 144       task_runner_.get(),
 145       FROM_HERE,
 146       base::Bind(&InitInternal<FileStreamDeleter>,
 147                  path_,
 148                  range_offset_,
 149                  range_length_,
 150                  expected_modification_time_,
 151                  file_stream,
 152                  content_length),
 153       base::Bind(&UploadFileElementReader::OnInitCompleted,
 154                  weak_ptr_factory_.GetWeakPtr(),
 155                  base::Owned(file_stream),
 156                  base::Owned(content_length),
 157                  callback));
 158   DCHECK(posted);
 159   return ERR_IO_PENDING;
 160 }
 161
 162 uint64 UploadFileElementReader::GetContentLength() const {
 163   if (overriding_content_length)
 164     return overriding_content_length;
 165   return content_length_;
 166 }
 167
 168 uint64 UploadFileElementReader::BytesRemaining() const {
 169   return bytes_remaining_;
 170 }
 171
 172 int UploadFileElementReader::Read(IOBuffer* buf,
 173                                   int buf_length,
 174                                   const CompletionCallback& callback) {
 175   DCHECK(!callback.is_null());
 176
 177   if (BytesRemaining() == 0)
 178     return 0;
 179
 180   // Save the value of file_stream_.get() before base::Passed() invalidates it.
 181   FileStream* file_stream_ptr = file_stream_.get();
 182   // Pass the ownership of file_stream_ to the worker pool to safely perform
 183   // operation even when |this| is destructed before the read completes.
 184   const bool posted = base::PostTaskAndReplyWithResult(
 185       task_runner_.get(),
 186       FROM_HERE,
 187       base::Bind(&ReadInternal,
 188                  scoped_refptr<IOBuffer>(buf),
 189                  buf_length,
 190                  BytesRemaining(),
 191                  file_stream_ptr),
 192       base::Bind(&UploadFileElementReader::OnReadCompleted,
 193                  weak_ptr_factory_.GetWeakPtr(),
 194                  base::Passed(&file_stream_),
 195                  callback));
 196   DCHECK(posted);
 197   return ERR_IO_PENDING;
 198 }
 199
 200 void UploadFileElementReader::Reset() {
 201   weak_ptr_factory_.InvalidateWeakPtrs();
 202   bytes_remaining_ = 0;
 203   content_length_ = 0;
 204   file_stream_.reset();
 205 }
 206
 207 void UploadFileElementReader::OnInitCompleted(
 208     ScopedFileStreamPtr* file_stream,
 209     uint64* content_length,
 210     const CompletionCallback& callback,
 211     int result) {
 212   file_stream_.swap(*file_stream);
 213   content_length_ = *content_length;
 214   bytes_remaining_ = GetContentLength();
 215   if (!callback.is_null())
 216     callback.Run(result);
 217 }
 218
 219 void UploadFileElementReader::OnReadCompleted(
 220     ScopedFileStreamPtr file_stream,
 221     const CompletionCallback& callback,
 222     int result) {
 223   file_stream_.swap(file_stream);
 224   if (result > 0) {
 225     DCHECK_GE(bytes_remaining_, static_cast<uint64>(result));
 226     bytes_remaining_ -= result;
 227   }
 228   if (!callback.is_null())
 229     callback.Run(result);
 230 }
 231
 232 UploadFileElementReader::ScopedOverridingContentLengthForTests::
 233 ScopedOverridingContentLengthForTests(uint64 value) {
 234   overriding_content_length = value;
 235 }
 236
 237 UploadFileElementReader::ScopedOverridingContentLengthForTests::
 238 ~ScopedOverridingContentLengthForTests() {
 239   overriding_content_length = 0;
 240 }
 241
 242 UploadFileElementReaderSync::UploadFileElementReaderSync(
 243     const base::FilePath& path,
 244     uint64 range_offset,
 245     uint64 range_length,
 246     const base::Time& expected_modification_time)
 247     : path_(path),
 248       range_offset_(range_offset),
 249       range_length_(range_length),
 250       expected_modification_time_(expected_modification_time),
 251       content_length_(0),
 252       bytes_remaining_(0) {
 253 }
 254
 255 UploadFileElementReaderSync::~UploadFileElementReaderSync() {
 256 }
 257
 258 int UploadFileElementReaderSync::Init(const CompletionCallback& callback) {
 259   bytes_remaining_ = 0;
 260   content_length_ = 0;
 261   file_stream_.reset();
 262
 263   const int result = InitInternal(path_, range_offset_, range_length_,
 264                                   expected_modification_time_,
 265                                   &file_stream_, &content_length_);
 266   bytes_remaining_ = GetContentLength();
 267   return result;
 268 }
 269
 270 uint64 UploadFileElementReaderSync::GetContentLength() const {
 271   return content_length_;
 272 }
 273
 274 uint64 UploadFileElementReaderSync::BytesRemaining() const {
 275   return bytes_remaining_;
 276 }
 277
 278 int UploadFileElementReaderSync::Read(IOBuffer* buf,
 279                                       int buf_length,
 280                                       const CompletionCallback& callback) {
 281   const int result = ReadInternal(buf, buf_length, BytesRemaining(),
 282                                   file_stream_.get());
 283   if (result > 0) {
 284     DCHECK_GE(bytes_remaining_, static_cast<uint64>(result));
 285     bytes_remaining_ -= result;
 286   }
 287   return result;
 288 }
 289
 290 }  // namespace net