com.hazelcast.query.impl.predicates

Class EvaluatePredicate

java.lang.Object

com.hazelcast.query.impl.predicates.EvaluatePredicate

All Implemented Interfaces:

IndexAwarePredicate, Predicate, Serializable

public final class EvaluatePredicate
extends Object
implements Predicate, IndexAwarePredicate

Wraps a predicate for which Index.canEvaluate(java.lang.Class<? extends com.hazelcast.query.Predicate>) returned true.

Used during predicate tree optimization done by EvaluateVisitor. Never transferred over the wire.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
EvaluatePredicate(Predicate predicate, String indexName) Constructs EvaluatePredicate instance for the given predicate which can be evaluated by the given index identified by its name.

Method Summary

Modifier and Type	Method and Description
boolean	apply(Map.Entry mapEntry) Applies this predicate to the given map entry.
Set<QueryableEntry>	filter(QueryContext queryContext) Produces a filtered entry set by utilizing the indexes available while executing the query in the given query context.
String	getIndexName()
Predicate	getPredicate()
boolean	isIndexed(QueryContext queryContext) Signals to the query engine that this predicate is able to utilize the indexes available while executing the query in the given query context.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

EvaluatePredicate

public EvaluatePredicate(Predicate predicate,
                         String indexName)

Constructs EvaluatePredicate instance for the given predicate which can be evaluated by the given index identified by its name.

Parameters:

predicate - the evaluable predicate to wrap.

indexName - the index which can evaluate the given predicate.

Method Detail

getPredicate

public Predicate getPredicate()

Returns:

the original evaluable predicate.

getIndexName

public String getIndexName()

Returns:

the index name of the index which can evaluate the predicate wrapped by this predicate instance.

apply

public boolean apply(Map.Entry mapEntry)

Description copied from interface: Predicate

Applies this predicate to the given map entry.

Implementations must be thread-safe, since this method may be called by multiple threads concurrently.

Specified by:

apply in interface Predicate

Parameters:

mapEntry - the map entry to apply this predicate to.

Returns:

true if the given map entry matches this predicate, false otherwise.

filter

public Set<QueryableEntry> filter(QueryContext queryContext)

Description copied from interface: IndexAwarePredicate

Produces a filtered entry set by utilizing the indexes available while executing the query in the given query context.

The query engine assumes this method produces the result set faster than a simple evaluation of the predicate on every entry.

Specified by:

filter in interface IndexAwarePredicate

Parameters:

queryContext - the query context to access the indexes. The passed query context is valid only for a duration of a single call to the method.

Returns:

the produced filtered entry set.

isIndexed

public boolean isIndexed(QueryContext queryContext)

Description copied from interface: IndexAwarePredicate

Signals to the query engine that this predicate is able to utilize the indexes available while executing the query in the given query context.

Specified by:

isIndexed in interface IndexAwarePredicate

Parameters:

queryContext - the query context to consult for the available indexes.

Returns:

true if this predicate is able to use the indexes to speed up the processing, false otherwise.

toString

public String toString()

Overrides:

toString in class Object