/*
 * PerfMetric.h
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2022 Apple Inc. and the FoundationDB project authors
 *
 * 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.
 */

#ifndef FLOW_PERFMETRIC_H
#define FLOW_PERFMETRIC_H
#pragma once

#include <vector>
#include <string>
#include "flow/BooleanParam.h"
#include "flow/flow.h"

FDB_DECLARE_BOOLEAN_PARAM(Averaged);

struct PerfMetric {
	constexpr static FileIdentifier file_identifier = 5980618;
	PerfMetric() : m_name(""), m_format_code("%.3g"), m_value(0), m_averaged(false) {}
	PerfMetric(std::string name, double value, Averaged averaged)
	  : m_name(name), m_format_code("%.3g"), m_value(value), m_averaged(averaged) {}
	PerfMetric(std::string name, double value, Averaged averaged, std::string format_code)
	  : m_name(name), m_format_code(format_code), m_value(value), m_averaged(averaged) {}

	std::string name() const { return m_name; }
	double value() const { return m_value; }
	std::string formatted() const { return format(m_format_code.c_str(), m_value); }
	std::string format_code() const { return m_format_code; }
	bool averaged() const { return m_averaged; }

	PerfMetric withPrefix(const std::string& pre) const {
		return PerfMetric(pre + name(), value(), Averaged{ averaged() }, format_code());
	}

	template <class Ar>
	void serialize(Ar& ar) {
		serializer(ar, m_name, m_format_code, m_value, m_averaged);
	}

private:
	std::string m_name, m_format_code;
	double m_value;
	bool m_averaged;
};

struct PerfIntCounter {
	PerfIntCounter(std::string name) : name(name), value(0) {}
	PerfIntCounter(std::string name, std::vector<PerfIntCounter*>& v) : name(name), value(0) { v.push_back(this); }
	void operator+=(int64_t delta) { value += delta; }
	void operator++() { value += 1; }
	PerfMetric getMetric() const { return PerfMetric(name, static_cast<double>(value), Averaged::False, "%.0lf"); }
	int64_t getValue() const { return value; }
	void clear() { value = 0; }

private:
	std::string name;
	int64_t value;
};

struct PerfDoubleCounter {
	PerfDoubleCounter(std::string name) : name(name), value(0) {}
	PerfDoubleCounter(std::string name, std::vector<PerfDoubleCounter*>& v) : name(name), value(0) {
		v.push_back(this);
	}
	void operator+=(double delta) { value += delta; }
	void operator++() { value += 1.0; }
	PerfMetric getMetric() const { return PerfMetric(name, value, Averaged::False); }
	double getValue() const { return value; }
	void clear() { value = 0.0; }

private:
	std::string name;
	double value;
};

#endif