xref: /dragonfly/usr.bin/mail/strings.c (revision 67640b13)
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  * 3. 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  * @(#)strings.c	8.1 (Berkeley) 6/6/93
30  * $FreeBSD: src/usr.bin/mail/strings.c,v 1.2.6.3 2003/01/06 05:46:03 mikeh Exp $
31  * $DragonFly: src/usr.bin/mail/strings.c,v 1.3 2003/10/04 20:36:48 hmp Exp $
32  */
33 
34 /*
35  * Mail -- a mail program
36  *
37  * String allocation routines.
38  * Strings handed out here are reclaimed at the top of the command
39  * loop each time, so they need not be freed.
40  */
41 
42 #include "rcv.h"
43 #include "extern.h"
44 
45 /*
46  * Allocate size more bytes of space and return the address of the
47  * first byte to the caller.  An even number of bytes are always
48  * allocated so that the space will always be on a word boundary.
49  * The string spaces are of exponentially increasing size, to satisfy
50  * the occasional user with enormous string size requests.
51  */
52 
53 char *
54 salloc(int size)
55 {
56 	char *t;
57 	int s, index;
58 	struct strings *sp;
59 
60 	s = size;
61 	s += (sizeof(char *) - 1);
62 	s &= ~(sizeof(char *) - 1);
63 	index = 0;
64 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
65 		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
66 			break;
67 		if (sp->s_nleft >= s)
68 			break;
69 		index++;
70 	}
71 	if (sp >= &stringdope[NSPACE])
72 		errx(1, "String too large");
73 	if (sp->s_topFree == NULL) {
74 		index = sp - &stringdope[0];
75 		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
76 			err(1, "No room for space %d", index);
77 		sp->s_nextFree = sp->s_topFree;
78 		sp->s_nleft = STRINGSIZE << index;
79 	}
80 	sp->s_nleft -= s;
81 	t = sp->s_nextFree;
82 	sp->s_nextFree += s;
83 	return (t);
84 }
85 
86 /*
87  * Reset the string area to be empty.
88  * Called to free all strings allocated
89  * since last reset.
90  */
91 void
92 sreset(void)
93 {
94 	struct strings *sp;
95 	int index;
96 
97 	if (noreset)
98 		return;
99 	index = 0;
100 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
101 		if (sp->s_topFree == NULL)
102 			continue;
103 		sp->s_nextFree = sp->s_topFree;
104 		sp->s_nleft = STRINGSIZE << index;
105 		index++;
106 	}
107 }
108 
109 /*
110  * Make the string area permanent.
111  * Meant to be called in main, after initialization.
112  */
113 void
114 spreserve(void)
115 {
116 	struct strings *sp;
117 
118 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
119 		sp->s_topFree = NULL;
120 }
121