org.apache.flink.statefun.sdk.state.Expiration Maven / Gradle / Ivy
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* 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.flink.statefun.sdk.state;
import java.io.Serializable;
import java.time.Duration;
import java.util.Objects;
import org.apache.flink.statefun.sdk.annotations.ForRuntime;
/**
* State Expiration Configuration
*
* This class defines the way state can be auto expired by the runtime. State expiration (also
* known as state TTL) can be used to keep state from growing arbitrarily by assigning an expiration
* date to a {@link PersistedAppendingBuffer}, {@link PersistedValue} or a {@link PersistedTable}.
*
*
State can be expired after a duration had passed since either from the last write to the
* state, or the last read.
*/
public final class Expiration implements Serializable {
private static final long serialVersionUID = 1L;
public enum Mode {
NONE,
AFTER_WRITE,
AFTER_READ_OR_WRITE;
}
/**
* Returns an Expiration configuration that would expire a @duration after the last write.
*
* @param duration a duration to wait before considering the state expired.
*/
public static Expiration expireAfterWriting(Duration duration) {
return new Expiration(Mode.AFTER_WRITE, duration);
}
/**
* Returns an Expiration configuration that would expire a @duration after the last write or read.
*
* @param duration a duration to wait before considering the state expired.
*/
public static Expiration expireAfterReadingOrWriting(Duration duration) {
return new Expiration(Mode.AFTER_READ_OR_WRITE, duration);
}
public static Expiration expireAfter(Duration duration, Mode mode) {
return new Expiration(mode, duration);
}
/** @return Returns a disabled expiration */
public static Expiration none() {
return new Expiration(Mode.NONE, Duration.ZERO);
}
private final Mode mode;
private final Duration duration;
@ForRuntime
public Expiration(Mode mode, Duration duration) {
this.mode = Objects.requireNonNull(mode);
this.duration = Objects.requireNonNull(duration);
}
public Mode mode() {
return mode;
}
public Duration duration() {
return duration;
}
@Override
public String toString() {
return String.format("Expiration{mode=%s, duration=%s}", mode, duration);
}
}