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queue.c revision 1.1.1.2 
      1 /*	$NetBSD: queue.c,v 1.1.1.2 2004/01/02 15:00:34 cjep Exp $	*/
      2 
      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 #include <sys/cdefs.h>
     31 #ifndef lint
     32 __RCSID("$NetBSD: queue.c,v 1.1.1.2 2004/01/02 15:00:34 cjep Exp $");
     33 #endif /* not lint */
     34 
     35 /*
     36  * A really poor man's queue.  It does only what it has to and gets out of
     37  * Dodge.
     38  */
     39 
     40 #include <sys/param.h>
     41 
     42 #include <stdlib.h>
     43 #include <string.h>
     44 
     45 #include "grep.h"
     46 
     47 typedef struct queue {
     48 	struct queue *next;
     49 	str_t data;
     50 } queue_t;
     51 
     52 static queue_t *q_head, *q_tail;
     53 static int count;
     54 
     55 static queue_t *dequeue(void);
     56 
     57 void
     58 initqueue(void)
     59 {
     60 	q_head = q_tail = NULL;
     61 }
     62 
     63 static void
     64 free_item(queue_t *item)
     65 {
     66 	free(item);
     67 }
     68 
     69 void
     70 enqueue(str_t *x)
     71 {
     72 	queue_t *item;
     73 
     74 	item = grep_malloc(sizeof *item + x->len);
     75 	item->data.len = x->len;
     76 	item->data.line_no = x->line_no;
     77 	item->data.off = x->off;
     78 	item->data.dat = (char *)item + sizeof *item;
     79 	memcpy(item->data.dat, x->dat, x->len);
     80 	item->data.file = x->file;
     81 	item->next = NULL;
     82 
     83 	if (!q_head) {
     84 		q_head = q_tail = item;
     85 	} else {
     86 		q_tail->next = item;
     87 		q_tail = item;
     88 	}
     89 
     90 	if (++count > Bflag)
     91 		free_item(dequeue());
     92 }
     93 
     94 static queue_t *
     95 dequeue(void)
     96 {
     97 	queue_t *item;
     98 
     99 	if (q_head == NULL)
    100 		return NULL;
    101 
    102 	--count;
    103 	item = q_head;
    104 	q_head = item->next;
    105 	if (q_head == NULL)
    106 		q_tail = NULL;
    107 	return item;
    108 }
    109 
    110 void
    111 printqueue(void)
    112 {
    113 	queue_t *item;
    114 
    115 	while ((item = dequeue()) != NULL) {
    116 		printline(&item->data, fn_dashchar, (regmatch_t *)NULL, 0);
    117 		free_item(item);
    118 	}
    119 }
    120 
    121 void
    122 clearqueue(void)
    123 {
    124 	queue_t	*item;
    125 
    126 	while ((item = dequeue()) != NULL)
    127 		free_item(item);
    128 }
    129