1 // Copyright 2011 Google Inc. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef NINJA_METRICS_H_ 16 #define NINJA_METRICS_H_ 17 18 #include <string> 19 #include <vector> 20 using namespace std; 21 22 #include "util.h" // For int64_t. 23 24 /// The Metrics module is used for the debug mode that dumps timing stats of 25 /// various actions. To use, see METRIC_RECORD below. 26 27 /// A single metrics we're tracking, like "depfile load time". 28 struct Metric { 29 string name; 30 /// Number of times we've hit the code path. 31 int count; 32 /// Total time (in micros) we've spent on the code path. 33 int64_t sum; 34 }; 35 36 37 /// A scoped object for recording a metric across the body of a function. 38 /// Used by the METRIC_RECORD macro. 39 struct ScopedMetric { 40 explicit ScopedMetric(Metric* metric); 41 ~ScopedMetric(); 42 43 private: 44 Metric* metric_; 45 /// Timestamp when the measurement started. 46 /// Value is platform-dependent. 47 int64_t start_; 48 }; 49 50 /// The singleton that stores metrics and prints the report. 51 struct Metrics { 52 Metric* NewMetric(const string& name); 53 54 /// Print a summary report to stdout. 55 void Report(); 56 57 private: 58 vector<Metric*> metrics_; 59 }; 60 61 /// Get the current time as relative to some epoch. 62 /// Epoch varies between platforms; only useful for measuring elapsed time. 63 int64_t GetTimeMillis(); 64 65 /// A simple stopwatch which returns the time 66 /// in seconds since Restart() was called. 67 struct Stopwatch { 68 public: StopwatchStopwatch69 Stopwatch() : started_(0) {} 70 71 /// Seconds since Restart() call. ElapsedStopwatch72 double Elapsed() const { 73 return 1e-6 * static_cast<double>(Now() - started_); 74 } 75 RestartStopwatch76 void Restart() { started_ = Now(); } 77 78 private: 79 uint64_t started_; 80 uint64_t Now() const; 81 }; 82 83 /// The primary interface to metrics. Use METRIC_RECORD("foobar") at the top 84 /// of a function to get timing stats recorded for each call of the function. 85 #define METRIC_RECORD(name) \ 86 static Metric* metrics_h_metric = \ 87 g_metrics ? g_metrics->NewMetric(name) : NULL; \ 88 ScopedMetric metrics_h_scoped(metrics_h_metric); 89 90 extern Metrics* g_metrics; 91 92 #endif // NINJA_METRICS_H_ 93