/usr.bin/mail/strings.c

  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 * 4. 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
 30#ifndef lint
 31#if 0
 32static char sccsid[] = "@(#)strings.c	8.1 (Berkeley) 6/6/93";
 33#endif
 34#endif /* not lint */
 35#include <sys/cdefs.h>
 36__FBSDID("$FreeBSD$");
 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
 57char *
 58salloc(int size)
 59{
 60	char *t;
 61	int s, index;
 62	struct strings *sp;
 63
 64	s = size;
 65	s += (sizeof(char *) - 1);
 66	s &= ~(sizeof(char *) - 1);
 67	index = 0;
 68	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
 69		if (sp->s_topFree == NULL && (STRINGSIZE << index) >= s)
 70			break;
 71		if (sp->s_nleft >= s)
 72			break;
 73		index++;
 74	}
 75	if (sp >= &stringdope[NSPACE])
 76		errx(1, "String too large");
 77	if (sp->s_topFree == NULL) {
 78		index = sp - &stringdope[0];
 79		if ((sp->s_topFree = malloc(STRINGSIZE << index)) == NULL)
 80			err(1, "No room for space %d", index);
 81		sp->s_nextFree = sp->s_topFree;
 82		sp->s_nleft = STRINGSIZE << index;
 83	}
 84	sp->s_nleft -= s;
 85	t = sp->s_nextFree;
 86	sp->s_nextFree += s;
 87	return (t);
 88}
 89
 90/*
 91 * Reset the string area to be empty.
 92 * Called to free all strings allocated
 93 * since last reset.
 94 */
 95void
 96sreset(void)
 97{
 98	struct strings *sp;
 99	int index;
100
101	if (noreset)
102		return;
103	index = 0;
104	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
105		if (sp->s_topFree == NULL)
106			continue;
107		sp->s_nextFree = sp->s_topFree;
108		sp->s_nleft = STRINGSIZE << index;
109		index++;
110	}
111}
112
113/*
114 * Make the string area permanent.
115 * Meant to be called in main, after initialization.
116 */
117void
118spreserve(void)
119{
120	struct strings *sp;
121
122	for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
123		sp->s_topFree = NULL;
124}