/**
 * @(#)JavaSerializationComponent.java	1.2 04/06/07
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.corba.se.impl.ior.iiop;

import org.omg.CORBA_2_3.portable.OutputStream;

import com.sun.corba.se.impl.orbutil.ORBConstants;
import com.sun.corba.se.impl.orbutil.ORBUtility;
import com.sun.corba.se.impl.protocol.giopmsgheaders.Message;

import com.sun.corba.se.spi.orb.ORB;
import com.sun.corba.se.spi.ior.TaggedComponentBase;

/**
 * Tagged component that contains a value that indicates the Java 
 * serialization version supported by the ORB.
 *
 * ORB Java serialization uses IIOP as the transport protocol, but uses
 * Java serialization mechanism and its accompanying encodings, instead
 * of IIOP CDR serialization mechanism. Java serialization is generally
 * observed to be faster than CDR.
 */ 
public class JavaSerializationComponent extends TaggedComponentBase {

    private byte version;

    private static JavaSerializationComponent singleton;

    public static JavaSerializationComponent singleton() {
	if (singleton == null) {
	    synchronized (JavaSerializationComponent.class) {
		singleton = 
		    new JavaSerializationComponent(Message.JAVA_ENC_VERSION);
	    }
	}
	return singleton;
    }

    public JavaSerializationComponent(byte version) {
        this.version = version;
    }

    public byte javaSerializationVersion() {
	return this.version;
    }

    public void writeContents(OutputStream os) {
        os.write_octet(version);
    }
    
    public int getId() {
	return ORBConstants.TAG_JAVA_SERIALIZATION_ID;
    }

    public boolean equals(Object obj) {
	if (!(obj instanceof JavaSerializationComponent)) {
	    return false;
	}
	JavaSerializationComponent other = (JavaSerializationComponent) obj;
	return this.version == other.version;
    }

    public int hashCode() {
	return this.version;
    }
}