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_ 107