1 // Copyright 2014 The Chromium Authors 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_SERIALIZATION_METRIC_SAMPLE_H_ 6 #define COMPONENTS_METRICS_SERIALIZATION_METRIC_SAMPLE_H_ 7 8 #include <memory> 9 #include <string> 10 11 namespace metrics { 12 13 // This class is used by libmetrics (ChromeOS) to serialize 14 // and deserialize measurements to send them to a metrics sending service. 15 // It is meant to be a simple container with serialization functions. 16 class MetricSample { 17 public: 18 // Types of metric sample used. 19 enum SampleType { 20 CRASH, 21 HISTOGRAM, 22 LINEAR_HISTOGRAM, 23 SPARSE_HISTOGRAM, 24 USER_ACTION 25 }; 26 27 // Use one of the static methods in this class instead of calling the 28 // constructor directly. 29 // 30 // The constructor is exposed for std::make_unique. 31 MetricSample(SampleType sample_type, 32 const std::string& metric_name, 33 const int sample, 34 const int min, 35 const int max, 36 const int bucket_count); 37 38 MetricSample(const MetricSample&) = delete; 39 MetricSample& operator=(const MetricSample&) = delete; 40 41 ~MetricSample(); 42 43 // Returns true if the sample is valid (can be serialized without ambiguity). 44 // 45 // This function should be used to filter bad samples before serializing them. 46 bool IsValid() const; 47 48 // Getters for type and name. All types of metrics have these so we do not 49 // need to check the type. type()50 SampleType type() const { return type_; } name()51 const std::string& name() const { return name_; } 52 53 // Getters for sample, min, max, bucket_count. 54 // Check the metric type to make sure the request make sense. (ex: a crash 55 // sample does not have a bucket_count so we crash if we call bucket_count() 56 // on it.) 57 int sample() const; 58 int min() const; 59 int max() const; 60 int bucket_count() const; 61 62 // Returns a serialized version of the sample. 63 // 64 // The serialized message for each type is: 65 // crash: crash\0|name_|\0 66 // user action: useraction\0|name_|\0 67 // histogram: histogram\0|name_| |sample_| |min_| |max_| |bucket_count_|\0 68 // sparsehistogram: sparsehistogram\0|name_| |sample_|\0 69 // linearhistogram: linearhistogram\0|name_| |sample_| |max_|\0 70 std::string ToString() const; 71 72 // Builds a crash sample. 73 static std::unique_ptr<MetricSample> CrashSample( 74 const std::string& crash_name); 75 76 // Builds a histogram sample. 77 static std::unique_ptr<MetricSample> HistogramSample( 78 const std::string& histogram_name, 79 int sample, 80 int min, 81 int max, 82 int bucket_count); 83 // Deserializes a histogram sample. 84 static std::unique_ptr<MetricSample> ParseHistogram( 85 const std::string& serialized); 86 87 // Builds a sparse histogram sample. 88 static std::unique_ptr<MetricSample> SparseHistogramSample( 89 const std::string& histogram_name, 90 int sample); 91 // Deserializes a sparse histogram sample. 92 static std::unique_ptr<MetricSample> ParseSparseHistogram( 93 const std::string& serialized); 94 95 // Builds a linear histogram sample. 96 static std::unique_ptr<MetricSample> 97 LinearHistogramSample(const std::string& histogram_name, int sample, int max); 98 // Deserializes a linear histogram sample. 99 static std::unique_ptr<MetricSample> ParseLinearHistogram( 100 const std::string& serialized); 101 102 // Builds a user action sample. 103 static std::unique_ptr<MetricSample> UserActionSample( 104 const std::string& action_name); 105 106 // Returns true if sample and this object represent the same sample (type, 107 // name, sample, min, max, bucket_count match). 108 bool IsEqual(const MetricSample& sample); 109 110 private: 111 const SampleType type_; 112 const std::string name_; 113 const int sample_; 114 const int min_; 115 const int max_; 116 const int bucket_count_; 117 }; 118 119 } // namespace metrics 120 121 #endif // COMPONENTS_METRICS_SERIALIZATION_METRIC_SAMPLE_H_ 122