xref: /netbsd-src/usr.bin/grep/queue.c (revision daf6c4152fcddc27c445489775ed1f66ab4ea9a9)
1 /*	$NetBSD: queue.c,v 1.2 2011/02/16 01:31:33 joerg Exp $	*/
2 /*	$FreeBSD: head/usr.bin/grep/queue.c 211496 2010-08-19 09:28:59Z des $	*/
3 /*-
4  * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * A really poor man's queue.  It does only what it has to and gets out of
31  * Dodge.  It is used in place of <sys/queue.h> to get a better performance.
32  */
33 
34 #include <sys/cdefs.h>
35 __RCSID("$NetBSD: queue.c,v 1.2 2011/02/16 01:31:33 joerg Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/queue.h>
39 
40 #include <stdlib.h>
41 #include <string.h>
42 
43 #include "grep.h"
44 
45 struct qentry {
46 	STAILQ_ENTRY(qentry)	list;
47 	struct str	 	data;
48 };
49 
50 static STAILQ_HEAD(, qentry)	queue = STAILQ_HEAD_INITIALIZER(queue);
51 static unsigned long long	count;
52 
53 static struct qentry	*dequeue(void);
54 
55 void
56 enqueue(struct str *x)
57 {
58 	struct qentry *item;
59 
60 	item = grep_malloc(sizeof(struct qentry));
61 	item->data.dat = grep_malloc(sizeof(char) * x->len);
62 	item->data.len = x->len;
63 	item->data.line_no = x->line_no;
64 	item->data.off = x->off;
65 	memcpy(item->data.dat, x->dat, x->len);
66 	item->data.file = x->file;
67 
68 	STAILQ_INSERT_TAIL(&queue, item, list);
69 
70 	if (++count > Bflag)
71 		free(dequeue());
72 }
73 
74 static struct qentry *
75 dequeue(void)
76 {
77 	struct qentry *item;
78 
79 	item = STAILQ_FIRST(&queue);
80 	if (item == NULL)
81 		return (NULL);
82 
83 	STAILQ_REMOVE_HEAD(&queue, list);
84 	--count;
85 	return (item);
86 }
87 
88 void
89 printqueue(void)
90 {
91 	struct qentry *item;
92 
93 	while ((item = dequeue()) != NULL) {
94 		printline(&item->data, '-', (regmatch_t *)NULL, 0);
95 		free(item);
96 	}
97 }
98 
99 void
100 clearqueue(void)
101 {
102 	struct qentry *item;
103 
104 	while ((item = dequeue()) != NULL)
105 		free(item);
106 }
107