shared
Class InstanceHashTable

java.lang.Object
  |
  +--shared.InstanceHashTable

public class InstanceHashTable

extends java.lang.Object

InstanceHashTable is a clean interface to the user of hash table of instances. This HashTable handles collisions by placing the colliding instances in an InstanceList at that position in the HashTable.

Because the hashCode function does not gaurantee distinct values, it is possible for colliding instances to not be equivalent.

Constructor Summary

InstanceHashTable(int estimatedNum)
Constructor with estimated number of instances in the hash table and an InstanceList.

InstanceHashTable(int estimatedNum, InstanceList ihl)
Constructor with estimated number of instances in the hash table and an InstanceList.

Method Summary

InstanceList	find(Instance instance) Returns the reference to the InstanceList matching the given Instance.
void	insert(Instance instance) Adds an instance into the hash table by converting the instance into a InstanceListSameAttr of the one instance.

Methods inherited from class java.lang.Object

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

Constructor Detail

InstanceHashTable

public InstanceHashTable(int estimatedNum)

Constructor with estimated number of instances in the hash table and an InstanceList. If a non-null InstanceList is given, all the instance in the InstanceList will be inserted into the hash table.

Parameters:

estimatedNum - The estimated number of Instances.

InstanceHashTable

public InstanceHashTable(int estimatedNum,
                         InstanceList ihl)

Constructor with estimated number of instances in the hash table and an InstanceList. If a non-null InstanceList is given, all the instance in the InstanceList will be inserted into the hash table.

Parameters:

estimatedNum - The estimated number of Instances.

ihl - The InstanceList of Instances to place in this InstanceHashTable.

Method Detail

find

public InstanceList find(Instance instance)

Returns the reference to the InstanceList matching the given Instance.

Parameters:

instance - The Instance used as a key in this Hashtable.

Returns:

An InstanceList if found or NULL if there is no such element.

insert

public void insert(Instance instance)

Adds an instance into the hash table by converting the instance into a InstanceListSameAttr of the one instance. Aborts if the instance is unlabelled. If there exists such an instance, it merge the existing InstanceListSameAttr with the just created one.

Parameters:

instance - The Instance that is to be inserted.