org.apache.kafka.streams.state.WindowBytesStoreSupplier 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kafka.streams.state;
import org.apache.kafka.common.utils.Bytes;
/**
* A store supplier that can be used to create one or more {@link WindowStore WindowStore<Byte, byte[]>} instances of type <Byte, byte[]>.
*
* For any stores implementing the {@link WindowStore WindowStore<Byte, byte[]>} interface, null value bytes are considered as "not exist". This means:
*
* 1. Null value bytes in put operations should be treated as delete.
* 2. Null value bytes should never be returned in range query results.
*/
public interface WindowBytesStoreSupplier extends StoreSupplier> {
/**
* The size of the segments (in milliseconds) the store has.
* If your store is segmented then this should be the size of segments in the underlying store.
* It is also used to reduce the amount of data that is scanned when caching is enabled.
*
* @return size of the segments (in milliseconds)
*/
long segmentIntervalMs();
/**
* The size of the windows (in milliseconds) any store created from this supplier is creating.
*
* @return window size
*/
long windowSize();
/**
* Whether or not this store is retaining duplicate keys.
* Usually only true if the store is being used for joins.
* Note this should return false if caching is enabled.
*
* @return true if duplicates should be retained
*/
boolean retainDuplicates();
/**
* The time period for which the {@link WindowStore} will retain historic data.
*
* @return retentionPeriod
*/
long retentionPeriod();
}