/*
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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 2006-2010 Sun Microsystems, Inc.
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* Portions Copyright 2011-2016 ForgeRock AS
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*/
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package org.opends.server.replication.plugin;
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import static org.opends.messages.ReplicationMessages.*;
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import static org.opends.server.replication.plugin.HistAttrModificationKey.*;
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import java.util.*;
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import org.forgerock.i18n.slf4j.LocalizedLogger;
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import org.forgerock.opendj.ldap.ByteString;
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import org.forgerock.opendj.ldap.ModificationType;
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import org.opends.server.core.DirectoryServer;
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import org.opends.server.replication.common.CSN;
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import org.opends.server.replication.protocol.OperationContext;
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import org.forgerock.opendj.ldap.schema.AttributeType;
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import org.opends.server.types.*;
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import org.opends.server.types.operation.PreOperationAddOperation;
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import org.opends.server.types.operation.PreOperationModifyDNOperation;
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import org.opends.server.types.operation.PreOperationModifyOperation;
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import org.opends.server.util.TimeThread;
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/**
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* This class is used to store historical information that is used to resolve modify conflicts
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* <p>
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* It is assumed that the common case is not to have conflict and therefore is optimized (in order
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* of importance) for:
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* <ol>
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* <li>detecting potential conflict</li>
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* <li>fast update of historical information for non-conflicting change</li>
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* <li>fast and efficient purge</li>
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* <li>compact</li>
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* <li>solve conflict. This should also be as fast as possible but not at the cost of any of the
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* other previous objectives</li>
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* </ol>
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* One Historical object is created for each entry in the entry cache each Historical Object
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* contains a list of attribute historical information
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*/
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public class EntryHistorical
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{
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private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();
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/** Name of the attribute used to store historical information. */
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public static final String HISTORICAL_ATTRIBUTE_NAME = "ds-sync-hist";
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/**
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* Name used to store attachment of historical information in the
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* operation. This attachment allows to use in several different places
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* the historical while reading/writing ONCE it from/to the entry.
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*/
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public static final String HISTORICAL = "ds-synch-historical";
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/** Name of the entryuuid attribute. */
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public static final String ENTRYUUID_ATTRIBUTE_NAME = "entryuuid";
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/**
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* The delay to purge the historical information.
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* <p>
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* This delay indicates the time the domain keeps the historical information
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* necessary to solve conflicts. When a change stored in the historical part
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* of the user entry has a date (from its replication CSN) older than this
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* delay, it is candidate to be purged. The purge is triggered on 2 events:
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* modify of the entry, dedicated purge task. The purge is done when the
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* historical is encoded.
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*/
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private long purgeDelayInMillisec = -1;
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/**
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* The oldest CSN stored in this entry historical attribute.
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* null when this historical object has been created from
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* an entry that has no historical attribute and after the last
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* historical has been purged.
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*/
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private CSN oldestCSN;
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/**
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* For stats/monitoring purpose, the number of historical values
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* purged the last time a purge has been applied on this entry historical.
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*/
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private int lastPurgedValuesCount;
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/** The date when the entry was added. */
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private CSN entryADDDate;
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/** The date when the entry was last renamed. */
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private CSN entryMODDNDate;
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/** Contains Historical information for each attribute description. */
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private final Map<AttributeDescription, AttrHistorical> attributesHistorical = new HashMap<>();
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@Override
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public String toString()
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{
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StringBuilder builder = new StringBuilder();
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builder.append(encodeAndPurge());
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return builder.toString();
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}
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/**
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* Process an operation.
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* This method is responsible for detecting and resolving conflict for
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* modifyOperation. This is done by using the historical information.
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*
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* @param modifyOperation the operation to be processed
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* @param modifiedEntry the entry that is being modified (before modification)
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* @return true if the replayed operation was in conflict
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*/
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public boolean replayOperation(PreOperationModifyOperation modifyOperation, Entry modifiedEntry)
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{
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boolean bConflict = false;
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List<Modification> mods = modifyOperation.getModifications();
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CSN modOpCSN = OperationContext.getCSN(modifyOperation);
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for (Iterator<Modification> it = mods.iterator(); it.hasNext(); )
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{
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Modification m = it.next();
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// Read or create the attr historical for the attribute type and option
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// contained in the mod
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AttrHistorical attrHist = getOrCreateAttrHistorical(m);
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if (attrHist.replayOperation(it, modOpCSN, modifiedEntry, m))
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{
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bConflict = true;
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}
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}
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return bConflict;
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}
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/**
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* Update the historical information for the provided operation.
