/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.beam.runners.core.metrics;
import com.google.auto.value.AutoValue;
import java.io.Serializable;
import org.apache.beam.sdk.metrics.GaugeResult;
import org.joda.time.Instant;
/**
* Data describing the gauge. This should retain enough detail that it can be combined with
* other {@link GaugeData}.
*/
@AutoValue
public abstract class GaugeData implements Serializable {
public abstract long value();
public abstract Instant timestamp();
public static GaugeData create(long value) {
return new AutoValue_GaugeData(value, Instant.now());
}
public static GaugeData empty() {
return EmptyGaugeData.INSTANCE;
}
public GaugeData combine(GaugeData other) {
if (this.timestamp().isAfter(other.timestamp())) {
return this;
} else {
return other;
}
}
public GaugeResult extractResult() {
return GaugeResult.create(value(), timestamp());
}
/**
* Empty {@link GaugeData}, representing no values reported.
*/
public static class EmptyGaugeData extends GaugeData {
private static final EmptyGaugeData INSTANCE = new EmptyGaugeData();
private static final Instant EPOCH = new Instant(0);
private EmptyGaugeData() {
}
@Override
public long value() {
return -1L;
}
@Override
public Instant timestamp() {
return EPOCH;
}
@Override
public GaugeResult extractResult() {
return GaugeResult.empty();
}
}
}