/***************************************************************************\
[*]    ___    ____   ____   __   __  ____ [*]   ROGUE: ROM With Attitude  [*]
[*]   /#/ )  /#/  ) /#/  ) /#/  /#/ /#/   [*]    All rights reserved      [*]
[*]  /#/ <  /#/  / /#/ _  /#/  /#/ /#/--  [*]   Copyright(C) 2000-2003    [*]
[*] /#/   \(#(__/ (#(__/ (#(__/#/ (#(___  [*] Kenneth Conley (Mendanbar)  [*]
[*]  Expression of Digital Creativity..   [*]  roguemud@yahoogroups.com   [*]
[-]---------------------------------------+-+-----------------------------[-]
[*] File: queue.cpp                                                       [*]
[*] Usage: Primary queue controls                                         [*]
\***************************************************************************/

#include "conf.h"
#include "sysdep.h"

#include "queue.h"

//	External variables
extern UInt32 pulse;

QueueElement::QueueElement(Ptr data, SInt32 key) {
    this->data = data;
    this->key = key;
    this->next = NULL;
    this->prev = NULL;
}


Queue::Queue(void) {
    memset(this, 0, sizeof(Queue));
}


Queue::~Queue(void) {
    SInt32 i;
    QueueElement *qe, *next_qe;
	
    for (i = 0; i < NUM_EVENT_QUEUES; i++) {
	for (qe = this->head[i]; qe; qe = next_qe) {
	    next_qe = qe->next;
	    delete qe;
	}
    }
}


QueueElement *Queue::Enqueue(Ptr data, SInt32 key) {
    QueueElement *qe, *i;
    SInt32	bucket;
	
    qe = new QueueElement(data, key);
    bucket = key % NUM_EVENT_QUEUES;
	
    if (!this->head[bucket]) {
	this->head[bucket] = qe;
	this->tail[bucket] = qe;
    } else {
	for (i = this->tail[bucket]; i; i = i->prev) {
	    if (i->key < key) {
		if (i == this->tail[bucket])
		    this->tail[bucket] = qe;
		else {
		    qe->next = i->next;
		    i->next->prev = qe;
		}
		qe->prev = i;
		i->next = qe;
		break;
	    }
	}
	if (i == NULL) {
	    qe->next = this->head[bucket];
	    this->head[bucket] = qe;
	    qe->next->prev = qe;
	}
    }
    return qe;
}


void Queue::Dequeue(QueueElement *qe) {
    SInt32 i;

    if (!qe)
	return;

    i = qe->key % NUM_EVENT_QUEUES;

    if (qe->prev)	qe->prev->next = qe->next;
    else		this->head[i] = qe->next;

    if (qe->next)	qe->next->prev = qe->prev;
    else		this->tail[i] = qe->prev;

    delete qe;
}


Ptr Queue::QueueHead(void) {
    Ptr data;
    SInt32 i;
	
    i = pulse % NUM_EVENT_QUEUES;
	
    if (!this->head[i])
	return NULL;
	
    data = this->head[i]->data;
    this->Dequeue(this->head[i]);
    return data;
}


SInt32 Queue::QueueKey(void) {
    UInt32 i;
	
    i = pulse % NUM_EVENT_QUEUES;
	
    if (this->head[i])	return this->head[i]->key;
    else		return LONG_MAX;
}