org.apache.parquet.column.values.bitpacking.ByteBitPackingValuesReader Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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package org.apache.parquet.column.values.bitpacking;
import java.io.IOException;
import java.nio.ByteBuffer;
import org.apache.parquet.bytes.ByteBufferInputStream;
import org.apache.parquet.bytes.BytesUtils;
import org.apache.parquet.column.values.ValuesReader;
import org.apache.parquet.io.ParquetDecodingException;
import com.facebook.presto.hive.$internal.org.slf4j.Logger;
import com.facebook.presto.hive.$internal.org.slf4j.LoggerFactory;
public class ByteBitPackingValuesReader extends ValuesReader {
private static final int VALUES_AT_A_TIME = 8; // because we're using unpack8Values()
private static final Logger LOG = LoggerFactory.getLogger(ByteBitPackingValuesReader.class);
private final int bitWidth;
private final BytePacker packer;
private final int[] decoded = new int[VALUES_AT_A_TIME];
private int decodedPosition = VALUES_AT_A_TIME - 1;
private ByteBufferInputStream in;
private final byte[] tempEncode;
public ByteBitPackingValuesReader(int bound, Packer packer) {
this.bitWidth = BytesUtils.getWidthFromMaxInt(bound);
this.packer = packer.newBytePacker(bitWidth);
// Create and retain byte array to avoid object creation in the critical path
this.tempEncode = new byte[this.bitWidth];
}
private void readMore() {
try {
int avail = in.available();
if (avail < bitWidth) {
in.read(tempEncode, 0, avail);
// Clear the portion of the array we didn't read into
for (int i=avail; i