Module org.elasticsearch.exponentialhistogram

Package org.elasticsearch.exponentialhistogram

Class ExponentialHistogramMerger

java.lang.Object

org.elasticsearch.exponentialhistogram.ExponentialHistogramMerger

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.lucene.util.Accountable, Releasable

public class ExponentialHistogramMerger
extends Object
implements org.apache.lucene.util.Accountable, Releasable

Allows accumulating multiple ExponentialHistogram into a single one while keeping the bucket count in the result below a given limit.

Field Summary

Fields inherited from interface org.apache.lucene.util.Accountable

NULL_ACCOUNTABLE

Method Summary

Modifier and Type	Method	Description
void	add(ExponentialHistogram toAdd)	Merges the given histogram into the current result.
void	addWithoutUpscaling(ExponentialHistogram toAdd)	Merges the given histogram into the current result, not upscaling it.
void	close()
static ExponentialHistogramMerger	create(int bucketLimit, ExponentialHistogramCircuitBreaker circuitBreaker)	Creates a new instance with the specified bucket limit.
static ExponentialHistogramMerger	create(ExponentialHistogramCircuitBreaker circuitBreaker)	Creates a new instance with the OpenTelemetry SDK default bucket limit of MAX_HISTOGRAM_BUCKETS
static ExponentialHistogramMerger	createWithMaxScale(int bucketLimit, int maxScale, ExponentialHistogramCircuitBreaker circuitBreaker)
ExponentialHistogram	get()	Gets the current merged histogram without clearing this merger.
ReleasableExponentialHistogram	getAndClear()	Returns the merged histogram and clears this merger.
long	ramBytesUsed()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.util.Accountable

getChildResources

Method Details

create

public static ExponentialHistogramMerger create(ExponentialHistogramCircuitBreaker circuitBreaker)

Creates a new instance with the OpenTelemetry SDK default bucket limit of MAX_HISTOGRAM_BUCKETS

Parameters:

circuitBreaker - the circuit breaker to use to limit memory allocations

create

public static ExponentialHistogramMerger create(int bucketLimit,
 ExponentialHistogramCircuitBreaker circuitBreaker)

Creates a new instance with the specified bucket limit.

Parameters:

bucketLimit - the maximum number of buckets the result histogram is allowed to have, must be at least 4

circuitBreaker - the circuit breaker to use to limit memory allocations

createWithMaxScale

public static ExponentialHistogramMerger createWithMaxScale(int bucketLimit,
 int maxScale,
 ExponentialHistogramCircuitBreaker circuitBreaker)

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface Releasable

ramBytesUsed

public long ramBytesUsed()

Specified by:

ramBytesUsed in interface org.apache.lucene.util.Accountable

getAndClear

public ReleasableExponentialHistogram getAndClear()

Returns the merged histogram and clears this merger. The caller takes ownership of the returned histogram and must ensure that close() is called.

Returns:

the merged histogram

get

public ExponentialHistogram get()

Gets the current merged histogram without clearing this merger. Note that the ownership of the returned histogram remains with this merger, so the caller must not close it. The returned histogram is only valid until the next call to add(ExponentialHistogram), or until the merger is closed.

Returns:

the current merged histogram

addWithoutUpscaling

public void addWithoutUpscaling(ExponentialHistogram toAdd)

Merges the given histogram into the current result, not upscaling it. This should be used when merging intermediate results to prevent accumulating errors.

Parameters:

toAdd - the histogram to merge

add

public void add(ExponentialHistogram toAdd)

Merges the given histogram into the current result. The histogram might be upscaled if needed.

Parameters:

toAdd - the histogram to merge