1 // Copyright 2011 Google Inc. All Rights Reserved.
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
7 // http://www.apache.org/licenses/LICENSE-2.0
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.
15 #ifndef NINJA_METRICS_H_
16 #define NINJA_METRICS_H_
22 #include "util.h" // For int64_t.
24 /// The Metrics module is used for the debug mode that dumps timing stats of
25 /// various actions. To use, see METRIC_RECORD below.
27 /// A single metrics we're tracking, like "depfile load time".
30 /// Number of times we've hit the code path.
32 /// Total time (in micros) we've spent on the code path.
37 /// A scoped object for recording a metric across the body of a function.
38 /// Used by the METRIC_RECORD macro.
40 explicit ScopedMetric(Metric* metric);
45 /// Timestamp when the measurement started.
46 /// Value is platform-dependent.
50 /// The singleton that stores metrics and prints the report.
52 Metric* NewMetric(const string& name);
54 /// Print a summary report to stdout.
58 vector<Metric*> metrics_;
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();
65 /// A simple stopwatch which returns the time
66 /// in seconds since Restart() was called.
69 Stopwatch() : started_(0) {}
71 /// Seconds since Restart() call.
72 double Elapsed() const {
73 return 1e-6 * static_cast<double>(Now() - started_);
76 void Restart() { started_ = Now(); }
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);
90 extern Metrics* g_metrics;
92 #endif // NINJA_METRICS_H_