/*
* 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.jackrabbit.rmi.remote;
import java.io.Serializable;
import java.util.NoSuchElementException;
/**
* A simple array-based remote iterator. Used when the iteration is
* short enough for all the elements to be sent over the network in
* one go.
*/
public class ArrayIterator implements RemoteIterator, Serializable {
/**
* The elements in this iterator. Set to <code>null</code> when
* all elements have been iterated.
*/
private Object[] elements;
/**
* The position of this iterator. Set to the size of the iterator
* when all elements have been iterated.
*/
private int position;
/**
* Creates an array-based remote iterator from the given array
* of remote references or serializable objects.
*
* @param elements elements of the iteration
*/
public ArrayIterator(Object[] elements) {
this.elements = elements;
this.position = 0;
}
/**
* Returns the size of the iterator.
*
* @return length of the iterator
* @see RemoteIterator#getSize()
*/
public long getSize() {
if (elements == null) {
return position;
} else {
return elements.length;
}
}
/**
* Skips the first <code>items</code> elements in the array.
* {@inheritDoc}
*/
public void skip(long items)
throws IllegalArgumentException, NoSuchElementException {
if (items < 0) {
throw new IllegalArgumentException("Negative skip is not allowed");
} else if (elements == null || items > elements.length) {
throw new NoSuchElementException("Skipped past the last element");
} else if (items == elements.length) {
position = elements.length;
elements = null;
} else {
Object[] tmp = new Object[elements.length - (int) items];
System.arraycopy(elements, (int) items, tmp, 0, tmp.length);
elements = tmp;
position += items;
}
}
/**
* Returns the underlying array.
* {@inheritDoc}
*/
public Object[] nextObjects() throws IllegalArgumentException {
if (elements == null) {
return null;
} else {
Object[] tmp = elements;
position += elements.length;
elements = null;
return tmp;
}
}
}