/*
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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 legal-notices/CDDLv1_0.txt
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* or http://forgerock.org/license/CDDLv1.0.html.
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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 legal-notices/CDDLv1_0.txt.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* 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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* Copyright 2013 ForgeRock AS
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*/
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package org.opends.server.replication.server.changelog.api;
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import java.io.Closeable;
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/**
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* Generic cursor interface into the changelog database. Once it is not used
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* anymore, a cursor must be closed to release all the resources into the
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* database.
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* <p>
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* Here is a typical usage pattern:
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*
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* <pre>
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* DBCursor<T> cursor = ...; // obtain a new cursor,
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* // already initialized
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* T record1 = cursor.getRecord(); // get the first record
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* while (cursor.next()) { // advance to the next record
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* T record = cursor.getRecord(); // get the next record
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* ... // etc.
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* }
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* </pre>
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*
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* @param <T>
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* type of the record being returned
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*/
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public interface DBCursor<T> extends Closeable
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{
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/**
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* Getter for the current record.
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*
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* @return The current record.
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*/
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T getRecord();
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/**
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* Skip to the next record of the database.
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*
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* @return true if has next, false otherwise
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* @throws ChangelogException
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* When database exception raised.
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*/
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boolean next() throws ChangelogException;
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/**
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* Release the resources and locks used by this Iterator. This method must be
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* called when the iterator is no longer used. Failure to do it could cause DB
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* deadlock.
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*/
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@Override
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void close();
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}
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