keychain/ckks/CKKSNearFutureScheduler.h

   1 /*
   2  * Copyright (c) 2017 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 #import <Foundation/Foundation.h>
  25 #import <dispatch/dispatch.h>
  26
  27 /*
  28  * The CKKSNearFutureScheduler is intended to rate-limit an operation. When
  29  * triggered, it will schedule the operation to take place in the future.
  30  * Further triggers during the delay period will not cause the operation to
  31  * occur again, but they may cause the delay period to extend.
  32  *
  33  * Triggers after the delay period will start another delay period.
  34  */
  35
  36 @interface CKKSNearFutureScheduler : NSObject
  37
  38 @property (readonly) NSDate* nextFireTime;
  39 @property void (^futureOperation)(void);
  40
  41 -(instancetype)initWithName:(NSString*)name
  42                       delay:(dispatch_time_t)ns
  43            keepProcessAlive:(bool)keepProcessAlive
  44                       block:(void (^)(void))futureOperation;
  45
  46 -(instancetype)initWithName:(NSString*)name
  47                initialDelay:(dispatch_time_t)initialDelay
  48             continuingDelay:(dispatch_time_t)continuingDelay
  49            keepProcessAlive:(bool)keepProcessAlive
  50                       block:(void (^)(void))futureOperation;
  51
  52 -(void)trigger;
  53
  54 -(void)cancel;
  55
  56 // Don't trigger again until at least this much time has passed.
  57 -(void)waitUntil:(uint64_t)delay;
  58
  59 @end