xref: /freebsd/usr.bin/mail/strings.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
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 #endif /* not lint */
34 #include <sys/cdefs.h>
35 /*
36  * Mail -- a mail program
37  *
38  * String allocation routines.
39  * Strings handed out here are reclaimed at the top of the command
40  * loop each time, so they need not be freed.
41  */
42 
43 #include "rcv.h"
44 #include "extern.h"
45 
46 struct strings stringdope[NSPACE];
47 
48 /*
49  * Allocate size more bytes of space and return the address of the
50  * first byte to the caller.  An even number of bytes are always
51  * allocated so that the space will always be on a word boundary.
52  * The string spaces are of exponentially increasing size, to satisfy
53  * the occasional user with enormous string size requests.
54  */
55 
56 char *
57 salloc(int size)
58 {
59 	char *t;
60 	int s, index;
61 	struct strings *sp;
62 
63 	s = size;
64 	s += (sizeof(char *) - 1);
65 	s &= ~(sizeof(char *) - 1);
66 	index = 0;
67 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
68 		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
69 			break;
70 		if (sp->s_nleft >= s)
71 			break;
72 		index++;
73 	}
74 	if (sp >= &stringdope[NSPACE])
75 		errx(1, "String too large");
76 	if (sp->s_topFree == NULL) {
77 		index = sp - &stringdope[0];
78 		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
79 			err(1, "No room for space %d", index);
80 		sp->s_nextFree = sp->s_topFree;
81 		sp->s_nleft = STRINGSIZE << index;
82 	}
83 	sp->s_nleft -= s;
84 	t = sp->s_nextFree;
85 	sp->s_nextFree += s;
86 	return (t);
87 }
88 
89 /*
90  * Reset the string area to be empty.
91  * Called to free all strings allocated
92  * since last reset.
93  */
94 void
95 sreset(void)
96 {
97 	struct strings *sp;
98 	int index;
99 
100 	if (noreset)
101 		return;
102 	index = 0;
103 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
104 		if (sp->s_topFree == NULL)
105 			continue;
106 		sp->s_nextFree = sp->s_topFree;
107 		sp->s_nleft = STRINGSIZE << index;
108 		index++;
109 	}
110 }
111 
112 /*
113  * Make the string area permanent.
114  * Meant to be called in main, after initialization.
115  */
116 void
117 spreserve(void)
118 {
119 	struct strings *sp;
120 
121 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
122 		sp->s_topFree = NULL;
123 }
124