com.pdd.pop.ext.glassfish.grizzly.attributes.Attribute Maven / Gradle / Ivy
The newest version!
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2008-2015 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.pdd.pop.ext.glassfish.grizzly.attributes;
import com.pdd.pop.ext.glassfish.grizzly.utils.NullaryFunction;
/**
* Class used to define dynamic typed attributes on {@link AttributeHolder}
* instances.
* Storing attribute values in {@link AttributeHolder} has two advantage
* comparing to Map storage:
* 1) Attribute value is typed, and could be checked at
* compile time.
* 2) Access to Attribute value, if used with
* {@link IndexedAttributeHolder}, could be as fast as access to array.
* @param
*/
public final class Attribute {
/**
* AttributeBuilder, which was used to create this attribute
*/
private final AttributeBuilder builder;
/**
* Attribute name
*/
private final String name;
/**
* Attribute initializer, which will be called, if attribute is not set.
*/
private final NullaryFunction initializer;
/**
* Attribute index in AttributeBuilder
*/
private final int attributeIndex;
@Override
public String toString() {
return "Attribute[" + name + ':' + attributeIndex + ']';
}
protected Attribute(final AttributeBuilder builder, final String name,
final int index, final T defaultValue) {
this(builder, name, index, new NullaryFunction() {
@Override
public T evaluate() {
return defaultValue;
}
});
}
protected Attribute(final AttributeBuilder builder, final String name,
final int index, final NullaryFunction initializer) {
this.builder = builder;
this.name = name;
this.attributeIndex = index;
this.initializer = initializer;
}
/**
* Get attribute value, stored on the {@link AttributeHolder},
* the difference from {@link #get(com.pdd.pop.ext.glassfish.grizzly.attributes.AttributeHolder)} is
* that default value or {@link NullaryFunction} won't be invoked.
*
* @param attributeHolder {@link AttributeHolder}.
* @return attribute value
*/
public T peek(final AttributeHolder attributeHolder) {
return get0(attributeHolder, null);
}
/**
* Get attribute value, stored on the {@link AttributeStorage},
* the difference from {@link #get(AttributeStorage)} is
* that default value or {@link NullaryFunction} won't be invoked.
*
* @param storage {@link AttributeStorage}.
* @return attribute value
*/
public T peek(final AttributeStorage storage) {
final AttributeHolder holder = storage.getAttributes();
if (holder != null) {
return peek(holder);
}
return null;
}
/**
* Get attribute value, stored on the {@link AttributeHolder}.
*
* @param attributeHolder {@link AttributeHolder}.
* @return attribute value
*/
public T get(final AttributeHolder attributeHolder) {
return get0(attributeHolder, initializer);
}
/**
* Get attribute value, stored on the {@link AttributeStorage}.
*
* @param storage {@link AttributeStorage}.
* @return attribute value
*/
public T get(final AttributeStorage storage) {
return get(storage.getAttributes());
}
/**
* Set attribute value, stored on the {@link AttributeHolder}.
*
* @param attributeHolder {@link AttributeHolder}.
* @param value attribute value to set.
*/
public void set(final AttributeHolder attributeHolder, final T value) {
final IndexedAttributeAccessor indexedAccessor =
attributeHolder.getIndexedAttributeAccessor();
if (indexedAccessor != null) {
indexedAccessor.setAttribute(attributeIndex, value);
} else {
attributeHolder.setAttribute(name, value);
}
}
/**
* Set attribute value, stored on the {@link AttributeStorage}.
*
* @param storage {@link AttributeStorage}.
* @param value attribute value to set.
*/
public void set(final AttributeStorage storage, final T value) {
set(storage.getAttributes(), value);
}
/**
* Remove attribute value, stored on the {@link AttributeHolder}.
*
* @param attributeHolder {@link AttributeHolder}.
* @return the previous value associated with the attribute
*/
@SuppressWarnings("unchecked")
public T remove(final AttributeHolder attributeHolder) {
final IndexedAttributeAccessor indexedAccessor =
attributeHolder.getIndexedAttributeAccessor();
return indexedAccessor != null
? (T) indexedAccessor.removeAttribute(attributeIndex)
: (T) attributeHolder.removeAttribute(name);
}
/**
* Remove attribute value, stored on the {@link AttributeStorage}.
*
* @param storage {@link AttributeStorage}.
*/
public T remove(final AttributeStorage storage) {
final AttributeHolder holder = storage.getAttributes();
if (holder != null) {
return remove(holder);
}
return null;
}
/**
* Checks if this attribute is set on the {@link AttributeHolder}.
* Returns true, if attribute is set, of false otherwise.
*
* @param attributeHolder {@link AttributeHolder}.
*
* @return true, if attribute is set, of false otherwise.
*/
public boolean isSet(final AttributeHolder attributeHolder) {
return get0(attributeHolder, null) != null;
}
/**
* Checks if this attribute is set on the {@link AttributeStorage}.
* Returns true, if attribute is set, of false otherwise.
*
* @param storage {@link AttributeStorage}.
*
* @return true, if attribute is set, of false otherwise.
*/
public boolean isSet(final AttributeStorage storage) {
final AttributeHolder holder = storage.getAttributes();
return holder != null && isSet(holder);
}
/**
* Return attribute name, which is used as attribute key on
* non-indexed {@link AttributeHolder}s.
*
* @return attribute name.
*/
public String name() {
return name;
}
/**
* Return attribute name, which is used as attribute key on
* indexed {@link AttributeHolder}s.
*
* @return attribute indexed.
*/
public int index() {
return attributeIndex;
}
@SuppressWarnings("unchecked")
private T get0(final AttributeHolder attributeHolder,
final NullaryFunction initializer) {
final IndexedAttributeAccessor indexedAccessor =
attributeHolder.getIndexedAttributeAccessor();
return indexedAccessor != null
? (T) indexedAccessor.getAttribute(attributeIndex, initializer)
: (T) attributeHolder.getAttribute(name, initializer);
}
}