usr.bin/mail/strings.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)strings.c        8.1 (Berkeley) 6/6/93
  30  * $FreeBSD: src/usr.bin/mail/strings.c,v 1.2.6.3 2003/01/06 05:46:03 mikeh Exp $
  31  * $DragonFly: src/usr.bin/mail/strings.c,v 1.3 2003/10/04 20:36:48 hmp Exp $
  32  */
  33
  34 /*
  35  * Mail -- a mail program
  36  *
  37  * String allocation routines.
  38  * Strings handed out here are reclaimed at the top of the command
  39  * loop each time, so they need not be freed.
  40  */
  41
  42 #include "rcv.h"
  43 #include "extern.h"
  44
  45 /*
  46  * Allocate size more bytes of space and return the address of the
  47  * first byte to the caller.  An even number of bytes are always
  48  * allocated so that the space will always be on a word boundary.
  49  * The string spaces are of exponentially increasing size, to satisfy
  50  * the occasional user with enormous string size requests.
  51  */
  52
  53 char *
  54 salloc(int size)
  55 {
  56         char *t;
  57         int s, index;
  58         struct strings *sp;
  59
  60         s = size;
  61         s += (sizeof(char *) - 1);
  62         s &= ~(sizeof(char *) - 1);
  63         index = 0;
  64         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
  65                 if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
  66                         break;
  67                 if (sp->s_nleft >= s)
  68                         break;
  69                 index++;
  70         }
  71         if (sp >= &stringdope[NSPACE])
  72                 errx(1, "String too large");
  73         if (sp->s_topFree == NULL) {
  74                 index = sp - &stringdope[0];
  75                 if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
  76                         err(1, "No room for space %d", index);
  77                 sp->s_nextFree = sp->s_topFree;
  78                 sp->s_nleft = STRINGSIZE << index;
  79         }
  80         sp->s_nleft -= s;
  81         t = sp->s_nextFree;
  82         sp->s_nextFree += s;
  83         return (t);
  84 }
  85
  86 /*
  87  * Reset the string area to be empty.
  88  * Called to free all strings allocated
  89  * since last reset.
  90  */
  91 void
  92 sreset(void)
  93 {
  94         struct strings *sp;
  95         int index;
  96
  97         if (noreset)
  98                 return;
  99         index = 0;
 100         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
 101                 if (sp->s_topFree == NULL)
 102                         continue;
 103                 sp->s_nextFree = sp->s_topFree;
 104                 sp->s_nleft = STRINGSIZE << index;
 105                 index++;
 106         }
 107 }
 108
 109 /*
 110  * Make the string area permanent.
 111  * Meant to be called in main, after initialization.
 112  */
 113 void
 114 spreserve(void)
 115 {
 116         struct strings *sp;
 117
 118         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
 119                 sp->s_topFree = NULL;
 120 }