1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #ifndef ANDROID_COUNTER_METRIC_H_ 17 #define ANDROID_COUNTER_METRIC_H_ 18 19 #include <functional> 20 #include <map> 21 #include <string> 22 23 #include <media/MediaAnalyticsItem.h> 24 #include <utils/Log.h> 25 26 namespace android { 27 28 29 // The CounterMetric class is used to hold counts of operations or events. 30 // A CounterMetric can break down counts by a dimension specified by the 31 // application. E.g. an application may want to track counts broken out by 32 // error code or the size of some parameter. 33 // 34 // Example: 35 // 36 // CounterMetric<status_t> workCounter; 37 // workCounter("workCounterName", "result_status"); 38 // 39 // status_t err = DoWork(); 40 // 41 // // Increments the number of times called with the given error code. 42 // workCounter.Increment(err); 43 // 44 // std::map<int, int64_t> values; 45 // metric.ExportValues( 46 // [&] (int attribute_value, int64_t value) { 47 // values[attribute_value] = value; 48 // }); 49 // 50 // // Do something with the exported stat. 51 // 52 template<typename AttributeType> 53 class CounterMetric { 54 public: 55 // Instantiate the counter with the given metric name and 56 // attribute names. |attribute_names| must not be null. CounterMetric(const std::string & metric_name,const std::string & attribute_name)57 CounterMetric( 58 const std::string& metric_name, 59 const std::string& attribute_name) 60 : metric_name_(metric_name), 61 attribute_name_(attribute_name) {} 62 63 // Increment the count of times the operation occurred with this 64 // combination of attributes. Increment(AttributeType attribute)65 void Increment(AttributeType attribute) { 66 if (values_.find(attribute) == values_.end()) { 67 values_[attribute] = 1; 68 } else { 69 values_[attribute] = values_[attribute] + 1; 70 } 71 }; 72 73 // Export the metrics to the provided |function|. Each value for Attribute 74 // has a separate count. As such, |function| will be called once per value 75 // of Attribute. ExportValues(std::function<void (const AttributeType &,const int64_t count)> function)76 void ExportValues( 77 std::function<void (const AttributeType&, 78 const int64_t count)> function) const { 79 for (auto it = values_.begin(); it != values_.end(); it++) { 80 function(it->first, it->second); 81 } 82 } 83 metric_name()84 const std::string& metric_name() const { return metric_name_; }; 85 86 private: 87 const std::string metric_name_; 88 const std::string attribute_name_; 89 std::map<AttributeType, int64_t> values_; 90 }; 91 92 } // namespace android 93 94 #endif // ANDROID_COUNTER_METRIC_H_ 95