1 /* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */
5 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
7 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
9 * Copyright (c) 2020 Kyle Evans <kevans@FreeBSD.org>
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * A really poor man's queue. It does only what it has to and gets out of
35 * Dodge. It is used in place of <sys/queue.h> to get a better performance.
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
41 #include <sys/param.h>
42 #include <sys/queue.h>
49 typedef struct str qentry_t;
51 static long long filled;
52 static qentry_t *qend, *qpool;
55 * qnext is the next entry to populate. qlist is where the list actually
56 * starts, for the purposes of printing.
58 static qentry_t *qlist, *qnext;
64 qlist = qnext = qpool = grep_calloc(Bflag, sizeof(*qpool));
65 qend = qpool + (Bflag - 1);
69 advqueue(qentry_t *itemp)
78 * Enqueue another line; return true if we've dequeued a line as a result
81 enqueue(struct str *x)
87 qnext = advqueue(qnext);
92 } else if (filled == Bflag) {
93 /* We had already filled up coming in; just rotate. */
94 qlist = advqueue(qlist);
98 item->dat = grep_malloc(sizeof(char) * x->len);
100 item->line_no = x->line_no;
101 item->boff = x->boff;
103 memcpy(item->dat, x->dat, x->len);
104 item->file = x->file;
116 /* Buffer must have ended early. */
117 if (item->dat == NULL)
120 grep_printline(item, '-');
123 item = advqueue(item);
124 } while (item != qlist);
126 qlist = qnext = qpool;
139 item = advqueue(item);
140 } while (item != qlist);
142 qlist = qnext = qpool;