org.apache.hadoop.hdfs.util.EnumDoubles 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.hdfs.util;
import java.util.Arrays;
import com.google.common.base.Preconditions;
/**
* Similar to {@link EnumCounters} except that the value type is double.
*
* @param the enum type
*/
public class EnumDoubles> {
/** The class of the enum. */
private final Class enumClass;
/** An array of doubles corresponding to the enum type. */
private final double[] doubles;
/**
* Construct doubles for the given enum constants.
* @param enumClass the enum class.
*/
public EnumDoubles(final Class enumClass) {
final E[] enumConstants = enumClass.getEnumConstants();
Preconditions.checkNotNull(enumConstants);
this.enumClass = enumClass;
this.doubles = new double[enumConstants.length];
}
/** @return the value corresponding to e. */
public final double get(final E e) {
return doubles[e.ordinal()];
}
/** Negate all values. */
public final void negation() {
for(int i = 0; i < doubles.length; i++) {
doubles[i] = -doubles[i];
}
}
/** Set e to the given value. */
public final void set(final E e, final double value) {
doubles[e.ordinal()] = value;
}
/** Set the values of this object to that object. */
public final void set(final EnumDoubles that) {
for(int i = 0; i < doubles.length; i++) {
this.doubles[i] = that.doubles[i];
}
}
/** Reset all values to zero. */
public final void reset() {
for(int i = 0; i < doubles.length; i++) {
this.doubles[i] = 0.0;
}
}
/** Add the given value to e. */
public final void add(final E e, final double value) {
doubles[e.ordinal()] += value;
}
/** Add the values of that object to this. */
public final void add(final EnumDoubles that) {
for(int i = 0; i < doubles.length; i++) {
this.doubles[i] += that.doubles[i];
}
}
/** Subtract the given value from e. */
public final void subtract(final E e, final double value) {
doubles[e.ordinal()] -= value;
}
/** Subtract the values of this object from that object. */
public final void subtract(final EnumDoubles that) {
for(int i = 0; i < doubles.length; i++) {
this.doubles[i] -= that.doubles[i];
}
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
} else if (obj == null || !(obj instanceof EnumDoubles)) {
return false;
}
final EnumDoubles that = (EnumDoubles)obj;
return this.enumClass == that.enumClass
&& Arrays.equals(this.doubles, that.doubles);
}
@Override
public int hashCode() {
return Arrays.hashCode(doubles);
}
@Override
public String toString() {
final E[] enumConstants = enumClass.getEnumConstants();
final StringBuilder b = new StringBuilder();
for(int i = 0; i < doubles.length; i++) {
final String name = enumConstants[i].name();
b.append(name).append("=").append(doubles[i]).append(", ");
}
return b.substring(0, b.length() - 2);
}
}