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      1 /*	$NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky 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 #if HAVE_NBTOOL_CONFIG_H
     35 #include "nbtool_config.h"
     36 #endif
     37 
     38 #include <sys/cdefs.h>
     39 __RCSID("$NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $");
     40 
     41 #include <sys/param.h>
     42 #include <sys/queue.h>
     43 
     44 #include <stdlib.h>
     45 #include <string.h>
     46 
     47 #include "grep.h"
     48 
     49 struct qentry {
     50 	STAILQ_ENTRY(qentry)	list;
     51 	struct str	 	data;
     52 };
     53 
     54 static STAILQ_HEAD(, qentry)	queue = STAILQ_HEAD_INITIALIZER(queue);
     55 static unsigned long long	count;
     56 
     57 static struct qentry	*dequeue(void);
     58 
     59 void
     60 enqueue(struct str *x)
     61 {
     62 	struct qentry *item;
     63 
     64 	item = grep_malloc(sizeof(struct qentry));
     65 	item->data.dat = grep_malloc(sizeof(char) * x->len);
     66 	item->data.len = x->len;
     67 	item->data.line_no = x->line_no;
     68 	item->data.off = x->off;
     69 	memcpy(item->data.dat, x->dat, x->len);
     70 	item->data.file = x->file;
     71 
     72 	STAILQ_INSERT_TAIL(&queue, item, list);
     73 
     74 	if (++count > Bflag) {
     75 		item = dequeue();
     76 		free(item->data.dat);
     77 		free(item);
     78 	}
     79 }
     80 
     81 static struct qentry *
     82 dequeue(void)
     83 {
     84 	struct qentry *item;
     85 
     86 	item = STAILQ_FIRST(&queue);
     87 	if (item == NULL)
     88 		return (NULL);
     89 
     90 	STAILQ_REMOVE_HEAD(&queue, list);
     91 	--count;
     92 	return (item);
     93 }
     94 
     95 void
     96 printqueue(void)
     97 {
     98 	struct qentry *item;
     99 
    100 	while ((item = dequeue()) != NULL) {
    101 		printline(&item->data, '-', NULL, 0);
    102 		free(item->data.dat);
    103 		free(item);
    104 	}
    105 }
    106 
    107 void
    108 clearqueue(void)
    109 {
    110 	struct qentry *item;
    111 
    112 	while ((item = dequeue()) != NULL) {
    113 		free(item->data.dat);
    114 		free(item);
    115 	}
    116 }
    117