content: /*
   * 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.arrow.vector.compare.util;
  
  import org.apache.arrow.vector.Float4Vector;
  import org.apache.arrow.vector.Float8Vector;
  import org.apache.arrow.vector.FloatingPointVector;
  import org.apache.arrow.vector.compare.VectorValueEqualizer;
  
  /**
   * Vector value equalizers that regard values as equal if their difference is within a small
   * threshold (epsilon).
   */
  public class ValueEpsilonEqualizers {
  
    private ValueEpsilonEqualizers() {}
  
    /** Difference function for floating point values. */
    public static class FloatingPointEpsilonEqualizer
        implements VectorValueEqualizer<FloatingPointVector> {
      private final double epsilon;
  
      public FloatingPointEpsilonEqualizer(double epsilon) {
        this.epsilon = epsilon;
      }
  
      @Override
      public final boolean valuesEqual(
          FloatingPointVector vector1, int index1, FloatingPointVector vector2, int index2) {
        boolean isNull1 = vector1.isNull(index1);
        boolean isNull2 = vector2.isNull(index2);
  
        if (isNull1 || isNull2) {
          return isNull1 == isNull2;
        }
  
        double d1 = vector1.getValueAsDouble(index1);
        double d2 = vector2.getValueAsDouble(index2);
  
        if (Double.isNaN(d1)) {
          return Double.isNaN(d2);
        }
        if (Double.isInfinite(d1)) {
          return Double.isInfinite(d2) && Math.signum(d1) == Math.signum(d2);
        }
  
        return Math.abs(d1 - d2) <= epsilon;
      }
  
      @Override
      public VectorValueEqualizer<FloatingPointVector> clone() {
        return new FloatingPointEpsilonEqualizer(epsilon);
      }
    }
  
    /** Difference function for float values. */
    public static class Float4EpsilonEqualizer implements VectorValueEqualizer<Float4Vector> {
      private final float epsilon;
  
      public Float4EpsilonEqualizer(float epsilon) {
        this.epsilon = epsilon;
      }
  
      @Override
      public final boolean valuesEqual(
          Float4Vector vector1, int index1, Float4Vector vector2, int index2) {
        boolean isNull1 = vector1.isNull(index1);
        boolean isNull2 = vector2.isNull(index2);
  
        if (isNull1 || isNull2) {
          return isNull1 == isNull2;
        }
  
        float f1 = vector1.get(index1);
        float f2 = vector2.get(index2);
  
        if (Float.isNaN(f1)) {
          return Float.isNaN(f2);
        }
        if (Float.isInfinite(f1)) {
          return Float.isInfinite(f2) && Math.signum(f1) == Math.signum(f2);
        }
  
        return Math.abs(f1 - f2) <= epsilon;
      }
  
      @Override
      public VectorValueEqualizer<Float4Vector> clone() {
        return new Float4EpsilonEqualizer(epsilon);
      }
    }
  
    /** Difference function for double values. */
    public static class Float8EpsilonEqualizer implements VectorValueEqualizer<Float8Vector> {
      private final double epsilon;
  
      public Float8EpsilonEqualizer(double epsilon) {
        this.epsilon = epsilon;
      }
  
      @Override
      public final boolean valuesEqual(
          Float8Vector vector1, int index1, Float8Vector vector2, int index2) {
        boolean isNull1 = vector1.isNull(index1);
        boolean isNull2 = vector2.isNull(index2);
  
        if (isNull1 || isNull2) {
          return isNull1 == isNull2;
        }
  
        double d1 = vector1.get(index1);
        double d2 = vector2.get(index2);
  
        if (Double.isNaN(d1)) {
          return Double.isNaN(d2);
        }
        if (Double.isInfinite(d1)) {
          return Double.isInfinite(d2) && Math.signum(d1) == Math.signum(d2);
        }
  
        return Math.abs(d1 - d2) <= epsilon;
      }
  
      @Override
      public VectorValueEqualizer<Float8Vector> clone() {
        return new Float8EpsilonEqualizer(epsilon);
      }
    }
  }
  