/**
 * Alipay.com Inc.
 * Copyright (c) 2004-2012 All Rights Reserved.
 */
package com.alipay.zdal.datasource.tm;

/**
 *  LocalId is a wrapper for a long value that identifies a transaction within 
 *  a JBoss server. This implementation is immutable and serializable at 
 *  runtime.
 *
 * @author ����
 * @version $Id: LocalId.java, v 0.1 2014-1-6 ����05:47:48 Exp $
 */
public class LocalId implements java.io.Externalizable {
    static final long serialVersionUID = 2076780468014328911L;
    /**
     *  Long value that identifies a transaction within a JBoss server.
     *  This is really a sequence number generated by the XidFactory.
     */
    private long      value;

    // Static --------------------------------------------------------

    public static void toByteArray(long localIdValue, byte[] dst, int dstBegin) {
        dst[dstBegin + 0] = (byte) (0xff & (localIdValue >>> 56));
        dst[dstBegin + 1] = (byte) (0xff & (localIdValue >>> 48));
        dst[dstBegin + 2] = (byte) (0xff & (localIdValue >>> 40));
        dst[dstBegin + 3] = (byte) (0xff & (localIdValue >>> 32));
        dst[dstBegin + 4] = (byte) (0xff & (localIdValue >>> 24));
        dst[dstBegin + 5] = (byte) (0xff & (localIdValue >>> 16));
        dst[dstBegin + 6] = (byte) (0xff & (localIdValue >>> 8));
        dst[dstBegin + 7] = (byte) (0xff & (localIdValue >>> 0));
    }

    public static long fromByteArray(byte[] src, int srcBegin) {
        return ((long) (src[srcBegin + 0] & 0xff) << 56)
               | ((long) (src[srcBegin + 1] & 0xff) << 48)
               | ((long) (src[srcBegin + 2] & 0xff) << 40)
               | ((long) (src[srcBegin + 3] & 0xff) << 32)
               | ((long) (src[srcBegin + 4] & 0xff) << 24)
               | ((long) (src[srcBegin + 5] & 0xff) << 16)
               | ((long) (src[srcBegin + 6] & 0xff) << 8) | ((long) (src[srcBegin + 7] & 0xff));
    }

    // Constructors --------------------------------------------------

    /**
     * No-arg constructor for Externalizable support.
     */
    public LocalId() {
    }

    /**
     *  Create a new instance. This constructor is public <em>only</em>
     *  to get around a class loader problem; it should be package-private.
     */
    public LocalId(long value) {
        this.value = value;
    }

    public LocalId(XidImpl xid) {
        this(xid.getLocalIdValue());
    }

    // Public --------------------------------------------------------

    public long getValue() {
        return value;
    }

    /**
     *  Compare for equality.
     */
    public boolean equals(Object obj) {
        return (obj instanceof LocalId) ? (value == ((LocalId) obj).value) : false;
    }

    public int hashCode() {
        return (int) value;
    }

    // Externalizable implementation ---------------------------------
    public void writeExternal(java.io.ObjectOutput out) throws java.io.IOException {
        out.writeLong(value);
    }

    public void readExternal(java.io.ObjectInput in) throws java.io.IOException,
                                                    ClassNotFoundException {
        value = in.readLong();
    }

}