net.obsearch.result
Class OBPriorityQueueByte<O>

java.lang.Object
  net.obsearch.AbstractOBPriorityQueue<OBResultByte<O>>
      net.obsearch.result.OBPriorityQueueByte<O>

All Implemented Interfaces:

Iterable<OBResultByte<O>>

public final class OBPriorityQueueByte<O>
extends AbstractOBPriorityQueue<OBResultByte<O>>

This is a class used to efficiently perform k-nn searches. This queue is meant to be used with objects OBByte.

Since:

0.7

Author:

Arnoldo Jose Muller Molina

Field Summary

Fields inherited from class net.obsearch.AbstractOBPriorityQueue

k, queue

Constructor Summary

OBPriorityQueueByte(int k)
Create the priority queue with k elements.

Method Summary

boolean	add(long id, O obj, byte distance) Add the given object, object id and distance of type byte to the queue.
void	addMax(long id, O obj, byte distance) Add the given object, object id and distance of type byte to the queue.
boolean	isCandidate(byte d) Returns true if the given distance can be a candidate for adding it into the queue.
byte	updateRange(byte r) If queue.size() == k, then if the user's range is greater than the greatest element of the queue, we can reduce the range to the biggest element of the priority queue, that is its queue.peek() element.

Methods inherited from class net.obsearch.AbstractOBPriorityQueue

equals, getK, getSize, getSortedElements, isFull, iterator, peek, poll, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

OBPriorityQueueByte

public OBPriorityQueueByte(int k)

Create the priority queue with k elements. This is how you set the k for a query. Use a negative value for a boundless queue.

Method Detail

add

public boolean add(long id,
                   O obj,
                   byte distance)
            throws InstantiationException,
                   IllegalAccessException

Add the given object, object id and distance of type byte to the queue. This method tries to minimize the sizes of distances of the priority queue.

Parameters:

id - The id of the object to be used

obj - The object to be added

distance - The distance to be added

Returns:

true if the range has changed.

Throws:

IllegalAccessException - If there is a problem when instantiating objects O

InstantiationException - If there is a problem when instantiating objects O

addMax

public void addMax(long id,
                   O obj,
                   byte distance)
            throws InstantiationException,
                   IllegalAccessException

Add the given object, object id and distance of type byte to the queue. This method tries to maximize the sizes of distances of the priority queue.

Parameters:

id - The id of the object to be used

obj - The object to be added

distance - The distance to be added

Throws:

IllegalAccessException - If there is a problem when instantiating objects O

InstantiationException - If there is a problem when instantiating objects O

updateRange

public byte updateRange(byte r)

If queue.size() == k, then if the user's range is greater than the greatest element of the queue, we can reduce the range to the biggest element of the priority queue, that is its queue.peek() element.

Parameters:

r - The new range we want to calculate.

Returns:

the new range or the old range if the above condition is not met

isCandidate

public boolean isCandidate(byte d)

Returns true if the given distance can be a candidate for adding it into the queue. The parameter d is an estimation of the real distance, and this method is used to decide if we should calculate the real distance.

Parameters:

d - The lower resolution distance.

Returns:

True if we should calculate the real distance and attempt add the corresponding object into this queue.