com.tangosol.util.UID Maven / Gradle / Ivy
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/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.util;
import com.tangosol.io.ExternalizableLite;
import com.tangosol.io.pof.PofReader;
import com.tangosol.io.pof.PofWriter;
import com.tangosol.io.pof.PortableObject;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.net.InetAddress;
import java.util.Date;
import java.util.Random;
import javax.json.bind.annotation.JsonbProperty;
/**
* A UID is a 128-bit identifier that is almost guaranteed to be unique.
*
* @author cp 2000.09.12
*/
public class UID
extends Base
implements Comparable, Serializable, ExternalizableLite, PortableObject
{
// ----- command line ---------------------------------------------------
/**
* Allow UID identifiers to be generated or parsed at the command line.
* For example, to generate 10 identifiers:
*
* java com.tangosol.util.UID 10
*/
public static void main(String[] asArgs)
{
try
{
if (asArgs.length >= 2)
{
InetAddress addr = InetAddress.getByName(asArgs[0]);
int nCnt = Integer.parseInt(asArgs[1]);
int nAddr = (int) (toLong(addr) & 0xFFFFFFFFL);
out(new UID(nAddr, new Date().getTime(), nCnt));
}
else
{
int cIds = Math.max(1, Integer.parseInt(asArgs[0]));
for (int i = 0; i < cIds; ++i)
{
UID uid = new UID();
String sUID = uid.toString();
azzert(uid.equals(new UID(sUID)));
out(uid);
}
}
}
catch (Exception e)
{
try
{
UID uid = new UID(asArgs[0]);
out("Address =" + toString(uid.getAddress()));
out("Timestamp=" + new Date(uid.getTimestamp()));
out("Port =" + (uid.getCount() & 0x0000FFFF));
out("MachineId=" + ((uid.getCount() & 0xFFFF0000) >>> 16));
}
catch (Exception ex)
{
out("Usage:");
out(" java com.tangosol.util.UID | | ( )");
}
}
}
// ----- constructors ---------------------------------------------------
/**
* Construct a UID (default constructor).
*/
public UID()
{
m_nAddr = s_nHostAddr;
m_lDatetime = getSafeTimeMillis();
synchronized (LOCK)
{
m_nCount = ++s_nLastCount;
}
}
/**
* Construct a UID from its constituent members (advanced constructor).
*
* @param nAddr the InetAddress-related portion of the UID
* @param lDatetime the creation date/time millis portion of the UID
* @param nCount the counter portion of the UID
*/
public UID(int nAddr, long lDatetime, int nCount)
{
m_nAddr = nAddr;
m_lDatetime = lDatetime;
m_nCount = nCount;
}
/**
* Construct a UID from a byte array.
*
* @param ab a byte array as would be returned from UID.toByteArray()
*/
public UID(byte[] ab)
{
azzert(ab != null && ab.length == 16);
m_nAddr = (int) (ab[ 0] & 0xFF) << 24
| (int) (ab[ 1] & 0xFF) << 16
| (int) (ab[ 2] & 0xFF) << 8
| (int) (ab[ 3] & 0xFF);
m_lDatetime = (long) (ab[ 4] & 0xFF) << 56
| (long) (ab[ 5] & 0xFF) << 48
| (long) (ab[ 6] & 0xFF) << 40
| (long) (ab[ 7] & 0xFF) << 32
| (long) (ab[ 8] & 0xFF) << 24
| (long) (ab[ 9] & 0xFF) << 16
| (long) (ab[10] & 0xFF) << 8
| (long) (ab[11] & 0xFF);
m_nCount = (int) (ab[12] & 0xFF) << 24
| (int) (ab[13] & 0xFF) << 16
| (int) (ab[14] & 0xFF) << 8
| (int) (ab[15] & 0xFF);
}
/**
* Construct a UID from a String.
*
* @param s a String as would be returned from UID.toString()
*/
public UID(String s)
{
this(parseHex(s));
}
/**
* Construct a UID from a stream.
*
* This is a custom serialization implementation that is unrelated to the
* Serializable interface and the Java implementation of persistence.
*
* @param stream an object implementing java.io.DataInput that contains
* the internal information that a previous UID wrote
*
* @exception IOException if an error occurs reading from the stream
*/
public UID(DataInput stream)
throws IOException
{
this(readBytes(stream));
}
/**
* Internal method to support construction from DataInput.
