| commit | author | age | ||
| bad748 | 1 | /* |
| W | 2 | * Copyright (c) 2014, Facebook, Inc. |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * This source code is licensed under the BSD-style license found in the | |
| 6 | * LICENSE file in the root directory of this source tree. An additional grant | |
| 7 | * of patent rights can be found in the PATENTS file in the same directory. | |
| 8 | * | |
| 9 | */ | |
| 10 | ||
| 11 | #import <Foundation/Foundation.h> | |
| 12 | ||
| 13 | #import <Bolts/BFCancellationToken.h> | |
| 14 | ||
| 15 | NS_ASSUME_NONNULL_BEGIN | |
| 16 | ||
| 17 | /*! | |
| 18 | Error domain used if there was multiple errors on <BFTask taskForCompletionOfAllTasks:>. | |
| 19 | */ | |
| 20 | extern NSString *const BFTaskErrorDomain; | |
| 21 | ||
| 22 | /*! | |
| 23 | An error code used for <BFTask taskForCompletionOfAllTasks:>, if there were multiple errors. | |
| 24 | */ | |
| 25 | extern NSInteger const kBFMultipleErrorsError; | |
| 26 | ||
| 27 | /*! | |
| 28 | An exception that is thrown if there was multiple exceptions on <BFTask taskForCompletionOfAllTasks:>. | |
| 29 | */ | |
| 30 | extern NSString *const BFTaskMultipleExceptionsException; | |
| 31 | ||
| 32 | /*! | |
| 33 | An error userInfo key used if there were multiple errors on <BFTask taskForCompletionOfAllTasks:>. | |
| 34 | Value type is `NSArray<NSError *> *`. | |
| 35 | */ | |
| 36 | extern NSString *const BFTaskMultipleErrorsUserInfoKey; | |
| 37 | ||
| 38 | /*! | |
| 39 | An error userInfo key used if there were multiple exceptions on <BFTask taskForCompletionOfAllTasks:>. | |
| 40 | Value type is `NSArray<NSException *> *`. | |
| 41 | */ | |
| 42 | extern NSString *const BFTaskMultipleExceptionsUserInfoKey; | |
| 43 | ||
| 44 | @class BFExecutor; | |
| 45 | @class BFTask; | |
| 46 | ||
| 47 | /*! | |
| 48 | The consumer view of a Task. A BFTask has methods to | |
| 49 | inspect the state of the task, and to add continuations to | |
| 50 | be run once the task is complete. | |
| 51 | */ | |
| 52 | @interface BFTask<__covariant ResultType> : NSObject | |
| 53 | ||
| 54 | /*! | |
| 55 | A block that can act as a continuation for a task. | |
| 56 | */ | |
| 57 | typedef __nullable id(^BFContinuationBlock)(BFTask<ResultType> *task); | |
| 58 | ||
| 59 | /*! | |
| 60 | Creates a task that is already completed with the given result. | |
| 61 | @param result The result for the task. | |
| 62 | */ | |
| 63 | + (instancetype)taskWithResult:(nullable ResultType)result; | |
| 64 | ||
| 65 | /*! | |
| 66 | Creates a task that is already completed with the given error. | |
| 67 | @param error The error for the task. | |
| 68 | */ | |
| 69 | + (instancetype)taskWithError:(NSError *)error; | |
| 70 | ||
| 71 | /*! | |
| 72 | Creates a task that is already completed with the given exception. | |
| 73 | @param exception The exception for the task. | |
| 74 | */ | |
| 75 | + (instancetype)taskWithException:(NSException *)exception; | |
| 76 | ||
| 77 | /*! | |
| 78 | Creates a task that is already cancelled. | |
| 79 | */ | |
| 80 | + (instancetype)cancelledTask; | |
| 81 | ||
| 82 | /*! | |
| 83 | Returns a task that will be completed (with result == nil) once | |
| 84 | all of the input tasks have completed. | |
| 85 | @param tasks An `NSArray` of the tasks to use as an input. | |
| 86 | */ | |
| 87 | + (instancetype)taskForCompletionOfAllTasks:(nullable NSArray<BFTask *> *)tasks; | |
| 88 | ||
| 89 | /*! | |
| 90 | Returns a task that will be completed once all of the input tasks have completed. | |
| 91 | If all tasks complete successfully without being faulted or cancelled the result will be | |
| 92 | an `NSArray` of all task results in the order they were provided. | |
| 93 | @param tasks An `NSArray` of the tasks to use as an input. | |
| 94 | */ | |
| 95 | + (instancetype)taskForCompletionOfAllTasksWithResults:(nullable NSArray<BFTask *> *)tasks; | |
| 96 | ||
| 97 | /*! | |
| 98 | Returns a task that will be completed once there is at least one successful task. | |
| 99 | The first task to successuly complete will set the result, all other tasks results are | |
| 100 | ignored. | |
| 101 | @param tasks An `NSArray` of the tasks to use as an input. | |
| 102 | */ | |
| 103 | + (instancetype)taskForCompletionOfAnyTask:(nullable NSArray<BFTask *> *)tasks; | |
| 104 | ||
| 105 | /*! | |
| 106 | Returns a task that will be completed a certain amount of time in the future. | |
| 107 | @param millis The approximate number of milliseconds to wait before the | |
| 108 | task will be finished (with result == nil). | |
