Module org.elasticsearch.compute

Package org.elasticsearch.compute.operator

Class SourceOperator

java.lang.Object

org.elasticsearch.compute.operator.SourceOperator

All Implemented Interfaces:

Closeable, AutoCloseable, Operator, org.elasticsearch.core.Releasable

Direct Known Subclasses:

EnrichQuerySourceOperator, ExchangeSourceOperator, LocalSourceOperator, LuceneOperator

public abstract class SourceOperator
extends Object
implements Operator

A source operator - produces output, accepts no input.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	SourceOperator.ShardLoad
static interface	SourceOperator.SourceOperatorFactory	A factory for creating source operators.

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

Operator.OperatorFactory, Operator.Status

Field Summary

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

MIN_TARGET_PAGE_SIZE, NOT_BLOCKED, TARGET_PAGE_SIZE

Constructor Summary

Constructors

Constructor	Description
SourceOperator()

Method Summary

Modifier and Type	Method	Description
final void	addInput(Page page)	A source operator does not accept input - unconditionally throws UnsupportedOperationException.
boolean	canProduceMoreDataWithoutExtraInput()	Returns true if the operator can produce more output pages without requiring additional input pages.
final boolean	needsInput()	A source operator needs no input - unconditionally returns false.
protected List<SourceOperator.ShardLoad>	shardLoadDelta(long now)	Returns a snapshot of shard load accumulated since the previous invocation.

Methods inherited from class java.lang.Object

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

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

close, finish, getOutput, isBlocked, isFinished, status

Constructor Details

SourceOperator

public SourceOperator()

Method Details

needsInput

public final boolean needsInput()

A source operator needs no input - unconditionally returns false.

Specified by:

needsInput in interface Operator

Returns:

false

addInput

public final void addInput(Page page)

A source operator does not accept input - unconditionally throws UnsupportedOperationException.

Specified by:

addInput in interface Operator

Parameters:

page - a page

canProduceMoreDataWithoutExtraInput

public boolean canProduceMoreDataWithoutExtraInput()

Description copied from interface: Operator

Returns true if the operator can produce more output pages without requiring additional input pages. This is useful for operators that buffer data or have internal state that can produce multiple output pages.

Operators that do not buffer data should return false - they cannot produce pages out of thin air. Examples of operators that may return true:

• Operators with internal buffers (e.g., AsyncOperator with pending results)
• Operators processing a single input page into multiple output pages
• Aggregation operators that buffer partial results

Specified by:

canProduceMoreDataWithoutExtraInput in interface Operator

Returns:

true if the operator has buffered data that can produce output, false otherwise

shardLoadDelta

protected List<SourceOperator.ShardLoad> shardLoadDelta(long now)

Returns a snapshot of shard load accumulated since the previous invocation.

This method is meant to be overridden by SourceOperator implementations that can attribute produced pages to shards or indices.

The snapshot represents a delta: implementations must reset their internal counters after the snapshot is taken so that each invocation reports only the load observed since the last call.

Source operators that do not operate on shards or indices can ignore this mechanism and rely on the default implementation, which returns an empty list.

Returns:

list of per-shard load since the last call