components/metrics/metrics_log_manager.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_METRICS_METRICS_LOG_MANAGER_H_
   6 #define COMPONENTS_METRICS_METRICS_LOG_MANAGER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "components/metrics/metrics_log.h"
  14 #include "components/metrics/persisted_logs.h"
  15
  16 namespace metrics {
  17
  18 // Manages all the log objects used by a MetricsService implementation. Keeps
  19 // track of both an in progress log and a log that is staged for uploading as
  20 // text, as well as saving logs to, and loading logs from, persistent storage.
  21 class MetricsLogManager {
  22  public:
  23   // The metrics log manager will persist it's unsent logs by storing them in
  24   // |local_state|, and will not persist ongoing logs over
  25   // |max_ongoing_log_size|.
  26   MetricsLogManager(PrefService* local_state, size_t max_ongoing_log_size);
  27   ~MetricsLogManager();
  28
  29   // Makes |log| the current_log. This should only be called if there is not a
  30   // current log.
  31   void BeginLoggingWithLog(scoped_ptr<MetricsLog> log);
  32
  33   // Returns the in-progress log.
  34   MetricsLog* current_log() { return current_log_.get(); }
  35
  36   // Closes current_log(), compresses it, and stores the compressed log for
  37   // later, leaving current_log() NULL.
  38   void FinishCurrentLog();
  39
  40   // Returns true if there are any logs waiting to be uploaded.
  41   bool has_unsent_logs() const {
  42     return initial_log_queue_.size() || ongoing_log_queue_.size();
  43   }
  44
  45   // Populates staged_log_text() with the next stored log to send.
  46   // Should only be called if has_unsent_logs() is true.
  47   void StageNextLogForUpload();
  48
  49   // Returns true if there is a log that needs to be, or is being, uploaded.
  50   bool has_staged_log() const {
  51     return initial_log_queue_.has_staged_log() ||
  52         ongoing_log_queue_.has_staged_log();
  53   }
  54
  55   // The text of the staged log, as a serialized protobuf.
  56   // Will trigger a DCHECK if there is no staged log.
  57   const std::string& staged_log() const {
  58     return initial_log_queue_.has_staged_log() ?
  59         initial_log_queue_.staged_log() : ongoing_log_queue_.staged_log();
  60   }
  61
  62   // The SHA1 hash of the staged log.
  63   // Will trigger a DCHECK if there is no staged log.
  64   const std::string& staged_log_hash() const {
  65     return initial_log_queue_.has_staged_log() ?
  66         initial_log_queue_.staged_log_hash() :
  67         ongoing_log_queue_.staged_log_hash();
  68   }
  69
  70   // Discards the staged log.
  71   void DiscardStagedLog();
  72
  73   // Closes and discards |current_log|.
  74   void DiscardCurrentLog();
  75
  76   // Sets current_log to NULL, but saves the current log for future use with
  77   // ResumePausedLog(). Only one log may be paused at a time.
  78   // TODO(stuartmorgan): Pause/resume support is really a workaround for a
  79   // design issue in initial log writing; that should be fixed, and pause/resume
  80   // removed.
  81   void PauseCurrentLog();
  82
  83   // Restores the previously paused log (if any) to current_log().
  84   // This should only be called if there is not a current log.
  85   void ResumePausedLog();
  86
  87   // Saves any unsent logs to persistent storage.
  88   void PersistUnsentLogs();
  89
  90   // Loads any unsent logs from persistent storage.
  91   void LoadPersistedUnsentLogs();
  92
  93  private:
  94   // Saves |log_data| as the given type.
  95   void StoreLog(const std::string& log_data, MetricsLog::LogType log_type);
  96
  97   // Tracks whether unsent logs (if any) have been loaded from the serializer.
  98   bool unsent_logs_loaded_;
  99
 100   // The log that we are still appending to.
 101   scoped_ptr<MetricsLog> current_log_;
 102
 103   // A paused, previously-current log.
 104   scoped_ptr<MetricsLog> paused_log_;
 105
 106   // Logs that have not yet been sent.
 107   PersistedLogs initial_log_queue_;
 108   PersistedLogs ongoing_log_queue_;
 109
 110   DISALLOW_COPY_AND_ASSIGN(MetricsLogManager);
 111 };
 112
 113 }  // namespace metrics
 114
 115 #endif  // COMPONENTS_METRICS_METRICS_LOG_MANAGER_H_