*/
private static byte[] readBytes(DataInput stream)
throws IOException
{
byte[] ab = new byte [16];
stream.readFully(ab);
return ab;
}
// ----- UID data access ------------------------------------------------
/**
* Determine the internet address of the host that generated the UID
* instance (or a random number if no internet address was available)
*
* @return a 4-byte integer value holding an internet address in the
* byte order that is used by InetAddress and LicensedObject
*/
public int getAddress()
{
return m_nAddr;
}
/**
* Determine the date/time value that the UID instance was generated.
*
* @return date/time value in millis that the UID instance was generated
*/
public long getTimestamp()
{
return m_lDatetime;
}
/**
* Determine the "counter" portion of the UID that ensures that two UIDs
* generated at the same exact time by the same process are unique.
*
* @return a number that helps to make the UID unique
*/
public int getCount()
{
return m_nCount;
}
/**
* Convert the UID to a printable String.
*
* @return the UID data as a 0x-prefixed hex string.
*/
public String toString()
{
return toHexEscape(toByteArray());
}
/**
* Convert the UID to a byte array of 16 bytes.
*
* @return the UID data as a byte array of 16 bytes
*/
public byte[] toByteArray()
{
byte[] ab = new byte[16];
int nAddr = m_nAddr;
long lDatetime = m_lDatetime;
int nCount = m_nCount;
ab[ 0] = (byte) (nAddr >>> 24);
ab[ 1] = (byte) (nAddr >>> 16);
ab[ 2] = (byte) (nAddr >>> 8);
ab[ 3] = (byte) nAddr;
ab[ 4] = (byte) (lDatetime >>> 56);
ab[ 5] = (byte) (lDatetime >>> 48);
ab[ 6] = (byte) (lDatetime >>> 40);
ab[ 7] = (byte) (lDatetime >>> 32);
ab[ 8] = (byte) (lDatetime >>> 24);
ab[ 9] = (byte) (lDatetime >>> 16);
ab[10] = (byte) (lDatetime >>> 8);
ab[11] = (byte) lDatetime;
ab[12] = (byte) (nCount >>> 24);
ab[13] = (byte) (nCount >>> 16);
ab[14] = (byte) (nCount >>> 8);
ab[15] = (byte) nCount;
return ab;
}
/**
* Convert the UID to a character array of 32 hex digits.
*
* @return the UID data as a character array of 32 hex digits
*/
public char[] toCharArray()
{
return toHex(toByteArray()).toCharArray();
}
// ----- hashing and comparison support ---------------------------------
/**
* Determine if two UIDs are equal.
*
* @param o the other UID
*
* @return true if the passed object is equal to this
*/
public boolean equals(Object o)
{
if (o instanceof UID)
{
UID that = (UID) o;
return this.m_nAddr == that.m_nAddr
&& this.m_lDatetime == that.m_lDatetime
&& this.m_nCount == that.m_nCount;
}
return false;
}
/**
* Compares this object with the specified object for order. Returns a
* negative integer, zero, or a positive integer as this object is less
* than, equal to, or greater than the specified object.
*
* @param o the Object to be compared.
*
* @return a negative integer, zero, or a positive integer as this object
* is less than, equal to, or greater than the specified object
*
* @throws ClassCastException if the specified object's type prevents it
* from being compared to this Object
*/
public int compareTo(Object o)
{
UID that = (UID) o;
if (this.m_lDatetime != that.m_lDatetime)
{
return this.m_lDatetime < that.m_lDatetime ? -1 : 1;
}
if (this.m_nAddr != that.m_nAddr)
{
return this.m_nAddr < that.m_nAddr ? -1 : 1;
}
if (this.m_nCount != that.m_nCount)
{
return this.m_nCount < that.m_nCount ? -1 : 1;
}
return 0;
}
/**
* Determine a hash code for the UID object.
*
* @return a hash code reflecting the UID's data
*/
public int hashCode()
{
return m_nAddr ^ (int) (m_lDatetime >>> 32) ^ (int) m_lDatetime ^ m_nCount;
}
// ----- persistence ----------------------------------------------------
/**
* Store this UID in a stream.
*
* This is a custom serialization implementation that is unrelated to the
* Serializable interface and the Java implementation of persistence.
*
* @param stream an object implementing java.io.DataOutput that this UID
* should write its internal information to.
