Don't create parallel request if download is about to complete

content/browser/download/parallel_download_utils.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_utils.h"
 
 #include "base/metrics/field_trial_params.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
 #include "content/public/browser/download_save_info.h"
@@ skipping 15 matching lines @@
 const char kParallelRequestCountFinchKey[] = "request_count";
 
 // Default value for |kParallelRequestCountFinchKey|, when no parameter is
 // specified.
 const int kParallelRequestCount = 2;
 
 // Finch parameter key value for the delay time in milliseconds to send
 // parallel requests after response of the original request is handled.
 const char kParallelRequestDelayFinchKey[] = "parallel_request_delay";
 
+// Finch parameter key value for the remaining time in seconds that is required
+// to send parallel requests.
+const char kParallelRequestRemainingTimeFinchKey[] =
+    "parallel_request_remaining_time";
+
+// The default remaining download time in seconds required for parallel request
+// creation.
+const int kDefaultRemainingTimeInSeconds = 10;
+
 // TODO(qinmin): replace this with a comparator operator in
 // DownloadItem::ReceivedSlice.
 bool compareReceivedSlices(const DownloadItem::ReceivedSlice& lhs,
                            const DownloadItem::ReceivedSlice& rhs) {
   return lhs.offset < rhs.offset;
 }
 
 }  // namespace
 
 std::vector<DownloadItem::ReceivedSlice> FindSlicesForRemainingContent(
@@ skipping 88 matching lines @@
 
 base::TimeDelta GetParallelRequestDelayConfig() {
   std::string finch_value = base::GetFieldTrialParamValueByFeature(
       features::kParallelDownloading, kParallelRequestDelayFinchKey);
   int64_t time_ms = 0;
   return base::StringToInt64(finch_value, &time_ms)
              ? base::TimeDelta::FromMilliseconds(time_ms)
              : base::TimeDelta::FromMilliseconds(0);
 }
 
+base::TimeDelta GetParallelRequestRemainingTimeConfig() {
+  std::string finch_value = base::GetFieldTrialParamValueByFeature(
+      features::kParallelDownloading, kParallelRequestRemainingTimeFinchKey);
+  int time_in_seconds = 0;
+  return base::StringToInt(finch_value, &time_in_seconds)
+             ? base::TimeDelta::FromSeconds(time_in_seconds)
+             : base::TimeDelta::FromSeconds(kDefaultRemainingTimeInSeconds);
+}
+
 void DebugSlicesInfo(const DownloadItem::ReceivedSlices& slices) {
   DVLOG(1) << "Received slices size : " << slices.size();
   for (const auto& it : slices) {
     DVLOG(1) << "Slice offset = " << it.offset
              << " , received_bytes = " << it.received_bytes;
   }
 }
 
 }  // namespace content