| 109 | */ | |
| 110 | + (instancetype)taskWithDelay:(int)millis; | |
| 111 | ||
| 112 | /*! | |
| 113 | Returns a task that will be completed a certain amount of time in the future. | |
| 114 | @param millis The approximate number of milliseconds to wait before the | |
| 115 | task will be finished (with result == nil). | |
| 116 | @param token The cancellation token (optional). | |
| 117 | */ | |
| 118 | + (instancetype)taskWithDelay:(int)millis cancellationToken:(nullable BFCancellationToken *)token; | |
| 119 | ||
| 120 | /*! | |
| 121 | Returns a task that will be completed after the given block completes with | |
| 122 | the specified executor. | |
| 123 | @param executor A BFExecutor responsible for determining how the | |
| 124 | continuation block will be run. | |
| 125 | @param block The block to immediately schedule to run with the given executor. | |
| 126 | @returns A task that will be completed after block has run. | |
| 127 | If block returns a BFTask, then the task returned from | |
| 128 | this method will not be completed until that task is completed. | |
| 129 | */ | |
| 130 | + (instancetype)taskFromExecutor:(BFExecutor *)executor withBlock:(nullable id (^)())block; | |
| 131 | ||
| 132 | // Properties that will be set on the task once it is completed. | |
| 133 | ||
| 134 | /*! | |
| 135 | The result of a successful task. | |
| 136 | */ | |
| 137 | @property (nullable, nonatomic, strong, readonly) ResultType result; | |
| 138 | ||
| 139 | /*! | |
| 140 | The error of a failed task. | |
| 141 | */ | |
| 142 | @property (nullable, nonatomic, strong, readonly) NSError *error; | |
| 143 | ||
| 144 | /*! | |
| 145 | The exception of a failed task. | |
| 146 | */ | |
| 147 | @property (nullable, nonatomic, strong, readonly) NSException *exception; | |
| 148 | ||
| 149 | /*! | |
| 150 | Whether this task has been cancelled. | |
| 151 | */ | |
| 152 | @property (nonatomic, assign, readonly, getter=isCancelled) BOOL cancelled; | |
| 153 | ||
| 154 | /*! | |
| 155 | Whether this task has completed due to an error or exception. | |
| 156 | */ | |
| 157 | @property (nonatomic, assign, readonly, getter=isFaulted) BOOL faulted; | |
| 158 | ||
| 159 | /*! | |
| 160 | Whether this task has completed. | |
| 161 | */ | |
| 162 | @property (nonatomic, assign, readonly, getter=isCompleted) BOOL completed; | |
| 163 | ||
| 164 | /*! | |
| 165 | Enqueues the given block to be run once this task is complete. | |
| 166 | This method uses a default execution strategy. The block will be | |
| 167 | run on the thread where the previous task completes, unless the | |
| 168 | the stack depth is too deep, in which case it will be run on a | |
| 169 | dispatch queue with default priority. | |
| 170 | @param block The block to be run once this task is complete. | |
| 171 | @returns A task that will be completed after block has run. | |
| 172 | If block returns a BFTask, then the task returned from | |
| 173 | this method will not be completed until that task is completed. | |
| 174 | */ | |
| 175 | - (BFTask *)continueWithBlock:(BFContinuationBlock)block; | |
| 176 | ||
| 177 | /*! | |
| 178 | Enqueues the given block to be run once this task is complete. | |
| 179 | This method uses a default execution strategy. The block will be | |
| 180 | run on the thread where the previous task completes, unless the | |
| 181 | the stack depth is too deep, in which case it will be run on a | |
| 182 | dispatch queue with default priority. | |
| 183 | @param block The block to be run once this task is complete. | |
| 184 | @param cancellationToken The cancellation token (optional). | |
| 185 | @returns A task that will be completed after block has run. | |
| 186 | If block returns a BFTask, then the task returned from | |
| 187 | this method will not be completed until that task is completed. | |
| 188 | */ | |
| 189 | - (BFTask *)continueWithBlock:(BFContinuationBlock)block cancellationToken:(nullable BFCancellationToken *)cancellationToken; | |
| 190 | ||
| 191 | /*! | |
| 192 | Enqueues the given block to be run once this task is complete. | |
| 193 | @param executor A BFExecutor responsible for determining how the | |
| 194 | continuation block will be run. | |
| 195 | @param block The block to be run once this task is complete. | |
| 196 | @returns A task that will be completed after block has run. | |
| 197 | If block returns a BFTask, then the task returned from | |
| 198 | this method will not be completed until that task is completed. | |
| 199 | */ | |
