org.apache.flink.runtime.io.network.partition.external.PartitionIndices Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.flink.runtime.io.network.partition.external;
import java.io.IOException;
import static
org.apache.flink.runtime.io.network.partition.external.ExternalBlockResultPartitionMeta.ExternalSubpartitionMeta;
/**
* The interface to load partition indices and provide subpartition metas.
*/
public interface PartitionIndices {
/**
* Initializes {@code PartitionIndices} including loading partition indices from index file.
* @throws IOException
*/
void initialize() throws IOException ;
/**
* Gets subpartition meta.
* @param subpartitionIndex the index of a specific subpartition
* @return subpartition meta specified by subpartitionIndex
* @throws Exception
*/
ExternalSubpartitionMeta getSubpartitionMeta(int subpartitionIndex) throws IOException;
/**
* Shrink the memory footprint used by PartitionIndices if possible.
* @return the size of memory footprint shrunk
*/
long shrinkMemoryFootprint();
/**
* Gets the size of memory footprint that can be shrunk.
* @return the size of memory footprint that can be shrunk
*/
long getShrinkableMemoryFootprint();
}