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* <p>
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* Steps:
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* <ul>
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* <li>compute the historical attribute</li>
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* <li>update the mods in the provided operation by adding the update of the
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* historical attribute</li>
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* <li>update the modifiedEntry, already computed by core since we are in the
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* preOperation plugin, that is called just before committing into the DB.
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* </li>
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* </ul>
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* </p>
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*
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* @param modifyOperation
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* the modification.
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*/
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public void setHistoricalAttrToOperation(PreOperationModifyOperation modifyOperation)
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{
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List<Modification> mods = modifyOperation.getModifications();
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Entry modifiedEntry = modifyOperation.getModifiedEntry();
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CSN csn = OperationContext.getCSN(modifyOperation);
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/*
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* If this is a local operation we need :
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* - first to update the historical information,
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* - then update the entry with the historical information
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* If this is a replicated operation the historical information has
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* already been set in the resolveConflict phase and we only need
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* to update the entry
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*/
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if (!modifyOperation.isSynchronizationOperation())
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{
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for (Modification mod : mods)
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{
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// Get the current historical for this attributeType/options
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// (eventually read from the provided modification)
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AttrHistorical attrHist = getOrCreateAttrHistorical(mod);
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if (attrHist != null)
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{
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attrHist.processLocalOrNonConflictModification(csn, mod);
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}
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}
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}
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// Now do the 2 updates required by the core to be consistent:
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//
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// - add the modification of the ds-sync-hist attribute,
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// to the current modifications of the MOD operation
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Attribute attr = encodeAndPurge();
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mods.add(new Modification(ModificationType.REPLACE, attr));
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// - update the already modified entry
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modifiedEntry.replaceAttribute(attr);
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}
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/**
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* For a MODDN operation, add new or update existing historical information.
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* <p>
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* This method is NOT static because it relies on this Historical object created in the
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* HandleConflictResolution phase.
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*
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* @param modifyDNOperation
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* the modification for which the historical information should be created.
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*/
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public void setHistoricalAttrToOperation(PreOperationModifyDNOperation modifyDNOperation)
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{
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// Update this historical information with the operation CSN.
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this.entryMODDNDate = OperationContext.getCSN(modifyDNOperation);
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// Update the operations mods and the modified entry so that the
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// historical information gets stored in the DB and indexed accordingly.
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Entry modifiedEntry = modifyDNOperation.getUpdatedEntry();
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List<Modification> mods = modifyDNOperation.getModifications();
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Attribute attr = encodeAndPurge();
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// Now do the 2 updates required by the core to be consistent:
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//
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// - add the modification of the ds-sync-hist attribute,
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// to the current modifications of the operation
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mods.add(new Modification(ModificationType.REPLACE, attr));
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// - update the already modified entry
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modifiedEntry.removeAttribute(attr.getAttributeType());
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modifiedEntry.addAttribute(attr, null);
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}
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/**
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* Generate an attribute containing the historical information
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* from the replication context attached to the provided operation
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* and set this attribute in the operation.
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*
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* For ADD, the historical is made of the CSN read from the
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* synchronization context attached to the operation.
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*
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* Called for both local and synchronization ADD preOperation.
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*
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* This historical information will be used to generate fake operation
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* in case a Directory Server can not find a Replication Server with
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* all its changes at connection time.
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* This should only happen if a Directory Server or a Replication Server
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* crashes.
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*
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* This method is static because there is no Historical object creation
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* required here or before(in the HandleConflictResolution phase)
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*
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* @param addOperation The Operation to which the historical attribute will be added.
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*/
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public static void setHistoricalAttrToOperation(PreOperationAddOperation addOperation)
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{
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AttributeType attrType = DirectoryServer.getAttributeTypeOrNull(HISTORICAL_ATTRIBUTE_NAME);
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String attrValue = encodeHistorical(OperationContext.getCSN(addOperation), "add");
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List<Attribute> attrs = Attributes.createAsList(attrType, attrValue);
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addOperation.setAttribute(attrType, attrs);
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}
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/**
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* Builds an attributeValue for the supplied historical information and
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* operation type . For ADD Operation : "dn:changeNumber:add", for MODDN
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* Operation : "dn:changeNumber:moddn", etc.
