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File: [local] / src / usr.bin / grep / queue.c (download)

Revision 1.7, Fri Jan 16 06:40:08 2015 UTC (9 years, 4 months ago) by deraadt
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE, OPENBSD_7_5, OPENBSD_7_4_BASE, OPENBSD_7_4, OPENBSD_7_3_BASE, OPENBSD_7_3, OPENBSD_7_2_BASE, OPENBSD_7_2, OPENBSD_7_1_BASE, OPENBSD_7_1, OPENBSD_7_0_BASE, OPENBSD_7_0, OPENBSD_6_9_BASE, OPENBSD_6_9, OPENBSD_6_8_BASE, OPENBSD_6_8, OPENBSD_6_7_BASE, OPENBSD_6_7, OPENBSD_6_6_BASE, OPENBSD_6_6, OPENBSD_6_5_BASE, OPENBSD_6_5, OPENBSD_6_4_BASE, OPENBSD_6_4, OPENBSD_6_3_BASE, OPENBSD_6_3, OPENBSD_6_2_BASE, OPENBSD_6_2, OPENBSD_6_1_BASE, OPENBSD_6_1, OPENBSD_6_0_BASE, OPENBSD_6_0, OPENBSD_5_9_BASE, OPENBSD_5_9, OPENBSD_5_8_BASE, OPENBSD_5_8, OPENBSD_5_7_BASE, OPENBSD_5_7, HEAD
Changes since 1.6: +1 -3 lines 

Replace <sys/param.h> with <limits.h> and other less dirty headers where
possible.  Annotate <sys/param.h> lines with their current reasons.  Switch
to PATH_MAX, NGROUPS_MAX, HOST_NAME_MAX+1, LOGIN_NAME_MAX, etc.  Change
MIN() and MAX() to local definitions of MINIMUM() and MAXIMUM() where
sensible to avoid pulling in the pollution.  These are the files confirmed
through binary verification.
ok guenther, millert, doug (helped with the verification protocol)

/*	$OpenBSD: queue.c,v 1.7 2015/01/16 06:40:08 deraadt Exp $	*/

/*-
 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
 * 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.
 *
 * 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.
 */

#include <stdlib.h>
#include <string.h>

#include "grep.h"

typedef struct queue {
	struct queue   *next;
	str_t		data;
} queue_t;

static queue_t	*q_head, *q_tail;
static int	 count;

static queue_t	*dequeue(void);

void
initqueue(void)
{
	q_head = q_tail = NULL;
}

static void
free_item(queue_t *item)
{
	free(item);
}

void
enqueue(str_t *x)
{
	queue_t	*item;

	item = grep_malloc(sizeof *item + x->len);
	item->data.len = x->len;
	item->data.line_no = x->line_no;
	item->data.off = x->off;
	item->data.dat = (char *)item + sizeof *item;
	memcpy(item->data.dat, x->dat, x->len);
	item->data.file = x->file;
	item->next = NULL;

	if (!q_head) {
		q_head = q_tail = item;
	} else {
		q_tail->next = item;
		q_tail = item;
	}

	if (++count > Bflag)
		free_item(dequeue());
}

static queue_t *
dequeue(void)
{
	queue_t	*item;

	if (q_head == NULL)
		return NULL;

	--count;
	item = q_head;
	q_head = item->next;
	if (q_head == NULL)
		q_tail = NULL;
	return item;
}

void
printqueue(void)
{
	queue_t *item;

	while ((item = dequeue()) != NULL) {
		printline(&item->data, '-', NULL);
		free_item(item);
	}
}

void
clearqueue(void)
{
	queue_t	*item;

	while ((item = dequeue()) != NULL)
		free_item(item);
}