package com.pardot.rhombus.util;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import java.util.UUID;
/**
* Pardot, an ExactTarget company
* User: Michael Frank
* Date: 5/6/13
*
UUID = time-low "-" time-mid "-"
time-high-and-version "-"
clock-seq-and-reserved
clock-seq-low "-" node
time-low = 4hexOctet
time-mid = 2hexOctet
time-high-and-version = 2hexOctet
clock-seq-and-reserved = hexOctet
clock-seq-low = hexOctet
node = 6hexOctet
hexOctet = hexDigit hexDigit
hexDigit =
"0" / "1" / "2" / "3" / "4" / "5" / "6" / "7" / "8" / "9" /
"a" / "b" / "c" / "d" / "e" / "f" /
"A" / "B" / "C" / "D" / "E" / "F"
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| time_low |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| time_mid | time_hi_and_version |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|clk_seq_hi_res | clk_seq_low | node (0-1) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| node (2-5) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
time-low "-" time-mid "-" time-high-and-version "-" clock-seq-and-reserved + clock-seq-low "-" node
*/
public class UuidUtil {
/**
* Generate a type 3 namespace uuid from an integer namespace and name
* Our primary objective is to store and retrieve our name and namespace, and we don't care about collisions,
* so we'll just shove the name and namespace values straight in rather than hashing them
*
* We will allow 4 bytes for the namespace and 8 bytes for the name. To avoid conflicts with reserved
* version/variant bits, we will put the namespace data in the time_low field, 6 least significant bytes of the name data
* in the node field, and the remaining 2 most significant name bytes in time_mid
*
* @param namespace Integer representing the namespace
* @param name Long representing the name
* @return Type 3 UUID built from the namespace and name
*/
public static UUID namespaceUUID(Integer namespace, Long name) {
//Create our msb and lsb return buffers
ByteBuffer msb = ByteBuffer.allocate(8);
msb.order(ByteOrder.BIG_ENDIAN);
ByteBuffer lsb = ByteBuffer.allocate(8);
msb.order(ByteOrder.BIG_ENDIAN);
// Insert the 4 byte namespace into the time_low field
msb.putInt(0, namespace);
// Slice off the most significant two bytes of name
char nameHigh = (char)(name >>> 48);
// Push the 2 MSB bytes of name into the time_mid field
msb.putChar(4, nameHigh);
//Set the four most significant bits of the time_hi_and_version field to the 4 bit version number
//(00110000 = 48)
msb.put(7, (byte) 48);
// Grab the least significant six bytes of name
char nameMid = (char)(name >>> 32);
int nameLow = (int)(long)name;
// Shove them into the node field
lsb.putChar(2, nameMid);
lsb.putInt(4, nameLow);
//Set the two most significant bits to 01 (01000000 = 64)
lsb.put(0, (byte)64);
return new UUID(msb.getLong(), lsb.getLong());
}
/**
* Retrieve the integer namespace from a namespace uuid generated using this class
* @param uuid UUID generated using
* @return Namespace retrieved from the UUID
*/
public static Integer namespaceFromUUID(UUID uuid) {
return (int)(uuid.getMostSignificantBits() >>> 32);
}
/**
* Retrieve the integer name from a namespace uuid generated using this class
* @param uuid UUID generated using
* @return Name retrieved from the UUID
*/
public static Long nameFromUUID(UUID uuid) {
char msb = (char)((uuid.getMostSignificantBits() >>> 16) & 0xffff);
long out = uuid.getLeastSignificantBits() & 0xffffffffffffL;
return out | ((long)msb << 48);
}
static final long NUMBER_OF_100NS_INTERVALS_SINCE_UUID_EPOCH = 0x01b21dd213814000L;
public static DateTime getDateFromUUID(UUID uuid) {
return new DateTime(convertUUIDToJavaMillis(uuid), DateTimeZone.UTC);
}
public static Long convertUUIDToJavaMillis(UUID uuid){
return (uuid.timestamp() - NUMBER_OF_100NS_INTERVALS_SINCE_UUID_EPOCH) / 10000;
}
}
