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      1 /*	$NetBSD: strings.c,v 1.19 2024/03/17 21:48:02 andvar 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 1.19 2024/03/17 21:48:02 andvar 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(EXIT_FAILURE, "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(EXIT_FAILURE, "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' elements 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 }
    156