org.apache.rocketmq.shaded.io.opentelemetry.sdk.metrics.internal.exemplar.ReservoirCell Maven / Gradle / Ivy
/*
* Copyright The OpenTelemetry Authors
* SPDX-License-Identifier: Apache-2.0
*/
package org.apache.rocketmq.shaded.io.opentelemetry.sdk.metrics.internal.exemplar;
import org.apache.rocketmq.shaded.io.opentelemetry.api.common.AttributeKey;
import org.apache.rocketmq.shaded.io.opentelemetry.api.common.Attributes;
import org.apache.rocketmq.shaded.io.opentelemetry.api.trace.Span;
import org.apache.rocketmq.shaded.io.opentelemetry.api.trace.SpanContext;
import org.apache.rocketmq.shaded.io.opentelemetry.context.Context;
import org.apache.rocketmq.shaded.io.opentelemetry.sdk.common.Clock;
import org.apache.rocketmq.shaded.io.opentelemetry.sdk.metrics.data.DoubleExemplarData;
import org.apache.rocketmq.shaded.io.opentelemetry.sdk.metrics.data.ExemplarData;
import org.apache.rocketmq.shaded.io.opentelemetry.sdk.metrics.data.LongExemplarData;
import org.apache.rocketmq.shaded.io.opentelemetry.sdk.metrics.internal.data.ImmutableDoubleExemplarData;
import org.apache.rocketmq.shaded.io.opentelemetry.sdk.metrics.internal.data.ImmutableLongExemplarData;
import java.util.Set;
import javax.annotation.Nullable;
/**
* A Reservoir cell pre-allocated memories for Exemplar data.
*
* We only allocate new objects during collection. This class should NOT cause allocations during
* sampling or within the synchronous metric hot-path.
*
*
Allocations are acceptable in the {@link #getAndResetDouble(Attributes)} and {@link
* #getAndResetLong(Attributes)} collection methods.
*/
class ReservoirCell {
private final Clock clock;
@Nullable private Attributes attributes;
private SpanContext spanContext = SpanContext.getInvalid();
private long recordTime;
// Cell stores either long or double values, but must not store both
private long longValue;
private double doubleValue;
ReservoirCell(Clock clock) {
this.clock = clock;
}
/**
* Record the long measurement to the cell.
*
*
Must be used in tandem with {@link #getAndResetLong(Attributes)}. {@link
* #recordDoubleMeasurement(double, Attributes, Context)} and {@link
* #getAndResetDouble(Attributes)} must not be used when a cell is recording longs.
*/
synchronized void recordLongMeasurement(long value, Attributes attributes, Context context) {
this.longValue = value;
offerMeasurement(attributes, context);
}
/**
* Record the long measurement to the cell.
*
*
Must be used in tandem with {@link #getAndResetDouble(Attributes)}. {@link
* #recordLongMeasurement(long, Attributes, Context)} and {@link #getAndResetLong(Attributes)}
* must not be used when a cell is recording longs.
*/
synchronized void recordDoubleMeasurement(double value, Attributes attributes, Context context) {
this.doubleValue = value;
offerMeasurement(attributes, context);
}
private void offerMeasurement(Attributes attributes, Context context) {
this.attributes = attributes;
// Note: It may make sense in the future to attempt to pull this from an active span.
this.recordTime = clock.now();
Span current = Span.fromContext(context);
if (current.getSpanContext().isValid()) {
this.spanContext = current.getSpanContext();
}
}
/**
* Retrieve the cell's {@link ExemplarData}.
*
*
Must be used in tandem with {@link #recordLongMeasurement(long, Attributes, Context)}.
*/
@Nullable
synchronized LongExemplarData getAndResetLong(Attributes pointAttributes) {
Attributes attributes = this.attributes;
if (attributes == null) {
return null;
}
LongExemplarData result =
ImmutableLongExemplarData.create(
filtered(attributes, pointAttributes), recordTime, spanContext, longValue);
reset();
return result;
}
/**
* Retrieve the cell's {@link ExemplarData}.
*
*
Must be used in tandem with {@link #recordDoubleMeasurement(double, Attributes, Context)}.
*/
@Nullable
synchronized DoubleExemplarData getAndResetDouble(Attributes pointAttributes) {
Attributes attributes = this.attributes;
if (attributes == null) {
return null;
}
DoubleExemplarData result =
ImmutableDoubleExemplarData.create(
filtered(attributes, pointAttributes), recordTime, spanContext, doubleValue);
reset();
return result;
}
synchronized void reset() {
this.attributes = null;
this.longValue = 0;
this.doubleValue = 0;
this.spanContext = SpanContext.getInvalid();
this.recordTime = 0;
}
/** Returns filtered attributes for exemplars. */
private static Attributes filtered(Attributes original, Attributes metricPoint) {
if (metricPoint.isEmpty()) {
return original;
}
Set> metricPointKeys = metricPoint.asMap().keySet();
return original.toBuilder().removeIf(metricPointKeys::contains).build();
}
}