*
* @exception IOException if an error occurs writing to the stream
*/
public void save(DataOutput stream)
throws IOException
{
stream.write(toByteArray());
}
// ----- shared members -------------------------------------------------
/**
* Random number generator.
*/
private static Random s_rnd = getRandom();
/**
* The IP address of the host or a random number if none available.
*/
private static int s_nHostAddr;
/**
* The last integer counter used to make a UID pseudo-unique.
*/
private static int s_nLastCount = s_rnd.nextInt();
/**
* A mutex for accessing/updating s_nLastCount.
*/
private static final Object LOCK = new Object();
/**
* Determine the IP address of this host or use a random number if
* an address is not available.
*/
static
{
s_nHostAddr = s_rnd.nextInt();
try
{
byte[] abIP = InetAddress.getLocalHost().getAddress();
int nIP = (abIP[0] & 0xFF) << 24
| (abIP[1] & 0xFF) << 16
| (abIP[2] & 0xFF) << 8
| (abIP[3] & 0xFF);
if (nIP != 0x00000000 && nIP != 0x7F000001)
{
s_nHostAddr = nIP;
}
}
catch (Exception e)
{
}
}
// ----- ExternalizableLite interface -----------------------------------
/**
* {@inheritDoc}
*/
public void readExternal(DataInput in)
throws IOException
{
m_nAddr = in.readInt();
m_lDatetime = in.readLong();
m_nCount = in.readInt();
}
/**
* {@inheritDoc}
*/
public void writeExternal(DataOutput out)
throws IOException
{
out.writeInt (m_nAddr);
out.writeLong(m_lDatetime);
out.writeInt (m_nCount);
}
// ----- PortableObject interface ---------------------------------------
/**
* {@inheritDoc}
*/
public void readExternal(PofReader in)
throws IOException
{
m_nAddr = in.readInt(0);
m_lDatetime = in.readLong(1);
m_nCount = in.readInt(2);
}
/**
* {@inheritDoc}
*/
public void writeExternal(PofWriter out)
throws IOException
{
out.writeInt (0, m_nAddr);
out.writeLong(1, m_lDatetime);
out.writeInt (2, m_nCount);
}
// ----- Serializable interface -----------------------------------------
/**
* Write this object to an ObjectOutputStream.
*
* @param out the ObjectOutputStream to write this object to
*
* @throws IOException thrown if an exception occurs writing this object
*/
private void writeObject(ObjectOutputStream out)
throws IOException
{
out.writeInt(m_nAddr);
out.writeLong(m_lDatetime);
out.writeInt(m_nCount);
}
/**
* Read this object from an ObjectInputStream.
*
* @param in the ObjectInputStream to read this object from
*
* @throws IOException if an exception occurs reading this object
* @throws ClassNotFoundException if the class for an object being
* read cannot be found
*/
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException
{
m_nAddr = in.readInt();
m_lDatetime = in.readLong();
m_nCount = in.readInt();
}
// ----- helpers --------------------------------------------------------
/**
* Converts and IP address to a long value.
*
* @param addr an instance of InetAddress to convert to a long
*
* @return a long value holding the IP address
*/
public static long toLong(InetAddress addr)
{
byte[] ab = addr.getAddress();
return ((((long) ab[0]) & 0xFFL) << 24)
| ((((long) ab[1]) & 0xFFL) << 16)
| ((((long) ab[2]) & 0xFFL) << 8)
| ((((long) ab[3]) & 0xFFL) );
}
/**
* Converts a long value to an address string in the form returned by
* InetAddress#getHostAddress.
*
* @param l the long value holding the IP address
*
* @return the IP address string "%d.%d.%d.%d"
*/
public static String toString(long l)
{
return ((l & 0xFF000000L) >>> 24) + "." +
((l & 0x00FF0000L) >>> 16) + "." +
((l & 0x0000FF00L) >>> 8) + "." +
((l & 0x000000FFL) );
}
// ----- data members ---------------------------------------------------
/**
* Internet address of host that generated the UID instance (or a
* random number).
*/
@JsonbProperty("address")
private int m_nAddr;
/**
* Date/time value that the UID instance was generated.
*/
@JsonbProperty("dateTime")
private long m_lDatetime;
/**
* A number that helps to make the UID unique.
*/
@JsonbProperty("count")
private int m_nCount;
}