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/files/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 }  // namespace
  24
  25 UploadFileElementReader::UploadFileElementReader(
  26     base::TaskRunner* task_runner,
  27     const base::FilePath& path,
  28     uint64 range_offset,
  29     uint64 range_length,
  30     const base::Time& expected_modification_time)
  31     : task_runner_(task_runner),
  32       path_(path),
  33       range_offset_(range_offset),
  34       range_length_(range_length),
  35       expected_modification_time_(expected_modification_time),
  36       content_length_(0),
  37       bytes_remaining_(0),
  38       weak_ptr_factory_(this) {
  39   DCHECK(task_runner_.get());
  40 }
  41
  42 UploadFileElementReader::~UploadFileElementReader() {
  43 }
  44
  45 const UploadFileElementReader* UploadFileElementReader::AsFileReader() const {
  46   return this;
  47 }
  48
  49 int UploadFileElementReader::Init(const CompletionCallback& callback) {
  50   DCHECK(!callback.is_null());
  51   Reset();
  52
  53   file_stream_.reset(new FileStream(task_runner_.get()));
  54   int result = file_stream_->Open(
  55       path_,
  56       base::File::FLAG_OPEN | base::File::FLAG_READ |
  57       base::File::FLAG_ASYNC,
  58       base::Bind(&UploadFileElementReader::OnOpenCompleted,
  59                  weak_ptr_factory_.GetWeakPtr(),
  60                  callback));
  61   DCHECK_GT(0, result);
  62   return result;
  63 }
  64
  65 uint64 UploadFileElementReader::GetContentLength() const {
  66   if (overriding_content_length)
  67     return overriding_content_length;
  68   return content_length_;
  69 }
  70
  71 uint64 UploadFileElementReader::BytesRemaining() const {
  72   return bytes_remaining_;
  73 }
  74
  75 int UploadFileElementReader::Read(IOBuffer* buf,
  76                                   int buf_length,
  77                                   const CompletionCallback& callback) {
  78   DCHECK(!callback.is_null());
  79
  80   int num_bytes_to_read = static_cast<int>(
  81       std::min(BytesRemaining(), static_cast<uint64>(buf_length)));
  82   if (num_bytes_to_read == 0)
  83     return 0;
  84
  85   int result = file_stream_->Read(
  86       buf, num_bytes_to_read,
  87       base::Bind(base::IgnoreResult(&UploadFileElementReader::OnReadCompleted),
  88                  weak_ptr_factory_.GetWeakPtr(),
  89                  callback));
  90   // Even in async mode, FileStream::Read() may return the result synchronously.
  91   if (result != ERR_IO_PENDING)
  92     return OnReadCompleted(CompletionCallback(), result);
  93   return ERR_IO_PENDING;
  94 }
  95
  96 void UploadFileElementReader::Reset() {
  97   weak_ptr_factory_.InvalidateWeakPtrs();
  98   bytes_remaining_ = 0;
  99   content_length_ = 0;
 100   file_stream_.reset();
 101 }
 102
 103 void UploadFileElementReader::OnOpenCompleted(
 104     const CompletionCallback& callback,
 105     int result) {
 106   DCHECK(!callback.is_null());
 107
 108   if (result < 0) {
 109     DLOG(WARNING) << "Failed to open \"" << path_.value()
 110                   << "\" for reading: " << result;
 111     callback.Run(result);
 112     return;
 113   }
 114
 115   if (range_offset_) {
 116     int seek_result = file_stream_->Seek(
 117         base::File::FROM_BEGIN, range_offset_,
 118         base::Bind(&UploadFileElementReader::OnSeekCompleted,
 119                    weak_ptr_factory_.GetWeakPtr(), callback));
 120     DCHECK_GT(0, seek_result);
 121     if (seek_result != ERR_IO_PENDING)
 122       callback.Run(seek_result);
 123   } else {
 124     OnSeekCompleted(callback, OK);
 125   }
 126 }
 127
 128 void UploadFileElementReader::OnSeekCompleted(
 129     const CompletionCallback& callback,
 130     int64 result) {
 131   DCHECK(!callback.is_null());
 132
 133   if (result < 0) {
 134     DLOG(WARNING) << "Failed to seek \"" << path_.value()
 135                   << "\" to offset: " << range_offset_ << " (" << result << ")";
 136     callback.Run(static_cast<int>(result));
 137     return;
 138   }
 139
 140   base::File::Info* file_info = new base::File::Info;
 141   bool posted = base::PostTaskAndReplyWithResult(
 142       task_runner_.get(),
 143       FROM_HERE,
 144       base::Bind(&base::GetFileInfo, path_, file_info),
 145       base::Bind(&UploadFileElementReader::OnGetFileInfoCompleted,
 146                  weak_ptr_factory_.GetWeakPtr(),
 147                  callback,
 148                  base::Owned(file_info)));
 149   DCHECK(posted);
 150 }
 151
 152 void UploadFileElementReader::OnGetFileInfoCompleted(
 153     const CompletionCallback& callback,
 154     base::File::Info* file_info,
 155     bool result) {
 156   DCHECK(!callback.is_null());
 157   if (!result) {
 158     DLOG(WARNING) << "Failed to get file info of \"" << path_.value() << "\"";
 159     callback.Run(ERR_FILE_NOT_FOUND);
 160     return;
 161   }
 162
 163   int64 length = file_info->size;
 164   if (range_offset_ < static_cast<uint64>(length)) {
 165     // Compensate for the offset.
 166     length = std::min(length - range_offset_, range_length_);
 167   }
 168
 169   // If the underlying file has been changed and the expected file modification
 170   // time is set, treat it as error. Note that |expected_modification_time_| may
 171   // have gone through multiple conversion steps involving loss of precision
 172   // (including conversion to time_t). Therefore the check below only verifies
 173   // that the timestamps are within one second of each other. This check is used
 174   // for sliced files.
 175   if (!expected_modification_time_.is_null() &&
 176       (expected_modification_time_ - file_info->last_modified)
 177               .magnitude()
 178               .InSeconds() != 0) {
 179     callback.Run(ERR_UPLOAD_FILE_CHANGED);
 180     return;
 181   }
 182
 183   content_length_ = length;
 184   bytes_remaining_ = GetContentLength();
 185   callback.Run(OK);
 186 }
 187
 188 int UploadFileElementReader::OnReadCompleted(
 189     const CompletionCallback& callback,
 190     int result) {
 191   if (result == 0)  // Reached end-of-file earlier than expected.
 192     result = ERR_UPLOAD_FILE_CHANGED;
 193
 194   if (result > 0) {
 195     DCHECK_GE(bytes_remaining_, static_cast<uint64>(result));
 196     bytes_remaining_ -= result;
 197   }
 198
 199   if (!callback.is_null())
 200     callback.Run(result);
 201   return result;
 202 }
 203
 204 UploadFileElementReader::ScopedOverridingContentLengthForTests::
 205 ScopedOverridingContentLengthForTests(uint64 value) {
 206   overriding_content_length = value;
 207 }
 208
 209 UploadFileElementReader::ScopedOverridingContentLengthForTests::
 210 ~ScopedOverridingContentLengthForTests() {
 211   overriding_content_length = 0;
 212 }
 213
 214 }  // namespace net