queue.c revision 210578 
1/*-
2 * Copyright (c) 1999 James Howard and Dag-Erling Co�dan Sm�rgrav
3 * 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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * A really poor man's queue.  It does only what it has to and gets out of
29 * Dodge.  It is used in place of <sys/queue.h> to get a better performance.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/usr.bin/grep/queue.c 210578 2010-07-29 00:11:14Z gabor $");
34
35#include <sys/param.h>
36#include <sys/queue.h>
37
38#include <stdlib.h>
39#include <string.h>
40
41#include "grep.h"
42
43struct qentry {
44	STAILQ_ENTRY(qentry)	list;
45	struct str	 	data;
46};
47
48static STAILQ_HEAD(, qentry)	queue = STAILQ_HEAD_INITIALIZER(queue);
49static unsigned long long	count;
50
51static struct qentry	*dequeue(void);
52
53void
54enqueue(struct str *x)
55{
56	struct qentry *item;
57
58	item = grep_malloc(sizeof(struct qentry));
59	item->data.dat = grep_malloc(sizeof(char) * x->len);
60	item->data.len = x->len;
61	item->data.line_no = x->line_no;
62	item->data.off = x->off;
63	strcpy(item->data.dat, x->dat);
64	item->data.file = x->file;
65
66	STAILQ_INSERT_TAIL(&queue, item, list);
67
68	if (++count > Bflag)
69		free(dequeue());
70}
71
72static struct qentry *
73dequeue(void)
74{
75	struct qentry *item;
76
77	item = STAILQ_FIRST(&queue);
78	if (item == NULL)
79		return (NULL);
80
81	STAILQ_REMOVE_HEAD(&queue, list);
82	--count;
83	return (item);
84}
85
86void
87printqueue(void)
88{
89	struct qentry *item;
90
91	while ((item = dequeue()) != NULL) {
92		printline(&item->data, '-', (regmatch_t *)NULL, 0);
93		free(item);
94	}
95}
96
97void
98clearqueue(void)
99{
100	struct qentry *item;
101
102	while ((item = dequeue()) != NULL)
103		free(item);
104}
105