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strings.c revision 1.11 
      1 /*	$NetBSD: strings.c,v 1.11 2005/07/19 01:38:38 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 1.11 2005/07/19 01:38:38 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 /*
     53  * Allocate size more bytes of space and return the address of the
     54  * first byte to the caller.  An even number of bytes are always
     55  * allocated so that the space will always be on a word boundary.
     56  * The string spaces are of exponentially increasing size, to satisfy
     57  * the occasional user with enormous string size requests.
     58  */
     59 
     60 void *
     61 salloc(int size)
     62 {
     63 	char *t;
     64 	int s;
     65 	struct strings *sp;
     66 	int idx;
     67 
     68 	s = size;
     69 	s += (sizeof (char *) - 1);
     70 	s &= ~(sizeof (char *) - 1);
     71 	idx = 0;
     72 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
     73 		if (sp->s_topFree == NULL && (STRINGSIZE << idx) >= s)
     74 			break;
     75 		if (sp->s_nleft >= s)
     76 			break;
     77 		idx++;
     78 	}
     79 	if (sp >= &stringdope[NSPACE])
     80 		errx(1, "String too large");
     81 	if (sp->s_topFree == NULL) {
     82 		idx = sp - &stringdope[0];
     83 		sp->s_topFree = malloc(STRINGSIZE << idx);
     84 		if (sp->s_topFree == NULL)
     85 			errx(1, "No room for space %d", idx);
     86 		sp->s_nextFree = sp->s_topFree;
     87 		sp->s_nleft = STRINGSIZE << idx;
     88 	}
     89 	sp->s_nleft -= s;
     90 	t = sp->s_nextFree;
     91 	sp->s_nextFree += s;
     92 	return(t);
     93 }
     94 
     95 /*
     96  * Reset the string area to be empty.
     97  * Called to free all strings allocated
     98  * since last reset.
     99  */
    100 void
    101 sreset(void)
    102 {
    103 	struct strings *sp;
    104 	int idx;
    105 
    106 	if (noreset)
    107 		return;
    108 	idx = 0;
    109 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
    110 		if (sp->s_topFree == NULL)
    111 			continue;
    112 		sp->s_nextFree = sp->s_topFree;
    113 		sp->s_nleft = STRINGSIZE << idx;
    114 		idx++;
    115 	}
    116 }
    117 
    118 /*
    119  * Make the string area permanent.
    120  * Meant to be called in main, after initialization.
    121  */
    122 void
    123 spreserve(void)
    124 {
    125 	struct strings *sp;
    126 
    127 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
    128 		sp->s_topFree = NULL;
    129 }
    130