net/base/upload_disk_cache_entry_element_reader.cc

   1 // Copyright 2015 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_disk_cache_entry_element_reader.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/logging.h"
  11 #include "net/base/io_buffer.h"
  12 #include "net/base/net_errors.h"
  13 #include "net/disk_cache/disk_cache.h"
  14
  15 namespace net {
  16
  17 UploadDiskCacheEntryElementReader::UploadDiskCacheEntryElementReader(
  18     disk_cache::Entry* disk_cache_entry,
  19     int disk_cache_stream_index,
  20     int range_offset,
  21     int range_length)
  22     : disk_cache_entry_(disk_cache_entry),
  23       disk_cache_stream_index_(disk_cache_stream_index),
  24       range_begin_offset_(range_offset),
  25       range_end_offset_(range_offset + range_length),
  26       current_read_offset_(range_offset),
  27       weak_factory_(this) {
  28   DCHECK_LE(0, range_offset);
  29   DCHECK_LT(0, range_length);
  30   DCHECK_LE(range_offset + range_length,
  31             disk_cache_entry_->GetDataSize(disk_cache_stream_index_));
  32 }
  33
  34 UploadDiskCacheEntryElementReader::~UploadDiskCacheEntryElementReader() {
  35 }
  36
  37 const UploadDiskCacheEntryElementReader*
  38 UploadDiskCacheEntryElementReader::AsDiskCacheEntryReaderForTests() const {
  39   return this;
  40 }
  41
  42 int UploadDiskCacheEntryElementReader::Init(
  43     const CompletionCallback& callback) {
  44   weak_factory_.InvalidateWeakPtrs();
  45   current_read_offset_ = range_begin_offset_;
  46   return OK;
  47 }
  48
  49 uint64_t UploadDiskCacheEntryElementReader::GetContentLength() const {
  50   return range_end_offset_ - range_begin_offset_;
  51 }
  52
  53 uint64_t UploadDiskCacheEntryElementReader::BytesRemaining() const {
  54   return range_end_offset_ - current_read_offset_;
  55 }
  56
  57 bool UploadDiskCacheEntryElementReader::IsInMemory() const {
  58   return false;
  59 }
  60
  61 int UploadDiskCacheEntryElementReader::Read(
  62     IOBuffer* buf,
  63     int buf_length,
  64     const CompletionCallback& callback) {
  65   DCHECK(!callback.is_null());
  66   int bytes_to_read = std::min(buf_length, static_cast<int>(BytesRemaining()));
  67
  68   CompletionCallback new_callback =
  69       base::Bind(&UploadDiskCacheEntryElementReader::OnReadCompleted,
  70                  weak_factory_.GetWeakPtr(), callback);
  71
  72   int result = disk_cache_entry_->ReadData(disk_cache_stream_index_,
  73                                            current_read_offset_, buf,
  74                                            bytes_to_read, new_callback);
  75   if (result == ERR_IO_PENDING)
  76     return ERR_IO_PENDING;
  77   if (result > 0)
  78     current_read_offset_ += result;
  79   return result;
  80 }
  81
  82 void UploadDiskCacheEntryElementReader::OnReadCompleted(
  83     const CompletionCallback& callback,
  84     int result) {
  85   if (result > 0)
  86     current_read_offset_ += result;
  87   callback.Run(result);
  88 }
  89
  90 }  // namespace net