timeval.h

// -*- mode: c++; c-file-style: "k&r"; c-basic-offset: 4 -*-
/***********************************************************************
 *
 * timeval.h:
 *   utility functions for manipulating timevals
 *
 * Copyright 2013-2015 Irene Zhang <iyzhang@cs.washington.edu>
 *                     Naveen Kr. Sharma <naveenks@cs.washington.edu>
 *                     Dan R. K. Ports  <drkp@cs.washington.edu>
 * Copyright 2009-2012 Massachusetts Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 **********************************************************************/

#ifndef _LIB_TIMEVAL_H_
#define _LIB_TIMEVAL_H_

#include <sys/time.h>
#include <time.h>               /* strftime */
#include <stdlib.h>             /* malloc */
#include <stdio.h>              /* sprintf */
#include <string.h>

static inline struct timeval
timeval_sub(struct timeval a, struct timeval b) {
    struct timeval result;
        
    if (a.tv_usec < b.tv_usec) {
        result.tv_sec = a.tv_sec - b.tv_sec - 1;
        result.tv_usec = a.tv_usec + 1000000 - b.tv_usec;
    } else {
        result.tv_sec = a.tv_sec - b.tv_sec;
        result.tv_usec = a.tv_usec - b.tv_usec;
    }
    return result;
};

static inline bool
timeval_lessthan(struct timeval a, struct timeval b) {
    return ((a.tv_sec < b.tv_sec) ||
            ((a.tv_sec == b.tv_sec) &&
             (a.tv_usec < b.tv_usec)));
};

static inline struct timeval
Timeval_FromSecs(double secs)
{
    struct timeval res;
    res.tv_sec = (time_t)secs;
    res.tv_usec = (time_t) (secs - (long long)secs) * 1000000;
    return res;
}

#define FMT_TIMEVAL_ABS "%s"
#define XVA_TIMEVAL_ABS(t) Message_DFree(Timeval_FmtAbs(t))

static inline char *
Timeval_FmtAbs(struct timeval tv)
{
    static const int LEN = 32;
    char *buf = (char *)malloc(LEN);
    if (!buf)
        return NULL;
    strftime(buf, LEN, "%H:%M:%S", localtime(&tv.tv_sec));
    sprintf(buf + strlen(buf), ":%06ld", tv.tv_usec);
    return buf;
}

#define FMT_TIMEVAL_DIFF "%ld.%06ld"
#define VA_TIMEVAL_DIFF(t) t.tv_sec, t.tv_usec

#endif