Package org.elasticsearch.xpack.esql.expression.function.scalar.histogram

Class ExtractHistogramComponent

java.lang.Object

org.elasticsearch.xpack.esql.core.tree.Node<Expression>

org.elasticsearch.xpack.esql.core.expression.Expression

org.elasticsearch.xpack.esql.core.expression.function.Function

org.elasticsearch.xpack.esql.core.expression.function.scalar.ScalarFunction

org.elasticsearch.xpack.esql.expression.function.scalar.EsqlScalarFunction

org.elasticsearch.xpack.esql.expression.function.scalar.histogram.ExtractHistogramComponent

All Implemented Interfaces:

NamedWriteable, Writeable, Resolvable, EvaluatorMapper

public class ExtractHistogramComponent
extends EsqlScalarFunction

Extracts a ExponentialHistogramBlock.Component from an exponential histogram. Note that this function is currently only intended for usage in surrogates and not available as a user-facing function. Therefore, it is intentionally not registered in EsqlFunctionRegistry.

Nested Class Summary

Nested classes/interfaces inherited from class org.elasticsearch.xpack.esql.core.expression.Expression

Expression.TypeResolution

Nested classes/interfaces inherited from interface org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper

EvaluatorMapper.ToEvaluator

Nested classes/interfaces inherited from interface org.elasticsearch.common.io.stream.Writeable

Writeable.Reader<V>, Writeable.Writer<V>

Field Summary

Fields

Modifier and Type	Field	Description
static final NamedWriteableRegistry.Entry	ENTRY

Fields inherited from class org.elasticsearch.xpack.esql.core.expression.function.scalar.ScalarFunction

MAX_BYTES_REF_RESULT_SIZE

Fields inherited from class org.elasticsearch.xpack.esql.core.tree.Node

TO_STRING_MAX_WIDTH

Constructor Summary

Constructors

Constructor	Description
ExtractHistogramComponent(Source source, Expression field, Expression componentOrdinal)	Constructor for this function.

Method Summary

Modifier and Type	Method	Description
static Expression	create(Source source, Expression field, ExponentialHistogramBlock.Component component)
DataType	dataType()
boolean	foldable()
String	getWriteableName()
protected NodeInfo<? extends Expression>	info()
Expression	replaceChildren(List<Expression> newChildren)
protected Expression.TypeResolution	resolveType()
EvalOperator.ExpressionEvaluator.Factory	toEvaluator(EvaluatorMapper.ToEvaluator toEvaluator)	Convert this into an EvalOperator.ExpressionEvaluator.
void	writeTo(StreamOutput out)

Methods inherited from class org.elasticsearch.xpack.esql.expression.function.scalar.EsqlScalarFunction

fold

Methods inherited from class org.elasticsearch.xpack.esql.core.expression.function.Function

arguments, equals, functionName, hashCode, nodeString, nullable

Methods inherited from class org.elasticsearch.xpack.esql.core.expression.Expression

canonical, canonicalize, childrenResolved, propertiesToString, references, resolved, semanticEquals, semanticHash, toString, typeResolved

Methods inherited from class org.elasticsearch.xpack.esql.core.tree.Node

anyMatch, children, collect, collectFirstChildren, collectLeaves, doCollectFirst, forEachDown, forEachDown, forEachDownMayReturnEarly, forEachProperty, forEachPropertyDown, forEachPropertyOnly, forEachPropertyUp, forEachUp, forEachUp, nodeName, nodeProperties, replaceChildrenSameSize, source, sourceLocation, sourceText, transformChildren, transformDown, transformDown, transformDown, transformNodeProps, transformPropertiesDown, transformPropertiesOnly, transformPropertiesUp, transformUp, transformUp, transformUp

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper

fold

Field Details

ENTRY

public static final NamedWriteableRegistry.Entry ENTRY

Constructor Details

ExtractHistogramComponent

public ExtractHistogramComponent(Source source,
 Expression field,
 Expression componentOrdinal)

Constructor for this function.

Parameters:

source - the source

field - the exponential_histogram field to extract the value from

componentOrdinal - The Enum.ordinal() as integer-expression, must be foldable

Method Details

create

public static Expression create(Source source,
 Expression field,
 ExponentialHistogramBlock.Component component)

writeTo

public void writeTo(StreamOutput out)
             throws IOException

Throws:

IOException

getWriteableName

public String getWriteableName()

dataType

public DataType dataType()

Specified by:

dataType in class Expression

replaceChildren

public Expression replaceChildren(List<Expression> newChildren)

Specified by:

replaceChildren in class Node<Expression>

info

protected NodeInfo<? extends Expression> info()

Specified by:

info in class Node<Expression>

resolveType

protected Expression.TypeResolution resolveType()

Overrides:

resolveType in class Expression

foldable

public boolean foldable()

Overrides:

foldable in class Expression

toEvaluator

public EvalOperator.ExpressionEvaluator.Factory toEvaluator(EvaluatorMapper.ToEvaluator toEvaluator)

Description copied from interface: EvaluatorMapper

Convert this into an EvalOperator.ExpressionEvaluator.

Note for implementors: If you are implementing this function, you should call the passed-in lambda on your children, after doing any other manipulation (casting, etc.) necessary.

Note for Callers: If you are attempting to call this method, and you have an Expression and a Layout, you likely want to call EvalMapper.toEvaluator(org.elasticsearch.xpack.esql.core.expression.FoldContext, org.elasticsearch.xpack.esql.core.expression.Expression, org.elasticsearch.xpack.esql.planner.Layout) instead. On the other hand, if you already have something that looks like the parameter for this method, you should call this method with that function.

Build an EvalOperator.ExpressionEvaluator.Factory for the tree of expressions rooted at this node. This is only guaranteed to return a sensible evaluator if this node has a valid type. If this node is a subclass of Expression then "valid type" means that Expression.typeResolved() returns a non-error resolution. If Expression.typeResolved() returns an error then this method may throw. Or return an evaluator that produces garbage. Or return an evaluator that throws when run.