jon-wei commented on a change in pull request #9360: Create splits of multiple files for parallel indexing URL: https://github.com/apache/druid/pull/9360#discussion_r382860923
########## File path: core/src/main/java/org/apache/druid/data/input/MaxSizeSplitHintSpec.java ########## @@ -0,0 +1,119 @@ +/* + * 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.druid.data.input; + +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonProperty; +import com.google.common.annotations.VisibleForTesting; + +import javax.annotation.Nullable; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; +import java.util.Objects; +import java.util.function.Function; + +/** + * A SplitHintSpec that can create splits of multiple files. + * A split created by this class can have one or more input files. + * If there is only one file in the split, its size can be larger than {@link #maxSplitSize}. + * If there are two or more files in the split, their total size cannot be larger than {@link #maxSplitSize}. + */ +public class MaxSizeSplitHintSpec implements SplitHintSpec +{ + public static final String TYPE = "maxSize"; + + @VisibleForTesting + static final long DEFAULT_MAX_SPLIT_SIZE = 512 * 1024 * 1024; + + private final long maxSplitSize; + + @JsonCreator + public MaxSizeSplitHintSpec(@JsonProperty("maxSplitSize") @Nullable Long maxSplitSize) + { + this.maxSplitSize = maxSplitSize == null ? DEFAULT_MAX_SPLIT_SIZE : maxSplitSize; + } + + @JsonProperty + public long getMaxSplitSize() + { + return maxSplitSize; + } + + @Override + public <T> Iterator<List<T>> split(Iterator<T> inputIterator, Function<T, InputFileAttribute> inputAttributeExtractor) + { + return new Iterator<List<T>>() + { + private T peeking; + + @Override + public boolean hasNext() + { + return peeking != null || inputIterator.hasNext(); + } + + @Override + public List<T> next() + { + final List<T> current = new ArrayList<>(); + long splitSize = 0; + while (splitSize < maxSplitSize && (peeking != null || inputIterator.hasNext())) { + if (peeking == null) { + peeking = inputIterator.next(); + } + final long size = inputAttributeExtractor.apply(peeking).getSize(); + if (current.isEmpty()) { + current.add(peeking); + splitSize += size; + peeking = null; + } else if (splitSize + size < maxSplitSize) { Review comment: Looks like the `splitSize + size < maxSplitSize` and `current.isEmpty()` block can be combined ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
