gzz.util
Class AbstractFlatHashMap

java.lang.Object
  |
  +--gzz.util.AbstractHashMap
        |
        +--gzz.util.AbstractFlatHashMap

All Implemented Interfaces:

java.util.Map

Direct Known Subclasses:

SecondaryHashMap

public abstract class AbstractFlatHashMap

extends AbstractHashMap

A flat hash class. Because of the Java overheads associated with objects, we can afford to make a flat hashtable (which does NOT have the overhead of an object per entry) large enough to more than cover the difference. This is especially so on Kaffe, where the overhead associated with object creation is considerable.

However, there is one considerable downside: Java always checks the array bounds on array access, which means that while creating a new entry is fast, putting a new value into an existing entry or accessing entries can actually be slower (and is, according to benchmarks).

Constructor Summary

AbstractFlatHashMap()

Method Summary

java.util.Set	keySet()
protected void	resize(int nsize, int nentrylimit)
int	size()

Methods inherited from class gzz.util.AbstractHashMap

clear, containsKey, containsValue, entrySet, equals, hashCode, isEmpty, putAll, remove, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

get, put

Constructor Detail

AbstractFlatHashMap

public AbstractFlatHashMap()

Method Detail

resize

protected void resize(int nsize,
                      int nentrylimit)

size

public int size()

keySet

public java.util.Set keySet()