org.apache.avalon.cornerstone.blocks.scheduler
Interface PriorityQueue

All Known Implementing Classes:
BinaryHeap, SynchronizedPriorityQueue

public interface PriorityQueue

Iterface for priority queues. This interface does not dictate whether it is min or max heap.

Since:
4.0
Version:
CVS $Revision: 1.1 $ $Date: 2004/03/16 12:49:52 $
Author:
Avalon Development Team

Method Summary
 void clear()
          Clear all elements from queue.
 void insert(java.lang.Object element)
          Insert an element into queue.
 boolean isEmpty()
          Test if queue is empty.
 java.lang.Object peek()
          Return element on top of heap but don't remove it.
 java.lang.Object pop()
          Return element on top of heap and remove it.
 

Method Detail

clear

public void clear()
Clear all elements from queue.


isEmpty

public boolean isEmpty()
Test if queue is empty.

Returns:
true if queue is empty else false.

insert

public void insert(java.lang.Object element)
Insert an element into queue.

Parameters:
element - the element to be inserted

peek

public java.lang.Object peek()
                      throws java.util.NoSuchElementException
Return element on top of heap but don't remove it.

Returns:
the element at top of heap
Throws:
java.util.NoSuchElementException - if isEmpty() == true

pop

public java.lang.Object pop()
                     throws java.util.NoSuchElementException
Return element on top of heap and remove it.

Returns:
the element at top of heap
Throws:
java.util.NoSuchElementException - if isEmpty() == true


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