org.elasticsearch.spark.sql.streaming.NullMetadataLog.scala Maven / Gradle / Ivy
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* the Apache License, Version 2.0 (the "License"); you may
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* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
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package org.elasticsearch.spark.sql.streaming
import org.apache.spark.sql.execution.streaming.MetadataLog
/**
* A null object style metadata log that discards incoming data, and otherwise
* acts like an empty log.
*/
class NullMetadataLog[T] extends MetadataLog[T] with Serializable {
// Always return successful storage
override def add(batchId: Long, metadata: T): Boolean = true
override def get(batchId: Long): Option[T] = None
override def get(startId: Option[Long], endId: Option[Long]): Array[(Long, T)] = Array()
override def getLatest(): Option[(Long, T)] = None
override def purge(thresholdBatchId: Long): Unit = ()
}