90 lines
2.2 KiB
Java
90 lines
2.2 KiB
Java
/*
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* Copyright 2012 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.util;
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import java.util.concurrent.atomic.AtomicLong;
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/**
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* Base implementation of {@link Constant}.
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*/
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public abstract class AbstractConstant<T extends AbstractConstant<T>> implements Constant<T> {
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private static final AtomicLong uniqueIdGenerator = new AtomicLong();
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private final int id;
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private final String name;
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private final long uniquifier;
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/**
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* Creates a new instance.
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*/
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protected AbstractConstant(int id, String name) {
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this.id = id;
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this.name = name;
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this.uniquifier = uniqueIdGenerator.getAndIncrement();
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}
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@Override
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public final String name() {
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return name;
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}
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@Override
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public final int id() {
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return id;
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}
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@Override
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public final String toString() {
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return name();
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}
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@Override
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public final int hashCode() {
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return super.hashCode();
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}
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@Override
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public final boolean equals(Object obj) {
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return super.equals(obj);
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}
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@Override
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public final int compareTo(T o) {
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if (this == o) {
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return 0;
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}
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@SuppressWarnings("UnnecessaryLocalVariable")
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AbstractConstant<T> other = o;
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int returnCode;
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returnCode = hashCode() - other.hashCode();
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if (returnCode != 0) {
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return returnCode;
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}
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if (uniquifier < other.uniquifier) {
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return -1;
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}
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if (uniquifier > other.uniquifier) {
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return 1;
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}
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throw new Error("failed to compare two different constants");
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}
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}
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