1/* 2 * Copyright (c) 2004 Apple Computer, Inc. All Rights Reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. Please obtain a copy of the License at 10 * http://www.opensource.apple.com/apsl/ and read it before using this 11 * file. 12 * 13 * The Original Code and all software distributed under the License are 14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 18 * Please see the License for the specific language governing rights and 19 * limitations under the License. 20 * 21 * @APPLE_LICENSE_HEADER_END@ 22 */ 23 24 25// 26// transactions - generic transaction frame support 27// 28#ifndef _H_TRANSACTIONS 29#define _H_TRANSACTIONS 30 31#include <security_utilities/utilities.h> 32#include <security_utilities/debugging.h> 33 34 35namespace Security { 36 37 38// 39// Implementation base class. Do not use directly. 40// 41class TransactionBase { 42public: 43 // what happens if this object gets destroyed? 44 enum Outcome { 45 successful, // succeeds as set 46 cancelled, // cancelled (rolled back) 47 conditional // succeeds normally, cancelled on exception 48 }; 49 50public: 51 virtual ~TransactionBase(); 52 53 void outcome(Outcome oc) { mOutcome = oc; } 54 Outcome outcome() const { return mOutcome; } 55 56protected: 57 TransactionBase(Outcome outcome) : mOutcome(outcome) { } 58 59 Outcome finalOutcome() const; 60 61private: 62 Outcome mOutcome; // current outcome setting 63}; 64 65 66// 67// A ManagedTransaction will call methods begin() and end() on the Carrier object 68// it belongs to, and manage the "outcome" state and semantics automatically. 69// You would usually subclass this, though the class is complete in itself if you 70// need nothing else out of your transaction objects. 71// 72template <class Carrier> 73class ManagedTransaction : public TransactionBase { 74public: 75 ManagedTransaction(Carrier &carrier, Outcome outcome = conditional) 76 : TransactionBase(outcome), mCarrier(carrier) 77 { 78 carrier.begin(); 79 } 80 81 ~ManagedTransaction() 82 { 83 switch (finalOutcome()) { 84 case successful: 85 this->commitAction(); 86 break; 87 case cancelled: 88 this->cancelAction(); 89 break; 90 default: 91 assert(false); 92 break; 93 } 94 } 95 96protected: 97 virtual void commitAction() { mCarrier.end(); } 98 virtual void cancelAction() { mCarrier.cancel(); } 99 100 Carrier &mCarrier; 101}; 102 103 104} // end namespace Security 105 106 107#endif //_H_TRANSACTIONS 108