/*

 * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.io;

/**

 * Constants written into the Object Serialization Stream.

 *

 * @author  unascribed

 * @since JDK 1.1

 */

public interface ObjectStreamConstants {

    /**

     * Magic number that is written to the stream header.

     */

    final static short STREAM_MAGIC = (short)0xaced;

    /**

     * Version number that is written to the stream header.

     */

    final static short STREAM_VERSION = 5;

    /* Each item in the stream is preceded by a tag

     */

    /**

     * First tag value.

     */

    final static byte TC_BASE = 0x70;

    /**

     * Null object reference.

     */

    final static byte TC_NULL =         (byte)0x70;

    /**

     * Reference to an object already written into the stream.

     */

    final static byte TC_REFERENCE =    (byte)0x71;

    /**

     * new Class Descriptor.

     */

    final static byte TC_CLASSDESC =    (byte)0x72;

    /**

     * new Object.

     */

    final static byte TC_OBJECT =       (byte)0x73;

    /**

     * new String.

     */

    final static byte TC_STRING =       (byte)0x74;

    /**

     * new Array.

     */

    final static byte TC_ARRAY =        (byte)0x75;

    /**

     * Reference to Class.

     */

    final static byte TC_CLASS =        (byte)0x76;

    /**

     * Block of optional data. Byte following tag indicates number

     * of bytes in this block data.

     */

    final static byte TC_BLOCKDATA =    (byte)0x77;

    /**

     * End of optional block data blocks for an object.

     */

    final static byte TC_ENDBLOCKDATA = (byte)0x78;

    /**

     * Reset stream context. All handles written into stream are reset.

     */

    final static byte TC_RESET =        (byte)0x79;

    /**

     * long Block data. The long following the tag indicates the

     * number of bytes in this block data.

     */

    final static byte TC_BLOCKDATALONG= (byte)0x7A;

    /**

     * Exception during write.

     */

    final static byte TC_EXCEPTION =    (byte)0x7B;

    /**

     * Long string.

     */

    final static byte TC_LONGSTRING =   (byte)0x7C;

    /**

     * new Proxy Class Descriptor.

     */

    final static byte TC_PROXYCLASSDESC =       (byte)0x7D;

    /**

     * new Enum constant.

     * @since 1.5

     */

    final static byte TC_ENUM =         (byte)0x7E;

    /**

     * Last tag value.

     */

    final static byte TC_MAX =          (byte)0x7E;

    /**

     * First wire handle to be assigned.

     */

    final static int baseWireHandle = 0x7e0000;

    /******************************************************/

    /* Bit masks for ObjectStreamClass flag.*/

    /**

     * Bit mask for ObjectStreamClass flag. Indicates a Serializable class

     * defines its own writeObject method.

     */

    final static byte SC_WRITE_METHOD = 0x01;

    /**

     * Bit mask for ObjectStreamClass flag. Indicates Externalizable data

     * written in Block Data mode.

     * Added for PROTOCOL_VERSION_2.

     *

     * @see #PROTOCOL_VERSION_2

     * @since 1.2

     */

    final static byte SC_BLOCK_DATA = 0x08;

    /**

     * Bit mask for ObjectStreamClass flag. Indicates class is Serializable.

     */

    final static byte SC_SERIALIZABLE = 0x02;

    /**

     * Bit mask for ObjectStreamClass flag. Indicates class is Externalizable.

     */

    final static byte SC_EXTERNALIZABLE = 0x04;

    /**

     * Bit mask for ObjectStreamClass flag. Indicates class is an enum type.

     * @since 1.5

     */

    final static byte SC_ENUM = 0x10;

    /* *******************************************************************/

    /* Security permissions */

    /**

     * Enable substitution of one object for another during

     * serialization/deserialization.

     *

     * @see java.io.ObjectOutputStream#enableReplaceObject(boolean)

     * @see java.io.ObjectInputStream#enableResolveObject(boolean)

     * @since 1.2

     */

    final static SerializablePermission SUBSTITUTION_PERMISSION =

                           new SerializablePermission("enableSubstitution");

    /**

     * Enable overriding of readObject and writeObject.

     *

     * @see java.io.ObjectOutputStream#writeObjectOverride(Object)

     * @see java.io.ObjectInputStream#readObjectOverride()

     * @since 1.2

     */

    final static SerializablePermission SUBCLASS_IMPLEMENTATION_PERMISSION =

                    new SerializablePermission("enableSubclassImplementation");

   /**

    * A Stream Protocol Version. <p>

    *

    * All externalizable data is written in JDK 1.1 external data

    * format after calling this method. This version is needed to write

    * streams containing Externalizable data that can be read by

    * pre-JDK 1.1.6 JVMs.

    *

    * @see java.io.ObjectOutputStream#useProtocolVersion(int)

    * @since 1.2

    */

    public final static int PROTOCOL_VERSION_1 = 1;

   /**

    * A Stream Protocol Version. <p>

    *

    * This protocol is written by JVM 1.2.

    *

    * Externalizable data is written in block data mode and is

    * terminated with TC_ENDBLOCKDATA. Externalizable classdescriptor

    * flags has SC_BLOCK_DATA enabled. JVM 1.1.6 and greater can

    * read this format change.

    *

    * Enables writing a nonSerializable class descriptor into the

    * stream. The serialVersionUID of a nonSerializable class is

    * set to 0L.

    *

    * @see java.io.ObjectOutputStream#useProtocolVersion(int)

    * @see #SC_BLOCK_DATA

    * @since 1.2

    */

    public final static int PROTOCOL_VERSION_2 = 2;

}