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4 changes: 4 additions & 0 deletions parquet/src/main/java/org/apache/iceberg/parquet/Parquet.java
Original file line number Diff line number Diff line change
Expand Up @@ -1011,8 +1011,12 @@ public <D> CloseableIterable<D> build() {
conf.unset(property);
}
optionsBuilder = HadoopReadOptions.builder(conf);
// page size not used by decompressors
optionsBuilder.withCodecFactory(new ParquetCodecFactory(conf, 0));
} else {
optionsBuilder = ParquetReadOptions.builder();
// page size not used by decompressors
optionsBuilder.withCodecFactory(new ParquetCodecFactory(new Configuration(), 0));
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Is it safe to pass 0 for page size? How is that option used?

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The page size isn't used for decompressors according to this comment. This is what is currently being set by default in the options builder.

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I added comments to make that more clear

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@kbendick kbendick Sep 1, 2022

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Idea: Maybe making this a named constant, like UNUSED_PARQUET_DECOMPRESSOR_PAGE_SIZE or something would be a good way of indicating that?

Given this solution is temporary, I don’t have a strong feeling either way, but I do like avoiding magic numbers.

Maybe a link to the upstream parquet-mr PR or an Iceberg issue related to zstd decompression would be more informative than just mentioning that page size is essentially ignored? The decompressor class itself might be sufficient documentation though.

}

for (Map.Entry<String, String> entry : properties.entrySet()) {
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,101 @@
/*
* 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.parquet;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.compress.CodecPool;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.Decompressor;
import org.apache.parquet.bytes.BytesInput;
import org.apache.parquet.hadoop.CodecFactory;
import org.apache.parquet.hadoop.codec.ZstandardCodec;
import org.apache.parquet.hadoop.metadata.CompressionCodecName;

/**
* This class implements a codec factory that is used when reading from Parquet. It adds a
* workaround for memory issues encountered when reading from zstd-compressed files.
*/
public class ParquetCodecFactory extends CodecFactory {

public ParquetCodecFactory(Configuration configuration, int pageSize) {
super(configuration, pageSize);
}

/** Copied and modified from CodecFactory.HeapBytesDecompressor */
class HeapBytesDecompressor extends BytesDecompressor {

private final CompressionCodec codec;
private final Decompressor decompressor;

HeapBytesDecompressor(CompressionCodecName codecName) {
this.codec = getCodec(codecName);
if (codec != null) {
decompressor = CodecPool.getDecompressor(codec);
} else {
decompressor = null;
}
}

@Override
public BytesInput decompress(BytesInput bytes, int uncompressedSize) throws IOException {
final BytesInput decompressed;
if (codec != null) {
if (decompressor != null) {
decompressor.reset();
}
if (codec instanceof ZstandardCodec) {
// we need to close the zstd input stream ASAP to free up native resources, so
// read everything into a buffer and then close it
try (InputStream is = codec.createInputStream(bytes.toInputStream(), decompressor)) {
decompressed = BytesInput.copy(BytesInput.from(is, uncompressedSize));
}
} else {
InputStream is = codec.createInputStream(bytes.toInputStream(), decompressor);
decompressed = BytesInput.from(is, uncompressedSize);
}
} else {
decompressed = bytes;
}
return decompressed;
}

@Override
public void decompress(
ByteBuffer input, int compressedSize, ByteBuffer output, int uncompressedSize)
throws IOException {
ByteBuffer decompressed = decompress(BytesInput.from(input), uncompressedSize).toByteBuffer();
output.put(decompressed);
}

@Override
public void release() {
if (decompressor != null) {
CodecPool.returnDecompressor(decompressor);
}
}
}

@Override
protected BytesDecompressor createDecompressor(CompressionCodecName codecName) {
return new HeapBytesDecompressor(codecName);
}
}