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*
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* @param csn
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* The date when the ADD Operation happened.
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* @param operationType
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* the operation type to encode
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* @return The attribute value containing the historical information for the Operation type.
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*/
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private static String encodeHistorical(CSN csn, String operationType)
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{
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return "dn:" + csn + ":" + operationType;
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}
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/**
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* Return an AttributeHistorical corresponding to the attribute type
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* and options contained in the provided mod,
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* The attributeHistorical is :
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* - either read from this EntryHistorical object if one exist,
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* - or created empty.
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* Should never return null.
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*
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* @param mod the provided mod from which we'll use attributeType
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* and options to retrieve/create the attribute historical
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* @return the attribute historical retrieved or created empty.
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*/
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private AttrHistorical getOrCreateAttrHistorical(Modification mod)
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{
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// Read the provided mod
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Attribute modAttr = mod.getAttribute();
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if (isHistoricalAttribute(modAttr))
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{
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// Don't keep historical information for the attribute that is
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// used to store the historical information.
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return null;
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}
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// Read from this entryHistorical,
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// Create one empty if none was existing in this entryHistorical.
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AttributeDescription attrDesc = AttributeDescription.create(modAttr);
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AttrHistorical attrHist = attributesHistorical.get(attrDesc);
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if (attrHist == null)
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{
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attrHist = AttrHistorical.createAttributeHistorical(modAttr.getAttributeType());
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attributesHistorical.put(attrDesc, attrHist);
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}
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return attrHist;
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}
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/**
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* For stats/monitoring purpose, returns the number of historical values
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* purged the last time a purge has been applied on this entry historical.
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*
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* @return the purged values count.
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*/
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public int getLastPurgedValuesCount()
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{
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return this.lastPurgedValuesCount;
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}
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/**
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* Encode this historical information object in an operational attribute and
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* purge it from the values older than the purge delay.
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*
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* @return The historical information encoded in an operational attribute.
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* @see HistoricalAttributeValue#HistoricalAttributeValue(String) the decode
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* operation in HistoricalAttributeValue
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*/
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public Attribute encodeAndPurge()
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{
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long purgeDate = 0;
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// Set the stats counter to 0 and compute the purgeDate to now minus
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// the potentially set purge delay.
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this.lastPurgedValuesCount = 0;
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if (purgeDelayInMillisec>0)
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{
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purgeDate = TimeThread.getTime() - purgeDelayInMillisec;
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}
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AttributeType historicalAttrType = DirectoryServer.getAttributeTypeOrNull(HISTORICAL_ATTRIBUTE_NAME);
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AttributeBuilder builder = new AttributeBuilder(historicalAttrType);
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for (Map.Entry<AttributeDescription, AttrHistorical> mapEntry : attributesHistorical.entrySet())
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{
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AttributeDescription attrDesc = mapEntry.getKey();
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String options = attrDesc.toString();
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AttrHistorical attrHist = mapEntry.getValue();
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CSN deleteTime = attrHist.getDeleteTime();
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/* generate the historical information for deleted attributes */
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boolean attrDel = deleteTime != null;
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for (AttrValueHistorical attrValHist : attrHist.getValuesHistorical())
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{
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final ByteString value = attrValHist.getAttributeValue();
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// Encode an attribute value
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if (attrValHist.getValueDeleteTime() != null)
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{
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if (needsPurge(attrValHist.getValueDeleteTime(), purgeDate))
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{
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// this hist must be purged now, so skip its encoding
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continue;
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}
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String strValue = encode(DEL, options, attrValHist.getValueDeleteTime(), value);
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builder.add(strValue);
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}
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else if (attrValHist.getValueUpdateTime() != null)
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{
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if (needsPurge(attrValHist.getValueUpdateTime(), purgeDate))
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{
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// this hist must be purged now, so skip its encoding
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continue;
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}
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String strValue;
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final CSN updateTime = attrValHist.getValueUpdateTime();
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// FIXME very suspicious use of == in the next if statement,
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// unit tests do not like changing it
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if (attrDel && updateTime == deleteTime && value != null)
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{
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strValue = encode(REPL, options, updateTime, value);
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attrDel = false;
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}
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else if (value != null)
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{
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strValue = encode(ADD, options, updateTime, value);
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}
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else
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{
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// "add" without any value is suspicious. Tests never go there.
