Umesh Krishnaswamy | 345ee99 | 2012-12-13 20:29:48 -0800 | [diff] [blame] | 1 | /** |
| 2 | * Copyright 2011, Big Switch Networks, Inc. |
| 3 | * Originally created by David Erickson, Stanford University |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 6 | * not use this file except in compliance with the License. You may obtain |
| 7 | * a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 13 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 14 | * License for the specific language governing permissions and limitations |
| 15 | * under the License. |
| 16 | **/ |
| 17 | |
| 18 | package net.floodlightcontroller.core.util; |
| 19 | |
| 20 | /*** |
| 21 | * FIXME Need a system for registering/binding applications to a unique ID |
| 22 | * |
| 23 | * @author capveg |
| 24 | * |
| 25 | */ |
| 26 | |
| 27 | public class AppCookie { |
| 28 | static final int APP_ID_BITS = 12; |
| 29 | static final int APP_ID_SHIFT = (64 - APP_ID_BITS); |
| 30 | // we have bits 13-31 unused here ... that's ok! |
| 31 | static final int USER_BITS = 32; |
| 32 | static final int USER_SHIFT = 0; |
| 33 | |
| 34 | |
| 35 | /** |
| 36 | * Encapsulate an application ID and a user block of stuff into a cookie |
| 37 | * |
| 38 | * @param application An ID to identify the application |
| 39 | * @param user Some application specific data |
| 40 | * @return a cookie for use in OFFlowMod.setCookie() |
| 41 | */ |
| 42 | |
| 43 | static public long makeCookie(int application, int user) { |
| 44 | return ((application & ((1L << APP_ID_BITS) - 1)) << APP_ID_SHIFT) | user; |
| 45 | } |
| 46 | |
| 47 | static public int extractApp(long cookie) { |
| 48 | return (int)((cookie>> APP_ID_SHIFT) & ((1L << APP_ID_BITS) - 1)); |
| 49 | } |
| 50 | |
| 51 | static public int extractUser(long cookie) { |
| 52 | return (int)((cookie>> USER_SHIFT) & ((1L << USER_BITS) - 1)); |
| 53 | } |
| 54 | } |