Handle early pause, cancel for parallel requests.

content/browser/download/parallel_download_job.cc

 // Copyright 2017 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/parallel_download_job.h"
 
 #include "base/memory/ptr_util.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/parallel_download_utils.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/storage_partition.h"
 
 namespace content {
+namespace {
+
+const int kVerboseLevel = 1;
+
+}  // namespace
 
 ParallelDownloadJob::ParallelDownloadJob(
     DownloadItemImpl* download_item,
     std::unique_ptr<DownloadRequestHandleInterface> request_handle,
     const DownloadCreateInfo& create_info)
     : DownloadJobImpl(download_item, std::move(request_handle)),
       initial_request_offset_(create_info.offset),
       content_length_(create_info.total_bytes),
-      requests_sent_(false) {}
+      requests_sent_(false),
+      is_canceled_(false) {}
 
 ParallelDownloadJob::~ParallelDownloadJob() = default;
 
 void ParallelDownloadJob::Start() {
   DownloadJobImpl::Start();
 
   BuildParallelRequestAfterDelay();
 }
 
 void ParallelDownloadJob::Cancel(bool user_cancel) {
+  is_canceled_ = true;
   DownloadJobImpl::Cancel(user_cancel);
 
   if (!requests_sent_) {
     timer_.Stop();
     return;
   }
 
   for (auto& worker : workers_)
     worker.second->Cancel();
 }
@@ skipping 19 matching lines @@
   if (!requests_sent_) {
     if (!timer_.IsRunning())
       BuildParallelRequestAfterDelay();
     return;
   }
 
   for (auto& worker : workers_)
     worker.second->Resume();
 }
 
-
 int ParallelDownloadJob::GetParallelRequestCount() const {
   return GetParallelRequestCountConfig();
 }
 
 bool ParallelDownloadJob::UsesParallelRequests() const {
   return true;
 }
 
 void ParallelDownloadJob::BuildParallelRequestAfterDelay() {
   DCHECK(workers_.empty());
   DCHECK(!requests_sent_);
   DCHECK(!timer_.IsRunning());
 
   timer_.Start(FROM_HERE, GetParallelRequestDelayConfig(), this,
                &ParallelDownloadJob::BuildParallelRequests);
 }
 
 void ParallelDownloadJob::OnByteStreamReady(
     DownloadWorker* worker,
     std::unique_ptr<ByteStreamReader> stream_reader) {
-  DownloadJob::AddByteStream(std::move(stream_reader), worker->offset(),
-                             worker->length());
+  bool success = DownloadJob::AddByteStream(std::move(stream_reader),
+                                            worker->offset(), worker->length());
+
+  // Destroy the request if the sink is gone.
+  if (!success) {
+    VLOG(kVerboseLevel)
+        << "Byte stream arrived after download file is released.";
+    worker->Cancel();
+  }
 }
 
 void ParallelDownloadJob::OnServerResponseError(
     DownloadWorker* worker,
     DownloadInterruptReason reason) {
   // TODO(xingliu): Consider to let the original request to cover the full
   // content if the sub-requests get invalid response. Consider retry on certain
   // error.
   DownloadJob::Interrupt(reason);
 }
 
 void ParallelDownloadJob::BuildParallelRequests() {
   DCHECK(!requests_sent_);
+  DCHECK(!is_paused());
+  if (is_canceled_)
+    return;
+
   // TODO(qinmin): The size of |slices_to_download| should be no larger than
   // |kParallelRequestCount| unless |kParallelRequestCount| is changed after
   // a download is interrupted. This could happen if we use finch to config
   // the number of parallel requests.
   // Get the next |kParallelRequestCount - 1| slices and fork
   // new requests. For the remaining slices, they will be handled once some
   // of the workers finish their job.
   DownloadItem::ReceivedSlices slices_to_download;
   if (download_item_->GetReceivedSlices().empty()) {
     slices_to_download = FindSlicesForRemainingContent(
@@ skipping 57 matching lines @@
   // download request.
   download_params->set_referrer(Referrer(download_item_->GetReferrerUrl(),
                                          blink::WebReferrerPolicyAlways));
   // Send the request.
   worker->SendRequest(std::move(download_params));
   DCHECK(workers_.find(offset) == workers_.end());
   workers_[offset] = std::move(worker);
 }
 
 }  // namespace content