Create Ukm ReportingService implementation.

components/ukm/ukm_reporting_service.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.
+
+// ReportingService specialized to report UKM metrics.
+
+#include "components/ukm/ukm_reporting_service.h"
+
+#include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial_params.h"
+#include "base/metrics/histogram_macros.h"
+#include "components/prefs/pref_registry_simple.h"
+#include "components/ukm/persisted_logs_metrics_impl.h"
+#include "components/ukm/ukm_pref_names.h"
+#include "components/ukm/ukm_service.h"
+
+namespace ukm {
+
+namespace {
+
+// The UKM server's URL.
+constexpr char kMimeType[] = "application/vnd.chrome.ukm";
+
+// The number of UKM logs that will be stored in PersistedLogs before logs
+// start being dropped.
+constexpr int kMinPersistedLogs = 8;
+
+// The number of bytes UKM logs that will be stored in PersistedLogs before
+// logs start being dropped.
+// This ensures that a reasonable amount of history will be stored even if there
+// is a long series of very small logs.
+constexpr int kMinPersistedBytes = 300000;
+
+// If an upload fails, and the transmission was over this byte count, then we
+// will discard the log, and not try to retransmit it.  We also don't persist
+// the log to the prefs for transmission during the next chrome session if this
+// limit is exceeded.
+constexpr size_t kMaxLogRetransmitSize = 100 * 1024;
+
+std::string GetServerUrl() {
+  constexpr char kDefaultServerUrl[] = "https://clients4.google.com/ukm";
+  std::string server_url =
+      base::GetFieldTrialParamValueByFeature(kUkmFeature, "ServerUrl");
+  if (!server_url.empty())
+    return server_url;
+  return kDefaultServerUrl;
+}
+
+}  // namespace
+
+// static
+void UkmReportingService::RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterListPref(prefs::kUkmPersistedLogs);
+  // Base class already registered by MetricsReportingService::RegisterPrefs
+  // ReportingService::RegisterPrefs(registry);
+}
+
+UkmReportingService::UkmReportingService(metrics::MetricsServiceClient* client,
+                                         PrefService* local_state)
+    : ReportingService(client, local_state, kMaxLogRetransmitSize),
+      persisted_logs_(base::MakeUnique<ukm::PersistedLogsMetricsImpl>(),
+                      local_state,
+                      prefs::kUkmPersistedLogs,
+                      kMinPersistedLogs,
+                      kMinPersistedBytes,
+                      kMaxLogRetransmitSize) {}
+
+UkmReportingService::~UkmReportingService() {}
+
+metrics::LogStore* UkmReportingService::log_store() {
+  return &persisted_logs_;
+}
+
+std::string UkmReportingService::GetUploadUrl() const {
+  return GetServerUrl();
+}
+
+base::StringPiece UkmReportingService::upload_mime_type() const {
+  return kMimeType;
+}
+
+metrics::MetricsLogUploader::MetricServiceType
+UkmReportingService::service_type() const {
+  return metrics::MetricsLogUploader::UKM;
+}
+
+void UkmReportingService::LogCellularConstraint(bool upload_canceled) {
+  UMA_HISTOGRAM_BOOLEAN("UKM.LogUpload.Canceled.CellularConstraint",
+                        upload_canceled);
+}
+
+void UkmReportingService::LogResponseCode(int response_code) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY("UKM.Upload.ResponseCode", response_code);
+}
+
+void UkmReportingService::LogSuccess(size_t log_size) {
+  UMA_HISTOGRAM_COUNTS_10000("UKM.LogSize.OnSuccess", log_size / 1024);
+}
+
+void UkmReportingService::LogLargeRejection(size_t log_size) {}
+
+}  // namespace metrics