org.argeo.api.uuid/src/org/argeo/api/uuid/NodeIdSupplier.java

   1 package org.argeo.api.uuid;
   2
   3 import java.security.SecureRandom;
   4 import java.util.function.Supplier;
   5
   6 /** A factory for node id base */
   7 public interface NodeIdSupplier extends Supplier<Long> {
   8         static long toNodeIdBase(byte[] node) {
   9                 assert node.length == 6;
  10                 return UuidFactory.LEAST_SIG_RFC4122_VARIANT | (node[0] & 0xFFL) //
  11                                 | ((node[1] & 0xFFL) << 8) //
  12                                 | ((node[2] & 0xFFL) << 16) //
  13                                 | ((node[3] & 0xFFL) << 24) //
  14                                 | ((node[4] & 0xFFL) << 32) //
  15                                 | ((node[5] & 0xFFL) << 40); //
  16         }
  17
  18         static boolean isNoMacAddressNodeId(byte[] nodeId) {
  19                 return (nodeId[0] & 1) != 0;
  20         }
  21
  22         static byte[] randomNodeId() {
  23                 SecureRandom random = new SecureRandom();
  24                 byte[] nodeId = new byte[6];
  25                 random.nextBytes(nodeId);
  26                 return nodeId;
  27         }
  28
  29         /**
  30          * Force this node id to be identified as no MAC address.
  31          *
  32          * @see "https://datatracker.ietf.org/doc/html/rfc4122#section-4.5"
  33          */
  34         static void forceToNoMacAddress(byte[] nodeId, int offset) {
  35                 assert nodeId != null && offset < nodeId.length;
  36                 nodeId[offset] = (byte) (nodeId[offset] | 1);
  37         }
  38
  39         /*
  40          * SPI UTILITIES
  41          */
  42         /** Guarantees that a byte array of length 6 will be returned. */
  43         static byte[] toNodeIdBytes(byte[] source, int offset) {
  44                 if (source == null)
  45                         return null;
  46                 if (offset < 0 || offset + 6 > source.length)
  47                         throw new ArrayIndexOutOfBoundsException(offset);
  48                 byte[] nodeId = new byte[6];
  49                 System.arraycopy(source, offset, nodeId, 0, 6);
  50                 return nodeId;
  51         }
  52 }