Module org.elasticsearch.compute

Package org.elasticsearch.compute.operator

Class HighlightOperator

java.lang.Object

org.elasticsearch.compute.operator.AbstractPageMappingOperator

org.elasticsearch.compute.operator.HighlightOperator

All Implemented Interfaces:

Closeable, AutoCloseable, Operator, Releasable

public class HighlightOperator
extends AbstractPageMappingOperator

Appends one highlighted keyword column per ON field to the input page.

Each ON field is evaluated to its BytesRefBlock value and highlighted per row using a Lucene MemoryIndex: the row's (possibly multi-valued) text is analyzed into a single in-memory document and the configured Query is run against it through a CustomUnifiedHighlighter. Matched terms are wrapped with the configured tags by the PassageFormatter. A row that the query does not match yields null (or, when no_match_size > 0, the leading text). Multiple fragments and multi-valued inputs become a multi-value keyword block.

The MemoryIndex is built with offsets, so we read them via UnifiedHighlighter.OffsetSource.POSTINGS. This is the same coordinator-side path that TOP_SNIPPETS already uses. Unlike Query DSL highlighting, this path truncates analyzed tokens at the configured/default offset instead of throwing the "field too long" error.

TODO: use real index offsets and per-field analyzers when highlighting can run directly against shard data.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	HighlightOperator.Factory

Nested classes/interfaces inherited from class org.elasticsearch.compute.operator.AbstractPageMappingOperator

AbstractPageMappingOperator.Status

Nested classes/interfaces inherited from interface org.elasticsearch.compute.operator.Operator

Operator.OperatorFactory

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CONTENT_FIELD	Synthetic field name under which each row's text is indexed in the per-row MemoryIndex.

Fields inherited from interface org.elasticsearch.compute.operator.Operator

MIN_TARGET_PAGE_SIZE, NOT_BLOCKED, TARGET_PAGE_SIZE

Constructor Summary

Constructors

Constructor	Description
HighlightOperator(BlockFactory blockFactory, HighlightConfig config, ExpressionEvaluator[] fieldEvaluators)

Method Summary

Modifier and Type	Method	Description
void	close()	notifies the operator that it won't be used anymore (i.e.
protected Page	process(Page page)
String	toString()

Methods inherited from class org.elasticsearch.compute.operator.AbstractPageMappingOperator

addInput, canProduceMoreDataWithoutExtraInput, finish, getOutput, isFinished, needsInput, status, status

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.elasticsearch.compute.operator.Operator

isBlocked, tryPromote

Field Details

CONTENT_FIELD

public static final String CONTENT_FIELD

Synthetic field name under which each row's text is indexed in the per-row MemoryIndex. The configured Query passed to the factory must be built against this same field name.

See Also:

• Constant Field Values

Constructor Details

HighlightOperator

public HighlightOperator(BlockFactory blockFactory,
 HighlightConfig config,
 ExpressionEvaluator[] fieldEvaluators)

Method Details

process

protected Page process(Page page)

Specified by:

process in class AbstractPageMappingOperator

toString

public String toString()

Specified by:

toString in class AbstractPageMappingOperator

close

public void close()

Description copied from interface: Operator

notifies the operator that it won't be used anymore (i.e. none of the other methods called), and its resources can be cleaned up

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface Operator

Specified by:

close in interface Releasable

Overrides:

close in class AbstractPageMappingOperator