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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)strings.c        8.1 (Berkeley) 6/6/93
  34  * $FreeBSD: src/usr.bin/mail/strings.c,v 1.2.6.3 2003/01/06 05:46:03 mikeh Exp $
  35  * $DragonFly: src/usr.bin/mail/strings.c,v 1.3 2003/10/04 20:36:48 hmp Exp $
  36  */
  37
  38 /*
  39  * Mail -- a mail program
  40  *
  41  * String allocation routines.
  42  * Strings handed out here are reclaimed at the top of the command
  43  * loop each time, so they need not be freed.
  44  */
  45
  46 #include "rcv.h"
  47 #include "extern.h"
  48
  49 /*
  50  * Allocate size more bytes of space and return the address of the
  51  * first byte to the caller.  An even number of bytes are always
  52  * allocated so that the space will always be on a word boundary.
  53  * The string spaces are of exponentially increasing size, to satisfy
  54  * the occasional user with enormous string size requests.
  55  */
  56
  57 char *
  58 salloc(int size)
  59 {
  60         char *t;
  61         int s, index;
  62         struct strings *sp;
  63
  64         s = size;
  65         s += (sizeof(char *) - 1);
  66         s &= ~(sizeof(char *) - 1);
  67         index = 0;
  68         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
  69                 if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
  70                         break;
  71                 if (sp->s_nleft >= s)
  72                         break;
  73                 index++;
  74         }
  75         if (sp >= &stringdope[NSPACE])
  76                 errx(1, "String too large");
  77         if (sp->s_topFree == NULL) {
  78                 index = sp - &stringdope[0];
  79                 if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
  80                         err(1, "No room for space %d", index);
  81                 sp->s_nextFree = sp->s_topFree;
  82                 sp->s_nleft = STRINGSIZE << index;
  83         }
  84         sp->s_nleft -= s;
  85         t = sp->s_nextFree;
  86         sp->s_nextFree += s;
  87         return (t);
  88 }
  89
  90 /*
  91  * Reset the string area to be empty.
  92  * Called to free all strings allocated
  93  * since last reset.
  94  */
  95 void
  96 sreset(void)
  97 {
  98         struct strings *sp;
  99         int index;
 100
 101         if (noreset)
 102                 return;
 103         index = 0;
 104         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
 105                 if (sp->s_topFree == NULL)
 106                         continue;
 107                 sp->s_nextFree = sp->s_topFree;
 108                 sp->s_nleft = STRINGSIZE << index;
 109                 index++;
 110         }
 111 }
 112
 113 /*
 114  * Make the string area permanent.
 115  * Meant to be called in main, after initialization.
 116  */
 117 void
 118 spreserve(void)
 119 {
 120         struct strings *sp;
 121
 122         for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
 123                 sp->s_topFree = NULL;
 124 }