mongodb/util/timer.h

// @file timer.h

/*    Copyright 2010 10gen Inc.
 *
 *    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 "time_support.h"

namespace mongo {

    /**
     *  simple scoped timer
     */
    class Timer {
    public:
        Timer() {
            reset();
        }

        Timer( unsigned long long start ) {
            old = start;
        }

        int seconds() const {
            return (int)(micros() / 1000000);
        }

        int millis() const {
            return (long)(micros() / 1000);
        }

        unsigned long long micros() const {
            unsigned long long n = curTimeMicros64();
            return n - old;
        }

        unsigned long long micros(unsigned long long & n) const { // returns cur time in addition to timer result
            n = curTimeMicros64();
            return n - old;
        }

        unsigned long long startTime() {
            return old;
        }

        void reset() {
            old = curTimeMicros64();
        }

    private:
        unsigned long long old;
    };

}  // namespace mongo