1 /* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */
4 * SPDX-License-Identifier: BSD-2-Clause
6 * Copyright (c) 1999 James Howard and Dag-Erling Smørgrav
8 * Copyright (c) 2020 Kyle Evans <kevans@FreeBSD.org>
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
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.
37 #include <sys/param.h>
38 #include <sys/queue.h>
45 typedef struct str qentry_t;
47 static long long filled;
48 static qentry_t *qend, *qpool;
51 * qnext is the next entry to populate. qlist is where the list actually
52 * starts, for the purposes of printing.
54 static qentry_t *qlist, *qnext;
60 qlist = qnext = qpool = grep_calloc(Bflag, sizeof(*qpool));
61 qend = qpool + (Bflag - 1);
65 advqueue(qentry_t *itemp)
74 * Enqueue another line; return true if we've dequeued a line as a result
77 enqueue(struct str *x)
83 qnext = advqueue(qnext);
88 } else if (filled == Bflag) {
89 /* We had already filled up coming in; just rotate. */
90 qlist = advqueue(qlist);
94 /* len + 1 for NUL-terminator */
95 item->dat = grep_malloc(sizeof(char) * x->len + 1);
97 item->line_no = x->line_no;
100 memcpy(item->dat, x->dat, x->len);
101 item->dat[x->len] = '\0';
102 item->file = x->file;
114 /* Buffer must have ended early. */
115 if (item->dat == NULL)
118 grep_printline(item, '-');
121 item = advqueue(item);
122 } while (item != qlist);
124 qlist = qnext = qpool;
137 item = advqueue(item);
138 } while (item != qlist);
140 qlist = qnext = qpool;