xref: /freebsd/usr.bin/mail/strings.c (revision 0c3a8314c00f58f16823e8cd6186757d5e8bcdcc)
1 /*
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 #if 0
36 static char sccsid[] = "@(#)strings.c	8.1 (Berkeley) 6/6/93";
37 #endif
38 static const char rcsid[] =
39   "$FreeBSD$";
40 #endif /* not lint */
41 
42 /*
43  * Mail -- a mail program
44  *
45  * String allocation routines.
46  * Strings handed out here are reclaimed at the top of the command
47  * loop each time, so they need not be freed.
48  */
49 
50 #include "rcv.h"
51 #include "extern.h"
52 
53 /*
54  * Allocate size more bytes of space and return the address of the
55  * first byte to the caller.  An even number of bytes are always
56  * allocated so that the space will always be on a word boundary.
57  * The string spaces are of exponentially increasing size, to satisfy
58  * the occasional user with enormous string size requests.
59  */
60 
61 char *
62 salloc(size)
63 	int size;
64 {
65 	register char *t;
66 	register int s;
67 	register struct strings *sp;
68 	int index;
69 
70 	s = size;
71 	s += (sizeof (char *) - 1);
72 	s &= ~(sizeof (char *) - 1);
73 	index = 0;
74 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
75 		if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
76 			break;
77 		if (sp->s_nleft >= s)
78 			break;
79 		index++;
80 	}
81 	if (sp >= &stringdope[NSPACE])
82 		errx(1, "String too large");
83 	if (sp->s_topFree == NOSTR) {
84 		index = sp - &stringdope[0];
85 		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NOSTR)
86 			err(1, "No room for space %d", index);
87 		sp->s_nextFree = sp->s_topFree;
88 		sp->s_nleft = STRINGSIZE << index;
89 	}
90 	sp->s_nleft -= s;
91 	t = sp->s_nextFree;
92 	sp->s_nextFree += s;
93 	return(t);
94 }
95 
96 /*
97  * Reset the string area to be empty.
98  * Called to free all strings allocated
99  * since last reset.
100  */
101 void
102 sreset()
103 {
104 	register struct strings *sp;
105 	register int index;
106 
107 	if (noreset)
108 		return;
109 	index = 0;
110 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
111 		if (sp->s_topFree == NOSTR)
112 			continue;
113 		sp->s_nextFree = sp->s_topFree;
114 		sp->s_nleft = STRINGSIZE << index;
115 		index++;
116 	}
117 }
118 
119 /*
120  * Make the string area permanent.
121  * Meant to be called in main, after initialization.
122  */
123 void
124 spreserve()
125 {
126 	register struct strings *sp;
127 
128 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
129 		sp->s_topFree = NOSTR;
130 }
131