xref: /openbsd/usr.bin/mail/strings.c (revision 5af055cd)
1 /*	$OpenBSD: strings.c,v 1.10 2015/10/16 17:56:07 mmcc Exp $	*/
2 /*	$NetBSD: strings.c,v 1.5 1996/06/08 19:48:40 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Mail -- a mail program
35  *
36  * String allocation routines.
37  * Strings handed out here are reclaimed at the top of the command
38  * loop each time, so they need not be freed.
39  */
40 
41 #include "rcv.h"
42 #include "extern.h"
43 
44 /*
45  * Allocate size more bytes of space and return the address of the
46  * first byte to the caller.  An even number of bytes are always
47  * allocated so that the space will always be on a word boundary.
48  * The string spaces are of exponentially increasing size, to satisfy
49  * the occasional user with enormous string size requests.
50  */
51 char *
52 salloc(int size)
53 {
54 	char *t;
55 	int s;
56 	struct strings *sp;
57 	int index;
58 
59 	s = size;
60 	s += (sizeof(char *) - 1);
61 	s &= ~(sizeof(char *) - 1);
62 	index = 0;
63 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
64 		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
65 			break;
66 		if (sp->s_nleft >= s)
67 			break;
68 		index++;
69 	}
70 	if (sp >= &stringdope[NSPACE])
71 		errx(1, "String too large");
72 	if (sp->s_topFree == NULL) {
73 		index = sp - &stringdope[0];
74 		sp->s_topFree = malloc(STRINGSIZE << index);
75 		if (sp->s_topFree == NULL)
76 			err(1, "malloc");
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