1 /* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */
2 /* $FreeBSD: head/usr.bin/grep/queue.c 318574 2017-05-20 11:20:03Z emaste $ */
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: head/usr.bin/grep/queue.c 318574 2017-05-20 11:20:03Z emaste $");
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 long long count;
53
54 static struct qentry *dequeue(void);
55
56 /*
57 * Enqueue another line; return true if we've dequeued a line as a result
58 */
59 bool
enqueue(struct str * x)60 enqueue(struct str *x)
61 {
62 struct qentry *item;
63
64 item = grep_malloc(sizeof(struct qentry));
65 item->data.dat = grep_malloc(sizeof(char) * x->len);
66 item->data.len = x->len;
67 item->data.line_no = x->line_no;
68 item->data.boff = x->boff;
69 item->data.off = x->off;
70 memcpy(item->data.dat, x->dat, x->len);
71 item->data.file = x->file;
72
73 STAILQ_INSERT_TAIL(&queue, item, list);
74
75 if (++count > Bflag) {
76 item = dequeue();
77 free(item->data.dat);
78 free(item);
79 return (true);
80 }
81 return (false);
82 }
83
84 static struct qentry *
dequeue(void)85 dequeue(void)
86 {
87 struct qentry *item;
88
89 item = STAILQ_FIRST(&queue);
90 if (item == NULL)
91 return (NULL);
92
93 STAILQ_REMOVE_HEAD(&queue, list);
94 --count;
95 return (item);
96 }
97
98 void
printqueue(void)99 printqueue(void)
100 {
101 struct qentry *item;
102
103 while ((item = dequeue()) != NULL) {
104 grep_printline(&item->data, '-');
105 free(item->data.dat);
106 free(item);
107 }
108 }
109
110 void
clearqueue(void)111 clearqueue(void)
112 {
113 struct qentry *item;
114
115 while ((item = dequeue()) != NULL) {
116 free(item->data.dat);
117 free(item);
118 }
119 }
120