| 200 | - (BFTask *)continueWithExecutor:(BFExecutor *)executor withBlock:(BFContinuationBlock)block; | |
| 201 | /*! | |
| 202 | Enqueues the given block to be run once this task is complete. | |
| 203 | @param executor A BFExecutor responsible for determining how the | |
| 204 | continuation block will be run. | |
| 205 | @param block The block to be run once this task is complete. | |
| 206 | @param cancellationToken The cancellation token (optional). | |
| 207 | @returns A task that will be completed after block has run. | |
| 208 | If block returns a BFTask, then the task returned from | |
| 209 | his method will not be completed until that task is completed. | |
| 210 | */ | |
| 211 | - (BFTask *)continueWithExecutor:(BFExecutor *)executor | |
| 212 | block:(BFContinuationBlock)block | |
| 213 | cancellationToken:(nullable BFCancellationToken *)cancellationToken; | |
| 214 | ||
| 215 | /*! | |
| 216 | Identical to continueWithBlock:, except that the block is only run | |
| 217 | if this task did not produce a cancellation, error, or exception. | |
| 218 | If it did, then the failure will be propagated to the returned | |
| 219 | task. | |
| 220 | @param block The block to be run once this task is complete. | |
| 221 | @returns A task that will be completed after block has run. | |
| 222 | If block returns a BFTask, then the task returned from | |
| 223 | this method will not be completed until that task is completed. | |
| 224 | */ | |
| 225 | - (BFTask *)continueWithSuccessBlock:(BFContinuationBlock)block; | |
| 226 | ||
| 227 | /*! | |
| 228 | Identical to continueWithBlock:, except that the block is only run | |
| 229 | if this task did not produce a cancellation, error, or exception. | |
| 230 | If it did, then the failure will be propagated to the returned | |
| 231 | task. | |
| 232 | @param block The block to be run once this task is complete. | |
| 233 | @param cancellationToken The cancellation token (optional). | |
| 234 | @returns A task that will be completed after block has run. | |
| 235 | If block returns a BFTask, then the task returned from | |
| 236 | this method will not be completed until that task is completed. | |
| 237 | */ | |
| 238 | - (BFTask *)continueWithSuccessBlock:(BFContinuationBlock)block cancellationToken:(nullable BFCancellationToken *)cancellationToken; | |
| 239 | ||
| 240 | /*! | |
| 241 | Identical to continueWithExecutor:withBlock:, except that the block | |
| 242 | is only run if this task did not produce a cancellation, error, or | |
| 243 | exception. If it did, then the failure will be propagated to the | |
| 244 | returned task. | |
| 245 | @param executor A BFExecutor responsible for determining how the | |
| 246 | continuation block will be run. | |
| 247 | @param block The block to be run once this task is complete. | |
| 248 | @returns A task that will be completed after block has run. | |
| 249 | If block returns a BFTask, then the task returned from | |
| 250 | this method will not be completed until that task is completed. | |
| 251 | */ | |
| 252 | - (BFTask *)continueWithExecutor:(BFExecutor *)executor withSuccessBlock:(BFContinuationBlock)block; | |
| 253 | ||
| 254 | /*! | |
| 255 | Identical to continueWithExecutor:withBlock:, except that the block | |
| 256 | is only run if this task did not produce a cancellation, error, or | |
| 257 | exception. If it did, then the failure will be propagated to the | |
| 258 | returned task. | |
| 259 | @param executor A BFExecutor responsible for determining how the | |
| 260 | continuation block will be run. | |
| 261 | @param block The block to be run once this task is complete. | |
| 262 | @param cancellationToken The cancellation token (optional). | |
| 263 | @returns A task that will be completed after block has run. | |
| 264 | If block returns a BFTask, then the task returned from | |
| 265 | this method will not be completed until that task is completed. | |
| 266 | */ | |
| 267 | - (BFTask *)continueWithExecutor:(BFExecutor *)executor | |
| 268 | successBlock:(BFContinuationBlock)block | |
| 269 | cancellationToken:(nullable BFCancellationToken *)cancellationToken; | |
| 270 | ||
| 271 | /*! | |
| 272 | Waits until this operation is completed. | |
| 273 | This method is inefficient and consumes a thread resource while | |
| 274 | it's running. It should be avoided. This method logs a warning | |
| 275 | message if it is used on the main thread. | |
| 276 | */ | |
| 277 | - (void)waitUntilFinished; | |
| 278 | ||
| 279 | @end | |
| 280 | ||
| 281 | NS_ASSUME_NONNULL_END | |
