vn-verdnaturachat/ios/Pods/Flipper-Folly/folly/experimental/AutoTimer.h

151 lines
4.4 KiB
C++

/*
* Copyright (c) Facebook, Inc. and its affiliates.
*
* 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.
*/
#pragma once
#include <chrono>
#include <string>
#include <type_traits>
#include <folly/Conv.h>
#include <folly/Format.h>
#include <folly/Optional.h>
#include <folly/String.h>
#include <glog/logging.h>
namespace folly {
// Default logger
enum class GoogleLoggerStyle { SECONDS, PRETTY };
template <GoogleLoggerStyle>
struct GoogleLogger;
/**
* Automatically times a block of code, printing a specified log message on
* destruction or whenever the log() method is called. For example:
*
* AutoTimer t("Foo() completed");
* doWork();
* t.log("Do work finished");
* doMoreWork();
*
* This would print something like:
* "Do work finished in 1.2 seconds"
* "Foo() completed in 4.3 seconds"
*
* You can customize what you use as the logger and clock. The logger needs
* to have an operator()(StringPiece, std::chrono::duration<double>) that
* gets a message and a duration. The clock needs to model Clock from
* std::chrono.
*
* The default logger logs usings glog. It only logs if the message is
* non-empty, so you can also just use this class for timing, e.g.:
*
* AutoTimer t;
* doWork()
* const auto how_long = t.log();
*/
template <
class Logger = GoogleLogger<GoogleLoggerStyle::PRETTY>,
class Clock = std::chrono::high_resolution_clock>
class AutoTimer final {
public:
using DoubleSeconds = std::chrono::duration<double>;
explicit AutoTimer(
std::string&& msg = "",
const DoubleSeconds& minTimetoLog = DoubleSeconds::zero(),
Logger&& logger = Logger())
: destructionMessage_(std::move(msg)),
minTimeToLog_(minTimetoLog),
logger_(std::move(logger)) {}
// It doesn't really make sense to copy AutoTimer
// Movable to make sure the helper method for creating an AutoTimer works.
AutoTimer(const AutoTimer&) = delete;
AutoTimer(AutoTimer&&) = default;
AutoTimer& operator=(const AutoTimer&) = delete;
AutoTimer& operator=(AutoTimer&&) = default;
~AutoTimer() {
if (destructionMessage_) {
log(destructionMessage_.value());
}
}
DoubleSeconds log(StringPiece msg = "") {
return logImpl(Clock::now(), msg);
}
template <typename... Args>
DoubleSeconds log(Args&&... args) {
auto now = Clock::now();
return logImpl(now, to<std::string>(std::forward<Args>(args)...));
}
template <typename... Args>
DoubleSeconds logFormat(Args&&... args) {
auto now = Clock::now();
return logImpl(now, format(std::forward<Args>(args)...).str());
}
private:
// We take in the current time so that we don't measure time to call
// to<std::string> or format() in the duration.
DoubleSeconds logImpl(std::chrono::time_point<Clock> now, StringPiece msg) {
auto duration = now - start_;
if (duration >= minTimeToLog_) {
logger_(msg, duration);
}
start_ = Clock::now(); // Don't measure logging time
return duration;
}
Optional<std::string> destructionMessage_;
std::chrono::time_point<Clock> start_ = Clock::now();
DoubleSeconds minTimeToLog_;
Logger logger_;
};
template <
class Logger = GoogleLogger<GoogleLoggerStyle::PRETTY>,
class Clock = std::chrono::high_resolution_clock>
auto makeAutoTimer(
std::string&& msg = "",
const std::chrono::duration<double>& minTimeToLog =
std::chrono::duration<double>::zero(),
Logger&& logger = Logger()) {
return AutoTimer<Logger, Clock>(
std::move(msg), minTimeToLog, std::move(logger));
}
template <GoogleLoggerStyle Style>
struct GoogleLogger final {
void operator()(StringPiece msg, const std::chrono::duration<double>& sec)
const {
if (msg.empty()) {
return;
}
if (Style == GoogleLoggerStyle::PRETTY) {
LOG(INFO) << msg << " in "
<< prettyPrint(sec.count(), PrettyType::PRETTY_TIME);
} else {
LOG(INFO) << msg << " in " << sec.count() << " seconds";
}
}
};
} // namespace folly