xref: /netbsd-src/usr.bin/mail/strings.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: strings.c,v 1.12 2005/07/19 23:07:10 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 1.12 2005/07/19 23:07:10 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(size_t 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