xref: /freebsd/usr.bin/mail/strings.c (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static char sccsid[] = "@(#)strings.c	8.1 (Berkeley) 6/6/93";
36 #endif /* not lint */
37 
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 /*
50  * Allocate size more bytes of space and return the address of the
51  * first byte to the caller.  An even number of bytes are always
52  * allocated so that the space will always be on a word boundary.
53  * The string spaces are of exponentially increasing size, to satisfy
54  * the occasional user with enormous string size requests.
55  */
56 
57 char *
58 salloc(size)
59 	int size;
60 {
61 	register char *t;
62 	register int s;
63 	register struct strings *sp;
64 	int index;
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 == NOSTR && (STRINGSIZE << index) >= s)
72 			break;
73 		if (sp->s_nleft >= s)
74 			break;
75 		index++;
76 	}
77 	if (sp >= &stringdope[NSPACE])
78 		panic("String too large");
79 	if (sp->s_topFree == NOSTR) {
80 		index = sp - &stringdope[0];
81 		sp->s_topFree = malloc(STRINGSIZE << index);
82 		if (sp->s_topFree == NOSTR) {
83 			fprintf(stderr, "No room for space %d\n", index);
84 			panic("Internal error");
85 		}
86 		sp->s_nextFree = sp->s_topFree;
87 		sp->s_nleft = STRINGSIZE << index;
88 	}
89 	sp->s_nleft -= s;
90 	t = sp->s_nextFree;
91 	sp->s_nextFree += s;
92 	return(t);
93 }
94 
95 /*
96  * Reset the string area to be empty.
97  * Called to free all strings allocated
98  * since last reset.
99  */
100 void
101 sreset()
102 {
103 	register struct strings *sp;
104 	register int index;
105 
106 	if (noreset)
107 		return;
108 	index = 0;
109 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
110 		if (sp->s_topFree == NOSTR)
111 			continue;
112 		sp->s_nextFree = sp->s_topFree;
113 		sp->s_nleft = STRINGSIZE << index;
114 		index++;
115 	}
116 }
117 
118 /*
119  * Make the string area permanent.
120  * Meant to be called in main, after initialization.
121  */
122 void
123 spreserve()
124 {
125 	register struct strings *sp;
126 
127 	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
128 		sp->s_topFree = NOSTR;
129 }
130