Merge MetricsLog and MetricsLogBase.

components/metrics/metrics_log_base.h

-// Copyright 2014 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 set of user experience metrics data recorded by
-// the MetricsService.  This is the unit of data that is sent to the server.
-
-#ifndef COMPONENTS_METRICS_METRICS_LOG_BASE_H_
-#define COMPONENTS_METRICS_METRICS_LOG_BASE_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/metrics/histogram.h"
-#include "base/time/time.h"
-#include "components/metrics/proto/chrome_user_metrics_extension.pb.h"
-
-namespace base {
-class HistogramSamples;
-}  // namespace base
-
-namespace metrics {
-
-// This class provides base functionality for logging metrics data.
-class MetricsLogBase {
- public:
-  enum LogType {
-    INITIAL_STABILITY_LOG,  // The initial log containing stability stats.
-    ONGOING_LOG,            // Subsequent logs in a session.
-  };
-
-  // Creates a new metrics log of the specified type.
-  // client_id is the identifier for this profile on this installation
-  // session_id is an integer that's incremented on each application launch
-  MetricsLogBase(const std::string& client_id,
-                 int session_id,
-                 LogType log_type,
-                 const std::string& version_string);
-  virtual ~MetricsLogBase();
-
-  // Computes the MD5 hash of the given string, and returns the first 8 bytes of
-  // the hash.
-  static uint64 Hash(const std::string& value);
-
-  // Get the GMT buildtime for the current binary, expressed in seconds since
-  // January 1, 1970 GMT.
-  // The value is used to identify when a new build is run, so that previous
-  // reliability stats, from other builds, can be abandoned.
-  static int64 GetBuildTime();
-
-  // Convenience function to return the current time at a resolution in seconds.
-  // This wraps base::TimeTicks, and hence provides an abstract time that is
-  // always incrementing for use in measuring time durations.
-  static int64 GetCurrentTime();
-
-  // Records a user-initiated action.
-  void RecordUserAction(const std::string& key);
-
-  // Record any changes in a given histogram for transmission.
-  void RecordHistogramDelta(const std::string& histogram_name,
-                            const base::HistogramSamples& snapshot);
-
-  // Stop writing to this record and generate the encoded representation.
-  // None of the Record* methods can be called after this is called.
-  void CloseLog();
-
-  // Fills |encoded_log| with the serialized protobuf representation of the
-  // record.  Must only be called after CloseLog() has been called.
-  void GetEncodedLog(std::string* encoded_log);
-
-  int num_events() const {
-    return uma_proto_.omnibox_event_size() +
-           uma_proto_.user_action_event_size();
-  }
-
-  LogType log_type() const { return log_type_; }
-
- protected:
-  bool locked() const { return locked_; }
-
-  metrics::ChromeUserMetricsExtension* uma_proto() { return &uma_proto_; }
-  const metrics::ChromeUserMetricsExtension* uma_proto() const {
-    return &uma_proto_;
-  }
-
- private:
-  // locked_ is true when record has been packed up for sending, and should
-  // no longer be written to.  It is only used for sanity checking and is
-  // not a real lock.
-  bool locked_;
-
-  // The type of the log, i.e. initial or ongoing.
-  const LogType log_type_;
-
-  // Stores the protocol buffer representation for this log.
-  metrics::ChromeUserMetricsExtension uma_proto_;
-
-  DISALLOW_COPY_AND_ASSIGN(MetricsLogBase);
-};
-
-}  // namespace metrics
-
-#endif  // COMPONENTS_METRICS_METRICS_LOG_BASE_H_