/* $OpenBSD: stats.c,v 1.12 2023/09/04 11:35:11 espie Exp $ */

/*
 * Copyright (c) 1999 Marc Espie.
 *
 * Code written for the OpenBSD project.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT 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 OPENBSD
 * PROJECT 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.
 */


/* statistics gathering */

/* collection across make invocations is done with an mmap shared file,
   to allow for concurrent adjustment to variables.
 */

#include "defines.h"
#include "stats.h"

#ifdef HAS_STATS
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/resource.h>
#include "memory.h"

static void print_stats(void);
void Init_Stats(void);
static float average_runs(unsigned long val);
unsigned long *statarray;

static bool mmapped = false;

static float
average_runs(unsigned long val)
{
        return (float)val / STAT_INVOCATIONS;
}

static void
print_stats(void)
{
        struct rusage ru;

        if (getrusage(RUSAGE_SELF, &ru) != -1) {
                STAT_USER_SECONDS += ru.ru_utime.tv_sec;
                STAT_USER_MS += ru.ru_utime.tv_usec;
                if (STAT_USER_MS > 1000000) {
                        STAT_USER_MS -= 1000000;
                        STAT_USER_SECONDS++;
                }
                STAT_SYS_SECONDS += ru.ru_stime.tv_sec;
                STAT_SYS_MS += ru.ru_stime.tv_usec;
                if (STAT_SYS_MS > 1000000) {
                        STAT_SYS_MS -= 1000000;
                        STAT_SYS_SECONDS++;
                }
        }
        fprintf(stderr, "Make runs: %lu\n", STAT_INVOCATIONS);
        fprintf(stderr, "Time user: %lu.%06lu, sys %lu.%06lu\n",
            STAT_USER_SECONDS, STAT_USER_MS,
            STAT_SYS_SECONDS, STAT_SYS_MS);
#ifdef STATS_VAR_LOOKUP
        /* to get the average total of MAXSIZE, we need this value */
        STAT_VAR_POWER +=
            STAT_VAR_HASH_MAXSIZE * STAT_VAR_HASH_CREATION;
        fprintf(stderr, "Var finds: %f, lookups: %f, average: %f, max: %lu\n",
            average_runs(STAT_VAR_FIND),
            average_runs(STAT_VAR_SEARCHES),
            (float)STAT_VAR_COUNT/STAT_VAR_SEARCHES,
            STAT_VAR_MAXCOUNT);
        fprintf(stderr, "Average hash: %f, creation: %f, from env %f\n",
            average_runs(STAT_VAR_HASH_CREATION),
            average_runs(STAT_VAR_CREATION),
            average_runs(STAT_VAR_FROM_ENV));
        fprintf(stderr, "Local hash max: %lu, global hash max: %lu, average local: %f\n",
            STAT_VAR_HASH_MAXSIZE,
            STAT_VAR_GHASH_MAXSIZE,
            (float)STAT_VAR_POWER/STAT_VAR_HASH_CREATION);
#endif
#ifdef STATS_GN_CREATION
        fprintf(stderr, "Average GN: %f\n", average_runs(STAT_GN_COUNT));
#endif
#ifdef STATS_SUFF
        fprintf(stderr, "Average Suffix lookup: %f, transforms: %f\n",
            average_runs(STAT_SUFF_LOOKUP_NAME),
            average_runs(STAT_TRANSFORM_LOOKUP_NAME));
#endif
#ifdef STATS_BUF
        fprintf(stderr, "Buf tot: %f, def: %f, exp %f, weird %f, bad %f\n",
            average_runs(STAT_TOTAL_BUFS),
            average_runs(STAT_DEFAULT_BUFS),
            average_runs(STAT_BUFS_EXPANSION),
            average_runs(STAT_WEIRD_BUFS),
            average_runs(STAT_WEIRD_INEFFICIENT));
#endif
#ifdef STATS_HASH
        fprintf(stderr, "Hashes new: %f, exp: %f, lookup %f, l: %f, +: %f, ent : %f\n",
            average_runs(STAT_HASH_CREATION),
            average_runs(STAT_HASH_EXPAND),
            average_runs(STAT_HASH_LOOKUP),
            (float)STAT_HASH_LENGTH/STAT_HASH_LOOKUP,
            (float)STAT_HASH_POSITIVE/STAT_HASH_LOOKUP,
            (float)STAT_HASH_ENTRIES/STAT_HASH_SIZE);
#endif
#ifdef STATS_GROW
        fprintf(stderr, "Grow: %f\n", average_runs(STAT_GROWARRAY));
#endif
        if (mmapped)
                munmap(statarray, STAT_NUMBER * sizeof(unsigned long));
}

void
Init_Stats(void)
{
        char *name;
        int fd;

        /* try to get ahold of a stats collecting file */
        name = getenv("MAKESTATS");
        if (name) {
                while ((fd = open(name, O_RDWR)) == -1) {
                        /* if collecting file does not already exist, fill it with
                         * zeros (so all stats starting values should be 0) */
                        unsigned long n;
                        int i;
                        FILE *f;

                        f = fopen(name, "w");

                        n = 0;
                        for (i = 0; i < STAT_NUMBER; i++)
                                fwrite(&n, sizeof(unsigned long), 1, f);
                        fclose(f);
                }

                /* either we've got the file -> share it across makes */
                if (fd) {
                        statarray = mmap(0, STAT_NUMBER * sizeof(unsigned long),
                            PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
                        if (statarray == MAP_FAILED)
                                exit(1);
                        mmapped = true;
                }
        } else
                /* or we don't -> simple stats gathering */
                statarray = ecalloc(STAT_NUMBER, sizeof(unsigned long));
        STAT_INVOCATIONS++;
        atexit(print_stats);
}

#endif