Package org.apache.ignite.internal.processors.cache.query.reducer

Class IndexQueryReducer<R>

java.lang.Object

org.apache.ignite.internal.util.lang.GridIteratorAdapter<T>

org.apache.ignite.internal.processors.cache.query.reducer.CacheQueryReducer<R>

org.apache.ignite.internal.processors.cache.query.reducer.IndexQueryReducer<R>

All Implemented Interfaces:

Serializable, Iterable<R>, Iterator<R>, GridSerializableIterator<R>, GridIterator<R>

public class IndexQueryReducer<R>
extends CacheQueryReducer<R>

Reducer for IndexQuery results.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.ignite.internal.processors.cache.query.reducer.CacheQueryReducer

pageStreams

Constructor Summary

Constructors

Constructor	Description
IndexQueryReducer(String valType, Map<UUID,NodePageStream<R>> pageStreams, GridCacheContext<?,?> cctx, CompletableFuture<IndexQueryResultMeta> meta)

Method Summary

Modifier and Type	Method	Description
boolean	hasNextX()	This method is the same as Iterator.hasNext(), but allows for failure with exception.
R	nextX()	This method is the same as Iterator.next(), but allows for failure with exception.
protected CompletableFuture<Comparator<NodePage<R>>>	pageComparator()

Methods inherited from class org.apache.ignite.internal.processors.cache.query.reducer.CacheQueryReducer

get, removeX

Methods inherited from class org.apache.ignite.internal.util.lang.GridIteratorAdapter

hasNext, iterator, next, remove

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

IndexQueryReducer

public IndexQueryReducer(String valType,
                         Map<UUID,NodePageStream<R>> pageStreams,
                         GridCacheContext<?,?> cctx,
                         CompletableFuture<IndexQueryResultMeta> meta)

Method Detail

pageComparator

protected CompletableFuture<Comparator<NodePage<R>>> pageComparator()

Returns:

Comparator for pages from nodes.

hasNextX

public boolean hasNextX()
                 throws IgniteCheckedException

This method is the same as Iterator.hasNext(), but allows for failure with exception. Often iterators are used to iterate through values that have not or have partially been received from remote nodes, and need to account for possible network failures, rather than just returning false out of Iterator.hasNext() method.

Returns:

True if iterator contains more elements.

Throws:

IgniteCheckedException - If no more elements can be returned due to some failure, like a network error for example.

See Also:

Iterator.hasNext()

nextX

public R nextX()
        throws IgniteCheckedException

This method is the same as Iterator.next(), but allows for failure with exception. Often iterators are used to iterate through values that have not or have partially been received from remote nodes, and need to account for possible network failures, rather than throwing NoSuchElementException runtime exception.s

Returns:

True if iterator contains more elements.

Throws:

IgniteCheckedException - If no more elements can be returned due to some failure, like a network error for example.

See Also:

Iterator.next()