/*
* Copyright (C) 2007, 2009 XStream Committers.
* All rights reserved.
*
* The software in this package is published under the terms of the BSD
* style license a copy of which has been included with this distribution in
* the LICENSE.txt file.
*
* Created on 04. May 2007 by Joerg Schaible
*/
package com.thoughtworks.xstream.tools.benchmark.strings.products;
import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.converters.basic.AbstractSingleValueConverter;
import com.thoughtworks.xstream.io.xml.XppDriver;
import com.thoughtworks.xstream.tools.benchmark.Product;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map;
import java.util.WeakHashMap;
import java.lang.ref.WeakReference;
/**
* Uses WeakHashMap for StringConverter.
*
* @author Jörg Schaible
* @see com.thoughtworks.xstream.tools.benchmark.Harness
* @see Product
*/
public class StringWithWeakHashMapConverter implements Product {
private final XStream xstream;
public StringWithWeakHashMapConverter() {
xstream = new XStream(new XppDriver());
xstream.registerConverter(new StringConverter());
}
public void serialize(Object object, OutputStream output) throws Exception {
xstream.toXML(object, output);
}
public Object deserialize(InputStream input) throws Exception {
return xstream.fromXML(input);
}
public String toString() {
return "StringConverter using WeakHashMap";
}
/**
* Converts a String to a String.
* <p>
* Well ok, it doesn't <i>actually</i> do any conversion. The converter uses a map to reuse
* instances. This map is by default a {@link WeakHashMap}.
* </p>
*
* @author Rene Schwietzke
* @author Jörg Schaible
* @see WeakHashMap
*/
public static class StringConverter extends AbstractSingleValueConverter {
/**
* A Map to store strings as long as needed to map similar strings onto the same
* instance and conserve memory. The map can be set from the outside during
* construction, so it can be a LRU map or a weak map, sychronized or not.
*/
private final Map cache;
public StringConverter(Map map) {
this.cache = map;
}
public StringConverter() {
this(new WeakHashMap());
}
public boolean canConvert(Class type) {
return type.equals(String.class);
}
public Object fromString(String str) {
WeakReference ref = (WeakReference)cache.get(str);
String s = (String)(ref == null ? null : ref.get());
if (s == null) {
// fill cache
cache.put(str, new WeakReference(str));
s = str;
}
return s;
}
}
}