contrib/sendmail/libsm/b-strcmp.c

   1 /*
   2  * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  *
   5  * By using this file, you agree to the terms and conditions set
   6  * forth in the LICENSE file which can be found at the top level of
   7  * the sendmail distribution.
   8  */
   9
  10 #include <sm/gen.h>
  11 SM_RCSID("@(#)$Id: b-strcmp.c,v 1.12 2001/09/11 04:04:47 gshapiro Exp $")
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <sys/types.h>
  16 #include <sys/time.h>
  17 #include <sm/string.h>
  18
  19 #define toseconds(x, y) (x.tv_sec - y.tv_sec)
  20 #define SIZE    512
  21 #define LOOPS   4000000L        /* initial number of loops */
  22 #define MAXTIME 30L     /* "maximum" time to run single test */
  23
  24 void
  25 fatal(str)
  26         char *str;
  27 {
  28         perror(str);
  29         exit(1);
  30 }
  31
  32 void
  33 purpose()
  34 {
  35         printf("This program benchmarks the performance differences between\n");
  36         printf("strcasecmp() and sm_strcasecmp().\n");
  37         printf("These tests may take several minutes to complete.\n");
  38 }
  39
  40 int
  41 main(argc, argv)
  42         int argc;
  43         char *argv[];
  44 {
  45         long a;
  46         int k;
  47         bool doit = false;
  48         long loops;
  49         long j;
  50         long one, two;
  51         struct timeval t1, t2;
  52         char src1[SIZE], src2[SIZE];
  53
  54 # define OPTIONS        "d"
  55         while ((k = getopt(argc, argv, OPTIONS)) != -1)
  56         {
  57                 switch ((char) k)
  58                 {
  59                   case 'd':
  60                         doit = true;
  61                         break;
  62
  63                   default:
  64                         break;
  65                 }
  66         }
  67
  68         if (!doit)
  69         {
  70                 purpose();
  71                 printf("If you want to run it, specify -d as option.\n");
  72                 return 0;
  73         }
  74
  75         /* Run-time comments to the user */
  76         purpose();
  77         printf("\n");
  78         for (k = 0; k < 3; k++)
  79         {
  80                 switch (k)
  81                 {
  82                   case 0:
  83                         (void) sm_strlcpy(src1, "1234567890", SIZE);
  84                         (void) sm_strlcpy(src2, "1234567890", SIZE);
  85                         break;
  86                   case 1:
  87                         (void) sm_strlcpy(src1, "1234567890", SIZE);
  88                         (void) sm_strlcpy(src2, "1234567891", SIZE);
  89                         break;
  90                   case 2:
  91                         (void) sm_strlcpy(src1, "1234567892", SIZE);
  92                         (void) sm_strlcpy(src2, "1234567891", SIZE);
  93                         break;
  94                 }
  95                 printf("Test %d: strcasecmp(%s, %s) versus sm_strcasecmp()\n",
  96                         k, src1, src2);
  97                 loops = LOOPS;
  98                 for (;;)
  99                 {
 100                         j = 0;
 101                         if (gettimeofday(&t1, NULL) < 0)
 102                                 fatal("gettimeofday");
 103                         for (a = 0; a < loops; a++)
 104                                 j += strcasecmp(src1, src2);
 105                         if (gettimeofday(&t2, NULL) < 0)
 106                                 fatal("gettimeofday");
 107                         one = toseconds(t2, t1);
 108                         printf("\tstrcasecmp() result: %ld seconds [%ld]\n",
 109                                 one, j);
 110
 111                         j = 0;
 112                         if (gettimeofday(&t1, NULL) < 0)
 113                                 fatal("gettimeofday");
 114                         for (a = 0; a < loops; a++)
 115                                 j += sm_strcasecmp(src1, src2);
 116                         if (gettimeofday(&t2, NULL) < 0)
 117                                 fatal("gettimeofday");
 118                         two = toseconds(t2, t1);
 119                         printf("\tsm_strcasecmp() result: %ld seconds [%ld]\n",
 120                                 two, j);
 121
 122                         if (abs(one - two) > 2)
 123                                 break;
 124                         loops += loops;
 125                         if (loops < 0L || one > MAXTIME)
 126                         {
 127                                 printf("\t\t** results too close: no decision\n");
 128                                 break;
 129                         }
 130                         else
 131                         {
 132                                 printf("\t\t** results too close redoing test %ld times **\n",
 133                                         loops);
 134                         }
 135                 }
 136         }
 137
 138         printf("\n\n");
 139         printf("Interpreting the results:\n");
 140         printf("\tFor differences larger than 2 seconds, the lower value is\n");
 141         printf("\tbetter and that function should be used for performance\n");
 142         printf("\treasons.\n\n");
 143         printf("This program will re-run the tests when the difference is\n");
 144         printf("less than 2 seconds.\n");
 145         printf("The result will vary depending on the compiler optimization\n");        printf("level used. Compiling the sendmail libsm library with a\n");
 146         printf("better optimization level can change the results.\n");
 147         return 0;
 148 }