/*
* Copyright (C) 2004-2008 Jive Software. All rights reserved.
*
* Licensed 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.jivesoftware.openfire.spi;
import org.apache.commons.lang.StringEscapeUtils;
import org.jivesoftware.openfire.StreamID;
import org.jivesoftware.openfire.StreamIDFactory;
import org.jivesoftware.util.cache.CacheSizes;
import org.jivesoftware.util.cache.Cacheable;
import org.jivesoftware.util.cache.CannotCalculateSizeException;
import java.math.BigInteger;
import java.security.SecureRandom;
import java.util.Random;
/**
* A basic stream ID factory that produces IDs using a cryptographically strong random number generator.
*
* @author Iain Shigeoka
*/
public class BasicStreamIDFactory implements StreamIDFactory {
/**
* The maximum amount of characters in a stream ID that's generated by this implementation.
*/
private static final int MAX_STRING_SIZE = 10;
/**
* The random number to use, someone with Java can predict stream IDs if they can guess the current seed
*/
Random random = new SecureRandom();
@Override
public StreamID createStreamID() {
return new BasicStreamID(new BigInteger( MAX_STRING_SIZE * 5, random ).toString( 36 ));
}
public static StreamID createStreamID(String name) {
return new BasicStreamID(name);
}
private static class BasicStreamID implements StreamID, Cacheable {
String id;
public BasicStreamID(String id) {
if ( id == null || id.isEmpty() ) {
throw new IllegalArgumentException( "Argument 'id' cannot be null." );
}
this.id = StringEscapeUtils.escapeXml( id );
}
@Override
public String getID() {
return id;
}
@Override
public String toString() {
return id;
}
@Override
public int hashCode() {
return id.hashCode();
}
@Override
public boolean equals( Object o )
{
if ( this == o ) return true;
if ( o == null || getClass() != o.getClass() ) return false;
return id.equals( ((BasicStreamID) o).id );
}
@Override
public int getCachedSize() throws CannotCalculateSizeException
{
// Approximate the size of the object in bytes by calculating the size of each field.
int size = 0;
size += CacheSizes.sizeOfObject(); // overhead of object
size += CacheSizes.sizeOfString(id); // id
return size;
}
}
}