| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| |
| package org.apache.directory.server.ldap.replication.provider; |
| |
| |
| import java.util.Iterator; |
| |
| import org.apache.directory.api.ldap.model.constants.Loggers; |
| import org.apache.directory.api.ldap.model.constants.SchemaConstants; |
| import org.apache.directory.api.ldap.model.cursor.AbstractCursor; |
| import org.apache.directory.api.ldap.model.cursor.Cursor; |
| import org.apache.directory.api.ldap.model.cursor.CursorException; |
| import org.apache.directory.api.ldap.model.cursor.Tuple; |
| import org.apache.directory.api.ldap.model.exception.LdapException; |
| import org.apache.directory.api.ldap.model.message.controls.ChangeType; |
| import org.apache.directory.server.core.partition.impl.btree.jdbm.JdbmTable; |
| import org.apache.directory.server.ldap.replication.ReplicaEventMessage; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| /** |
| * Define a cursor on top of a replication journal. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class ReplicaJournalCursor extends AbstractCursor<ReplicaEventMessage> |
| { |
| /** Logger for this class */ |
| private static final Logger LOG = LoggerFactory.getLogger( ReplicaJournalCursor.class ); |
| |
| /** A dedicated log for cursors */ |
| private static final Logger LOG_CURSOR = LoggerFactory.getLogger( Loggers.CURSOR_LOG.getName() ); |
| |
| /** Speedup for logs */ |
| private static final boolean IS_DEBUG = LOG_CURSOR.isDebugEnabled(); |
| |
| /** the underlying journal's cursor */ |
| private Cursor<Tuple<String, ReplicaEventMessage>> tupleCursor; |
| |
| /** the event log journal */ |
| private JdbmTable<String, ReplicaEventMessage> journal; |
| |
| /** the consumer's CSN based on which messages will be qualified for sending */ |
| private String consumerCsn; |
| |
| private ReplicaEventMessage qualifiedEvtMsg; |
| |
| /** used while cleaning up the log */ |
| private boolean skipQualifying; |
| |
| |
| /** |
| * Creates a cursor on top of the given journal |
| * @param journal the log journal |
| * @param consumerCsn the consumer's CSN taken from cookie |
| * @throws Exception |
| */ |
| public ReplicaJournalCursor( JdbmTable<String, ReplicaEventMessage> journal, String consumerCsn ) throws Exception |
| { |
| if ( IS_DEBUG ) |
| { |
| LOG_CURSOR.debug( "Creating ReplicaJournalCursor {}", this ); |
| } |
| |
| this.journal = journal; |
| this.tupleCursor = journal.cursor(); |
| this.consumerCsn = consumerCsn; |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void after( ReplicaEventMessage arg0 ) throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void afterLast() throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean available() |
| { |
| return ( qualifiedEvtMsg != null ); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void before( ReplicaEventMessage arg0 ) throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void beforeFirst() throws LdapException, CursorException |
| { |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean first() throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public ReplicaEventMessage get() throws CursorException |
| { |
| return qualifiedEvtMsg; |
| } |
| |
| |
| /** |
| * selects the current queue entry if qualified for sending to the consumer |
| * |
| * @throws Exception |
| */ |
| private boolean isQualified( String csn, ReplicaEventMessage evtMsg ) throws LdapException |
| { |
| LOG.debug( "ReplicaEventMessage: {}", evtMsg ); |
| |
| if ( evtMsg.isEventOlderThan( consumerCsn ) ) |
| { |
| if ( LOG.isDebugEnabled() ) |
| { |
| String evt = "MODDN"; // take this as default cause the event type for MODDN is null |
| |
| ChangeType changeType = evtMsg.getChangeType(); |
| |
| if ( changeType != null ) |
| { |
| evt = changeType.name(); |
| } |
| |
| LOG.debug( "event {} for dn {} is not qualified for sending", evt, evtMsg.getEntry().getDn() ); |
| } |
| |
| return false; |
| } |
| |
| return true; |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean last() throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean next() throws LdapException, CursorException |
| { |
| while ( tupleCursor.next() ) |
| { |
| Tuple<String, ReplicaEventMessage> tuple = tupleCursor.get(); |
| |
| String csn = tuple.getKey(); |
| ReplicaEventMessage message = tuple.getValue(); |
| |
| if ( skipQualifying ) |
| { |
| qualifiedEvtMsg = message; |
| return true; |
| } |
| |
| boolean qualified = isQualified( csn, message ); |
| |
| if ( qualified ) |
| { |
| qualifiedEvtMsg = message; |
| return true; |
| } |
| else |
| { |
| journal.remove( csn ); |
| } |
| } |
| |
| qualifiedEvtMsg = null; |
| |
| return false; |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean previous() throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void close() |
| { |
| if ( IS_DEBUG ) |
| { |
| LOG_CURSOR.debug( "Closing ReplicaJournalCursor {}", this ); |
| } |
| |
| tupleCursor.close(); |
| super.close(); |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public void close( Exception cause ) |
| { |
| if ( IS_DEBUG ) |
| { |
| LOG_CURSOR.debug( "Closing ReplicaJournalCursor {}", this ); |
| } |
| |
| tupleCursor.close(); |
| super.close( cause ); |
| } |
| |
| |
| /** |
| * sets the flag to skip CSN based checking while traversing |
| * used for internal log cleanup ONLY |
| */ |
| protected void skipQualifyingWhileFetching() |
| { |
| skipQualifying = true; |
| } |
| |
| |
| /** |
| * delete the current message |
| * used for internal log cleanup ONLY |
| */ |
| protected void delete() |
| { |
| try |
| { |
| if ( qualifiedEvtMsg != null ) |
| { |
| journal.remove( qualifiedEvtMsg.getEntry().get( SchemaConstants.ENTRY_CSN_AT ).getString() ); |
| } |
| } |
| catch ( Exception e ) |
| { |
| |
| } |
| } |
| |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public Iterator<ReplicaEventMessage> iterator() |
| { |
| throw new UnsupportedOperationException(); |
| } |
| } |