Glue parallel download job and download file together.

content/browser/download/download_file_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/download/download_file_impl.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 24 matching lines @@
 const int kMaxTimeBlockingFileThreadMs = 1000;
 
 // These constants control the default retry behavior for failing renames. Each
 // retry is performed after a delay that is twice the previous delay. The
 // initial delay is specified by kInitialRenameRetryDelayMs.
 const int kInitialRenameRetryDelayMs = 200;
 
 // Number of times a failing rename is retried before giving up.
 const int kMaxRenameRetries = 3;
 
-DownloadFileImpl::SourceStream::SourceStream(int64_t offset, int64_t length)
+DownloadFileImpl::SourceStream::SourceStream(
+    int64_t offset,
+    int64_t length,
+    std::unique_ptr<ByteStreamReader> stream_reader)
     : offset_(offset),
       length_(length),
       bytes_written_(0),
       finished_(false),
-      index_(0u) {}
+      index_(0u),
+      stream_reader_(std::move(stream_reader)) {}
 
 DownloadFileImpl::SourceStream::~SourceStream() = default;
 
-void DownloadFileImpl::SourceStream::SetByteStream(
-    std::unique_ptr<ByteStreamReader> stream_reader) {
-  stream_reader_ = std::move(stream_reader);
-}
-
 void DownloadFileImpl::SourceStream::OnWriteBytesToDisk(int64_t bytes_write) {
   bytes_written_ += bytes_write;
 }
 
 DownloadFileImpl::DownloadFileImpl(
     std::unique_ptr<DownloadSaveInfo> save_info,
     const base::FilePath& default_download_directory,
     std::unique_ptr<ByteStreamReader> stream_reader,
     const std::vector<DownloadItem::ReceivedSlice>& received_slices,
     const net::NetLogWithSource& download_item_net_log,
     bool is_sparse_file,
     base::WeakPtr<DownloadDestinationObserver> observer)
     : net_log_(
           net::NetLogWithSource::Make(download_item_net_log.net_log(),
                                       net::NetLogSourceType::DOWNLOAD_FILE)),
       file_(net_log_),
       save_info_(std::move(save_info)),
       default_download_directory_(default_download_directory),
       is_sparse_file_(is_sparse_file),
       bytes_seen_(0),
       received_slices_(received_slices),
       observer_(observer),
       weak_factory_(this) {
   source_streams_[save_info_->offset] = base::MakeUnique<SourceStream>(
-      save_info_->offset, DownloadSaveInfo::kLengthFullContent);
-  DCHECK(source_streams_.size() == static_cast<size_t>(1));
-  source_streams_[save_info_->offset]->SetByteStream(std::move(stream_reader));
+      save_info_->offset, save_info_->length, std::move(stream_reader));
 
   download_item_net_log.AddEvent(
       net::NetLogEventType::DOWNLOAD_FILE_CREATED,
       net_log_.source().ToEventParametersCallback());
   net_log_.BeginEvent(
       net::NetLogEventType::DOWNLOAD_FILE_ACTIVE,
       download_item_net_log.source().ToEventParametersCallback());
 }
 
 DownloadFileImpl::~DownloadFileImpl() {
@@ skipping 22 matching lines @@
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE, base::Bind(callback, result));
     return;
   }
 
   download_start_ = base::TimeTicks::Now();
 
   // Primarily to make reset to zero in restart visible to owner.
   SendUpdate();
 
-  // Initial pull from the straw.
-  for (auto& source_stream : source_streams_)
-    RegisterAndActivateStream(source_stream.second.get());
-
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE, base::Bind(
           callback, DOWNLOAD_INTERRUPT_REASON_NONE));
+
+  // Initial pull from the straw from all source streams.
+  for (auto& source_stream : source_streams_)
+    RegisterAndActivateStream(source_stream.second.get());
 }
 
 void DownloadFileImpl::AddByteStream(
     std::unique_ptr<ByteStreamReader> stream_reader,
-    int64_t offset) {
+    int64_t offset,
+    int64_t length) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 
-  // The |source_streams_| must have an existing entry for the stream reader.
-  auto current_source_stream = source_streams_.find(offset);
-  DCHECK(current_source_stream != source_streams_.end());
-  SourceStream* stream = current_source_stream->second.get();
-  stream->SetByteStream(std::move(stream_reader));
+  source_streams_[offset] =
+      base::MakeUnique<SourceStream>(offset, length, std::move(stream_reader));
 
-  RegisterAndActivateStream(stream);
+  // If the file is initialized, start to write data, or wait until file opened.
+  if (file_.in_progress())
+    RegisterAndActivateStream(source_streams_[offset].get());
 }
 
 DownloadInterruptReason DownloadFileImpl::WriteDataToFile(int64_t offset,
                                                           const char* data,
                                                           size_t data_len) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   WillWriteToDisk(data_len);
   return file_.WriteDataToFile(offset, data, data_len);
 }
 
 bool DownloadFileImpl::CalculateBytesToWrite(SourceStream* source_stream,
                                              size_t bytes_available_to_write,
                                              size_t* bytes_to_write) {
   // If a new slice finds that its target position has already been written,
   // terminate the stream.
   if (source_stream->bytes_written() == 0) {
     for (const auto& received_slice : received_slices_) {
       if (received_slice.offset <= source_stream->offset() &&
           received_slice.offset + received_slice.received_bytes >
               source_stream->offset()) {
         *bytes_to_write = 0;
         return true;
       }
     }
   }
 
   if (source_stream->length() != DownloadSaveInfo::kLengthFullContent &&
       source_stream->bytes_written() +
-              static_cast<int64_t>(bytes_available_to_write) >=
+              static_cast<int64_t>(bytes_available_to_write) >
           source_stream->length()) {
     // Write a partial buffer as the incoming data exceeds the length limit.
     *bytes_to_write = source_stream->length() - source_stream->bytes_written();
     return true;
   }
 
   *bytes_to_write = bytes_available_to_write;
   return false;
 }
 
@@ skipping 356 matching lines @@
     const base::FilePath& new_path,
     const RenameCompletionCallback& completion_callback)
     : option(option),
       new_path(new_path),
       retries_left(kMaxRenameRetries),
       completion_callback(completion_callback) {}
 
 DownloadFileImpl::RenameParameters::~RenameParameters() {}
 
 }  // namespace content