org.apache.giraph.utils

Class PairList<U,V>

java.lang.Object

org.apache.giraph.utils.PairList<U,V>

Type Parameters:

U - Type of the first element in a pair

V - Type of the second element in a pair

public class PairList<U,V>
extends Object

Collection to keep pairs in, without creating a wrapper object around each pair of objects.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	PairList.Iterator Special iterator class which we'll use to iterate through elements of PairList, without having to create new object as wrapper for each pair.

Field Summary

Fields

Modifier and Type	Field and Description
protected List<U>	firstList List to keep first elements of pairs in
protected List<V>	secondList List to keep second elements of pairs in

Constructor Summary

Constructors

Constructor and Description
PairList() Constructor

Method Summary

Modifier and Type	Method and Description
void	add(U first, V second) Add a pair to the collection.
PairList.Iterator	getIterator() Get iterator through elements of this object.
int	getSize() Get number of pairs in this list.
void	initialize() Initialize the inner state.
void	initialize(int size) Initialize the inner state, with a known size.
boolean	isEmpty() Check if the list is empty.

Methods inherited from class java.lang.Object

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

Field Detail

firstList

protected List<U> firstList

List to keep first elements of pairs in

secondList

protected List<V> secondList

List to keep second elements of pairs in

Constructor Detail

PairList

public PairList()

Constructor

Method Detail

initialize

public void initialize()

Initialize the inner state. Must be called before add() is called.

initialize

public void initialize(int size)

Initialize the inner state, with a known size. Must be called before add() is called.

Parameters:

size - Number of pairs which will be added to the list

add

public void add(U first,
                V second)

Add a pair to the collection.

Parameters:

first - First element of the pair

second - Second element of the pair

getSize

public int getSize()

Get number of pairs in this list.

Returns:

Number of pairs in the list

isEmpty

public boolean isEmpty()

Check if the list is empty.

Returns:

True iff there are no pairs in the list

getIterator

public PairList.Iterator getIterator()

Get iterator through elements of this object.

Returns:

PairList.Iterator iterator