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113 lines
2.0 KiB
113 lines
2.0 KiB
//
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// Queue.cc
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//
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// Queue: This class implements a linked list of objects. It itself is also an
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// object
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//
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// Part of the ht://Dig package <http://www.htdig.org/>
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// Copyright (c) 1999-2004 The ht://Dig Group
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// For copyright details, see the file COPYING in your distribution
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// or the GNU Library General Public License (LGPL) version 2 or later
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// <http://www.gnu.org/copyleft/lgpl.html>
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//
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// $Id: Queue.cc,v 1.6 2004/05/28 13:15:21 lha Exp $
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//
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#ifdef HAVE_CONFIG_H
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#include "htconfig.h"
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#endif /* HAVE_CONFIG_H */
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#include "Queue.h"
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struct Queuenode
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{
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Queuenode *next;
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Object *obj;
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};
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//***************************************************************************
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// Queue::Queue()
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//
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Queue::Queue()
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{
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head = tail = 0;
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size = 0;
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}
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//***************************************************************************
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// Queue::~Queue()
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//
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Queue::~Queue()
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{
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destroy();
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}
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//***************************************************************************
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// void Queue::destroy()
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//
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void Queue::destroy()
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{
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while (head)
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{
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Object *obj = pop();
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delete obj;
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}
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size = 0;
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head = tail = 0;
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}
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//***************************************************************************
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// void Queue::push(Object *obj)
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// Push an object onto the Queue.
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//
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void Queue::push(Object *obj)
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{
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Queuenode *node = new Queuenode;
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node->obj = obj;
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node->next = 0;
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if (tail)
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((Queuenode *) tail)->next = node;
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tail = node;
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if (!head)
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head = tail;
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size++;
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}
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//***************************************************************************
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// Object *Queue::pop()
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// Return the object at the head of the Queue and remove it
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//
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Object *Queue::pop()
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{
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if (size == 0)
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return 0;
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Queuenode *node = (Queuenode *) head;
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Object *obj = node->obj;
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head = (void *) node->next;
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delete node;
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size--;
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if (!head)
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tail = 0;
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return obj;
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}
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//***************************************************************************
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// Object *Queue::peek()
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// Return the object at the top of the Queue.
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//
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Object *Queue::peek()
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{
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if (size == 0)
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return 0;
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return ((Queuenode *)head)->obj;
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}
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