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// Is this used to encode "add" with an empty string?
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strValue = encode(ADD, options, updateTime);
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}
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builder.add(strValue);
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}
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}
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if (attrDel)
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{
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if (needsPurge(deleteTime, purgeDate))
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{
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// this hist must be purged now, so skip its encoding
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continue;
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}
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builder.add(encode(ATTRDEL, options, deleteTime));
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}
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}
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if (entryADDDate != null && !needsPurge(entryADDDate, purgeDate))
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{
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// Encode the historical information for the ADD Operation.
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// Stores the ADDDate when not older than the purge delay
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builder.add(encodeHistorical(entryADDDate, "add"));
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}
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if (entryMODDNDate != null && !needsPurge(entryMODDNDate, purgeDate))
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{
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// Encode the historical information for the MODDN Operation.
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// Stores the MODDNDate when not older than the purge delay
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builder.add(encodeHistorical(entryMODDNDate, "moddn"));
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}
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return builder.toAttribute();
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}
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private boolean needsPurge(CSN csn, long purgeDate)
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{
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boolean needsPurge = purgeDelayInMillisec > 0 && csn.getTime() <= purgeDate;
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if (needsPurge)
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{
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// this hist must be purged now, because older than the purge delay
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this.lastPurgedValuesCount++;
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}
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return needsPurge;
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}
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private String encode(HistAttrModificationKey modKey, String options, CSN changeTime)
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{
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return options + ":" + changeTime + ":" + modKey;
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}
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private String encode(HistAttrModificationKey modKey, String options, CSN changeTime, ByteString value)
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{
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return options + ":" + changeTime + ":" + modKey + ":" + value;
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}
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/**
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* Set the delay to purge the historical information. The purge is applied
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* only when historical attribute is updated (write operations).
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*
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* @param purgeDelay the purge delay in ms
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*/
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public void setPurgeDelay(long purgeDelay)
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{
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this.purgeDelayInMillisec = purgeDelay;
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}
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/**
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* Indicates if the Entry was renamed or added after the CSN that is given as
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* a parameter.
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*
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* @param csn
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* The CSN with which the ADD or Rename date must be compared.
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* @return A boolean indicating if the Entry was renamed or added after the
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* CSN that is given as a parameter.
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*/
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public boolean addedOrRenamedAfter(CSN csn)
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{
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return csn.isOlderThan(entryADDDate) || csn.isOlderThan(entryMODDNDate);
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}
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/**
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* Returns the lastCSN when the entry DN was modified.
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*
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* @return The lastCSN when the entry DN was modified.
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*/
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public CSN getDNDate()
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{
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if (entryADDDate == null)
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{
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return entryMODDNDate;
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}
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if (entryMODDNDate == null)
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{
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return entryADDDate;
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}
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if (entryMODDNDate.isOlderThan(entryADDDate))
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{
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return entryMODDNDate;
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}
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else
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{
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return entryADDDate;
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}
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}
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/**
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* Construct an Historical object from the provided entry by reading the historical attribute.
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* Return an empty object when the entry does not contain any historical attribute.
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*
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* @param entry The entry which historical information must be loaded
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* @return The constructed Historical information object
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*/
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public static EntryHistorical newInstanceFromEntry(Entry entry)
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{
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// Read the DB historical attribute from the entry
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List<Attribute> histAttrWithOptionsFromEntry = getHistoricalAttr(entry);
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// Now we'll build the Historical object we want to construct
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final EntryHistorical newHistorical = new EntryHistorical();
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if (histAttrWithOptionsFromEntry.isEmpty())
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{
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// No historical attribute in the entry, return empty object
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return newHistorical;
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}
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try
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{
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// For each value of the historical attr read (mod. on a user attribute)
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// build an AttrInfo sub-object
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// Traverse the Attributes (when several options for the hist attr)
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// of the historical attribute read from the entry
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for (Attribute histAttrFromEntry : histAttrWithOptionsFromEntry)
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{
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// For each Attribute (option), traverse the values
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for (ByteString histAttrValueFromEntry : histAttrFromEntry)
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{
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// From each value of the hist attr, create an object
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final HistoricalAttributeValue histVal = new HistoricalAttributeValue(histAttrValueFromEntry.toString());
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final CSN csn = histVal.getCSN();
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// update the oldest CSN stored in the new entry historical
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newHistorical.updateOldestCSN(csn);
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if (histVal.isADDOperation())
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{
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newHistorical.entryADDDate = csn;
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}
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else if (histVal.isMODDNOperation())
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{
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newHistorical.entryMODDNDate = csn;
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}
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else
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{
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AttributeDescription attrDesc = histVal.getAttributeDescription();
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if (attrDesc == null)
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{
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/*
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* This attribute is unknown from the schema
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* Just skip it, the modification will be processed but no
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* historical information is going to be kept.
