67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
/* Copyright 2010, 2011, 2012 Tony Garnock-Jones <tonygarnockjones@gmail.com>.
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*
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* This file is part of Hop.
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*
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* Hop is free software: you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* Hop is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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* License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Hop. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <stdio.h>
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#include <assert.h>
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#include "dataq.h"
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#define QLINK(q,x) (*((void **)(((char *) x) + (q)->link_offset)))
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void enqueue(queue_t *q, void *x) {
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QLINK(q, x) = NULL;
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if (q->head == NULL) {
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q->head = x;
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} else {
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QLINK(q, q->tail) = x;
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}
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q->tail = x;
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q->count++;
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}
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void *dequeue(queue_t *q) {
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if (q->head == NULL) {
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return NULL;
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} else {
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void *x = q->head;
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q->head = QLINK(q, x);
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QLINK(q, x) = NULL;
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if (q->head == NULL) {
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q->tail = NULL;
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}
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q->count--;
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return x;
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}
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}
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void queue_append(queue_t *q1, queue_t *q2) {
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assert(q1->link_offset == q2->link_offset);
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if (q2->head != NULL) {
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if (q1->head != NULL) {
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QLINK(q1, q1->tail) = q2->head;
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} else {
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q1->head = q2->head;
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}
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q1->tail = q2->tail;
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q2->head = NULL;
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q2->tail = NULL;
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}
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}
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