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/* $OpenBSD: queue.c,v 1.7 2015/01/16 06:40:08 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 <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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✓✓ |
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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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✓✓ |
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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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✓✓ |
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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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✓✓ |
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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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✓✓ |
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while ((item = dequeue()) != NULL) { |
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printline(&item->data, '-', NULL); |
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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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✗✓ |
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while ((item = dequeue()) != NULL) |
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free_item(item); |
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} |