Home | History | Annotate | Line # | Download | only in grep
queue.c revision 1.2 
      1 /*	$NetBSD: queue.c,v 1.2 2011/02/16 01:31:33 joerg Exp $	*/
      2 /*	$FreeBSD: head/usr.bin/grep/queue.c 211496 2010-08-19 09:28:59Z des $	*/
      3 /*-
      4  * Copyright (c) 1999 James Howard and Dag-Erling Codan Smrgrav
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 /*
     30  * A really poor man's queue.  It does only what it has to and gets out of
     31  * Dodge.  It is used in place of <sys/queue.h> to get a better performance.
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 __RCSID("$NetBSD: queue.c,v 1.2 2011/02/16 01:31:33 joerg Exp $");
     36 
     37 #include <sys/param.h>
     38 #include <sys/queue.h>
     39 
     40 #include <stdlib.h>
     41 #include <string.h>
     42 
     43 #include "grep.h"
     44 
     45 struct qentry {
     46 	STAILQ_ENTRY(qentry)	list;
     47 	struct str	 	data;
     48 };
     49 
     50 static STAILQ_HEAD(, qentry)	queue = STAILQ_HEAD_INITIALIZER(queue);
     51 static unsigned long long	count;
     52 
     53 static struct qentry	*dequeue(void);
     54 
     55 void
     56 enqueue(struct str *x)
     57 {
     58 	struct qentry *item;
     59 
     60 	item = grep_malloc(sizeof(struct qentry));
     61 	item->data.dat = grep_malloc(sizeof(char) * x->len);
     62 	item->data.len = x->len;
     63 	item->data.line_no = x->line_no;
     64 	item->data.off = x->off;
     65 	memcpy(item->data.dat, x->dat, x->len);
     66 	item->data.file = x->file;
     67 
     68 	STAILQ_INSERT_TAIL(&queue, item, list);
     69 
     70 	if (++count > Bflag)
     71 		free(dequeue());
     72 }
     73 
     74 static struct qentry *
     75 dequeue(void)
     76 {
     77 	struct qentry *item;
     78 
     79 	item = STAILQ_FIRST(&queue);
     80 	if (item == NULL)
     81 		return (NULL);
     82 
     83 	STAILQ_REMOVE_HEAD(&queue, list);
     84 	--count;
     85 	return (item);
     86 }
     87 
     88 void
     89 printqueue(void)
     90 {
     91 	struct qentry *item;
     92 
     93 	while ((item = dequeue()) != NULL) {
     94 		printline(&item->data, '-', (regmatch_t *)NULL, 0);
     95 		free(item);
     96 	}
     97 }
     98 
     99 void
    100 clearqueue(void)
    101 {
    102 	struct qentry *item;
    103 
    104 	while ((item = dequeue()) != NULL)
    105 		free(item);
    106 }
    107