xref: /freebsd/usr.bin/mail/strings.c (revision da52b4caaf187775f6b56a72c6b16e94ad728f7b)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 #if 0
32 static char sccsid[] = "@(#)strings.c	8.1 (Berkeley) 6/6/93";
33 #endif
34 #endif /* not lint */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 /*
39  * Mail -- a mail program
40  *
41  * String allocation routines.
42  * Strings handed out here are reclaimed at the top of the command
43  * loop each time, so they need not be freed.
44  */
45 
46 #include "rcv.h"
47 #include "extern.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 	int size;
60 {
61 	char *t;
62 	int s, index;
63 	struct strings *sp;
64 
65 	s = size;
66 	s += (sizeof(char *) - 1);
67 	s &= ~(sizeof(char *) - 1);
68 	index = 0;
69 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
70 		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
71 			break;
72 		if (sp->s_nleft >= s)
73 			break;
74 		index++;
75 	}
76 	if (sp >= &stringdope[NSPACE])
77 		errx(1, "String too large");
78 	if (sp->s_topFree == NULL) {
79 		index = sp - &stringdope[0];
80 		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
81 			err(1, "No room for space %d", index);
82 		sp->s_nextFree = sp->s_topFree;
83 		sp->s_nleft = STRINGSIZE << index;
84 	}
85 	sp->s_nleft -= s;
86 	t = sp->s_nextFree;
87 	sp->s_nextFree += s;
88 	return (t);
89 }
90 
91 /*
92  * Reset the string area to be empty.
93  * Called to free all strings allocated
94  * since last reset.
95  */
96 void
97 sreset()
98 {
99 	struct strings *sp;
100 	int index;
101 
102 	if (noreset)
103 		return;
104 	index = 0;
105 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
106 		if (sp->s_topFree == NULL)
107 			continue;
108 		sp->s_nextFree = sp->s_topFree;
109 		sp->s_nleft = STRINGSIZE << index;
110 		index++;
111 	}
112 }
113 
114 /*
115  * Make the string area permanent.
116  * Meant to be called in main, after initialization.
117  */
118 void
119 spreserve()
120 {
121 	struct strings *sp;
122 
123 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
124 		sp->s_topFree = NULL;
125 }
126