xref: /netbsd-src/usr.bin/mail/strings.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: strings.c,v 1.6 1997/10/19 05:03:54 lukem 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)strings.c	8.1 (Berkeley) 6/6/93";
40 #else
41 __RCSID("$NetBSD: strings.c,v 1.6 1997/10/19 05:03:54 lukem Exp $");
42 #endif
43 #endif /* not lint */
44 
45 /*
46  * Mail -- a mail program
47  *
48  * String allocation routines.
49  * Strings handed out here are reclaimed at the top of the command
50  * loop each time, so they need not be freed.
51  */
52 
53 #include "rcv.h"
54 #include "extern.h"
55 
56 /*
57  * Allocate size more bytes of space and return the address of the
58  * first byte to the caller.  An even number of bytes are always
59  * allocated so that the space will always be on a word boundary.
60  * The string spaces are of exponentially increasing size, to satisfy
61  * the occasional user with enormous string size requests.
62  */
63 
64 char *
65 salloc(size)
66 	int size;
67 {
68 	char *t;
69 	int s;
70 	struct strings *sp;
71 	int index;
72 
73 	s = size;
74 	s += (sizeof (char *) - 1);
75 	s &= ~(sizeof (char *) - 1);
76 	index = 0;
77 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
78 		if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
79 			break;
80 		if (sp->s_nleft >= s)
81 			break;
82 		index++;
83 	}
84 	if (sp >= &stringdope[NSPACE])
85 		errx(1, "String too large");
86 	if (sp->s_topFree == NOSTR) {
87 		index = sp - &stringdope[0];
88 		sp->s_topFree = malloc(STRINGSIZE << index);
89 		if (sp->s_topFree == NOSTR)
90 			errx(1, "No room for space %d", index);
91 		sp->s_nextFree = sp->s_topFree;
92 		sp->s_nleft = STRINGSIZE << index;
93 	}
94 	sp->s_nleft -= s;
95 	t = sp->s_nextFree;
96 	sp->s_nextFree += s;
97 	return(t);
98 }
99 
100 /*
101  * Reset the string area to be empty.
102  * Called to free all strings allocated
103  * since last reset.
104  */
105 void
106 sreset()
107 {
108 	struct strings *sp;
109 	int index;
110 
111 	if (noreset)
112 		return;
113 	index = 0;
114 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
115 		if (sp->s_topFree == NOSTR)
116 			continue;
117 		sp->s_nextFree = sp->s_topFree;
118 		sp->s_nleft = STRINGSIZE << index;
119 		index++;
120 	}
121 }
122 
123 /*
124  * Make the string area permanent.
125  * Meant to be called in main, after initialization.
126  */
127 void
128 spreserve()
129 {
130 	struct strings *sp;
131 
132 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
133 		sp->s_topFree = NOSTR;
134 }
135