src/backend/utils/mb/wstrncmp.c

   1 /*
   2  * $PostgreSQL$
   3  *
   4  *
   5  * Copyright (c) 1989, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from FreeBSD 2.2.1-RELEASE software.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *        notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *        notice, this list of conditions and the following disclaimer in the
  17  *        documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *        may be used to endorse or promote products derived from this software
  20  *        without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.      IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 /* can be used in either frontend or backend */
  35 #include "postgres_fe.h"
  36
  37 #include "mb/pg_wchar.h"
  38
  39 int
  40 pg_wchar_strncmp(const pg_wchar *s1, const pg_wchar *s2, size_t n)
  41 {
  42         if (n == 0)
  43                 return 0;
  44         do
  45         {
  46                 if (*s1 != *s2++)
  47                         return (*s1 - *(s2 - 1));
  48                 if (*s1++ == 0)
  49                         break;
  50         } while (--n != 0);
  51         return 0;
  52 }
  53
  54 int
  55 pg_char_and_wchar_strncmp(const char *s1, const pg_wchar *s2, size_t n)
  56 {
  57         if (n == 0)
  58                 return 0;
  59         do
  60         {
  61                 if ((pg_wchar) ((unsigned char) *s1) != *s2++)
  62                         return ((pg_wchar) ((unsigned char) *s1) - *(s2 - 1));
  63                 if (*s1++ == 0)
  64                         break;
  65         } while (--n != 0);
  66         return 0;
  67 }
  68
  69 size_t
  70 pg_wchar_strlen(const pg_wchar *str)
  71 {
  72         const pg_wchar *s;
  73
  74         for (s = str; *s; ++s)
  75                 ;
  76         return (s - str);
  77 }