1 /* 2 * util/timeval_func.c - helpers to work with struct timeval values. 3 * 4 * Copyright (c) 2023, NLnet Labs. All rights reserved. 5 * 6 * This software is open source. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * Redistributions of source code must retain the above copyright notice, 13 * this list of conditions and the following disclaimer. 14 * 15 * Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 19 * Neither the name of the NLNET LABS nor the names of its contributors may 20 * be used to endorse or promote products derived from this software without 21 * specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /** 37 * \file 38 * 39 * This file contains helpers to manipulate struct timeval values. 40 */ 41 42 #include "config.h" 43 #include "timeval_func.h" 44 45 /** subtract timers and the values do not overflow or become negative */ 46 void timeval_subtract(struct timeval * d,const struct timeval * end,const struct timeval * start)47 timeval_subtract(struct timeval* d, const struct timeval* end, const struct timeval* start) 48 { 49 #ifndef S_SPLINT_S 50 time_t end_usec = end->tv_usec; 51 d->tv_sec = end->tv_sec - start->tv_sec; 52 if(end_usec < start->tv_usec) { 53 end_usec += 1000000; 54 d->tv_sec--; 55 } 56 d->tv_usec = end_usec - start->tv_usec; 57 #endif 58 } 59 60 /** add timers and the values do not overflow or become negative */ 61 void timeval_add(struct timeval * d,const struct timeval * add)62 timeval_add(struct timeval* d, const struct timeval* add) 63 { 64 #ifndef S_SPLINT_S 65 d->tv_sec += add->tv_sec; 66 d->tv_usec += add->tv_usec; 67 if(d->tv_usec >= 1000000 ) { 68 d->tv_usec -= 1000000; 69 d->tv_sec++; 70 } 71 #endif 72 } 73 74 /** divide sum of timers to get average */ 75 void timeval_divide(struct timeval * avg,const struct timeval * sum,long long d)76 timeval_divide(struct timeval* avg, const struct timeval* sum, long long d) 77 { 78 #ifndef S_SPLINT_S 79 long long leftover; 80 if(d <= 0) { 81 avg->tv_sec = 0; 82 avg->tv_usec = 0; 83 return; 84 } 85 avg->tv_sec = sum->tv_sec / d; 86 avg->tv_usec = sum->tv_usec / d; 87 /* handle fraction from seconds divide */ 88 leftover = sum->tv_sec - avg->tv_sec*d; 89 if(leftover <= 0) 90 leftover = 0; 91 avg->tv_usec += (((long long)leftover)*((long long)1000000))/d; 92 if(avg->tv_sec < 0) 93 avg->tv_sec = 0; 94 if(avg->tv_usec < 0) 95 avg->tv_usec = 0; 96 #endif 97 } 98 99 /** histogram compare of time values */ 100 int timeval_smaller(const struct timeval * x,const struct timeval * y)101 timeval_smaller(const struct timeval* x, const struct timeval* y) 102 { 103 #ifndef S_SPLINT_S 104 if(x->tv_sec < y->tv_sec) 105 return 1; 106 else if(x->tv_sec == y->tv_sec) { 107 if(x->tv_usec <= y->tv_usec) 108 return 1; 109 else return 0; 110 } 111 else return 0; 112 #endif 113 } 114