Update of Mongo's ObjectID for ActionScript (from ActionBSON)

ObjectID.as

/*
 * Copyright (c) 2010 Claudio Alberto Andreoni.
 * Modifications by Eric Socolofsky: http://transmote.com.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */

package org.serialization.bson {
	import flash.net.NetworkInfo;
	import flash.net.NetworkInterface;
	import flash.utils.ByteArray;
	import flash.utils.Endian;

	public class ObjectID {
		private static var incrementer : uint = Math.random() * uint.MAX_VALUE;
		private static var machineAndProcessID : ByteArray = null;

		// BSON is little-endian
		private var rep : ByteArray;
		private var time : uint;

		/**
		 * @brief Create a new ObjectID
		 * @param bytearray A little-endian, 12-byte ByteArray containing the ID
		 */
		public function ObjectID( bytearray : ByteArray = null ) :void {
			if (bytearray == null) {
				bytearray = generateObjectID();
			}
			setFromBytes( bytearray );
		}



		/**
		 * @brief Set the value of this ObjectID
		 * @param bytearray A little-endian, 12-byte ByteArray containing the ID
		 */
		public function setFromBytes( bytearray : ByteArray ) :void {
			rep = new ByteArray();
			for ( var i : int = 0; i < 12; ++i ) {
				rep[i] = bytearray.readByte();
			}
			
			time = rep.readUnsignedInt();
			rep.position = 0;
		}



		/**
		 * @brief Get the value of this ObjectID
		 * @return A little-endian, 12-byte ByteArray containing the ID
		 */
		public function getAsBytes() : ByteArray {
			return rep;
		}

		public function toString() : String {
			var str:String = "";
			for ( var i : int = 0; i < 12; ++i ) {
				str += rep[i].toString( 16 );
			}
			return str;
		}
		
		public function toDate() : Date {
			return new Date( time * 1000 );
		}
		
		private function generateObjectID() :ByteArray {
			// from: http://www.mongodb.org/display/DOCS/Object+IDs
			
			// 4-byte timestamp
			time = new Date().getTime();
			var timeBytes:ByteArray = new ByteArray();
			timeBytes.endian = Endian.BIG_ENDIAN;
			timeBytes.writeInt( time );
			timeBytes.length = 4;	// truncate as needed
			
			// 3-byte machine id + 2-byte process id
			if ( machineAndProcessID == null ) {
				generateMachineID();
			}
			
			// 3-byte increment
			var incBytes:ByteArray = new ByteArray();
			incBytes.endian = Endian.BIG_ENDIAN;
			incBytes.writeUnsignedInt( incrementer++ );
			incBytes.length = 3;		// truncate as needed
			
			var idBytes:ByteArray = new ByteArray();
			idBytes.writeBytes( timeBytes );
			idBytes.writeBytes( machineAndProcessID );
			idBytes.writeBytes( incBytes );
			
			idBytes.position = 0;
			return idBytes;
		}
		
		private function generateMachineID() :void {
			machineAndProcessID = new ByteArray();
			machineAndProcessID.endian = Endian.LITTLE_ENDIAN;
			
			var useRandom:Boolean = true;
			for each ( var i : NetworkInterface in NetworkInfo.networkInfo.findInterfaces() ) {
				if ( i.hardwareAddress ) {
					machineAndProcessID.writeUTFBytes( i.hardwareAddress );
					useRandom = false;
					break;
				}
			}
			
			if ( useRandom ) {
				// if no NetworkInterfaces with valid hardware addresses found, use random
				var randomMachineID : uint = Math.floor( Math.random() * uint.MAX_VALUE );
				machineAndProcessID.writeUnsignedInt( randomMachineID );
			}
			
			machineAndProcessID.length = 3;		// truncate as needed
			
			// not possible to get process id from flash without launching a NativeProcess,
			// which requires AIR application with extendedDesktop profile.
			// so, use a random.
			var processID:uint = Math.floor( Math.random() * uint.MAX_VALUE );
			machineAndProcessID.writeUnsignedInt( processID );
			
			machineAndProcessID.length = 5;		// truncate as needed
		}
	}
}

i'm working with AIR, and neglected to notice that my solution is AIR-specific.
i believe omar is working on a non-AIR-specific solution to generating the machine+process ID portion of an ObjectID, not sure which route he's taking. in the meantime, you'll have to edit out the NetworkInfo and NetworkInterface parts and use the block within if ( useRandom ) { } instead.