/* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */
/* $FreeBSD$ */
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
* All rights reserved.
* Copyright (c) 2020 Kyle Evans <kevans@FreeBSD.org>
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/*
* A really poor man's queue. It does only what it has to and gets out of
* Dodge. It is used in place of <sys/queue.h> to get a better performance.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/queue.h>
#include <stdlib.h>
#include <string.h>
#include "grep.h"
typedef struct str qentry_t;
static long long filled;
static qentry_t *qend, *qpool;
/*
* qnext is the next entry to populate. qlist is where the list actually
* starts, for the purposes of printing.
*/
static qentry_t *qlist, *qnext;
void
initqueue(void)
{
qlist = qnext = qpool = grep_calloc(Bflag, sizeof(*qpool));
qend = qpool + (Bflag - 1);
}
static qentry_t *
advqueue(qentry_t *itemp)
{
if (itemp == qend)
return (qpool);
return (itemp + 1);
}
/*
* Enqueue another line; return true if we've dequeued a line as a result
*/
bool
enqueue(struct str *x)
{
qentry_t *item;
bool rotated;
item = qnext;
qnext = advqueue(qnext);
rotated = false;
if (filled < Bflag) {
filled++;
} else if (filled == Bflag) {
/* We had already filled up coming in; just rotate. */
qlist = advqueue(qlist);
rotated = true;
free(item->dat);
}
/* len + 1 for NUL-terminator */
item->dat = grep_malloc(sizeof(char) * x->len + 1);
item->len = x->len;
item->line_no = x->line_no;
item->boff = x->boff;
item->off = x->off;
memcpy(item->dat, x->dat, x->len);
item->dat[x->len] = '\0';
item->file = x->file;
return (rotated);
}
void
printqueue(void)
{
qentry_t *item;
item = qlist;
do {
/* Buffer must have ended early. */
if (item->dat == NULL)
break;
grep_printline(item, '-');
free(item->dat);
item->dat = NULL;
item = advqueue(item);
} while (item != qlist);
qlist = qnext = qpool;
filled = 0;
}
void
clearqueue(void)
{
qentry_t *item;
item = qlist;
do {
free(item->dat);
item->dat = NULL;
item = advqueue(item);
} while (item != qlist);
qlist = qnext = qpool;
filled = 0;
}
