org.jboss.cache.eviction
Class MRUQueue

java.lang.Object
  org.jboss.cache.eviction.MRUQueue

All Implemented Interfaces:

Iterable<NodeEntry>, EvictionQueue

public class MRUQueue
extends Object
implements EvictionQueue

MRU Eviction Queue implementation.

This nodeMap is sorted by MRU. The first entry in the nodeMap will also be the most recently used entry. The sort is implicit based on a Stack that we can implicitly sort to the top by moving a node that is used to the top of the eviction stack.

Version:

$Revision: 7168 $

Author:

Daniel Huang (dhuang@jboss.org)

Constructor Summary

protected

MRUQueue()

Method Summary

void	addNodeEntry(NodeEntry entry) Add a NodeEntry to the queue.
void	clear() Clear the queue.
boolean	containsNodeEntry(NodeEntry entry) Check if queue contains the given NodeEntry.
NodeEntry	getFirstNodeEntry() Will return the first entry in the nodeMap.
NodeEntry	getNodeEntry(Fqn fqn) Retrieve a node entry by Fqn.
NodeEntry	getNodeEntry(String fqn)
int	getNumberOfElements() Get the number of elements in the queue.
int	getNumberOfNodes() Get the number of nodes in the queue.
Iterator<NodeEntry>	iterator()
void	modifyElementCount(int difference)
protected void	moveToTopOfStack(Fqn fqn) This call moves a NodeEntry to the top of the stack.
void	removeNodeEntry(NodeEntry entry) Remove a NodeEntry from queue.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

MRUQueue

protected MRUQueue()

Method Detail

moveToTopOfStack

protected void moveToTopOfStack(Fqn fqn)

This call moves a NodeEntry to the top of the stack.

When a node is visited this method should be called to guarantee MRU ordering.

Parameters:

fqn - Fqn of the nodeEntry to move to the top of the stack.

getFirstNodeEntry

public NodeEntry getFirstNodeEntry()

Will return the first entry in the nodeMap.

The first entry in this nodeMap will also be the most recently used entry.

Specified by:

getFirstNodeEntry in interface EvictionQueue

Returns:

The first node entry in nodeMap.

getNodeEntry

public NodeEntry getNodeEntry(Fqn fqn)

Description copied from interface: EvictionQueue

Retrieve a node entry by Fqn.

This will return null if the entry is not found.

Specified by:

getNodeEntry in interface EvictionQueue

Parameters:

fqn - Fqn of the node entry to retrieve.

Returns:

Node Entry object associated with given Fqn param.

getNodeEntry

public NodeEntry getNodeEntry(String fqn)

Specified by:

getNodeEntry in interface EvictionQueue

containsNodeEntry

public boolean containsNodeEntry(NodeEntry entry)

Description copied from interface: EvictionQueue

Check if queue contains the given NodeEntry.

Specified by:

containsNodeEntry in interface EvictionQueue

Parameters:

entry - NodeEntry to check for existence in queue.

Returns:

true/false if NodeEntry exists in queue.

removeNodeEntry

public void removeNodeEntry(NodeEntry entry)

Description copied from interface: EvictionQueue

Remove a NodeEntry from queue.

If the NodeEntry does not exist in the queue, this method will return normally.

Specified by:

removeNodeEntry in interface EvictionQueue

Parameters:

entry - The NodeEntry to remove from queue.

addNodeEntry

public void addNodeEntry(NodeEntry entry)

Description copied from interface: EvictionQueue

Add a NodeEntry to the queue.

Specified by:

addNodeEntry in interface EvictionQueue

Parameters:

entry - The NodeEntry to add to queue.

getNumberOfNodes

public int getNumberOfNodes()

Description copied from interface: EvictionQueue

Get the number of nodes in the queue.

Specified by:

getNumberOfNodes in interface EvictionQueue

Returns:

The number of nodes in the queue.

getNumberOfElements

public int getNumberOfElements()

Description copied from interface: EvictionQueue

Get the number of elements in the queue.

Specified by:

getNumberOfElements in interface EvictionQueue

Returns:

The number of elements in the queue.

modifyElementCount

public void modifyElementCount(int difference)

Specified by:

modifyElementCount in interface EvictionQueue

clear

public void clear()

Description copied from interface: EvictionQueue

Clear the queue.

Specified by:

clear in interface EvictionQueue

iterator

public Iterator<NodeEntry> iterator()

Specified by:

iterator in interface Iterable<NodeEntry>

toString

public String toString()

Overrides:

toString in class Object