xref: /netbsd-src/usr.bin/mail/strings.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1980 Regents of the University of California.
3  * 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 /*static char sccsid[] = "from: @(#)strings.c	5.9 (Berkeley) 6/1/90";*/
36 static char rcsid[] = "$Id: strings.c,v 1.2 1993/08/01 18:12:56 mycroft Exp $";
37 #endif /* not lint */
38 
39 /*
40  * Mail -- a mail program
41  *
42  * String allocation routines.
43  * Strings handed out here are reclaimed at the top of the command
44  * loop each time, so they need not be freed.
45  */
46 
47 #include "rcv.h"
48 
49 /*
50  * Allocate size more bytes of space and return the address of the
51  * first byte to the caller.  An even number of bytes are always
52  * allocated so that the space will always be on a word boundary.
53  * The string spaces are of exponentially increasing size, to satisfy
54  * the occasional user with enormous string size requests.
55  */
56 
57 char *
58 salloc(size)
59 {
60 	register char *t;
61 	register int s;
62 	register struct strings *sp;
63 	int index;
64 
65 	s = size;
66 	s += 3;
67 	s &= ~03;
68 	index = 0;
69 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
70 		if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
71 			break;
72 		if (sp->s_nleft >= s)
73 			break;
74 		index++;
75 	}
76 	if (sp >= &stringdope[NSPACE])
77 		panic("String too large");
78 	if (sp->s_topFree == NOSTR) {
79 		index = sp - &stringdope[0];
80 		sp->s_topFree = malloc(STRINGSIZE << index);
81 		if (sp->s_topFree == NOSTR) {
82 			fprintf(stderr, "No room for space %d\n", index);
83 			panic("Internal error");
84 		}
85 		sp->s_nextFree = sp->s_topFree;
86 		sp->s_nleft = STRINGSIZE << index;
87 	}
88 	sp->s_nleft -= s;
89 	t = sp->s_nextFree;
90 	sp->s_nextFree += s;
91 	return(t);
92 }
93 
94 /*
95  * Reset the string area to be empty.
96  * Called to free all strings allocated
97  * since last reset.
98  */
99 sreset()
100 {
101 	register struct strings *sp;
102 	register int index;
103 
104 	if (noreset)
105 		return;
106 	index = 0;
107 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
108 		if (sp->s_topFree == NOSTR)
109 			continue;
110 		sp->s_nextFree = sp->s_topFree;
111 		sp->s_nleft = STRINGSIZE << index;
112 		index++;
113 	}
114 }
115 
116 /*
117  * Make the string area permanent.
118  * Meant to be called in main, after initialization.
119  */
120 spreserve()
121 {
122 	register struct strings *sp;
123 
124 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
125 		sp->s_topFree = NOSTR;
126 }
127