chrome/browser/chromeos/external_metrics.h

   1 // Copyright (c) 2010 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 CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_
   6 #define CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_
   7
   8 #include <string>
   9
  10 #include "base/compiler_specific.h"
  11 #include "base/containers/hash_tables.h"
  12 #include "base/gtest_prod_util.h"
  13 #include "base/memory/ref_counted.h"
  14
  15 namespace metrics {
  16 class MetricSample;
  17 }  // namespace metrics
  18
  19 namespace chromeos {
  20
  21 // ExternalMetrics is a service that Chrome offers to Chrome OS to upload
  22 // metrics to the UMA server on its behalf.  Chrome periodically reads the
  23 // content of a well-know file, and parses it into name-value pairs, each
  24 // representing a Chrome OS metrics event. The events are logged using the
  25 // normal UMA mechanism. The file is then truncated to zero size. Chrome uses
  26 // flock() to synchronize accesses to the file.
  27 class ExternalMetrics : public base::RefCountedThreadSafe<ExternalMetrics> {
  28  public:
  29   ExternalMetrics();
  30
  31   // Begins the external data collection.  This service is started and stopped
  32   // by the chrome metrics service.  Calls to RecordAction originate in the
  33   // File thread but are executed in the UI thread.
  34   void Start();
  35
  36   // Creates an ExternalMetrics instance reading from |filename| for testing
  37   // purpose.
  38   static scoped_refptr<ExternalMetrics> CreateForTesting(
  39       const std::string& filename);
  40
  41  private:
  42   friend class base::RefCountedThreadSafe<ExternalMetrics>;
  43   friend class ExternalMetricsTest;
  44
  45   FRIEND_TEST_ALL_PREFIXES(ExternalMetricsTest, CanReceiveHistogram);
  46   FRIEND_TEST_ALL_PREFIXES(ExternalMetricsTest, HandleMissingFile);
  47   FRIEND_TEST_ALL_PREFIXES(ExternalMetricsTest,
  48                            IncorrectHistogramsAreDiscarded);
  49
  50   // The max length of a message (name-value pair, plus header)
  51   static const int kMetricsMessageMaxLength = 1024;  // be generous
  52
  53   ~ExternalMetrics();
  54
  55   // Passes an action event to the UMA service on the UI thread.
  56   void RecordActionUI(std::string action_string);
  57
  58   // Passes an action event to the UMA service.
  59   void RecordAction(const std::string& action_name);
  60
  61   // Records an external crash of the given string description to
  62   // UMA service on the UI thread.
  63   void RecordCrashUI(const std::string& crash_kind);
  64
  65   // Records an external crash of the given string description.
  66   void RecordCrash(const std::string& crash_kind);
  67
  68   // Records an histogram. |sample| is expected to be an histogram.
  69   void RecordHistogram(const metrics::MetricSample& sample);
  70
  71   // Records a sparse histogram. |sample| is expected to be a sparse histogram.
  72   void RecordSparseHistogram(const metrics::MetricSample& sample);
  73
  74   // Records a linear histogram. |sample| is expected to be a linear histogram.
  75   void RecordLinearHistogram(const metrics::MetricSample& sample);
  76
  77   // Collects external events from metrics log file.  This is run at periodic
  78   // intervals.
  79   //
  80   // Returns the number of events collected.
  81   int CollectEvents();
  82
  83   // Calls CollectEvents and reschedules a future collection.
  84   void CollectEventsAndReschedule();
  85
  86   // Schedules a metrics event collection in the future.
  87   void ScheduleCollector();
  88
  89   // Calls setup methods for Chrome OS field trials that need to be initialized
  90   // based on data from the file system.  They are setup here so that we can
  91   // make absolutely sure that they are setup before we gather UMA statistics
  92   // from ChromeOS.
  93   void SetupFieldTrialsOnFileThread();
  94
  95   // Set containing known user actions.
  96   base::hash_set<std::string> valid_user_actions_;
  97
  98   // File used by libmetrics to send metrics to Chrome.
  99   std::string uma_events_file_;
 100
 101   DISALLOW_COPY_AND_ASSIGN(ExternalMetrics);
 102 };
 103
 104 }  // namespace chromeos
 105
 106 #endif  // CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_