org.apache.flink.runtime.iterative.io.HashPartitionIterator Maven / Gradle / Ivy
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* 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.iterative.io;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.runtime.operators.hash.HashPartition;
import org.apache.flink.util.MutableObjectIterator;
import java.io.EOFException;
import java.io.IOException;
import java.util.Iterator;
/**
* {@link Iterator} over the build side entries of a {@link HashPartition}.
*
* @param
*/
public class HashPartitionIterator implements MutableObjectIterator {
private final Iterator> partitions;
private final TypeSerializer serializer;
private HashPartition currentPartition;
public HashPartitionIterator(Iterator> partitions, TypeSerializer serializer) {
this.partitions = partitions;
this.serializer = serializer;
currentPartition = null;
}
@Override
public BT next(BT reuse) throws IOException {
if (currentPartition == null) {
if (!partitions.hasNext()) {
return null;
}
currentPartition = partitions.next();
currentPartition.setReadPosition(0);
}
try {
reuse = serializer.deserialize(reuse, currentPartition);
} catch (EOFException e) {
reuse = advanceAndRead(reuse);
}
return reuse;
}
@Override
public BT next() throws IOException {
if (currentPartition == null) {
if (!partitions.hasNext()) {
return null;
}
currentPartition = partitions.next();
currentPartition.setReadPosition(0);
}
try {
return serializer.deserialize(currentPartition);
} catch (EOFException e) {
return advanceAndRead();
}
}
/* jump to the next partition and continue reading from that */
private BT advanceAndRead(BT reuse) throws IOException {
if (!partitions.hasNext()) {
return null;
}
currentPartition = partitions.next();
currentPartition.setReadPosition(0);
try {
reuse = serializer.deserialize(reuse, currentPartition);
} catch (EOFException e) {
reuse = advanceAndRead(reuse);
}
return reuse;
}
/* jump to the next partition and continue reading from that */
private BT advanceAndRead() throws IOException {
if (!partitions.hasNext()) {
return null;
}
currentPartition = partitions.next();
currentPartition.setReadPosition(0);
try {
return serializer.deserialize(currentPartition);
} catch (EOFException e) {
return advanceAndRead();
}
}
}