diff options
Diffstat (limited to 'usr.bin/grep/queue.c')
| -rw-r--r-- | usr.bin/grep/queue.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/usr.bin/grep/queue.c b/usr.bin/grep/queue.c new file mode 100644 index 000000000000..296e19fb0f6d --- /dev/null +++ b/usr.bin/grep/queue.c @@ -0,0 +1,142 @@ +/* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */ + +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 1999 James Howard and Dag-Erling Smørgrav + * All rights reserved. + * Copyright (c) 2020 Kyle Evans <kevans@FreeBSD.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * A really poor man's queue. It does only what it has to and gets out of + * Dodge. It is used in place of <sys/queue.h> to get a better performance. + */ + +#include <sys/param.h> +#include <sys/queue.h> + +#include <stdlib.h> +#include <string.h> + +#include "grep.h" + +typedef struct str qentry_t; + +static long long filled; +static qentry_t *qend, *qpool; + +/* + * qnext is the next entry to populate. qlist is where the list actually + * starts, for the purposes of printing. + */ +static qentry_t *qlist, *qnext; + +void +initqueue(void) +{ + + qlist = qnext = qpool = grep_calloc(Bflag, sizeof(*qpool)); + qend = qpool + (Bflag - 1); +} + +static qentry_t * +advqueue(qentry_t *itemp) +{ + + if (itemp == qend) + return (qpool); + return (itemp + 1); +} + +/* + * Enqueue another line; return true if we've dequeued a line as a result + */ +bool +enqueue(struct str *x) +{ + qentry_t *item; + bool rotated; + + item = qnext; + qnext = advqueue(qnext); + rotated = false; + + if (filled < Bflag) { + filled++; + } else if (filled == Bflag) { + /* We had already filled up coming in; just rotate. */ + qlist = advqueue(qlist); + rotated = true; + free(item->dat); + } + /* len + 1 for NUL-terminator */ + item->dat = grep_malloc(sizeof(char) * x->len + 1); + item->len = x->len; + item->line_no = x->line_no; + item->boff = x->boff; + item->off = x->off; + memcpy(item->dat, x->dat, x->len); + item->dat[x->len] = '\0'; + item->file = x->file; + + return (rotated); +} + +void +printqueue(void) +{ + qentry_t *item; + + item = qlist; + do { + /* Buffer must have ended early. */ + if (item->dat == NULL) + break; + + grep_printline(item, '-'); + free(item->dat); + item->dat = NULL; + item = advqueue(item); + } while (item != qlist); + + qlist = qnext = qpool; + filled = 0; +} + +void +clearqueue(void) +{ + qentry_t *item; + + item = qlist; + do { + free(item->dat); + item->dat = NULL; + item = advqueue(item); + } while (item != qlist); + + qlist = qnext = qpool; + filled = 0; +} |