xref: /freebsd/usr.bin/mail/strings.c (revision 5e3190f700637fcfc1a52daeaa4a031fdd2557c7)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)strings.c	8.1 (Berkeley) 6/6/93";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
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 struct strings stringdope[NSPACE];
50 
51 /*
52  * Allocate size more bytes of space and return the address of the
53  * first byte to the caller.  An even number of bytes are always
54  * allocated so that the space will always be on a word boundary.
55  * The string spaces are of exponentially increasing size, to satisfy
56  * the occasional user with enormous string size requests.
57  */
58 
59 char *
60 salloc(int size)
61 {
62 	char *t;
63 	int s, index;
64 	struct strings *sp;
65 
66 	s = size;
67 	s += (sizeof(char *) - 1);
68 	s &= ~(sizeof(char *) - 1);
69 	index = 0;
70 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
71 		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
72 			break;
73 		if (sp->s_nleft >= s)
74 			break;
75 		index++;
76 	}
77 	if (sp >= &stringdope[NSPACE])
78 		errx(1, "String too large");
79 	if (sp->s_topFree == NULL) {
80 		index = sp - &stringdope[0];
81 		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
82 			err(1, "No room for space %d", index);
83 		sp->s_nextFree = sp->s_topFree;
84 		sp->s_nleft = STRINGSIZE << index;
85 	}
86 	sp->s_nleft -= s;
87 	t = sp->s_nextFree;
88 	sp->s_nextFree += s;
89 	return (t);
90 }
91 
92 /*
93  * Reset the string area to be empty.
94  * Called to free all strings allocated
95  * since last reset.
96  */
97 void
98 sreset(void)
99 {
100 	struct strings *sp;
101 	int index;
102 
103 	if (noreset)
104 		return;
105 	index = 0;
106 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
107 		if (sp->s_topFree == NULL)
108 			continue;
109 		sp->s_nextFree = sp->s_topFree;
110 		sp->s_nleft = STRINGSIZE << index;
111 		index++;
112 	}
113 }
114 
115 /*
116  * Make the string area permanent.
117  * Meant to be called in main, after initialization.
118  */
119 void
120 spreserve(void)
121 {
122 	struct strings *sp;
123 
124 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
125 		sp->s_topFree = NULL;
126 }
127