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* Log information for the repair tool.
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*/
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logger.error(ERR_UNKNOWN_ATTRIBUTE_IN_HISTORICAL, entry.getName(), histVal.getAttrString());
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continue;
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}
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/* if attribute type does not match we create new
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* AttrInfoWithOptions and AttrInfo
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* we also add old AttrInfoWithOptions into histObj.attributesInfo
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* if attribute type match but options does not match we create new
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* AttrInfo that we add to AttrInfoWithOptions
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* if both match we keep everything
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*/
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AttrHistorical attrInfo = newHistorical.attributesHistorical.get(attrDesc);
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if (attrInfo == null)
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{
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attrInfo = AttrHistorical.createAttributeHistorical(attrDesc.getAttributeType());
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newHistorical.attributesHistorical.put(attrDesc, attrInfo);
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}
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attrInfo.assign(histVal.getHistKey(), histVal.getAttributeValue(), csn);
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}
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}
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}
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} catch (Exception e)
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{
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// Any exception happening here means that the coding of the historical
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// information was wrong.
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// Log an error and continue with an empty historical.
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logger.error(ERR_BAD_HISTORICAL, entry.getName());
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}
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/* set the reference to the historical information in the entry */
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return newHistorical;
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}
|
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/**
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* Use this historical information to generate fake operations that would
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* result in this historical information.
|
* TODO : This is only implemented for MODIFY, MODRDN and ADD
|
* need to complete with DELETE.
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* @param entry The Entry to use to generate the FakeOperation Iterable.
|
*
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* @return an Iterable of FakeOperation that would result in this historical information.
|
*/
|
public static Iterable<FakeOperation> generateFakeOperations(Entry entry)
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{
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TreeMap<CSN, FakeOperation> operations = new TreeMap<>();
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for (Attribute attr : getHistoricalAttr(entry))
|
{
|
for (ByteString val : attr)
|
{
|
HistoricalAttributeValue histVal = new HistoricalAttributeValue(val.toString());
|
if (histVal.isADDOperation())
|
{
|
// Found some historical information indicating that this entry was just added.
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// Create the corresponding ADD operation.
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operations.put(histVal.getCSN(), new FakeAddOperation(histVal.getCSN(), entry));
|
}
|
else if (histVal.isMODDNOperation())
|
{
|
// Found some historical information indicating that this entry was just renamed.
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// Create the corresponding ADD operation.
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operations.put(histVal.getCSN(), new FakeModdnOperation(histVal.getCSN(), entry));
|
}
|
else
|
{
|
// Found some historical information for modify operation.
|
// Generate the corresponding ModifyOperation or update
|
// the already generated Operation if it can be found.
|
CSN csn = histVal.getCSN();
|
Modification mod = histVal.generateMod();
|
FakeOperation fakeOperation = operations.get(csn);
|
|
if (fakeOperation instanceof FakeModifyOperation)
|
{
|
FakeModifyOperation modifyFakeOperation = (FakeModifyOperation) fakeOperation;
|
modifyFakeOperation.addModification(mod);
|
}
|
else
|
{
|
String uuidString = getEntryUUID(entry);
|
FakeModifyOperation modifyFakeOperation = new FakeModifyOperation(entry.getName(), csn, uuidString);
|
modifyFakeOperation.addModification(mod);
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operations.put(histVal.getCSN(), modifyFakeOperation);
|
}
|
}
|
}
|
}
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return operations.values();
|
}
|
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/**
|
* Get the attribute used to store the historical information from the provided Entry.
