org.apache.commons.id.uuid.Constants Maven / Gradle / Ivy

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.commons.id.uuid;

/**
 * Constant values commonly needed in the uuid classes.
 *
 * @author Commons-Id Team
 * @version $Revision: 480488 $ $Date: 2006-11-29 00:57:26 -0800 (Wed, 29 Nov 2006) $
 *
 */
public interface Constants {

    //** Magic number constants
    /** Bits in a UUID. */
    int UUID_BIT_LENGTH = 128;

    /** Number of bytes in a UUID. */
    int UUID_BYTE_LENGTH = 16;


    //** Formatting and validation constants
    /** Chars in a UUID String. */
    int UUID_UNFORMATTED_LENGTH = 32;

    /** Chars in a UUID String. */
    int UUID_FORMATTED_LENGTH = 36;

    /** Token length of '-' separated tokens. */
    int TOKENS_IN_UUID = 5;

    /** Array to check tokenized UUID's segment lengths */
    int[] TOKEN_LENGTHS = {8, 4, 4, 4, 12};

    /** Insertion point 1 for dashes in the string format */
    int FORMAT_POSITION1 = 8;

    /** Insertion point 2 for dashes in the string format */
    int FORMAT_POSITION2 = 13;

    /** Insertion point 3 for dashes in the string format */
    int FORMAT_POSITION3 = 18;

    /** Insertion point 4 for dashes in the string format */
    int FORMAT_POSITION4 = 23;

    /** The string prefix for a urn UUID identifier. */
    String URN_PREFIX = "urn:uuid:";


    //** UUID Variant Constants
    /** UUID variant bits described in the IETF Draft MSB order,
     *  this is the "Reserved, NCS backward compatibility field" 0 x x with unknown bits as 0*/
    int VARIANT_NCS_COMPAT = 0;

    /** UUID variant bits described in the IETF Draft MSB order,
     *  this is the IETF Draft memo variant field 1 0 x with unknown bits as 0*/
    int VARIANT_IETF_DRAFT = 2;

    /** UUID variant bits described in the IETF Draft MSB order,
     *  this is the IETF Draft "Microsoft Corporation" field variant 1 1 0 x with unknown bits as 0*/
    int VARIANT_MS = (byte) 6;

    /** UUID variant bits described in the IETF Draft MSB order,
     *  this is the "Future Reserved variant 1 1 1 x with unknown bits as 0*/
    int VARIANT_FUTURE = 7;


    //** UUID Version Constants
    /** Version one constant for UUID version one of four */
    int VERSION_ONE = 1;

    /** Version two constant for UUID version two of four */
    int VERSION_TWO = 2;

    /** Version three constant for UUID version three of four */
    int VERSION_THREE = 3;

    /** Version four constant for UUID version four of four */
    int VERSION_FOUR = 4;

    /** Version five constant for UUID version five - identical to version 3 */
    int VERSION_FIVE = 3;

    /** Constants that correspond to the encoding being used, a la 
     * http://www.ietf.org/internet-drafts/draft-mealling-uuid-urn-04.txt.
     * Current legal values are "MD5" and "SHA1"
     */
    String MD5_ENCODING = "MD5";
    String SHA1_ENCODING = "SHA1";

    //** Exception message constants
    /** Message indicating this is not a version one UUID */
    String WRONG_VAR_VER_MSG = "Not a ietf variant 2 or version 1 (time-based UUID)";

    // ** Array positions and lengths of UUID fields ** //
    /** Byte length of time low field */
    int TIME_LOW_BYTE_LEN = 4;
    /** Byte length of time low field */
    int TIME_MID_BYTE_LEN = 2;
    /** Byte length of time low field */
    int TIME_HI_BYTE_LEN = 2;
    /** Timestamp byte[] position of time low field */
    int TIME_LOW_TS_POS = 4;
    /** Timestamp byte[]  position mid field */
    int TIME_MID_TS_POS = 2;
    /** Timestamp byte[]  position hi field */
    int TIME_HI_TS_POS = 0;
    /** uuid array position start of time low field */
    int TIME_LOW_START_POS = 0;
    /** uuid array position start of mid field */
    int TIME_MID_START_POS = 4;
    /** uuid array position start of hi field */
    int TIME_HI_START_POS = 6;
    /** Byte position of the clock sequence and reserved field */
    short TIME_HI_AND_VERSION_BYTE_6 = 6;
    /** Byte position of the clock sequence and reserved field */
    short CLOCK_SEQ_HI_AND_RESERVED_BYTE_8 = 8;
}