1/*	$NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $	*/
2/*	$FreeBSD: stable/11/usr.bin/grep/queue.c 330449 2018-03-05 07:26:05Z eadler $	*/
3
4/*-
5 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
6 *
7 * Copyright (c) 1999 James Howard and Dag-Erling Co��dan Sm��rgrav
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: stable/11/usr.bin/grep/queue.c 330449 2018-03-05 07:26:05Z eadler $");
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
48struct qentry {
49	STAILQ_ENTRY(qentry)	list;
50	struct str	 	data;
51};
52
53static STAILQ_HEAD(, qentry)	queue = STAILQ_HEAD_INITIALIZER(queue);
54static long long		count;
55
56static struct qentry	*dequeue(void);
57
58/*
59 * Enqueue another line; return true if we've dequeued a line as a result
60 */
61bool
62enqueue(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
86static struct qentry *
87dequeue(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
100void
101printqueue(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
112void
113clearqueue(void)
114{
115	struct qentry *item;
116
117	while ((item = dequeue()) != NULL) {
118		free(item->data.dat);
119		free(item);
120	}
121}
122