Home | History | Annotate | Line # | Download | only in mail
strings.c revision 1.15 
      1 /*	$NetBSD: strings.c,v 1.15 2006/11/28 18:45:32 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 1.15 2006/11/28 18:45:32 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 	unsigned 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 
     75 PUBLIC void *
     76 salloc(size_t size)
     77 {
     78 	char *t;
     79 	size_t s;
     80 	struct strings *sp;
     81 	int idx;
     82 
     83 	s = size;
     84 	s += (sizeof (char *) - 1);
     85 	s &= ~(sizeof (char *) - 1);
     86 	idx = 0;
     87 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
     88 		if (sp->s_topFree == NULL && (STRINGSIZE << idx) >= s)
     89 			break;
     90 		if (sp->s_nleft >= s)
     91 			break;
     92 		idx++;
     93 	}
     94 	if (sp >= &stringdope[NSPACE])
     95 		errx(1, "String too large");
     96 	if (sp->s_topFree == NULL) {
     97 		idx = sp - &stringdope[0];
     98 		sp->s_topFree = malloc(STRINGSIZE << idx);
     99 		if (sp->s_topFree == NULL)
    100 			errx(1, "No room for space %d", idx);
    101 		sp->s_nextFree = sp->s_topFree;
    102 		sp->s_nleft = STRINGSIZE << idx;
    103 	}
    104 	sp->s_nleft -= s;
    105 	t = sp->s_nextFree;
    106 	sp->s_nextFree += s;
    107 	return t;
    108 }
    109 
    110 /*
    111  * Allocate zeroed space for 'number' elments of size 'size'.
    112  */
    113 PUBLIC void *
    114 csalloc(size_t number, size_t size)
    115 {
    116 	void *p;
    117 	p = salloc(number * size);
    118 	(void)memset(p, 0, number * size);
    119 	return p;
    120 }
    121 
    122 /*
    123  * Reset the string area to be empty.
    124  * Called to free all strings allocated
    125  * since last reset.
    126  */
    127 PUBLIC void
    128 sreset(void)
    129 {
    130 	struct strings *sp;
    131 	int idx;
    132 
    133 	if (noreset)
    134 		return;
    135 	idx = 0;
    136 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
    137 		if (sp->s_topFree == NULL)
    138 			continue;
    139 		sp->s_nextFree = sp->s_topFree;
    140 		sp->s_nleft = STRINGSIZE << idx;
    141 		idx++;
    142 	}
    143 }
    144 
    145 /*
    146  * Make the string area permanent.
    147  * Meant to be called in main, after initialization.
    148  */
    149 PUBLIC void
    150 spreserve(void)
    151 {
    152 	struct strings *sp;
    153 
    154 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
    155 		sp->s_topFree = NULL;
    156 }
    157