yabola commented on code in PR #1042: URL: https://github.com/apache/parquet-mr/pull/1042#discussion_r1180115504
########## parquet-column/src/main/java/org/apache/parquet/column/values/bloomfilter/DynamicBlockBloomFilter.java: ########## @@ -0,0 +1,314 @@ +/* + * 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.parquet.column.values.bloomfilter; + +import static org.apache.parquet.column.values.bloomfilter.BlockSplitBloomFilter.LOWER_BOUND_BYTES; +import static org.apache.parquet.column.values.bloomfilter.BlockSplitBloomFilter.UPPER_BOUND_BYTES; + +import java.io.IOException; +import java.io.OutputStream; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import java.util.Objects; +import java.util.Optional; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.parquet.Preconditions; +import org.apache.parquet.column.ColumnDescriptor; +import org.apache.parquet.io.api.Binary; + +/** + * `DynamicBlockBloomFilter` contains multiple `BlockSplitBloomFilter` as candidates and inserts values in + * the candidates at the same time. + * The purpose of this is to finally generate a bloom filter with the optimal bit size according to the number + * of real data distinct values. Use the largest bloom filter as an approximate deduplication counter, and then + * remove incapable bloom filter candidate during data insertion. + */ +public class DynamicBlockBloomFilter implements BloomFilter { + + private static final Logger LOG = LoggerFactory.getLogger(DynamicBlockBloomFilter.class); + + // multiple candidates, inserting data at the same time. If the distinct values are greater than the + // expected NDV of candidates, it will be removed. Finally we will choose the smallest candidate to write out. + private final List<BloomFilterCandidate> candidates = new ArrayList<>(); + + // the largest among candidates and used as an approximate deduplication counter + private BloomFilterCandidate maxCandidate; + + // the accumulator of the number of distinct values that have been inserted so far + private int distinctValueCounter = 0; Review Comment: I changed to use `long` -- 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]
