string/test-memmem.c

   1 /* Test and measure memmem functions.
   2    Copyright (C) 2008-2012 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Written by Ulrich Drepper <drepper@redhat.com>, 2008.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #define TEST_MAIN
  21 #define TEST_NAME "memmem"
  22 #define BUF1PAGES 20
  23 #define ITERATIONS 500
  24 #include "test-string.h"
  25
  26 typedef char *(*proto_t) (const void *, size_t, const void *, size_t);
  27 void *simple_memmem (const void *, size_t, const void *, size_t);
  28
  29 IMPL (simple_memmem, 0)
  30 IMPL (memmem, 1)
  31
  32 void *
  33 simple_memmem (const void *haystack, size_t haystack_len, const void *needle,
  34                size_t needle_len)
  35 {
  36   const char *begin;
  37   const char *const last_possible
  38     = (const char *) haystack + haystack_len - needle_len;
  39
  40   if (needle_len == 0)
  41     /* The first occurrence of the empty string is deemed to occur at
  42        the beginning of the string.  */
  43     return (void *) haystack;
  44
  45   /* Sanity check, otherwise the loop might search through the whole
  46      memory.  */
  47   if (__builtin_expect (haystack_len < needle_len, 0))
  48     return NULL;
  49
  50   for (begin = (const char *) haystack; begin <= last_possible; ++begin)
  51     if (begin[0] == ((const char *) needle)[0] &&
  52         !memcmp ((const void *) &begin[1],
  53                  (const void *) ((const char *) needle + 1),
  54                  needle_len - 1))
  55       return (void *) begin;
  56
  57   return NULL;
  58 }
  59
  60 static int
  61 check_result (impl_t *impl, const void *haystack, size_t haystack_len,
  62              const void *needle, size_t needle_len, const void *expected)
  63 {
  64   void *res;
  65
  66   res = CALL (impl, haystack, haystack_len, needle, needle_len);
  67   if (res != expected)
  68     {
  69       error (0, 0, "Wrong result in function %s %p %p", impl->name,
  70              res, expected);
  71       ret = 1;
  72       return -1;
  73     }
  74
  75   return 0;
  76 }
  77
  78 static void
  79 do_one_test (impl_t *impl, const void *haystack, size_t haystack_len,
  80              const void *needle, size_t needle_len, const void *expected)
  81 {
  82   if (check_result (impl, haystack, haystack_len, needle, needle_len,
  83                     expected) < 0)
  84     return;
  85
  86   if (HP_TIMING_AVAIL)
  87     {
  88       hp_timing_t start __attribute ((unused));
  89       hp_timing_t stop __attribute ((unused));
  90       hp_timing_t best_time = ~ (hp_timing_t) 0;
  91       size_t i;
  92
  93       for (i = 0; i < 32; ++i)
  94         {
  95           HP_TIMING_NOW (start);
  96           CALL (impl, haystack, haystack_len, needle, needle_len);
  97           HP_TIMING_NOW (stop);
  98           HP_TIMING_BEST (best_time, start, stop);
  99         }
 100
 101       printf ("\t%zd", (size_t) best_time);
 102     }
 103 }
 104
 105 static void
 106 do_test (const char *str, size_t len, size_t idx)
 107 {
 108   char tmpbuf[len];
 109
 110   memcpy (tmpbuf, buf1 + idx, len);
 111   memcpy (buf1 + idx, str, len);
 112
 113   if (HP_TIMING_AVAIL)
 114     printf ("String %s, offset %zd:", str, idx);
 115
 116   FOR_EACH_IMPL (impl, 0)
 117     do_one_test (impl, buf1, BUF1PAGES * page_size, str, len, buf1 + idx);
 118
 119   memcpy (buf1 + idx, tmpbuf, len);
 120
 121   if (HP_TIMING_AVAIL)
 122     putchar ('\n');
 123 }
 124
 125 static void
 126 do_random_tests (void)
 127 {
 128   for (size_t n = 0; n < ITERATIONS; ++n)
 129     {
 130       char tmpbuf[32];
 131
 132       size_t shift = random () % 11;
 133       size_t rel = random () % ((2 << (shift + 1)) * 64);
 134       size_t idx = MIN ((2 << shift) * 64 + rel, BUF1PAGES * page_size - 2);
 135       size_t len = random () % (sizeof (tmpbuf) - 1) + 1;
 136       len = MIN (len, BUF1PAGES * page_size - idx - 1);
 137       memcpy (tmpbuf, buf1 + idx, len);
 138       for (size_t i = random () % len / 2 + 1; i > 0; --i)
 139         {
 140           size_t off = random () % len;
 141           char ch = '0' + random () % 10;
 142
 143           buf1[idx + off] = ch;
 144         }
 145
 146       if (HP_TIMING_AVAIL)
 147         printf ("String %.*s, offset %zd:", (int) len, buf1 + idx, idx);
 148
 149       FOR_EACH_IMPL (impl, 0)
 150         do_one_test (impl, buf1, BUF1PAGES * page_size, buf1 + idx, len,
 151                      buf1 + idx);
 152
 153       if (HP_TIMING_AVAIL)
 154         putchar ('\n');
 155
 156       memcpy (buf1 + idx, tmpbuf, len);
 157     }
 158 }
 159
 160 static void
 161 check1 (void)
 162 {
 163
 164   const char search_buf_data[5] = { 0x56, 0x34, 0x12, 0x78, 0x78 };
 165   const char pattern[2] = { 0x78, 0x56 };
 166   void *search_buf = (void *) buf1 + page_size - sizeof search_buf_data;
 167   void *exp_result;
 168
 169   memcpy (search_buf, search_buf_data, sizeof search_buf_data);
 170   exp_result = simple_memmem (search_buf, sizeof search_buf_data,
 171                               pattern, sizeof pattern);
 172   FOR_EACH_IMPL (impl, 0)
 173     check_result (impl, search_buf, sizeof search_buf_data,
 174                   pattern, sizeof pattern, exp_result);
 175 }
 176
 177 static const char *const strs[] =
 178   {
 179     "00000", "00112233", "0123456789", "0000111100001111",
 180     "00000111110000022222", "012345678901234567890",
 181     "abc0", "aaaa0", "abcabc0"
 182   };
 183
 184
 185 int
 186 test_main (void)
 187 {
 188   size_t i;
 189
 190   test_init ();
 191
 192   check1 ();
 193
 194   printf ("%23s", "");
 195   FOR_EACH_IMPL (impl, 0)
 196     printf ("\t%s", impl->name);
 197   putchar ('\n');
 198
 199   for (i = 0; i < BUF1PAGES * page_size; ++i)
 200     buf1[i] = 60 + random () % 32;
 201
 202   for (i = 0; i < sizeof (strs) / sizeof (strs[0]); ++i)
 203     for (size_t j = 0; j < 120; j += 7)
 204       {
 205         size_t len = strlen (strs[i]);
 206
 207         do_test (strs[i], len, j);
 208       }
 209
 210   do_random_tests ();
 211   return ret;
 212 }
 213
 214 #include "../test-skeleton.c"