org.apache.hadoop.hive.ql.exec.vector.expressions.CastLongToTimestamp Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of hive-exec
There is a newer version: 4.0.0
/*
 * 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 java.util.Arrays;

import org.apache.hadoop.hive.ql.exec.vector.*;
import org.apache.hadoop.hive.ql.metadata.HiveException;

public class CastLongToTimestamp extends VectorExpression {
  private static final long serialVersionUID = 1L;

  private final int colNum;

  public CastLongToTimestamp(int colNum, int outputColumnNum) {
    super(outputColumnNum);
    this.colNum = colNum;
  }

  public CastLongToTimestamp() {
    super();

    // Dummy final assignments.
    colNum = -1;
  }

  private void setSeconds(TimestampColumnVector timestampColVector, long[] vector, int elementNum) {
    timestampColVector.getScratchTimestamp().setTime(vector[elementNum] * 1000);
    timestampColVector.setFromScratchTimestamp(elementNum);
  }

  @Override
  public void evaluate(VectorizedRowBatch batch) throws HiveException {

    if (childExpressions != null) {
      this.evaluateChildren(batch);
    }

    LongColumnVector inputColVector = (LongColumnVector) batch.cols[colNum];
    TimestampColumnVector outputColVector = (TimestampColumnVector) batch.cols[outputColumnNum];
    int[] sel = batch.selected;
    boolean[] inputIsNull = inputColVector.isNull;
    boolean[] outputIsNull = outputColVector.isNull;
    int n = batch.size;
    long[] vector = inputColVector.vector;

    // return immediately if batch is empty
    if (n == 0) {
      return;
    }

    // We do not need to do a column reset since we are carefully changing the output.
    outputColVector.isRepeating = false;

    if (inputColVector.isRepeating) {
      if (inputColVector.noNulls || !inputIsNull[0]) {
        // Set isNull before call in case it changes it mind.
        outputIsNull[0] = false;
        setSeconds(outputColVector, vector, 0);
      } else {
        outputIsNull[0] = true;
        outputColVector.noNulls = false;
      }
      outputColVector.isRepeating = true;
      return;
    }

    if (inputColVector.noNulls) {
      if (batch.selectedInUse) {

        // CONSIDER: For large n, fill n or all of isNull array and use the tighter ELSE loop.

        if (!outputColVector.noNulls) {
          for(int j = 0; j != n; j++) {
           final int i = sel[j];
           // Set isNull before call in case it changes it mind.
           outputIsNull[i] = false;
           setSeconds(outputColVector, vector, i);
         }
        } else {
          for(int j = 0; j != n; j++) {
            final int i = sel[j];
            setSeconds(outputColVector, vector, i);
          }
        }
      } else {
        if (!outputColVector.noNulls) {

          // Assume it is almost always a performance win to fill all of isNull so we can
          // safely reset noNulls.
          Arrays.fill(outputIsNull, false);
          outputColVector.noNulls = true;
        }
        for(int i = 0; i != n; i++) {
          setSeconds(outputColVector, vector, i);
        }
      }
    } else /* there are NULLs in the inputColVector */ {

      /*
       * Do careful maintenance of the outputColVector.noNulls flag.
       */

      if (batch.selectedInUse) {
        for(int j = 0; j != n; j++) {
          int i = sel[j];
          if (!inputIsNull[i]) {
            // Set isNull before call in case it changes it mind.
            outputIsNull[i] = false;
            setSeconds(outputColVector, vector, i);
          } else {
            outputIsNull[i] = true;
            outputColVector.noNulls = false;
          }
        }
      } else {
        // Set isNull before call in case it changes it mind.
        System.arraycopy(inputIsNull, 0, outputIsNull, 0, n);
        for(int i = 0; i != n; i++) {
          if (!inputIsNull[i]) {
            setSeconds(outputColVector, vector, i);
          }
        }
      }
    }
  }

  @Override
  public String vectorExpressionParameters() {
    return getColumnParamString(0, colNum);
  }

  @Override
  public VectorExpressionDescriptor.Descriptor getDescriptor() {
    return (new VectorExpressionDescriptor.Builder())
        .setMode(
            VectorExpressionDescriptor.Mode.PROJECTION)
        .setNumArguments(1)
        .setArgumentTypes(
            VectorExpressionDescriptor.ArgumentType.getType("long"))
        .setInputExpressionTypes(
            VectorExpressionDescriptor.InputExpressionType.COLUMN).build();
  }
}