xref: /freebsd/usr.bin/grep/queue.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
1 /*	$NetBSD: queue.c,v 1.2 2011/02/16 01:31:33 joerg Exp $	*/
2 /*	$FreeBSD$	*/
3 
4 /*-
5  * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * A really poor man's queue.  It does only what it has to and gets out of
32  * Dodge.  It is used in place of <sys/queue.h> to get a better performance.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/queue.h>
40 
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include "grep.h"
45 
46 struct qentry {
47 	STAILQ_ENTRY(qentry)	list;
48 	struct str	 	data;
49 };
50 
51 static STAILQ_HEAD(, qentry)	queue = STAILQ_HEAD_INITIALIZER(queue);
52 static unsigned long long	count;
53 
54 static struct qentry	*dequeue(void);
55 
56 void
57 enqueue(struct str *x)
58 {
59 	struct qentry *item;
60 
61 	item = grep_malloc(sizeof(struct qentry));
62 	item->data.dat = grep_malloc(sizeof(char) * x->len);
63 	item->data.len = x->len;
64 	item->data.line_no = x->line_no;
65 	item->data.off = x->off;
66 	memcpy(item->data.dat, x->dat, x->len);
67 	item->data.file = x->file;
68 
69 	STAILQ_INSERT_TAIL(&queue, item, list);
70 
71 	if (++count > Bflag)
72 		free(dequeue());
73 }
74 
75 static struct qentry *
76 dequeue(void)
77 {
78 	struct qentry *item;
79 
80 	item = STAILQ_FIRST(&queue);
81 	if (item == NULL)
82 		return (NULL);
83 
84 	STAILQ_REMOVE_HEAD(&queue, list);
85 	--count;
86 	return (item);
87 }
88 
89 void
90 printqueue(void)
91 {
92 	struct qentry *item;
93 
94 	while ((item = dequeue()) != NULL) {
95 		printline(&item->data, '-', (regmatch_t *)NULL, 0);
96 		free(item);
97 	}
98 }
99 
100 void
101 clearqueue(void)
102 {
103 	struct qentry *item;
104 
105 	while ((item = dequeue()) != NULL)
106 		free(item);
107 }
108