Configuration for download service.

components/download/internal/config.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 "components/download/internal/config.h"
+
+#include <string>
+
+#include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial_params.h"
+#include "base/strings/string_number_conversions.h"
+#include "components/download/public/features.h"
+
+namespace download {
+
+namespace {
+
+// Default value for max concurrent downloads configuration.
+const int kDefaultMaxConcurrentDownloads = 4;
+
+// Default value for maximum running downloads of the download service.
+const int kDefaultMaxRunningDownloads = 1;
+
+// Default value for maximum scheduled downloads.
+const int kDefaultMaxScheduledDownloads = 15;
+
+// Default value for maximum retry count.
+const int kDefaultMaxRetryCount = 5;
+
+// Default value for file keep alive time in minutes, keep the file alive for
+// 12 hours by default.
+const int kDefaultFileKeepAliveTimeMinutes = 12 * 60;
+
+// Helper routine to get Finch experiment parameter. If no Finch seed was found,
+// use the |default_value|. The |name| should match an experiment
+// parameter in Finch server configuration.
+int GetFinchConfigInt(const std::string& name, int default_value) {
+  std::string finch_value =
+      base::GetFieldTrialParamValueByFeature(kDownloadServiceFeature, name);
+  int result;
+  return base::StringToInt(finch_value, &result) ? result : default_value;
+}
+
+}  // namespace
+
+// static
+std::unique_ptr<Configuration> Configuration::CreateFromFinch() {
+  std::unique_ptr<Configuration> config(new Configuration());
+  config->max_concurrent_downloads = GetFinchConfigInt(
+      kMaxConcurrentDownloadsConfig, kDefaultMaxConcurrentDownloads);
+  config->max_running_downloads = GetFinchConfigInt(
+      kMaxRunningDownloadsConfig, kDefaultMaxRunningDownloads);
+  config->max_scheduled_downloads = GetFinchConfigInt(
+      kMaxScheduledDownloadsConfig, kDefaultMaxScheduledDownloads);
+  config->max_retry_count =
+      GetFinchConfigInt(kMaxRetryCountConfig, kDefaultMaxRetryCount);
+  config->file_keep_alive_time = base::TimeDelta::FromMinutes(GetFinchConfigInt(
+      kFileKeepAliveTimeMinutesConfig, kDefaultFileKeepAliveTimeMinutes));
+  return config;
+}
+
+Configuration::Configuration()
+    : max_concurrent_downloads(kDefaultMaxConcurrentDownloads),
+      max_running_downloads(kDefaultMaxRunningDownloads),
+      max_scheduled_downloads(kDefaultMaxScheduledDownloads),
+      max_retry_count(kDefaultMaxRetryCount),
+      file_keep_alive_time(
+          base::TimeDelta::FromMinutes(kDefaultFileKeepAliveTimeMinutes)) {}
+
+}  // namespace download