keychain/ot/OctagonStateMachineHelpers.h

   1 /*
   2  * Copyright (c) 2018 Apple 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 #if OCTAGON
  25
  26 #import <Foundation/Foundation.h>
  27 #import "keychain/ckks/CKKSResultOperation.h"
  28 #import "keychain/ckks/CKKSAnalytics.h"
  29
  30 NS_ASSUME_NONNULL_BEGIN
  31
  32 @protocol OctagonStateString <NSObject>
  33 @end
  34 typedef NSString<OctagonStateString> OctagonState;
  35
  36 @protocol OctagonFlagString <NSObject>
  37 @end
  38 typedef NSString<OctagonFlagString> OctagonFlag;
  39
  40 // NotStarted indicates that this state machine is not yet started
  41 extern OctagonState* const OctagonStateMachineNotStarted;
  42
  43 // Halted indicates that the state machine is halted, and won't move again
  44 extern OctagonState* const OctagonStateMachineHalted;
  45
  46 @protocol OctagonStateTransitionOperationProtocol
  47 // Holds this operation's opinion of the next state, given that this operation just ran
  48 @property OctagonState* nextState;
  49
  50 // Hold the state this operation was originally hoping to enter
  51 @property (readonly) OctagonState* intendedState;
  52 @end
  53
  54
  55 @interface OctagonStateTransitionOperation : CKKSResultOperation <OctagonStateTransitionOperationProtocol>
  56 @property OctagonState* nextState;
  57 @property (readonly) OctagonState* intendedState;
  58
  59 + (instancetype)named:(NSString*)name
  60             intending:(OctagonState*)intendedState
  61            errorState:(OctagonState*)errorState
  62   withBlockTakingSelf:(void(^)(OctagonStateTransitionOperation* op))block;
  63
  64 // convenience constructor. Will always succeed at entering the state.
  65 + (instancetype)named:(NSString*)name
  66              entering:(OctagonState*)intendedState NS_SWIFT_NAME(init(name:entering:));
  67 @end
  68
  69
  70 @interface OctagonStateTransitionRequest<__covariant OperationType : CKKSResultOperation<OctagonStateTransitionOperationProtocol>*> : NSObject
  71 @property (readonly) NSString* name;
  72 @property (readonly) NSSet<OctagonState*>* sourceStates;
  73 @property (readonly) OperationType transitionOperation;
  74
  75 - (instancetype)timeout:(dispatch_time_t)timeout;
  76 - (OperationType _Nullable)_onqueueStart;
  77
  78 - (instancetype)init:(NSString*)name
  79         sourceStates:(NSSet<OctagonState*>*)sourceStates
  80          serialQueue:(dispatch_queue_t)queue
  81              timeout:(dispatch_time_t)timeout
  82         transitionOp:(OperationType)transitionOp;
  83 @end
  84
  85 NS_ASSUME_NONNULL_END
  86
  87 #endif // OCTAGON