Move logic for uploading logs into a ReportingService object.

components/metrics/reporting_service.h

+// 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.
+
+// This file defines a service that sends metrics logs to a server.
+
+#ifndef COMPONENTS_METRICS_REPORTING_SERVICE_H_
+#define COMPONENTS_METRICS_REPORTING_SERVICE_H_
+
+#include <stdint.h>
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/time/time.h"
+#include "build/build_config.h"
+#include "components/metrics/data_use_tracker.h"
+#include "components/metrics/metrics_log_uploader.h"
+
+class PrefService;
+class PrefRegistrySimple;
+
+namespace metrics {
+
+class LogStore;
+class MetricsUploadScheduler;
+class MetricsServiceClient;
+
+// See metrics_service.cc for a detailed description.

[Alexei Svitkine (slow), 2017/02/28 18:03:45]

I think this should have its own description. Or at least a summary of what this
class is from.

[Steven Holte, 2017/03/01 02:02:33]

Done.

+class ReportingService {
+ public:
+  // Creates the MetricsService with the given |client|, |max_retransmit_size|
+  // and

[Alexei Svitkine (slow), 2017/02/28 18:03:45]

Nit: Wrapping is off.

[Steven Holte, 2017/03/01 02:02:33]

Done.

+  // |local_state|.  Does not take ownership of the paramaters; instead stores
+  // a weak pointer to each. Caller should ensure that the parameters are valid
+  // for the lifetime of this class.
+  ReportingService(MetricsServiceClient* client,
+                   PrefService* local_state,
+                   size_t max_retransmit_size);
+  virtual ~ReportingService();
+
+  // Complete any setup tasks that can't be done at construction time.
+  virtual void Initialize();
+
+  // Starts the metrics reporting system.
+  // Should be called when metrics enabled or new logs are created.
+  // When the service is already running, this is a safe no-op.
+  void Start();
+
+  // Shuts down the metrics system. Should be called at shutdown, or if metrics
+  // are turned off.
+  void Stop();
+
+  // Enable/disable transmission of accumulated logs and crash reports (dumps).
+  // Calling Start() automatically enables reporting, but sending is
+  // asyncronous so this can be called immediately after Start() to prevent
+  // any uploading.
+  void EnableReporting();
+  void DisableReporting();
+
+  // True iff reporting is currently enabled.
+  bool reporting_active() const;
+
+  // Updates data usage tracking prefs with the specified values.
+  void UpdateMetricsUsagePrefs(const std::string& service_name,
+                               int message_size,
+                               bool is_cellular);
+
+  // At startup, prefs needs to be called with a list of all the pref names and

[Alexei Svitkine (slow), 2017/02/28 18:03:45]

"prefs needs to be called" isn't very clear to me. Can you rephrase? i.e. "pref
names should be registered".

Is this call meant to be done only once - and not once per subclass? If so,
mention that.

[Steven Holte, 2017/03/01 02:02:33]

Rephrased (on MetricsService too) and mentioned here that it should only be
called once.

+  // types we'll be using.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
+ protected:
+  MetricsServiceClient* client() { return client_; };
+
+ private:
+  // Retrieves the log store backing this service.
+  virtual LogStore* log_store() = 0;
+
+  // Getters for MetricsLogUploader parameters.
+  virtual std::string upload_url() = 0;

[Alexei Svitkine (slow), 2017/02/28 18:03:45]

return by const string ref?

[Steven Holte, 2017/03/01 02:02:33]

I can return const strings, but not const string refs, since these both
construct the strings.  However, the strings should still only be constructed
once, due to RVO.

[Alexei Svitkine (slow), 2017/03/01 16:06:29]

I don't think returning const strings makes much sense. If it's being returned
by value, the const isn't really useful.

Also upload_url() runs non-trivial code (body of GetMetricsServerUrl()), so
please don't use hacker_style for it.

Whereas upload_mime_type() is returning a char[] constant. So maybe return it by
StringPiece? And change the params where its passed to also use StringPiece.

Also, can the functions be const? (rather than their return types)

[Steven Holte, 2017/03/04 01:35:51]

Done.

+  virtual std::string upload_mime_type() = 0;
+  virtual MetricsLogUploader::MetricServiceType service_type() = 0;
+
+  // Methods for recording data to histograms.
+  virtual void LogActualUploadInterval(base::TimeDelta interval){};

[Alexei Svitkine (slow), 2017/02/28 18:03:45]

Nit: Add space before {

Same for others.

[Steven Holte, 2017/03/01 02:02:33]

clang-format deletes these spaces

[Alexei Svitkine (slow), 2017/03/01 16:06:29]

Weird.

I noticed you have semicolons at the end - which are unecessary when you have a
body. Can you remove them? Also on line 74. Does clang format still remove the
spaces?

[Steven Holte, 2017/03/04 01:35:51]

Ah, yes it was the semicolons.  Fixed.

+  virtual void LogCellularConstraint(bool upload_canceled){};
+  virtual void LogResponseCode(int response_code){};
+  virtual void LogSuccess(size_t log_size){};
+  virtual void LogLargeRejection(size_t log_size){};
+
+  // If recording is enabled, begins uploading the next completed log from
+  // the log manager, staging it if necessary.
+  void SendNextLog();
+
+  // Uploads the currently staged log (which must be non-null).
+  void SendStagedLog();
+
+  // Called after transmission completes (either successfully or with failure).
+  void OnLogUploadComplete(int response_code);
+
+  // Used to interact with the embedder. Weak pointer; must outlive |this|
+  // instance.
+  MetricsServiceClient* const client_;
+
+  // Largest log size to attempt to retransmit.
+  size_t max_retransmit_size_;
+
+  // Indicate whether recording and reporting are currently happening.
+  // These should not be set directly, but by calling SetRecording and
+  // SetReporting.
+  bool reporting_active_;
+
+  // Instance of the helper class for uploading logs.
+  std::unique_ptr<MetricsLogUploader> log_uploader_;
+
+  // Whether there is a current log upload in progress.
+  bool log_upload_in_progress_;
+
+  // The scheduler for determining when uploads should happen.
+  std::unique_ptr<MetricsUploadScheduler> upload_scheduler_;
+
+  // Pointer used for obtaining data use pref updater callback on above layers.
+  std::unique_ptr<DataUseTracker> data_use_tracker_;
+
+  // The tick count of the last time log upload has been finished and null if no
+  // upload has been done yet.
+  base::TimeTicks last_upload_finish_time_;
+
+  base::ThreadChecker thread_checker_;
+
+  // Weak pointers factory used to post task on different threads. All weak
+  // pointers managed by this factory have the same lifetime as
+  // ReportingService.
+  base::WeakPtrFactory<ReportingService> self_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ReportingService);
+};
+
+}  // namespace metrics
+
+#endif  // COMPONENTS_METRICS_REPORTING_SERVICE_H_