org.apache.parquet.column.values.bitpacking.BytePacker Maven / Gradle / Ivy
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* 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.bitpacking;
import java.nio.ByteBuffer;
/**
* Packs and unpacks into bytes
*
* packing unpacking treats:
* - n values at a time (with n % 8 == 0)
* - bitWidth * (n/8) bytes at a time.
*/
public abstract class BytePacker {
private final int bitWidth;
/**
* Number of integer values to be unpacked at a time.
* unpackCount is a multiple of 8
* For AVX512, the register is 512 bits, so output values at a time maybe different when different bitWidth.
*/
protected int unpackCount;
BytePacker(int bitWidth) {
this.bitWidth = bitWidth;
}
/**
* @return the width in bits used for encoding, also how many bytes are packed/unpacked at a time by pack8Values/unpack8Values
*/
public final int getBitWidth() {
return bitWidth;
}
public int getUnpackCount() {
throw new RuntimeException("getUnpackCount must be implemented by subclass!");
}
/**
* pack 8 values from input at inPos into bitWidth bytes in output at outPos.
* nextPosition: inPos += 8; outPos += getBitWidth()
*
* @param input the input values
* @param inPos where to read from in input
* @param output the output bytes
* @param outPos where to write to in output
*/
public abstract void pack8Values(final int[] input, final int inPos, final byte[] output, final int outPos);
/**
* pack 32 values from input at inPos into bitWidth * 4 bytes in output at outPos.
* nextPosition: inPos += 32; outPos += getBitWidth() * 4
*
* @param input the input values
* @param inPos where to read from in input
* @param output the output bytes
* @param outPos where to write to in output
*/
public abstract void pack32Values(int[] input, int inPos, byte[] output, int outPos);
/**
* unpack bitWidth bytes from input at inPos into 8 values in output at outPos.
* nextPosition: inPos += getBitWidth(); outPos += 8
*
* @param input the input bytes
* @param inPos where to read from in input
* @param output the output values
* @param outPos where to write to in output
*/
public abstract void unpack8Values(final ByteBuffer input, final int inPos, final int[] output, final int outPos);
/**
* Compatibility API
*
* @param input the input bytes
* @param inPos where to read from in input
* @param output the output values
* @param outPos where to write to in output
*/
@Deprecated
public void unpack8Values(final byte[] input, final int inPos, final int[] output, final int outPos) {
unpack8Values(ByteBuffer.wrap(input), inPos, output, outPos);
}
/**
* unpack bitWidth * 4 bytes from input at inPos into 32 values in output at outPos.
* nextPosition: inPos += getBitWidth() * 4; outPos += 32
*
* @param input the input bytes
* @param inPos where to read from in input
* @param output the output values
* @param outPos where to write to in output
*/
public abstract void unpack32Values(ByteBuffer input, int inPos, int[] output, int outPos);
/**
* Compatibility API
*
* @param input the input bytes
* @param inPos where to read from in input
* @param output the output values
* @param outPos where to write to in output
*/
@Deprecated
public void unpack32Values(byte[] input, int inPos, int[] output, int outPos) {
unpack32Values(ByteBuffer.wrap(input), inPos, output, outPos);
}
/**
* unpack bitWidth bytes from input at inPos into {unpackCount} values in output at outPos using Java Vector API.
*
* @param input the input bytes
* @param inPos where to read from in input
* @param output the output values
* @param outPos where to write to in output
*/
public void unpackValuesUsingVector(final byte[] input, final int inPos, final int[] output, final int outPos) {
throw new RuntimeException("unpackValuesUsingVector must be implemented by subclass!");
}
/**
* unpack bitWidth bytes from input at inPos into {unpackCount} values in output at outPos using Java Vector API.
*
* @param input the input bytes
* @param inPos where to read from in input
* @param output the output values
* @param outPos where to write to in output
*/
public void unpackValuesUsingVector(final ByteBuffer input, final int inPos, final int[] output, final int outPos) {
throw new RuntimeException("unpackValuesUsingVector must be implemented by subclass!");
}
}