aishikbh commented on code in PR #12049: URL: https://github.com/apache/pinot/pull/12049#discussion_r1414906892
########## pinot-segment-spi/src/main/java/org/apache/pinot/segment/spi/partition/Murmur3PartitionFunction.java: ########## @@ -0,0 +1,453 @@ +/** + * 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.pinot.segment.spi.partition; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Preconditions; +import com.google.common.hash.Hashing; +import java.util.Map; + +import static java.nio.charset.StandardCharsets.UTF_8; + + +/** + * Implementation of {@link PartitionFunction} which partitions based on 32 bit murmur3 hash + */ +public class Murmur3PartitionFunction implements PartitionFunction { + public static final byte INVALID_CHAR = (byte) '?'; + private static final String NAME = "Murmur3"; + private static final String SEED_KEY = "seed"; + private static final String MURMUR3_VARIANT = "variant"; + private final int _numPartitions; + private final int _hashSeed; + private final String _variant; + + /** + * Constructor for the class. + * @param numPartitions Number of partitions. + * @param functionConfig to extract configurations for the partition function. + */ + public Murmur3PartitionFunction(int numPartitions, Map<String, String> functionConfig) { + Preconditions.checkArgument(numPartitions > 0, "Number of partitions must be > 0"); + Preconditions.checkArgument( + functionConfig == null || functionConfig.get(MURMUR3_VARIANT) == null || functionConfig.get(MURMUR3_VARIANT) + .isEmpty() || functionConfig.get(MURMUR3_VARIANT).equals("x86_32") || functionConfig.get(MURMUR3_VARIANT) + .equals("x64_32"), "Murmur3 variant must be either x86_32 or x64_32"); + _numPartitions = numPartitions; + + // default value of the hash seed is 0. + _hashSeed = + (functionConfig == null || functionConfig.get(SEED_KEY) == null || functionConfig.get(SEED_KEY).isEmpty()) ? 0 + : Integer.parseInt(functionConfig.get(SEED_KEY)); + + // default value of the murmur3 variant is x86_32. + _variant = + (functionConfig == null || functionConfig.get(MURMUR3_VARIANT) == null || functionConfig.get(MURMUR3_VARIANT) + .isEmpty()) ? "x86_32" : functionConfig.get(MURMUR3_VARIANT); + } + + @Override + public int getPartition(Object value) { + if (_variant.equals("x86_32")) { + return (murmurHash332BitsX86(value.toString().getBytes(UTF_8), _hashSeed) & Integer.MAX_VALUE) % _numPartitions; Review Comment: makes sense. This name is better for readability. -- 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: commits-unsubscr...@pinot.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
