Module org.elasticsearch.server

Package org.elasticsearch.index.codec.vectors.diskbbq

Class PrefetchingCentroidIterator

java.lang.Object

org.elasticsearch.index.codec.vectors.diskbbq.PrefetchingCentroidIterator

All Implemented Interfaces:

CentroidIterator

public final class PrefetchingCentroidIterator
extends Object
implements CentroidIterator

A configurable iterator that prefetches posting lists ahead of consumption to optimize disk I/O performance. This iterator wraps another CentroidIterator and maintains a configurable buffer of prefetched posting list locations. The iterator is not thread-safe and is designed for single-threaded access.

Constructor Summary

Constructors

Constructor	Description
PrefetchingCentroidIterator(CentroidIterator delegate, org.apache.lucene.store.IndexInput postingListSlice)	Creates a prefetching iterator with default prefetch depth of 1.
PrefetchingCentroidIterator(CentroidIterator delegate, org.apache.lucene.store.IndexInput postingListSlice, int prefetchAhead)	Creates a prefetching iterator with configurable prefetch depth.

Method Summary

Modifier and Type	Method	Description
boolean	hasNext()
PostingMetadata	nextPosting()

Methods inherited from class java.lang.Object

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

Constructor Details

PrefetchingCentroidIterator

public PrefetchingCentroidIterator(CentroidIterator delegate,
 org.apache.lucene.store.IndexInput postingListSlice)
                            throws IOException

Creates a prefetching iterator with default prefetch depth of 1.

Parameters:

delegate - the underlying centroid iterator

postingListSlice - the index input for posting lists

Throws:

IOException - if prefetching fails during initialization

PrefetchingCentroidIterator

public PrefetchingCentroidIterator(CentroidIterator delegate,
 org.apache.lucene.store.IndexInput postingListSlice,
 int prefetchAhead)
                            throws IOException

Creates a prefetching iterator with configurable prefetch depth.

Parameters:

delegate - the underlying centroid iterator

postingListSlice - the index input for posting lists

prefetchAhead - number of posting lists to prefetch ahead (must be >= 1)

Throws:

IOException - if prefetching fails during initialization

IllegalArgumentException - if prefetchAhead < 1

Method Details

hasNext

public boolean hasNext()

Specified by:

hasNext in interface CentroidIterator

nextPosting

public PostingMetadata nextPosting()
                            throws IOException

Specified by:

nextPosting in interface CentroidIterator

Throws:

IOException