/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE
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* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at
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* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
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* add the following below this CDDL HEADER, with the fields enclosed
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* by brackets "[]" replaced with your own identifying * information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Portions Copyright 2006 Sun Microsystems, Inc.
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*/
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package org.opends.server;
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/**
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* A fixture factory that guarantees that at most only one instance of a
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* fixture is instantiated. The singleton factory uses reference
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* counting to guarantee that the fixture instance is torn down at the
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* correct time.
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*
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* @param <T> The type of fixture managed by this factory.
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*/
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public final class SingletonFixtureFactory<T> implements FixtureFactory<T> {
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// The underlying fixture factory.
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private FixtureFactory<T> pimpl;
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// The underlying fixture instance.
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private T instance;
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// Reference count used to determine when tearDown can be performed.
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private int refCount;
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/**
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* Create a new singleton fixture factory.
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*
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* @param pimpl
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* The underlying fixture factory.
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*/
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public SingletonFixtureFactory(FixtureFactory<T> pimpl) {
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this.pimpl = pimpl;
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this.instance = null;
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this.refCount = 0;
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}
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/**
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* {@inheritDoc}
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*/
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public T setUp() throws Exception {
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if (refCount == 0) {
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instance = pimpl.setUp();
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}
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refCount++;
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return instance;
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}
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/**
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* {@inheritDoc}
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*/
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public void tearDown() throws Exception {
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if (refCount <= 0) {
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throw new IllegalStateException("SingletonFixtureFactory tearDown "
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+ "called more often than setUp");
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}
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refCount--;
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if (refCount == 0) {
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pimpl.tearDown();
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instance = null;
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}
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}
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}
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