org.h2.util
Class SmallMap

java.lang.Object
  org.h2.util.SmallMap

public class SmallMap
extends java.lang.Object

A simple hash table with an optimization for the last recently used object.

Constructor Summary

SmallMap(int maxElements)
Create a map with the given maximum number of entries.

Method Summary

int	addObject(int id, java.lang.Object o) Add an object to the map.
void	freeObject(int id) Remove an object from the map.
java.lang.Object	getObject(int id, boolean ifAvailable) Get an object from the map if it is stored.

Methods inherited from class java.lang.Object

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

Constructor Detail

SmallMap

public SmallMap(int maxElements)

Create a map with the given maximum number of entries.

Parameters:

maxElements - the maximum number of entries

Method Detail

addObject

public int addObject(int id,
                     java.lang.Object o)

Add an object to the map. If the size of the map is larger than twice the maximum size, objects with a low id are removed.

Parameters:

id - the object id

o - the object

Returns:

the id

freeObject

public void freeObject(int id)

Remove an object from the map.

Parameters:

id - the id of the object to remove

getObject

public java.lang.Object getObject(int id,
                                  boolean ifAvailable)

Get an object from the map if it is stored.

Parameters:

id - the id of the object

ifAvailable - only return it if available, otherwise return null

Returns:

the object or null

Throws:

DbException - if isAvailable is false and the object has not been found