gnu.kawa.util
Class GeneralHashTable

java.lang.Object
  gnu.kawa.util.GeneralHashTable

Direct Known Subclasses:

NameLookup

public class GeneralHashTable
extends java.lang.Object

A generic hash table. Supports deletions, and re-allocates the table when too big. The equivalence relation can be customized.

Field Summary

protected int	mask
protected int	num_bindings
protected HashNode[]	table

Constructor Summary

GeneralHashTable()

GeneralHashTable(int capacity)

Method Summary

void	clear()
java.lang.Object	get(java.lang.Object key, java.lang.Object defaultValue)
HashNode	getNode(java.lang.Object key)
int	hash(HashNode node)
int	hash(java.lang.Object key) Calculate hash code of a key.
protected HashNode	makeEntry(java.lang.Object key, int hash, java.lang.Object value) Allocate a new node in the hash table.
boolean	matches(java.lang.Object key, int hash, HashNode node)
boolean	matches(java.lang.Object value1, java.lang.Object value2) Compare two keys for equivalence.
protected static HashNode	next(HashNode node)
java.lang.Object	put(java.lang.Object key, int hash, java.lang.Object value)
java.lang.Object	put(java.lang.Object key, java.lang.Object value)
protected void	rehash()
java.lang.Object	remove(java.lang.Object key)
int	size()

Methods inherited from class java.lang.Object

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

Field Detail

table

protected HashNode[] table

mask

protected int mask

num_bindings

protected int num_bindings

Constructor Detail

GeneralHashTable

public GeneralHashTable()

GeneralHashTable

public GeneralHashTable(int capacity)

Method Detail

makeEntry

protected HashNode makeEntry(java.lang.Object key,
                             int hash,
                             java.lang.Object value)

Allocate a new node in the hash table.

hash

public int hash(java.lang.Object key)

Calculate hash code of a key. You may need to override this if you override the matches method.

hash

public int hash(HashNode node)

matches

public boolean matches(java.lang.Object key,
                       int hash,
                       HashNode node)

matches

public boolean matches(java.lang.Object value1,
                       java.lang.Object value2)

Compare two keys for equivalence. Override this and the hash(Object) method if you want a different equivalence relation.

get

public java.lang.Object get(java.lang.Object key,
                            java.lang.Object defaultValue)

getNode

public HashNode getNode(java.lang.Object key)

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

put

public java.lang.Object put(java.lang.Object key,
                            int hash,
                            java.lang.Object value)

remove

public java.lang.Object remove(java.lang.Object key)

rehash

protected void rehash()

clear

public void clear()

size

public int size()

next

protected static HashNode next(HashNode node)