1 /* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */
2 /* $FreeBSD$ */
3
4 /*-
5 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
6 *
7 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * A really poor man's queue. It does only what it has to and gets out of
34 * Dodge. It is used in place of <sys/queue.h> to get a better performance.
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39
40 #include <sys/param.h>
41 #include <sys/queue.h>
42
43 #include <stdlib.h>
44 #include <string.h>
45
46 #include "grep.h"
47
48 struct qentry {
49 STAILQ_ENTRY(qentry) list;
50 struct str data;
51 };
52
53 static STAILQ_HEAD(, qentry) queue = STAILQ_HEAD_INITIALIZER(queue);
54 static long long count;
55
56 static struct qentry *dequeue(void);
57
58 /*
59 * Enqueue another line; return true if we've dequeued a line as a result
60 */
61 bool
enqueue(struct str * x)62 enqueue(struct str *x)
63 {
64 struct qentry *item;
65
66 item = grep_malloc(sizeof(struct qentry));
67 item->data.dat = grep_malloc(sizeof(char) * x->len);
68 item->data.len = x->len;
69 item->data.line_no = x->line_no;
70 item->data.boff = x->boff;
71 item->data.off = x->off;
72 memcpy(item->data.dat, x->dat, x->len);
73 item->data.file = x->file;
74
75 STAILQ_INSERT_TAIL(&queue, item, list);
76
77 if (++count > Bflag) {
78 item = dequeue();
79 free(item->data.dat);
80 free(item);
81 return (true);
82 }
83 return (false);
84 }
85
86 static struct qentry *
dequeue(void)87 dequeue(void)
88 {
89 struct qentry *item;
90
91 item = STAILQ_FIRST(&queue);
92 if (item == NULL)
93 return (NULL);
94
95 STAILQ_REMOVE_HEAD(&queue, list);
96 --count;
97 return (item);
98 }
99
100 void
printqueue(void)101 printqueue(void)
102 {
103 struct qentry *item;
104
105 while ((item = dequeue()) != NULL) {
106 grep_printline(&item->data, '-');
107 free(item->data.dat);
108 free(item);
109 }
110 }
111
112 void
clearqueue(void)113 clearqueue(void)
114 {
115 struct qentry *item;
116
117 while ((item = dequeue()) != NULL) {
118 free(item->data.dat);
119 free(item);
120 }
121 }
122