1 /* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky 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
enqueue(struct str * x)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 item = dequeue();
73 free(item->data.dat);
74 free(item);
75 }
76 }
77
78 static struct qentry *
dequeue(void)79 dequeue(void)
80 {
81 struct qentry *item;
82
83 item = STAILQ_FIRST(&queue);
84 if (item == NULL)
85 return (NULL);
86
87 STAILQ_REMOVE_HEAD(&queue, list);
88 --count;
89 return (item);
90 }
91
92 void
printqueue(void)93 printqueue(void)
94 {
95 struct qentry *item;
96
97 while ((item = dequeue()) != NULL) {
98 printline(&item->data, '-', NULL, 0);
99 free(item->data.dat);
100 free(item);
101 }
102 }
103
104 void
clearqueue(void)105 clearqueue(void)
106 {
107 struct qentry *item;
108
109 while ((item = dequeue()) != NULL) {
110 free(item->data.dat);
111 free(item);
112 }
113 }
114