content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * 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 io.activej.dataflow.dataset;
  
  import io.activej.dataflow.graph.StreamSchema;
  
  import java.util.Comparator;
  import java.util.function.Function;
  
  /**
   * Represents a locally sorted dataset, which means that data on each stream is sorted by key independently.
   * <p>However, values with any specific key may belong to multiple partitions.
   * In other words, there may be duplicates of the same key in different partitions.</p>
   *
   * @param <K> data item key
   * @param <T> data item type
   */
  public abstract class LocallySortedDataset<K, T> extends Dataset<T> {
  	private final Comparator<K> keyComparator;
  
  	private final Class<K> keyType;
  
  	private final Function<T, K> keyFunction;
  
  	protected LocallySortedDataset(
  		StreamSchema<T> streamSchema, Comparator<K> keyComparator, Class<K> keyType, Function<T, K> keyFunction
  	) {
  		super(streamSchema);
  		this.keyComparator = keyComparator;
  		this.keyType = keyType;
  		this.keyFunction = keyFunction;
  	}
  
  	public final Comparator<K> keyComparator() {
  		return keyComparator;
  	}
  
  	public final Class<K> keyType() {
  		return keyType;
  	}
  
  	public final Function<T, K> keyFunction() {
  		return keyFunction;
  	}
  }
  