org.wildfly.common.ref.Reference Maven / Gradle / Ivy
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* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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.wildfly.common.ref;
import java.util.EnumSet;
/**
* An enhanced reference type with a type-safe attachment.
*
* @param the reference value type
* @param the attachment type
*
* @see java.lang.ref.Reference
*
* @author David M. Lloyd
*/
public interface Reference {
/**
* Get the value, or {@code null} if the reference has been cleared.
*
* @return the value
*/
T get();
/**
* Get the attachment, if any.
*
* @return the attachment
*/
A getAttachment();
/**
* Clear the reference.
*/
void clear();
/**
* Get the type of the reference.
*
* @return the type
*/
Type getType();
/**
* A reference type.
*
* @apiviz.exclude
*/
enum Type {
/**
* A strong reference.
*/
STRONG,
/**
* A weak reference.
*/
WEAK,
/**
* A phantom reference.
*/
PHANTOM,
/**
* A soft reference.
*/
SOFT,
/**
* A {@code null} reference.
*/
NULL,
;
private static final int fullSize = values().length;
/**
* Determine whether the given set is fully populated (or "full"), meaning it contains all possible values.
*
* @param set the set
*
* @return {@code true} if the set is full, {@code false} otherwise
*/
public static boolean isFull(final EnumSet set) {
return set != null && set.size() == fullSize;
}
/**
* Determine whether this instance is equal to one of the given instances.
*
* @param v1 the first instance
*
* @return {@code true} if one of the instances matches this one, {@code false} otherwise
*/
public boolean in(final Type v1) {
return this == v1;
}
/**
* Determine whether this instance is equal to one of the given instances.
*
* @param v1 the first instance
* @param v2 the second instance
*
* @return {@code true} if one of the instances matches this one, {@code false} otherwise
*/
public boolean in(final Type v1, final Type v2) {
return this == v1 || this == v2;
}
/**
* Determine whether this instance is equal to one of the given instances.
*
* @param v1 the first instance
* @param v2 the second instance
* @param v3 the third instance
*
* @return {@code true} if one of the instances matches this one, {@code false} otherwise
*/
public boolean in(final Type v1, final Type v2, final Type v3) {
return this == v1 || this == v2 || this == v3;
}
/**
* Determine whether this instance is equal to one of the given instances.
*
* @param values the possible values
*
* @return {@code true} if one of the instances matches this one, {@code false} otherwise
*/
public boolean in(final Type... values) {
if (values != null) for (Type value : values) {
if (this == value) return true;
}
return false;
}
}
}