xref: /freebsd/usr.bin/mail/strings.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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(int size)
59 {
60 	char *t;
61 	int s, index;
62 	struct strings *sp;
63 
64 	s = size;
65 	s += (sizeof(char *) - 1);
66 	s &= ~(sizeof(char *) - 1);
67 	index = 0;
68 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
69 		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
70 			break;
71 		if (sp->s_nleft >= s)
72 			break;
73 		index++;
74 	}
75 	if (sp >= &stringdope[NSPACE])
76 		errx(1, "String too large");
77 	if (sp->s_topFree == NULL) {
78 		index = sp - &stringdope[0];
79 		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
80 			err(1, "No room for space %d", index);
81 		sp->s_nextFree = sp->s_topFree;
82 		sp->s_nleft = STRINGSIZE << index;
83 	}
84 	sp->s_nleft -= s;
85 	t = sp->s_nextFree;
86 	sp->s_nextFree += s;
87 	return (t);
88 }
89 
90 /*
91  * Reset the string area to be empty.
92  * Called to free all strings allocated
93  * since last reset.
94  */
95 void
96 sreset(void)
97 {
98 	struct strings *sp;
99 	int index;
100 
101 	if (noreset)
102 		return;
103 	index = 0;
104 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
105 		if (sp->s_topFree == NULL)
106 			continue;
107 		sp->s_nextFree = sp->s_topFree;
108 		sp->s_nleft = STRINGSIZE << index;
109 		index++;
110 	}
111 }
112 
113 /*
114  * Make the string area permanent.
115  * Meant to be called in main, after initialization.
116  */
117 void
118 spreserve(void)
119 {
120 	struct strings *sp;
121 
122 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
123 		sp->s_topFree = NULL;
124 }
125