org.drools.core.util
Class BinaryHeapQueue

java.lang.Object
  org.drools.core.util.BinaryHeapQueue

All Implemented Interfaces:

Externalizable, Serializable, Queue

public class BinaryHeapQueue
extends Object
implements Queue, Externalizable

See Also:

Serialized Form

Field Summary

protected static org.slf4j.Logger

log

Constructor Summary

BinaryHeapQueue()

BinaryHeapQueue(Comparator comparator)
Constructs a new BinaryHeap that will use the given comparator to order its elements.

BinaryHeapQueue(Comparator comparator, int capacity)
Constructs a new BinaryHeap.

Method Summary

void	clear() Clears all elements from queue.
Activation	dequeue() Returns the Queueable on top of heap and remove it.
Activation	dequeue(int index)
void	enqueue(Activation element) Inserts an Queueable into queue.
Activation[]	getAndClear()
boolean	isEmpty() Tests if queue is empty.
boolean	isFull() Tests if queue is full.
Activation	peek()
protected void	percolateDownMaxHeap(int index) Percolates element down heap from the position given by the index.
protected void	percolateUpMaxHeap(Activation element) Percolates a new element up heap from the bottom.
protected void	percolateUpMaxHeap(int index) Percolates element up heap from from the position given by the index.
void	readExternal(ObjectInput in)
int	size() Returns the number of elements in this heap.
Object[]	toArray(Object[] a)
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

log

protected static transient org.slf4j.Logger log

Constructor Detail

BinaryHeapQueue

public BinaryHeapQueue()

BinaryHeapQueue

public BinaryHeapQueue(Comparator comparator)

Constructs a new BinaryHeap that will use the given comparator to order its elements.

Parameters:

comparator - the comparator used to order the elements, null means use natural order

BinaryHeapQueue

public BinaryHeapQueue(Comparator comparator,
                       int capacity)

Constructs a new BinaryHeap.

Parameters:

comparator - the comparator used to order the elements, null means use natural order

capacity - the initial capacity for the heap

Throws:

IllegalArgumentException - if capacity is <= 0

Method Detail

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException

clear

public void clear()

Clears all elements from queue.

getAndClear

public Activation[] getAndClear()

isEmpty

public boolean isEmpty()

Tests if queue is empty.

Specified by:

isEmpty in interface Queue

Returns:

true if queue is empty; false otherwise.

isFull

public boolean isFull()

Tests if queue is full.

Returns:

true if queue is full; false otherwise.

size

public int size()

Returns the number of elements in this heap.

Returns:

the number of elements in this heap

peek

public Activation peek()

enqueue

public void enqueue(Activation element)

Inserts an Queueable into queue.

Specified by:

enqueue in interface Queue

Parameters:

element - the Queueable to be inserted

dequeue

public Activation dequeue()
                   throws NoSuchElementException

Returns the Queueable on top of heap and remove it.

Specified by:

dequeue in interface Queue

Returns:

the Queueable at top of heap

Throws:

NoSuchElementException - if isEmpty() == true

dequeue

public Activation dequeue(int index)

Specified by:

dequeue in interface Queue

Parameters:

index -

percolateDownMaxHeap

protected void percolateDownMaxHeap(int index)

Percolates element down heap from the position given by the index.

Assumes it is a maximum heap.

Parameters:

index - the index of the element

percolateUpMaxHeap

protected void percolateUpMaxHeap(int index)

Percolates element up heap from from the position given by the index.

Assume it is a maximum heap.

Parameters:

index - the index of the element to be percolated up

percolateUpMaxHeap

protected void percolateUpMaxHeap(Activation element)

Percolates a new element up heap from the bottom.

Assume it is a maximum heap.

Parameters:

element - the element

toArray

public Object[] toArray(Object[] a)