xref: /freebsd/usr.bin/mail/strings.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
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 __FBSDID("$FreeBSD$");
39 
40 /*
41  * Mail -- a mail program
42  *
43  * String allocation routines.
44  * Strings handed out here are reclaimed at the top of the command
45  * loop each time, so they need not be freed.
46  */
47 
48 #include "rcv.h"
49 #include "extern.h"
50 
51 struct strings stringdope[NSPACE];
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(int size)
63 {
64 	char *t;
65 	int s, index;
66 	struct strings *sp;
67 
68 	s = size;
69 	s += (sizeof(char *) - 1);
70 	s &= ~(sizeof(char *) - 1);
71 	index = 0;
72 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
73 		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
74 			break;
75 		if (sp->s_nleft >= s)
76 			break;
77 		index++;
78 	}
79 	if (sp >= &stringdope[NSPACE])
80 		errx(1, "String too large");
81 	if (sp->s_topFree == NULL) {
82 		index = sp - &stringdope[0];
83 		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
84 			err(1, "No room for space %d", index);
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 void
100 sreset(void)
101 {
102 	struct strings *sp;
103 	int index;
104 
105 	if (noreset)
106 		return;
107 	index = 0;
108 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
109 		if (sp->s_topFree == NULL)
110 			continue;
111 		sp->s_nextFree = sp->s_topFree;
112 		sp->s_nleft = STRINGSIZE << index;
113 		index++;
114 	}
115 }
116 
117 /*
118  * Make the string area permanent.
119  * Meant to be called in main, after initialization.
120  */
121 void
122 spreserve(void)
123 {
124 	struct strings *sp;
125 
126 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
127 		sp->s_topFree = NULL;
128 }
129