/*
* 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.core.partition.impl.btree;
import java.util.Arrays;
import java.util.List;
import org.apache.directory.server.i18n.I18n;
import org.apache.directory.server.xdbm.Tuple;
import org.apache.directory.shared.ldap.NotImplementedException;
import org.apache.directory.shared.ldap.cursor.AbstractCursor;
import org.apache.directory.shared.ldap.cursor.InvalidCursorPositionException;
/**
* A Cursor which returns the values of a single key as Tuples.
*
* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
* @version $Rev$, $Date$
*/
public class ValueArrayCursor<K, V> extends AbstractCursor<Tuple<K, V>>
{
private static final int BEFORE_FIRST = -1;
private final K key;
private final List<V> values;
private final Tuple<K, V> tuple = new Tuple<K, V>();
private int pos = BEFORE_FIRST;
public ValueArrayCursor( final K key, final V[] values )
{
this.key = key;
this.tuple.setKey( key );
this.values = Arrays.asList( values );
}
public ValueArrayCursor( final K key, final List<V> values )
{
this.key = key;
this.tuple.setKey( key );
this.values = values;
}
public boolean available()
{
return inRangeOnValue();
}
public void before( Tuple<K, V> element ) throws Exception
{
throw new NotImplementedException();
}
public void after( Tuple<K, V> element ) throws Exception
{
throw new NotImplementedException();
}
public void beforeFirst() throws Exception
{
checkNotClosed( "beforeFirst()" );
pos = BEFORE_FIRST;
}
public void afterLast() throws Exception
{
checkNotClosed( "afterLast()" );
pos = values.size();
}
public boolean absolute( int absolutePosition ) throws Exception
{
checkNotClosed( "absolute()" );
if ( absolutePosition >= values.size() )
{
pos = values.size();
return false;
}
if ( absolutePosition < 0 )
{
pos = BEFORE_FIRST;
return false;
}
pos = absolutePosition;
return true;
}
public boolean first() throws Exception
{
checkNotClosed( "first()" );
pos = 0;
return true;
}
public boolean last() throws Exception
{
checkNotClosed( "last()" );
pos = values.size() - 1;
return true;
}
public boolean isFirst() throws Exception
{
checkNotClosed( "isFirst()" );
return pos == 0;
}
public boolean isLast() throws Exception
{
checkNotClosed( "isLast()" );
return pos == values.size() - 1;
}
public boolean isAfterLast() throws Exception
{
checkNotClosed( "isAfterLast()" );
return pos == values.size();
}
public boolean isBeforeFirst() throws Exception
{
checkNotClosed( "isBeforeFirst()" );
return pos == BEFORE_FIRST;
}
public boolean previous() throws Exception
{
checkNotClosed( "previous()" );
if ( pos <= BEFORE_FIRST )
{
return false;
}
pos--;
return inRangeOnValue();
}
private boolean inRangeOnValue()
{
return pos > BEFORE_FIRST && pos < values.size();
}
public boolean next() throws Exception
{
checkNotClosed( "next()" );
if ( pos >= values.size() )
{
return false;
}
pos++;
return inRangeOnValue();
}
public Tuple<K, V> get() throws Exception
{
checkNotClosed( "get()" );
if ( inRangeOnValue() )
{
return tuple.setBoth( key, values.get( pos ) );
}
throw new InvalidCursorPositionException( I18n.err( I18n.ERR_701, pos, ( values.size() - 1 ) ) );
}
public boolean isElementReused()
{
return true;
}
}