org.apache.parquet.hadoop.BloomFilterReader Maven / Gradle / Ivy
/*
* 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.hadoop;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.apache.parquet.column.values.bloomfilter.BloomFilter;
import org.apache.parquet.filter2.compat.RowGroupFilter;
import org.apache.parquet.hadoop.metadata.BlockMetaData;
import org.apache.parquet.hadoop.metadata.ColumnChunkMetaData;
import org.apache.parquet.hadoop.metadata.ColumnPath;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Bloom filter reader that reads Bloom filter data from an open {@link ParquetFileReader}.
*/
public class BloomFilterReader {
private final ParquetFileReader reader;
private final Map columns;
private final Map cache = new HashMap<>();
private Logger logger = LoggerFactory.getLogger(BloomFilterReader.class);
public BloomFilterReader(ParquetFileReader fileReader, BlockMetaData block) {
this.reader = fileReader;
this.columns = new HashMap<>();
for (ColumnChunkMetaData column : block.getColumns()) {
columns.put(column.getPath(), column);
}
}
public BloomFilter readBloomFilter(ColumnChunkMetaData meta) {
if (cache.containsKey(meta.getPath())) {
return cache.get(meta.getPath());
}
try {
if (!cache.containsKey(meta.getPath())) {
BloomFilter bloomFilter = reader.readBloomFilter(meta);
if (bloomFilter == null) {
return null;
}
cache.put(meta.getPath(), bloomFilter);
}
return cache.get(meta.getPath());
} catch (IOException e) {
logger.error("Failed to read Bloom filter data", e);
}
return null;
}
}