InMemory.java

/**
 *  Copyright 2007-2008 University Of Southern California
 *
 *  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 edu.isi.pegasus.planner.provenance.pasoa.producer;

import edu.isi.pegasus.planner.provenance.pasoa.XMLProducer;

import java.io.*;

/**
 * An implementation of the XMLProducer interface backed by a StringBuffer.
 * It does not check for any wellformedness of the XML. It is basically a
 * data store.
 *
 * @author Karan Vahi
 * @version $Revision$
 */
public class InMemory
    implements XMLProducer {


    /**
     * The StringBuffer store.
     */
    private StringBuffer mStore;

    /**
     * The initial size of the buffer.
     */
    private int mSize;

    /**
     * The default constructor.
     */
    public InMemory() {
        mSize = 32;
        reset();
    }

    /**
     * The overloaded constructor.
     *
     * @param size the intial number of characters it can store.
     */
    public InMemory( int size ){
        mSize = size;
        reset();
    }

    /**
     * Adds to the internal XML representation.
     *
     * @param xml the XML fragment to be added.
     *
     */
    public void add( String xml ) {
        mStore.append( xml );
    }

    /**
     * Clears the internal state.
     *
     *
     */
    public void clear() {
        reset();
    }

    /**
     * Returns the xml description of the object.
     *
     * @param writer is a Writer opened and ready for writing. This can also
     *   be a StringWriter for efficient output.
     * @throws IOException if something fishy happens to the stream.
     */
    public void toXML( Writer writer ) throws IOException {
        writer.write( mStore.toString() );
    }

    /**
     * Returns the interaction assertions as a XML blob.
     *
     * @return String
     * @throws IOException if something fishy happens to the stream.
     */
    public String toXML() throws IOException {
        Writer writer = new StringWriter( mSize );
        toXML( writer );
        return writer.toString();

    }

    /**
     * Resets the internal store.
     */
    private void reset(){
        mStore = new StringBuffer( mSize );
    }
}