net.fortytwo.stream.shj

Class JoinHelper<K,V>

java.lang.Object

net.fortytwo.stream.shj.JoinHelper<K,V>

Type Parameters:

K - the key type, e.g. String

V - the value type, e.g. an RDF value class

All Implemented Interfaces:

java.util.function.Consumer<Solution<V>>

public class JoinHelper<K,V>
extends Object
implements java.util.function.Consumer<Solution<V>>

A wrapper for a solution index which applies query-specific variable bindings There is one wrapper for each query containing a triple pattern, ignoring variable names

Author:

Joshua Shinavier (http://fortytwo.net)

Constructor Summary

Constructors

Constructor and Description
JoinHelper(SolutionIndex<V> solutionIndex, Map<K,Integer> indexByKey)

Method Summary

Modifier and Type	Method and Description
void	accept(Solution<V> solution)
K[]	getKeys()
Set<Solution<V>>	getSolutions()
Set<Solution<V>>	getSolutions(K key, V val) Finds all solutions with the given key/value pair
void	initialize(List<JoinHelper<K,V>> allHelpers, Map<K,Set<JoinHelper<K,V>>> helpersByVariable, java.util.function.BiConsumer<Map<K,V>,Long> solutionConsumer)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.function.Consumer

andThen

Constructor Detail

JoinHelper

public JoinHelper(SolutionIndex<V> solutionIndex,
                  Map<K,Integer> indexByKey)

Method Detail

getSolutions

public Set<Solution<V>> getSolutions()

getSolutions

public Set<Solution<V>> getSolutions(K key,
                                     V val)

Finds all solutions with the given key/value pair

Parameters:

key - a key present in any matching solutions

val - the corresponding value for the key in any matching solutions

Returns:

a set of all matching solutions. A null is returned for a logically empty set.

getKeys

public K[] getKeys()

initialize

public void initialize(List<JoinHelper<K,V>> allHelpers,
                       Map<K,Set<JoinHelper<K,V>>> helpersByVariable,
                       java.util.function.BiConsumer<Map<K,V>,Long> solutionConsumer)

accept

public void accept(Solution<V> solution)

Specified by:

accept in interface java.util.function.Consumer<Solution<V>>