| /* |
| * 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.mavibot; |
| |
| |
| import java.io.IOException; |
| |
| import org.apache.directory.api.ldap.model.cursor.AbstractCursor; |
| import org.apache.directory.api.ldap.model.cursor.CursorException; |
| import org.apache.directory.api.ldap.model.exception.LdapException; |
| import org.apache.directory.mavibot.btree.ValueCursor; |
| import org.apache.directory.server.i18n.I18n; |
| |
| |
| /** |
| * TODO ValueTreeCursor. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class ValueTreeCursor<V> extends AbstractCursor<V> |
| { |
| |
| private ValueCursor<V> wrapped; |
| |
| private V available; |
| |
| // marker to detect the availability (cause Mavibot supports null values also) |
| private V notAvailable = ( V ) new Object(); |
| |
| |
| public ValueTreeCursor( ValueCursor<V> cursor ) |
| { |
| this.wrapped = cursor; |
| } |
| |
| |
| @Override |
| public boolean available() |
| { |
| return ( available != notAvailable ); |
| } |
| |
| |
| @Override |
| public void before( V element ) throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException( I18n.err( I18n.ERR_446 ) ); |
| } |
| |
| |
| @Override |
| public void after( V element ) throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException( I18n.err( I18n.ERR_446 ) ); |
| } |
| |
| |
| @Override |
| public void beforeFirst() throws LdapException, CursorException |
| { |
| } |
| |
| |
| @Override |
| public void afterLast() throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException( I18n.err( I18n.ERR_446 ) ); |
| } |
| |
| |
| @Override |
| public boolean first() throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException( I18n.err( I18n.ERR_446 ) ); |
| } |
| |
| |
| @Override |
| public boolean last() throws LdapException, CursorException |
| { |
| throw new UnsupportedOperationException( I18n.err( I18n.ERR_446 ) ); |
| } |
| |
| |
| @Override |
| public boolean previous() throws LdapException, CursorException |
| { |
| try |
| { |
| if ( wrapped.hasPrev() ) |
| { |
| available = wrapped.prev(); |
| return true; |
| } |
| else |
| { |
| available = notAvailable; |
| return false; |
| } |
| } |
| catch ( IOException e ) |
| { |
| throw new CursorException( e ); |
| } |
| } |
| |
| |
| @Override |
| public boolean next() throws LdapException, CursorException |
| { |
| try |
| { |
| if ( wrapped.hasNext() ) |
| { |
| available = wrapped.next(); |
| return true; |
| } |
| else |
| { |
| available = notAvailable; |
| return false; |
| } |
| } |
| catch ( IOException e ) |
| { |
| throw new CursorException( e ); |
| } |
| } |
| |
| |
| @Override |
| public V get() throws CursorException |
| { |
| return available; |
| } |
| |
| } |