|
*
|
* @param entry The entry containing the historical information.
|
* @return The Attribute used to store the historical information.
|
* Several values on the list if several options for this attribute.
|
* Null if not present.
|
*/
|
public static List<Attribute> getHistoricalAttr(Entry entry)
|
{
|
return entry.getAttribute(HISTORICAL_ATTRIBUTE_NAME);
|
}
|
|
/**
|
* Get the entry unique Id in String form.
|
*
|
* @param entry The entry for which the unique id should be returned.
|
* @return The Unique Id of the entry, or a fake one if none is found.
|
*/
|
public static String getEntryUUID(Entry entry)
|
{
|
AttributeType attrType = DirectoryServer.getAttributeTypeOrNull(ENTRYUUID_ATTRIBUTE_NAME);
|
List<Attribute> uuidAttrs = entry.getOperationalAttribute(attrType);
|
return extractEntryUUID(uuidAttrs, entry.getName());
|
}
|
|
/**
|
* Get the Entry Unique Id from an add operation.
|
* This must be called after the entry uuid pre-op plugin (i.e no
|
* sooner than the replication provider pre-op)
|
*
|
* @param op The operation
|
* @return The Entry Unique Id String form.
|
*/
|
public static String getEntryUUID(PreOperationAddOperation op)
|
{
|
AttributeType attrType = DirectoryServer.getAttributeTypeOrNull(ENTRYUUID_ATTRIBUTE_NAME);
|
List<Attribute> uuidAttrs = op.getOperationalAttributes().get(attrType);
|
return extractEntryUUID(uuidAttrs, op.getEntryDN());
|
}
|
|
/**
|
* Check if a given attribute is an attribute used to store historical
|
* information.
|
*
|
* @param attr The attribute that needs to be checked.
|
*
|
* @return a boolean indicating if the given attribute is
|
* used to store historical information.
|
*/
|
public static boolean isHistoricalAttribute(Attribute attr)
|
{
|
AttributeType attrType = attr.getAttributeType();
|
return HISTORICAL_ATTRIBUTE_NAME.equals(attrType.getNameOrOID());
|
}
|
|
/**
|
* Potentially update the oldest CSN stored in this entry historical
|
* with the provided CSN when its older than the current oldest.
|
*
|
* @param csn the provided CSN.
|
*/
|
private void updateOldestCSN(CSN csn)
|
{
|
if (csn != null
|
&& (this.oldestCSN == null || csn.isOlderThan(this.oldestCSN)))
|
{
|
this.oldestCSN = csn;
|
}
|
}
|
|
/**
|
* Returns the oldest CSN stored in this entry historical attribute.
|
*
|
* @return the oldest CSN stored in this entry historical attribute.
|
* Returns null when this historical object has been created from
|
* an entry that has no historical attribute and after the last
|
* historical has been purged.
|
*/
|
public CSN getOldestCSN()
|
{
|
return this.oldestCSN;
|
}
|
|
/**
|
* Extracts the entryUUID attribute value from the provided list of
|
* attributes. If the attribute is not present one is generated from the DN
|
* using the same algorithm as the entryUUID virtual attribute provider.
|
*/
|
private static String extractEntryUUID(List<Attribute> entryUUIDAttributes, DN entryDN)
|
{
|
if (!entryUUIDAttributes.isEmpty())
|
{
|
Attribute uuidAttr = entryUUIDAttributes.get(0);
|
if (!uuidAttr.isEmpty())
|
{
|
return uuidAttr.iterator().next().toString();
|
}
|
}
|
|
// Generate a fake entryUUID: see OPENDJ-181. In rare pathological cases
|
// an entryUUID attribute may not be present and this causes severe side effects
|
// for replication which requires the attribute to always be present
|
if (logger.isTraceEnabled())
|
{
|
logger.trace(
|
"Replication requires an entryUUID attribute in order "
|
+ "to perform conflict resolution, but none was "
|
+ "found in entry \"%s\": generating virtual entryUUID instead",
|
entryDN);
|
}
|
|
return UUID.nameUUIDFromBytes(entryDN.toNormalizedByteString().toByteArray()).toString();
|
}
|
}
|
