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// Copyright 2011 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "metrics.h"
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <chrono>
#include "util.h"
using namespace std;
Metrics* g_metrics = NULL;
namespace {
/// Compute a platform-specific high-res timer value that fits into an int64.
int64_t HighResTimer() {
auto now = chrono::steady_clock::now();
return chrono::duration_cast<chrono::steady_clock::duration>(
now.time_since_epoch())
.count();
}
constexpr int64_t GetFrequency() {
// If numerator isn't 1 then we lose precision and that will need to be
// assessed.
static_assert(std::chrono::steady_clock::period::num == 1,
"Numerator must be 1");
return std::chrono::steady_clock::period::den /
std::chrono::steady_clock::period::num;
}
int64_t TimerToMicros(int64_t dt) {
// dt is in ticks. We want microseconds.
return (dt * 1000000) / GetFrequency();
}
int64_t TimerToMicros(double dt) {
// dt is in ticks. We want microseconds.
return (dt * 1000000) / GetFrequency();
}
} // anonymous namespace
ScopedMetric::ScopedMetric(Metric* metric) {
metric_ = metric;
if (!metric_)
return;
start_ = HighResTimer();
}
ScopedMetric::~ScopedMetric() {
if (!metric_)
return;
metric_->count++;
// Leave in the timer's natural frequency to avoid paying the conversion cost
// on every measurement.
int64_t dt = HighResTimer() - start_;
metric_->sum += dt;
}
Metric* Metrics::NewMetric(const string& name) {
Metric* metric = new Metric;
metric->name = name;
metric->count = 0;
metric->sum = 0;
metrics_.push_back(metric);
return metric;
}
void Metrics::Report() {
int width = 0;
for (vector<Metric*>::iterator i = metrics_.begin();
i != metrics_.end(); ++i) {
width = max((int)(*i)->name.size(), width);
}
printf("%-*s\t%-6s\t%-9s\t%s\n", width,
"metric", "count", "avg (us)", "total (ms)");
for (vector<Metric*>::iterator i = metrics_.begin();
i != metrics_.end(); ++i) {
Metric* metric = *i;
uint64_t micros = TimerToMicros(metric->sum);
double total = micros / (double)1000;
double avg = micros / (double)metric->count;
printf("%-*s\t%-6d\t%-8.1f\t%.1f\n", width, metric->name.c_str(),
metric->count, avg, total);
}
}
double Stopwatch::Elapsed() const {
// Convert to micros after converting to double to minimize error.
return 1e-6 * TimerToMicros(static_cast<double>(NowRaw() - started_));
}
uint64_t Stopwatch::NowRaw() const {
return HighResTimer();
}
int64_t GetTimeMillis() {
return TimerToMicros(HighResTimer()) / 1000;
}
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