org.apache.flink.runtime.operators.hash

Class InPlaceMutableHashTable.HashTableProber<PT>

java.lang.Object

org.apache.flink.runtime.operators.hash.AbstractHashTableProber<PT,T>

org.apache.flink.runtime.operators.hash.InPlaceMutableHashTable.HashTableProber<PT>

Type Parameters:

PT - The type of the records that we are probing with

Enclosing class:

InPlaceMutableHashTable<T>

public final class InPlaceMutableHashTable.HashTableProber<PT>
extends AbstractHashTableProber<PT,T>

A prober for accessing the table. In addition to getMatchFor and updateMatch, it also has insertAfterNoMatch. Warning: Don't modify the table between calling getMatchFor and the other methods!

Field Summary

Fields inherited from class org.apache.flink.runtime.operators.hash.AbstractHashTableProber

pairComparator, probeTypeComparator

Constructor Summary

Constructors

Constructor and Description
HashTableProber(org.apache.flink.api.common.typeutils.TypeComparator<PT> probeTypeComparator, org.apache.flink.api.common.typeutils.TypePairComparator<PT,T> pairComparator)

Method Summary

Modifier and Type	Method and Description
T	getMatchFor(PT probeSideRecord)
T	getMatchFor(PT record, T targetForMatch) Searches the hash table for the record with the given key.
void	insertAfterNoMatch(T record) This method can be called after getMatchFor returned null.
void	updateMatch(T newRecord) This method can be called after getMatchFor returned a match.

Methods inherited from class java.lang.Object

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

Constructor Detail

HashTableProber

public HashTableProber(org.apache.flink.api.common.typeutils.TypeComparator<PT> probeTypeComparator,
                       org.apache.flink.api.common.typeutils.TypePairComparator<PT,T> pairComparator)

Method Detail

getMatchFor

public T getMatchFor(PT record,
                     T targetForMatch)

Searches the hash table for the record with the given key. (If there would be multiple matches, only one is returned.)

Specified by:

getMatchFor in class AbstractHashTableProber<PT,T>

Parameters:

record - The record whose key we are searching for

targetForMatch - If a match is found, it will be written here

Returns:

targetForMatch if a match is found, otherwise null.

getMatchFor

public T getMatchFor(PT probeSideRecord)

Specified by:

getMatchFor in class AbstractHashTableProber<PT,T>

updateMatch

public void updateMatch(T newRecord)
                 throws IOException

This method can be called after getMatchFor returned a match. It will overwrite the record that was found by getMatchFor. Warning: The new record should have the same key as the old! WARNING; Don't do any modifications to the table between getMatchFor and updateMatch!

Specified by:

updateMatch in class AbstractHashTableProber<PT,T>

Parameters:

newRecord - The record to override the old record with.

Throws:

IOException - (EOFException specifically, if memory ran out)

insertAfterNoMatch

public void insertAfterNoMatch(T record)
                        throws IOException

This method can be called after getMatchFor returned null. It inserts the given record to the hash table. Important: The given record should have the same key as the record that was given to getMatchFor! WARNING; Don't do any modifications to the table between getMatchFor and insertAfterNoMatch!

Throws:

IOException - (EOFException specifically, if memory ran out)