123 lines
2.7 KiB
C
123 lines
2.7 KiB
C
/* $OpenBSD: queue.c,v 1.4 2003/06/25 05:31:11 deraadt Exp $ */
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/*-
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* Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* A really poor man's queue. It does only what it has to and gets out of
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* Dodge.
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*/
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#include <sys/param.h>
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#include <stdlib.h>
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#include <string.h>
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#include "grep.h"
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typedef struct queue {
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struct queue *next;
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str_t data;
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} queue_t;
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static queue_t *q_head, *q_tail;
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static int count;
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static queue_t *dequeue(void);
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void
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initqueue(void)
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{
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q_head = q_tail = NULL;
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}
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static void
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free_item(queue_t *item)
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{
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free(item);
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}
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void
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enqueue(str_t *x)
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{
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queue_t *item;
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item = grep_malloc(sizeof *item + x->len);
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item->data.len = x->len;
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item->data.line_no = x->line_no;
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item->data.off = x->off;
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item->data.dat = (char *)item + sizeof *item;
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memcpy(item->data.dat, x->dat, x->len);
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item->data.file = x->file;
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item->next = NULL;
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if (!q_head) {
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q_head = q_tail = item;
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} else {
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q_tail->next = item;
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q_tail = item;
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}
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if (++count > Bflag)
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free_item(dequeue());
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}
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static queue_t *
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dequeue(void)
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{
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queue_t *item;
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if (q_head == NULL)
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return NULL;
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--count;
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item = q_head;
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q_head = item->next;
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if (q_head == NULL)
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q_tail = NULL;
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return item;
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}
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void
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printqueue(void)
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{
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queue_t *item;
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while ((item = dequeue()) != NULL) {
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printline(&item->data, '-');
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free_item(item);
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}
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}
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void
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clearqueue(void)
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{
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queue_t *item;
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while ((item = dequeue()) != NULL)
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free_item(item);
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}
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