aokolnychyi commented on a change in pull request #3164: URL: https://github.com/apache/iceberg/pull/3164#discussion_r715118116
########## File path: core/src/main/java/org/apache/iceberg/io/ClusteredWriter.java ########## @@ -0,0 +1,127 @@ +/* + * 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.iceberg.io; + +import java.io.IOException; +import java.util.Comparator; +import java.util.Set; +import org.apache.iceberg.PartitionSpec; +import org.apache.iceberg.StructLike; +import org.apache.iceberg.encryption.EncryptedOutputFile; +import org.apache.iceberg.relocated.com.google.common.base.Preconditions; +import org.apache.iceberg.relocated.com.google.common.collect.Sets; +import org.apache.iceberg.types.Comparators; +import org.apache.iceberg.types.Types.StructType; +import org.apache.iceberg.util.StructLikeSet; + +/** + * A writer capable of writing to multiple specs and partitions that requires the incoming records + * to be clustered by partition spec and by partition within each spec. + * <p> + * As opposed to {@link FanoutWriter}, this writer keeps at most one file open to reduce + * the memory consumption. Prefer using this writer whenever the incoming records can be clustered + * by spec/partition. + */ +abstract class ClusteredWriter<T, R> implements PartitioningWriter<T, R> { + + private final Set<Integer> completedSpecIds = Sets.newHashSet(); + + private PartitionSpec currentSpec = null; + private Comparator<StructLike> partitionComparator = null; + private Set<StructLike> completedPartitions = null; + private StructLike currentPartition = null; + private FileWriter<T, R> currentWriter = null; + + private boolean closed = false; + + protected abstract FileWriter<T, R> newWriter(PartitionSpec spec, StructLike partition); + + protected abstract void addResult(R result); + + protected abstract R aggregatedResult(); + + @Override + public void write(T row, PartitionSpec spec, StructLike partition) throws IOException { + if (!spec.equals(currentSpec)) { + if (currentSpec != null) { + closeCurrentWriter(); + completedSpecIds.add(currentSpec.specId()); + completedPartitions.clear(); + } + + if (completedSpecIds.contains(spec.specId())) { + throw new IllegalStateException("Already closed files for spec: " + spec.specId()); + } + + StructType partitionType = spec.partitionType(); + + currentSpec = spec; + partitionComparator = Comparators.forType(partitionType); + completedPartitions = StructLikeSet.create(partitionType); + // copy the partition key as the key object may be reused + currentPartition = StructCopy.copy(partition); + currentWriter = newWriter(currentSpec, currentPartition); + + } else if (partition != currentPartition && partitionComparator.compare(partition, currentPartition) != 0) { Review comment: You are right the comparator will throw an NPE but I think `partition != currentPartition` prevents us from calling the comparator whenever at least one value is null. Partition can be null only for unpartitioned specs. As long as we are writing unpartitioned records, `partition != currentPartition` will be false. Whenever `partition != currentPartition` and at least one of them is null, it means we are changing the spec. If so, it will be handled by the if block above and we won't call the comparator at all. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
