/*
* 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.ldap.client.api;
import java.util.concurrent.TimeUnit;
import org.apache.directory.ldap.client.api.exception.LdapException;
import org.apache.directory.ldap.client.api.future.SearchFuture;
import org.apache.directory.ldap.client.api.message.SearchResponse;
import org.apache.directory.ldap.client.api.message.SearchResultDone;
import org.apache.directory.shared.ldap.cursor.AbstractCursor;
import org.apache.directory.shared.ldap.cursor.InvalidCursorPositionException;
/**
* An implementation of Cursor based on the underlying SearchFuture instance.
*
* Note: This is a forward only cursor hence the only valid operations are next(), get() and close()
*
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
* @version $Rev$, $Date$
*/
public class SearchCursor extends AbstractCursor
{
/** the search future */
private SearchFuture future;
/** wait time while polling for a SearchResponse */
private long timeout;
/** time units of timeout value */
private TimeUnit timeUnit;
/** a reference to hold the retrieved SearchResponse object from SearchFuture */
private SearchResponse response;
private boolean done;
public SearchCursor( SearchFuture future, long timeout, TimeUnit timeUnit )
{
this.future = future;
this.timeout = timeout;
this.timeUnit = timeUnit;
}
public boolean next() throws Exception
{
try
{
if( future.isCancelled() )
{
response = null;
done = true;
return false;
}
response = future.get( timeout, timeUnit );
}
catch ( Exception e )
{
LdapException ldapException = new LdapException( LdapConnection.NO_RESPONSE_ERROR );
ldapException.initCause( e );
// Send an abandon request
if ( !future.isCancelled() )
{
future.cancel( true );
}
// close the cursor
close( ldapException );
throw ldapException;
}
if ( response == null )
{
future.cancel( true );
throw new LdapException( LdapConnection.TIME_OUT_ERROR );
}
done = ( response instanceof SearchResultDone );
if ( done )
{
response = null;
}
return !done;
}
public SearchResponse get() throws Exception
{
if ( !available() )
{
throw new InvalidCursorPositionException();
}
return response;
}
public boolean isElementReused()
{
return true;
}
public boolean available()
{
return response != null;
}
@Override
public void close() throws Exception
{
close( null );
}
@Override
public void close( Exception cause ) throws Exception
{
if( done )
{
super.close();
return;
}
if ( !future.isCancelled() )
{
future.cancel( true );
}
if ( cause != null )
{
super.close( cause );
}
else
{
super.close();
}
}
// rest of all operations will throw UnsupportedOperationException
public void after( Object element ) throws Exception
{
throw new UnsupportedOperationException();
}
public void afterLast() throws Exception
{
throw new UnsupportedOperationException();
}
public void before( Object element ) throws Exception
{
throw new UnsupportedOperationException();
}
public void beforeFirst() throws Exception
{
throw new UnsupportedOperationException();
}
public boolean first() throws Exception
{
throw new UnsupportedOperationException();
}
public boolean last() throws Exception
{
throw new UnsupportedOperationException();
}
public boolean previous() throws Exception
{
throw new UnsupportedOperationException();
}
}