/*
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* Copyright (c) International Business Machines Corp., 2001-2004
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public 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 this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <stdlib.h>
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#include <assert.h>
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#include "cirlist.h"
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#include "util.h"
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void init_cirlist(struct cirlist *cl)
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{
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cl->count = 0;
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cl->head = NULL;
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}
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int cl_empty(struct cirlist *cl)
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{
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return !(cl->count);
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}
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void cl_insert_tail(struct cirlist *cl, cldatatype object)
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{
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struct cnode *new = ffsb_malloc(sizeof(struct cnode));
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new->obj = object;
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if (cl->count == 0) {
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assert(cl->head == NULL);
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cl->head = new;
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cl->head->next = cl->head;
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cl->head->prev = cl->head;
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cl->count = 1;
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} else {
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if (cl->count == 1) {
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assert(cl->head->next == cl->head);
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assert(cl->head->prev == cl->head);
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cl->head->next = new;
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cl->head->prev = new;
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new->next = cl->head;
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new->prev = cl->head;
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} else {
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assert(cl->head->next != cl->head);
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assert(cl->head->prev != cl->head);
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new->next = cl->head;
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new->prev = (cl->head)->prev;
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cl->head->prev->next = new;
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cl->head->prev = new;
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}
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cl->count++;
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}
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}
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cldatatype cl_remove_head(struct cirlist *cl)
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{
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struct cnode *oldhead = NULL;
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struct cnode *newhead = NULL;
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cldatatype ret = NULL;
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if (cl->count == 0) {
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assert(cl->head == NULL);
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return NULL;
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}
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if (cl->count == 1) {
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assert(cl->head->next == cl->head);
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assert(cl->head->prev == cl->head);
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oldhead = cl->head;
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cl->head = NULL;
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cl->count = 0;
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} else if (cl->count == 2) {
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oldhead = cl->head;
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newhead = oldhead->next;
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newhead->next = newhead;
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newhead->prev = newhead;
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cl->head = newhead;
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cl->count = 1;
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} else {
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assert(cl->head->next != cl->head);
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assert(cl->head->prev != cl->head);
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oldhead = cl->head;
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newhead = oldhead->next;
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newhead->prev = oldhead->prev;
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newhead->prev->next = newhead;
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cl->head = newhead;
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cl->count--;
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}
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ret = oldhead->obj;
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oldhead->obj = (void *)(-1);
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oldhead->next = (void *)(-1);
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oldhead->prev = (void *)(-1);
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free(oldhead);
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return ret;
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}
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