/* * Copyright (c) 2017 Pantheon Technologies, s.r.o. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.yangtools.util; import com.google.common.annotations.Beta; import edu.umd.cs.findbugs.annotations.SuppressFBWarnings; import java.util.Optional; import org.eclipse.jdt.annotation.NonNull; import org.eclipse.jdt.annotation.Nullable; /** * Utility class for storing an optional boolean in a single byte value. This cuts down the memory requirement quite * at very small computational cost. * *
* Note: fields do not have to be explicitly initialized, as default initialization value for 'byte', 0, is used to
* represent 'absent' condition.
*
* @author Robert Varga
*/
@Beta
public final class OptionalBoolean {
private static final byte ABSENT = 0;
private static final byte FALSE = 1;
private static final byte TRUE = 2;
private OptionalBoolean() {
throw new UnsupportedOperationException();
}
/**
* Check if a field value has been set, just like {@link Optional#isPresent()}.
*
* @param value field value
* @return True if the value is set.
* @throws IllegalArgumentException if value is invalid
*/
public static boolean isPresent(final byte value) {
switch (value) {
case ABSENT:
return false;
case FALSE:
case TRUE:
return true;
default:
throw invalidValue(value);
}
}
/**
* Decode boolean from a field value, just like {@link Optional#get()}.
*
* @param value Field value
* @return Decoded boolean.
* @throws IllegalArgumentException if value is invalid
* @throws IllegalStateException if value has not been set
*/
public static boolean get(final byte value) {
switch (value) {
case ABSENT:
throw new IllegalStateException("Field has not been initialized");
case FALSE:
return false;
case TRUE:
return true;
default:
throw invalidValue(value);
}
}
/**
* Encode a boolean to a field value, just like {@link Optional#of(Object)}.
*
* @param bool Boolean value.
* @return Field value.
*/
public static byte of(final boolean bool) {
return bool ? TRUE : FALSE;
}
/**
* Convert a nullable {@link Boolean} into a field value, just like {@link Optional#ofNullable(Object)}.
*
* @param bool Boolean value.
* @return Field value.
*/
public static byte ofNullable(final @Nullable Boolean bool) {
return bool == null ? ABSENT : of(bool.booleanValue());
}
/**
* Convert a field value to a nullable {@link Boolean}. Similar to {@code Optional.orElse(null)}.
*
* @param value Field value.
* @return Nullable Boolean.
*/
@SuppressFBWarnings("NP_BOOLEAN_RETURN_NULL")
public static @Nullable Boolean toNullable(final byte value) {
switch (value) {
case ABSENT:
return null;
case FALSE:
return Boolean.FALSE;
case TRUE:
return Boolean.TRUE;
default:
throw invalidValue(value);
}
}
/**
* Convert a field value into an {@link Optional} {@link Boolean}.
*
* @param value Field value.
* @return Optional {@link Boolean}.
* @throws IllegalArgumentException if value is invalid.
*/
public static @NonNull Optional