exec/java-exec/src/main/java/org/apache/drill/exec/planner/types/decimal/DrillBaseComputeScalePrecision.java


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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.drill.exec.planner.types.decimal;

import static org.apache.drill.exec.planner.types.DrillRelDataTypeSystem.DRILL_REL_DATATYPE_SYSTEM;

public abstract class DrillBaseComputeScalePrecision {
  protected final static int MAX_NUMERIC_PRECISION = DRILL_REL_DATATYPE_SYSTEM.getMaxNumericPrecision();

  protected int outputScale = 0;
  protected int outputPrecision = 0;

  public DrillBaseComputeScalePrecision(int leftPrecision, int leftScale, int rightPrecision, int rightScale) {
    computeScalePrecision(leftPrecision, leftScale, rightPrecision, rightScale);
  }

  public abstract void computeScalePrecision(int leftPrecision, int leftScale, int rightPrecision, int rightScale);

  public int getOutputScale() {
    return outputScale;
  }

  public int getOutputPrecision() {
    return outputPrecision;
  }

  /**
   * Cuts down the fractional part if the current precision
   * exceeds the maximum precision range.
   */
  protected void checkPrecisionRange() {
    if (outputPrecision > MAX_NUMERIC_PRECISION) {
      outputScale = outputScale - (outputPrecision - MAX_NUMERIC_PRECISION);
      outputPrecision = MAX_NUMERIC_PRECISION;
    }
  }
}