TimeMeasurement.cpp

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/*
 * TimeMeasurement.cpp
 *
 * Copyright (C) 2011 IBR, TU Braunschweig
 *
 * Written-by: Johannes Morgenroth <morgenroth@ibr.cs.tu-bs.de>
 *
 * 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 "ibrcommon/config.h"
#include "ibrcommon/TimeMeasurement.h"
#include "ibrcommon/MonotonicClock.h"

#include <stdio.h>
#include <iostream>
#include <iomanip>

namespace ibrcommon
{
        TimeMeasurement::TimeMeasurement()
        {
                start(); stop();
        }

        TimeMeasurement::~TimeMeasurement()
        {
        }

        void TimeMeasurement::start()
        {
                // set start time
                MonotonicClock::gettime(_start);
        }

        void TimeMeasurement::stop()
        {
                // set stop time
                MonotonicClock::gettime(_end);
        }

        double TimeMeasurement::getMilliseconds() const
        {
                struct timespec diff;
                getTime(diff);

                // merge seconds and nanoseconds
                double delay_ms = ((double)diff.tv_sec * 1000.0) + ((double)diff.tv_nsec / 1000000.0);

                return delay_ms;
        }

        double TimeMeasurement::getMicroseconds() const
        {
                struct timespec diff;
                getTime(diff);

                // merge seconds and nanoseconds
                double delay_us = ((double)diff.tv_sec * 1000000.0) + ((double)diff.tv_nsec / 1000.0);

                return delay_us;
        }

        time_t TimeMeasurement::getSeconds() const
        {
                return _end.tv_sec - _start.tv_sec;
        }

        std::ostream& TimeMeasurement::format(std::ostream &stream, const double value)
        {
#ifdef __UCLIBC__
                char buf[32];
                snprintf(buf, 32, "%4.2f", value);
                stream << std::string(buf);
#else
                stream << std::setiosflags(std::ios::fixed) << std::setprecision(2) << value;
#endif
                return stream;
        }

        std::ostream &operator<<(std::ostream &stream, const TimeMeasurement &measurement)
        {
                struct timespec diff;
                measurement.getTime(diff);

                // convert nanoseconds to milliseconds
                double delay_ms = (double)diff.tv_nsec / 1000000.0;

                if (diff.tv_sec < 1)
                {
                        TimeMeasurement::format(stream, delay_ms); stream << " ms";
                        return stream;
                }

                // convert time interval to seconds
                double seconds = (double)diff.tv_sec + (delay_ms / 1000.0);

                if (diff.tv_sec >= 3600)
                {
                        TimeMeasurement::format(stream, seconds / 3600.0); stream << " h";
                }
                else if (diff.tv_sec >= 60)
                {
                        TimeMeasurement::format(stream, seconds / 60.0); stream << " m";
                }
                else
                {
                        TimeMeasurement::format(stream, seconds); stream << " s";
                }

                return stream;
        }

        void TimeMeasurement::getTime(struct timespec &diff) const
        {
                MonotonicClock::diff(_start, _end, diff);
        }
}