edu.vt.marian.search
Class InsertionOrderWtdObjTable

java.lang.Object
  |
  +--java.util.Dictionary
        |
        +--java.util.Hashtable
              |
              +--edu.vt.marian.search.FullIDTable
                    |
                    +--edu.vt.marian.search.WtdObjTable
                          |
                          +--edu.vt.marian.search.InsertionOrderWtdObjTable

public class InsertionOrderWtdObjTable

extends WtdObjTable

implements java.util.Enumeration

Provides hash table functionality for (singly-linked) weighted objects keyed on FullIDs, implicitly ordered on the order in which they were inserted. This class is essentially a wrapper around WtdObjTable to impose the insertion order semantics.

This method implicitly relies upon the hashCode method to be defined in the object that is going to be used as a key object.

See Also:

WtdObjTable, WtdObjSingleLink, WtdObj, Hashtable, Debug, Serialized Form

Field Summary

protected edu.vt.marian.common.FullID	first FullID key of first item inserted into table, for resetting order for enumerations
protected edu.vt.marian.common.FullID	prevKeyInserted FullID key of the WtdObj we last inserted into the list, for maintaining insertion ordering

Fields inherited from class edu.vt.marian.search.WtdObjTable

enum

Fields inherited from class edu.vt.marian.search.FullIDTable

BAD_PARAMS, debug, NULL_STREAM, OK

Constructor Summary

InsertionOrderWtdObjTable(edu.vt.marian.common.Debug debug)
Create an empty hash table for (singly-linked) weighted objects

InsertionOrderWtdObjTable(int initialCapacity, edu.vt.marian.common.Debug debug)
Create an empty hash table for (singly-linked) weighted objects specifying initial capacity, but with default load factor.

InsertionOrderWtdObjTable(int initialCapacity, float loadFactor, edu.vt.marian.common.Debug debug)
Create an empty hash table for (singly-linked) weighted objects specifying initial capacity and load factor.

Method Summary

void	clear() Clear hash table.
java.util.Enumeration	elements() Return an Enumeration for the weighted objects in this table.
java.lang.Object	insert(edu.vt.marian.common.WtdObj wtdObj) Add a weighted object to the table.
java.lang.Object	nextElement() Return the next weighted object element in this table's enumeration.
java.lang.String	profile()
java.lang.String	toString()

Methods inherited from class edu.vt.marian.search.WtdObjTable

elements, getNext, hasMoreElements

Methods inherited from class edu.vt.marian.search.FullIDTable

toStream

Methods inherited from class java.util.Hashtable

clone, contains, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keys, keySet, put, putAll, rehash, remove, size, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

prevKeyInserted

protected edu.vt.marian.common.FullID prevKeyInserted

FullID key of the WtdObj we last inserted into the list, for maintaining insertion ordering

first

protected edu.vt.marian.common.FullID first

FullID key of first item inserted into table, for resetting order for enumerations

Constructor Detail

InsertionOrderWtdObjTable

public InsertionOrderWtdObjTable(edu.vt.marian.common.Debug debug)

Create an empty hash table for (singly-linked) weighted objects

InsertionOrderWtdObjTable

public InsertionOrderWtdObjTable(int initialCapacity,
                                 float loadFactor,
                                 edu.vt.marian.common.Debug debug)

Create an empty hash table for (singly-linked) weighted objects specifying initial capacity and load factor.

Parameters:

initialCapacity - initial size of hash table

loadFactor - occupancy threshold before growth needed

debug - debugging object

InsertionOrderWtdObjTable

public InsertionOrderWtdObjTable(int initialCapacity,
                                 edu.vt.marian.common.Debug debug)

Create an empty hash table for (singly-linked) weighted objects specifying initial capacity, but with default load factor.

Parameters:

initialCapacity - initial size of hash table

debug - debugging object

Method Detail

insert

public java.lang.Object insert(edu.vt.marian.common.WtdObj wtdObj)

Add a weighted object to the table. This not only adds the weighted object, but also makes the previously inserted weighted object point to this one, to effect a linked list of weighted objects in insertion order.

Parameters:

wtdObj - weighted object to be inserted

Returns:

null if the weighted object was not already present, otherwise return the Object that was already there.

elements

public java.util.Enumeration elements()

Return an Enumeration for the weighted objects in this table. We actually return this object, but set up to point to the first element in the table, ready for nextElement() and hasMoreElements(). This first element is actually the one pointed to by prevKeyInserted.

Returns:

Enumeration containing weighted object elements in table

Overrides:

elements in class WtdObjTable

See Also:

nextElement(), WtdObjTable.hasMoreElements()

nextElement

public java.lang.Object nextElement()
                             throws java.util.NoSuchElementException

Return the next weighted object element in this table's enumeration. Also, set up the enum to be the next weighted object in the threaded sequence.

Specified by:

nextElement in interface java.util.Enumeration

Returns:

Object that is the next in the sequence

Overrides:

nextElement in class WtdObjTable

See Also:

Enumeration.nextElement()

clear

public void clear()

Clear hash table. This basically just calls the superclass clear() method, but also resets enum and prevKeyInserted to null to reflect initial table status.

Overrides:

clear in class java.util.Hashtable

See Also:

Hashtable

toString

public java.lang.String toString()

Overrides:

toString in class FullIDTable

profile

public java.lang.String profile()