com.expediagroup.rhapsody.api.Deduplication Maven / Gradle / Ivy
/**
* Copyright 2019 Expedia, Inc.
*
* Licensed 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 com.expediagroup.rhapsody.api;
/**
* Configures how to deduplicate data items.
*
* @param The type of data item being deduplicated
*/
@FunctionalInterface
public interface Deduplication {
/**
* Returns the key on which to implement deduplication
*
* @param t The data item that deduplication is being enforced on
* @return Some Object representing a "key" on which to base deduplication
*/
Object extractKey(T t);
/**
* Upon occurrence of duplication, apply a reduction to produce a deduplicated result
*
* @return A reduction of two items deemed to be duplicates (have same key)
*/
default T reduceDuplicates(T t1, T t2) {
return t1;
}
}