usr.bin/mail/strings.c

   1 /*      $NetBSD: strings.c,v 1.16 2007/10/29 23:20:39 christos Exp $    */
   2
   3 /*
   4  * Copyright (c) 1980, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)strings.c   8.1 (Berkeley) 6/6/93";
  36 #else
  37 __RCSID("$NetBSD: strings.c,v 1.16 2007/10/29 23:20:39 christos Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 /*
  42  * Mail -- a mail program
  43  *
  44  * String allocation routines.
  45  * Strings handed out here are reclaimed at the top of the command
  46  * loop each time, so they need not be freed.
  47  */
  48
  49 #include "rcv.h"
  50 #include "extern.h"
  51
  52 #define STRINGSIZE      ((unsigned) 128)/* Dynamic allocation units */
  53
  54 /*
  55  * The pointers for the string allocation routines,
  56  * there are NSPACE independent areas.
  57  * The first holds STRINGSIZE bytes, the next
  58  * twice as much, and so on.
  59  */
  60 #define NSPACE  25                      /* Total number of string spaces */
  61 static struct strings {
  62         char    *s_topFree;             /* Beginning of this area */
  63         char    *s_nextFree;            /* Next alloctable place here */
  64         size_t  s_nleft;                /* Number of bytes left here */
  65 } stringdope[NSPACE];
  66
  67 /*
  68  * Allocate size more bytes of space and return the address of the
  69  * first byte to the caller.  An even number of bytes are always
  70  * allocated so that the space will always be on a word boundary.
  71  * The string spaces are of exponentially increasing size, to satisfy
  72  * the occasional user with enormous string size requests.
  73  */
  74 PUBLIC void *
  75 salloc(size_t size)
  76 {
  77         char *t;
  78         size_t s;
  79         struct strings *sp;
  80         int idx;
  81
  82         s = size;
  83         s += (sizeof(char *) - 1);
  84         s &= ~(sizeof(char *) - 1);
  85         idx = 0;
  86         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
  87                 if (sp->s_topFree == NULL && (STRINGSIZE << idx) >= s)
  88                         break;
  89                 if (sp->s_nleft >= s)
  90                         break;
  91                 idx++;
  92         }
  93         if (sp >= &stringdope[NSPACE])
  94                 errx(1, "String too large");
  95         if (sp->s_topFree == NULL) {
  96                 idx = (int)(sp - &stringdope[0]);
  97                 sp->s_topFree = malloc(STRINGSIZE << idx);
  98                 if (sp->s_topFree == NULL)
  99                         errx(1, "No room for space %d", idx);
 100                 sp->s_nextFree = sp->s_topFree;
 101                 sp->s_nleft = STRINGSIZE << idx;
 102         }
 103         sp->s_nleft -= s;
 104         t = sp->s_nextFree;
 105         sp->s_nextFree += s;
 106         return t;
 107 }
 108
 109 /*
 110  * Allocate zeroed space for 'number' elments of size 'size'.
 111  */
 112 PUBLIC void *
 113 csalloc(size_t number, size_t size)
 114 {
 115         void *p;
 116         p = salloc(number * size);
 117         (void)memset(p, 0, number * size);
 118         return p;
 119 }
 120
 121 /*
 122  * Reset the string area to be empty.
 123  * Called to free all strings allocated
 124  * since last reset.
 125  */
 126 PUBLIC void
 127 sreset(void)
 128 {
 129         struct strings *sp;
 130         int idx;
 131
 132         if (noreset)
 133                 return;
 134         idx = 0;
 135         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
 136                 if (sp->s_topFree == NULL)
 137                         continue;
 138                 sp->s_nextFree = sp->s_topFree;
 139                 sp->s_nleft = STRINGSIZE << idx;
 140                 idx++;
 141         }
 142 }
 143
 144 /*
 145  * Make the string area permanent.
 146  * Meant to be called in main, after initialization.
 147  */
 148 PUBLIC void
 149 spreserve(void)
 150 {
 151         struct strings *sp;
 152
 153         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
 154                 sp->s_topFree = NULL;
 155 }