#ifndef _bench_h_
#define _bench_h_

#include <iostream>
#include <iomanip>
#include <boost/format.hpp>
#include <boost/foreach.hpp>
#include <time.h>

#ifndef NSEC_PER_SEC
# define NSEC_PER_SEC                   1000000000ULL
#endif

inline static long timespec_diff_ns(struct timespec *start, struct timespec *end)
{
	long ret;

	ret = (long)(end->tv_sec - start->tv_sec)*NSEC_PER_SEC;
	ret += (long)(end->tv_nsec - start->tv_nsec);
	return ret;
}

class Bench
{
public:
	Bench(const std::string& benchname)
	:	m_benchname(benchname)
	{
		start();
	}

	void start()
	{
		::clock_gettime(CLOCK_MONOTONIC, &m_ts_start);
	}

	void end()
	{
		::clock_gettime(CLOCK_MONOTONIC, &m_ts_end);
	}

	void cp(const char* cpname)
	{
		struct checkpoint cp;
		cp.name = cpname;
		::clock_gettime(CLOCK_MONOTONIC, &cp.ts);
		m_cps.push_back(cp);
	}

	void dump()
	{
		std::cout << "hgrev\tbenchname\ttotal";
		BOOST_FOREACH(struct checkpoint& cp, m_cps)
		{
			std::cout << '\t' << cp.name;
		}
		std::cout << std::endl;
		std::cout << HGNUM << '\t' << m_benchname << '\t' << std::setiosflags(std::ios::fixed) << std::setprecision(4) << (double)timespec_diff_ns(&m_ts_start, &m_ts_end) / NSEC_PER_SEC;
		BOOST_FOREACH(struct checkpoint& cp, m_cps)
		{
			std::cout << '\t' << std::setiosflags(std::ios::fixed) << std::setprecision(4) << (double)timespec_diff_ns(&m_ts_start, &cp.ts) / NSEC_PER_SEC;
		}
		std::cout << std::endl;
	}

private:
	std::string m_benchname;

	struct timespec m_ts_start, m_ts_end;
	struct checkpoint
	{
		struct timespec ts;
		const char* name;
	};
	std::vector<checkpoint> m_cps;
};

#endif // _bench_h_