/*
 * Copyright (C) 2015 SoftIndex 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.datakernel.aggregation;

import io.datakernel.async.CompletionCallback;
import io.datakernel.codegen.DefiningClassLoader;
import io.datakernel.stream.StreamProducer;

import java.util.List;

/**
 * Manages persistence of aggregations (chunks of data).
 */
public interface AggregationChunkStorage {
	/**
	 * Creates a {@code StreamProducer} that streams records contained in the chunk.
	 * The chunk to read is determined by {@code aggregationId} and {@code id}.
	 *
	 * @param recordClass class of chunk record
	 * @param id          id of chunk
	 * @return StreamProducer, which will stream read records to its wired consumer.
	 */
	<T> StreamProducer<T> chunkReader(Aggregation aggregation, List<String> keys, List<String> fields,
	                                  Class<T> recordClass, long id, DefiningClassLoader classLoader);

	/**
	 * Creates a {@code StreamConsumer} that persists streamed records.
	 * The chunk to write is determined by {@code aggregationId} and {@code id}.
	 *
	 * @param fields      fields of chunk record
	 * @param recordClass class of chunk record
	 * @param id          id of chunk
	 * @param producer    producer of records
	 */
	<T> void chunkWriter(Aggregation aggregation, List<String> keys, List<String> fields, Class<T>
			recordClass, long id, StreamProducer<T> producer, DefiningClassLoader classLoader, CompletionCallback callback);

	/**
	 * Removes the chunk determined by {@code aggregationId} and {@code id}.
	 *
	 * @param id       id of chunk
	 * @param callback callback
	 */
	void removeChunk(long id, CompletionCallback callback);
}