NetBSD/usr.bin/mail/strings.c

156 lines
4.4 KiB
C

/* $NetBSD: strings.c,v 1.18 2010/01/12 14:45:31 christos Exp $ */
/*
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)strings.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: strings.c,v 1.18 2010/01/12 14:45:31 christos Exp $");
#endif
#endif /* not lint */
/*
* Mail -- a mail program
*
* String allocation routines.
* Strings handed out here are reclaimed at the top of the command
* loop each time, so they need not be freed.
*/
#include "rcv.h"
#include "extern.h"
#define STRINGSIZE ((unsigned) 128)/* Dynamic allocation units */
/*
* The pointers for the string allocation routines,
* there are NSPACE independent areas.
* The first holds STRINGSIZE bytes, the next
* twice as much, and so on.
*/
#define NSPACE 25 /* Total number of string spaces */
static struct strings {
char *s_topFree; /* Beginning of this area */
char *s_nextFree; /* Next alloctable place here */
size_t s_nleft; /* Number of bytes left here */
} stringdope[NSPACE];
/*
* 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.
*/
PUBLIC void *
salloc(size_t size)
{
char *t;
size_t s;
struct strings *sp;
int idx;
s = size;
s += (sizeof(char *) - 1);
s &= ~(sizeof(char *) - 1);
idx = 0;
for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
if (sp->s_topFree == NULL && (STRINGSIZE << idx) >= s)
break;
if (sp->s_nleft >= s)
break;
idx++;
}
if (sp >= &stringdope[NSPACE])
errx(EXIT_FAILURE, "String too large");
if (sp->s_topFree == NULL) {
idx = (int)(sp - &stringdope[0]);
sp->s_topFree = malloc(STRINGSIZE << idx);
if (sp->s_topFree == NULL)
errx(EXIT_FAILURE, "No room for space %d", idx);
sp->s_nextFree = sp->s_topFree;
sp->s_nleft = STRINGSIZE << idx;
}
sp->s_nleft -= s;
t = sp->s_nextFree;
sp->s_nextFree += s;
return t;
}
/*
* Allocate zeroed space for 'number' elments of size 'size'.
*/
PUBLIC void *
csalloc(size_t number, size_t size)
{
void *p;
p = salloc(number * size);
(void)memset(p, 0, number * size);
return p;
}
/*
* Reset the string area to be empty.
* Called to free all strings allocated
* since last reset.
*/
PUBLIC void
sreset(void)
{
struct strings *sp;
int idx;
if (noreset)
return;
idx = 0;
for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++) {
if (sp->s_topFree == NULL)
continue;
sp->s_nextFree = sp->s_topFree;
sp->s_nleft = STRINGSIZE << idx;
idx++;
}
}
/*
* Make the string area permanent.
* Meant to be called in main, after initialization.
*/
PUBLIC void
spreserve(void)
{
struct strings *sp;
for (sp = &stringdope[0]; sp < &stringdope[NSPACE]; sp++)
sp->s_topFree = NULL;
}