org.apache.hadoop.hive.ql.exec.vector.expressions.CastDecimalToString 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
* 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,
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package org.apache.hadoop.hive.ql.exec.vector.expressions;
import org.apache.hadoop.hive.common.type.HiveDecimal;
import org.apache.hadoop.hive.ql.exec.vector.BytesColumnVector;
import org.apache.hadoop.hive.ql.exec.vector.DecimalColumnVector;
import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.hive.serde2.io.HiveDecimalWritable;
/**
* To support vectorized cast of decimal to string.
*/
public class CastDecimalToString extends DecimalToStringUnaryUDF {
private static final long serialVersionUID = 1L;
// Transient members initialized by transientInit method.
// We use a scratch buffer with the HiveDecimalWritable toBytes method so
// we don't incur poor performance creating a String result.
private transient byte[] scratchBuffer;
public CastDecimalToString() {
super();
}
public CastDecimalToString(int inputColumn, int outputColumnNum) {
super(inputColumn, outputColumnNum);
}
@Override
public void transientInit() throws HiveException {
super.transientInit();
scratchBuffer = new byte[HiveDecimal.SCRATCH_BUFFER_LEN_TO_BYTES];
}
// The assign method will be overridden for CHAR and VARCHAR.
protected void assign(BytesColumnVector outV, int i, byte[] bytes, int offset, int length) {
outV.setVal(i, bytes, offset, length);
}
@Override
protected void func(BytesColumnVector outV, DecimalColumnVector inV, int i) {
HiveDecimalWritable decWritable = inV.vector[i];
final int byteIndex = decWritable.toBytes(scratchBuffer);
assign(outV, i, scratchBuffer, byteIndex, HiveDecimal.SCRATCH_BUFFER_LEN_TO_BYTES - byteIndex);
}
}