org.apache.hudi.common.model.HoodieRecordPayload Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
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package org.apache.hudi.common.model;
import java.io.IOException;
import java.io.Serializable;
import java.util.Map;
import org.apache.avro.Schema;
import org.apache.avro.generic.IndexedRecord;
import org.apache.hudi.common.util.Option;
/**
* Every Hoodie dataset has an implementation of the HoodieRecordPayload This abstracts out callbacks which
* depend on record specific logic
*/
public interface HoodieRecordPayload extends Serializable {
/**
* When more than one HoodieRecord have the same HoodieKey, this function combines them before attempting to
* insert/upsert (if combining turned on in HoodieClientConfig)
*/
T preCombine(T another);
/**
* This methods lets you write custom merging/combining logic to produce new values as a function of current value on
* storage and whats contained in this object.
*
* eg: 1) You are updating counters, you may want to add counts to currentValue and write back updated counts 2) You
* may be reading DB redo logs, and merge them with current image for a database row on storage
*
* @param currentValue Current value in storage, to merge/combine this payload with
* @param schema Schema used for record
* @return new combined/merged value to be written back to storage. EMPTY to skip writing this record.
*/
Option combineAndGetUpdateValue(IndexedRecord currentValue, Schema schema) throws IOException;
/**
* Generates an avro record out of the given HoodieRecordPayload, to be written out to storage. Called when writing a
* new value for the given HoodieKey, wherein there is no existing record in storage to be combined against. (i.e
* insert) Return EMPTY to skip writing this record.
*/
Option getInsertValue(Schema schema) throws IOException;
/**
* This method can be used to extract some metadata from HoodieRecordPayload. The metadata is passed to
* {@code WriteStatus.markSuccess()} and {@code WriteStatus.markFailure()} in order to compute some aggregate metrics
* using the metadata in the context of a write success or failure.
*/
default Option> getMetadata() {
return Option.empty();
}
}