org.apache.hadoop.hive.ql.exec.vector.expressions.StringLength 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.hadoop.hive.ql.exec.vector.expressions;
import org.apache.hadoop.hive.ql.exec.vector.BytesColumnVector;
import org.apache.hadoop.hive.ql.exec.vector.LongColumnVector;
import org.apache.hadoop.hive.ql.exec.vector.VectorExpressionDescriptor;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedRowBatch;
/**
* Calculate the length of the strings in the input column vector, and store
* it in the output column vector.
*/
public class StringLength extends VectorExpression {
private static final long serialVersionUID = 1L;
private int colNum;
private int outputColumn;
public StringLength(int colNum, int outputColumn) {
this();
this.colNum = colNum;
this.outputColumn = outputColumn;
}
public StringLength() {
super();
}
// Calculate the length of the UTF-8 strings in input vector and place results in output vector.
@Override
public void evaluate(VectorizedRowBatch batch) {
if (childExpressions != null) {
super.evaluateChildren(batch);
}
BytesColumnVector inputColVector = (BytesColumnVector) batch.cols[colNum];
LongColumnVector outV = (LongColumnVector) batch.cols[outputColumn];
int[] sel = batch.selected;
int n = batch.size;
byte[][] vector = inputColVector.vector;
int [] start = inputColVector.start;
int [] length = inputColVector.length;
long[] resultLen = outV.vector;
if (n == 0) {
//Nothing to do
return;
}
if (inputColVector.noNulls) {
outV.noNulls = true;
if (inputColVector.isRepeating) {
outV.isRepeating = true;
resultLen[0] = utf8StringLength(vector[0], start[0], length[0]);
} else if (batch.selectedInUse) {
for(int j = 0; j != n; j++) {
int i = sel[j];
resultLen[i] = utf8StringLength(vector[i], start[i], length[i]);
}
outV.isRepeating = false;
} else {
for(int i = 0; i != n; i++) {
resultLen[i] = utf8StringLength(vector[i], start[i], length[i]);
}
outV.isRepeating = false;
}
} else {
/*
* Handle case with nulls. Don't do function if the value is null, to save time,
* because calling the function can be expensive.
*/
outV.noNulls = false;
if (inputColVector.isRepeating) {
outV.isRepeating = true;
outV.isNull[0] = inputColVector.isNull[0];
if (!inputColVector.isNull[0]) {
resultLen[0] = utf8StringLength(vector[0], start[0], length[0]);
}
} else if (batch.selectedInUse) {
for(int j = 0; j != n; j++) {
int i = sel[j];
if (!inputColVector.isNull[i]) {
resultLen[i] = utf8StringLength(vector[i], start[i], length[i]);
}
outV.isNull[i] = inputColVector.isNull[i];
}
outV.isRepeating = false;
} else {
for(int i = 0; i != n; i++) {
if (!inputColVector.isNull[i]) {
resultLen[i] = utf8StringLength(vector[i], start[i], length[i]);
}
outV.isNull[i] = inputColVector.isNull[i];
}
outV.isRepeating = false;
}
}
}
/*
* Return length in characters of UTF8 string in byte array
* beginning at start that is len bytes long.
*/
static long utf8StringLength(byte[] s, int start, int len) {
long resultLength = 0;
for (int i = start; i < start + len; i++) {
/* Byte bit patterns of the form 10xxxxxx are continuation
* bytes. All other bit patterns are the first byte of
* a character.
*/
if ((s[i] & 0xc0) != 0x80) {
resultLength++;
}
}
return resultLength;
}
@Override
public int getOutputColumn() {
return outputColumn;
}
@Override
public String getOutputType() {
return "Long";
}
public int getColNum() {
return colNum;
}
public void setColNum(int colNum) {
this.colNum = colNum;
}
public void setOutputColumn(int outputColumn) {
this.outputColumn = outputColumn;
}
@Override
public VectorExpressionDescriptor.Descriptor getDescriptor() {
VectorExpressionDescriptor.Builder b = new VectorExpressionDescriptor.Builder();
b.setMode(VectorExpressionDescriptor.Mode.PROJECTION)
.setNumArguments(1)
.setArgumentTypes(
VectorExpressionDescriptor.ArgumentType.STRING_FAMILY)
.setInputExpressionTypes(
VectorExpressionDescriptor.InputExpressionType.COLUMN);
return b.build();
}
}