/*
* util/timehist.c - make histogram of time values.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains functions to make a histogram of time values.
*/
#include "config.h"
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#include <sys/time.h>
#include <sys/types.h>
#include "util/timehist.h"
#include "util/log.h"
/** special timestwo operation for time values in histogram setup */
static void
timestwo(struct timeval* v)
{
#ifndef S_SPLINT_S
if(v->tv_sec == 0 && v->tv_usec == 0) {
v->tv_usec = 1;
return;
}
v->tv_sec *= 2;
v->tv_usec *= 2;
if(v->tv_usec == 1024*1024) {
/* nice values and easy to compute */
v->tv_sec = 1;
v->tv_usec = 0;
}
#endif
}
/** do setup exponentially */
static void
dosetup(struct timehist* hist)
{
struct timeval last;
size_t i;
memset(&last, 0, sizeof(last));
for(i=0; i<hist->num; i++) {
hist->buckets[i].lower = last;
timestwo(&last);
hist->buckets[i].upper = last;
hist->buckets[i].count = 0;
}
}
struct timehist* timehist_setup(void)
{
struct timehist* hist = (struct timehist*)calloc(1,
sizeof(struct timehist));
if(!hist)
return NULL;
hist->num = NUM_BUCKETS_HIST;
hist->buckets = (struct th_buck*)calloc(hist->num,
sizeof(struct th_buck));
if(!hist->buckets) {
free(hist);
return NULL;
}
/* setup the buckets */
dosetup(hist);
return hist;
}
void timehist_delete(struct timehist* hist)
{
if(!hist)
return;
free(hist->buckets);
free(hist);
}
void timehist_clear(struct timehist* hist)
{
size_t i;
for(i=0; i<hist->num; i++)
hist->buckets[i].count = 0;
}
/** histogram compare of time values */
static int
timeval_smaller(const struct timeval* x, const struct timeval* y)
{
#ifndef S_SPLINT_S
if(x->tv_sec < y->tv_sec)
return 1;
else if(x->tv_sec == y->tv_sec) {
if(x->tv_usec <= y->tv_usec)
return 1;
else return 0;
}
else return 0;
#endif
}
void timehist_insert(struct timehist* hist, struct timeval* tv)
{
size_t i;
for(i=0; i<hist->num; i++) {
if(timeval_smaller(tv, &hist->buckets[i].upper)) {
hist->buckets[i].count++;
return;
}
}
/* dump in last bucket */
hist->buckets[hist->num-1].count++;
}
void timehist_print(struct timehist* hist)
{
#ifndef S_SPLINT_S
size_t i;
for(i=0; i<hist->num; i++) {
if(hist->buckets[i].count != 0) {
printf("%4d.%6.6d %4d.%6.6d %u\n",
(int)hist->buckets[i].lower.tv_sec,
(int)hist->buckets[i].lower.tv_usec,
(int)hist->buckets[i].upper.tv_sec,
(int)hist->buckets[i].upper.tv_usec,
(unsigned)hist->buckets[i].count);
}
}
#endif
}
void timehist_log(struct timehist* hist, const char* name)
{
#ifndef S_SPLINT_S
size_t i;
log_info("[25%%]=%g median[50%%]=%g [75%%]=%g",
timehist_quartile(hist, 0.25),
timehist_quartile(hist, 0.50),
timehist_quartile(hist, 0.75));
/* 0000.000000 0000.000000 0 */
log_info("lower(secs) upper(secs) %s", name);
for(i=0; i<hist->num; i++) {
if(hist->buckets[i].count != 0) {
log_info("%4d.%6.6d %4d.%6.6d %u",
(int)hist->buckets[i].lower.tv_sec,
(int)hist->buckets[i].lower.tv_usec,
(int)hist->buckets[i].upper.tv_sec,
(int)hist->buckets[i].upper.tv_usec,
(unsigned)hist->buckets[i].count);
}
}
#endif
}
/** total number in histogram */
static size_t
timehist_count(struct timehist* hist)
{
size_t i, res = 0;
for(i=0; i<hist->num; i++)
res += hist->buckets[i].count;
return res;
}
double
timehist_quartile(struct timehist* hist, double q)
{
double lookfor, passed, res;
double low = 0, up = 0;
size_t i;
if(!hist || hist->num == 0)
return 0.;
/* look for i'th element, interpolated */
lookfor = (double)timehist_count(hist);
if(lookfor < 4)
return 0.; /* not enough elements for a good estimate */
lookfor *= q;
passed = 0;
i = 0;
while(i+1 < hist->num &&
passed+(double)hist->buckets[i].count < lookfor) {
passed += (double)hist->buckets[i++].count;
}
/* got the right bucket */
#ifndef S_SPLINT_S
low = (double)hist->buckets[i].lower.tv_sec +
(double)hist->buckets[i].lower.tv_usec/1000000.;
up = (double)hist->buckets[i].upper.tv_sec +
(double)hist->buckets[i].upper.tv_usec/1000000.;
#endif
res = (lookfor - passed)*(up-low)/((double)hist->buckets[i].count);
return low+res;
}
void
timehist_export(struct timehist* hist, size_t* array, size_t sz)
{
size_t i;
if(!hist) return;
if(sz > hist->num)
sz = hist->num;
for(i=0; i<sz; i++)
array[i] = hist->buckets[i].count;
}
void
timehist_import(struct timehist* hist, size_t* array, size_t sz)
{
size_t i;
if(!hist) return;
if(sz > hist->num)
sz = hist->num;
for(i=0; i<sz; i++)
hist->buckets[i].count = array[i];
}
