summaryrefslogtreecommitdiff
path: root/usr/src/cmd/mailx/stralloc.c
blob: 447586cc5784ae66b2ecf9008d3017e7f18654e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 1997 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
/*	  All Rights Reserved  	*/


/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * mailx -- a modified version of a University of California at Berkeley
 *	mail program
 *
 * Memory allocation routines.
 * Memory handed out here are reclaimed at the top of the command
 * loop each time, so they need not be freed.
 */

#include "rcv.h"
#include <locale.h>

static void		*lastptr;	/* addr of last buffer allocated */
static struct strings	*lastsp;	/* last string space allocated from */

/*
 * Allocate size more bytes of space and return the address of the
 * first byte to the caller.  An even number of bytes are always
 * allocated so that the space will always be on a word boundary.
 * The string spaces are of exponentially increasing size, to satisfy
 * the occasional user with enormous string size requests.
 */

void *
salloc(unsigned size)
{
	register char *t;
	register unsigned s;
	register struct strings *sp;
	int index;

	s = size;
#if defined(u3b) || defined(sparc)
	s += 3;		/* needs alignment on quad boundary */
	s &= ~03;
#elif defined(i386)
	s++;
	s &= ~01;
#else
#error Unknown architecture!
#endif
	index = 0;
	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
		if (sp->s_topFree == NOSTR && (STRINGSIZE << index) >= s)
			break;
		if (sp->s_nleft >= s)
			break;
		index++;
	}
	if (sp >= &stringdope[NSPACE])
		panic("String too large");
	if (sp->s_topFree == NOSTR) {
		index = sp - &stringdope[0];
		sp->s_topFree = (char *) calloc(STRINGSIZE << index,
		    (unsigned) 1);
		if (sp->s_topFree == NOSTR) {
			fprintf(stderr, gettext("No room for space %d\n"),
			    index);
			panic("Internal error");
		}
		sp->s_nextFree = sp->s_topFree;
		sp->s_nleft = STRINGSIZE << index;
	}
	sp->s_nleft -= s;
	t = sp->s_nextFree;
	sp->s_nextFree += s;
	lastptr = t;
	lastsp = sp;
	return(t);
}

/*
 * Reallocate size bytes of space and return the address of the
 * first byte to the caller.  The old data is copied into the new area.
 */

void *
srealloc(void *optr, unsigned size)
{
	void *nptr;

	/* if we just want to expand the last allocation, that's easy */
	if (optr == lastptr) {
		register unsigned s, delta;
		register struct strings *sp = lastsp;

		s = size;
#if defined(u3b) || defined(sparc)
		s += 3;		/* needs alignment on quad boundary */
		s &= ~03;
#elif defined(i386)
		s++;
		s &= ~01;
#else
#error Unknown architecture!
#endif /* defined(u3b) || defined(sparc) */
		delta = s - (sp->s_nextFree - (char *)optr);
		if (delta <= sp->s_nleft) {
			sp->s_nextFree += delta;
			sp->s_nleft -= delta;
			return (optr);
		}
	}
	nptr = salloc(size);
	if (nptr)
		memcpy(nptr, optr, size);	/* XXX - copying too much */
	return nptr;
}

/*
 * Reset the string area to be empty.
 * Called to free all strings allocated
 * since last reset.
 */
void 
sreset(void)
{
	register struct strings *sp;
	register int index;

	if (noreset)
		return;
	minit();
	index = 0;
	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
		if (sp->s_topFree == NOSTR)
			continue;
		sp->s_nextFree = sp->s_topFree;
		sp->s_nleft = STRINGSIZE << index;
		index++;
	}
	lastptr = NULL;
	lastsp = NULL;
}