Merge pull request #1295 from kielgillard/cancellation-improvements

Improves the behaviour and fixes some issues…

Frameworks/Account/Feedly/Operations/FeedlyOperation.swift

@@ -21,8 +21,8 @@ class FeedlyOperation: Operation {
 	func didFinish() {
 		assert(Thread.isMainThread)
 		assert(!isFinished, "Finished operation is attempting to finish again.")
-		self.isExecutingOperation = false
+		isExecutingOperation = false
-		self.isFinishedOperation = true
+		isFinishedOperation = true
 	}
 	
 	func didFinish(_ error: Error) {
@@ -33,16 +33,18 @@ class FeedlyOperation: Operation {
 	}
 	
 	override func start() {
+		guard !isCancelled else {
+			isExecutingOperation = false
+			isFinishedOperation = true
+			return
+		}
+		
 		isExecutingOperation = true
 		DispatchQueue.main.async {
 			self.main()
 		}
 	}
 	
-	override func cancel() {
-		super.cancel()
-	}
-	
 	override var isExecuting: Bool {
 		return isExecutingOperation
 	}

Frameworks/Account/Feedly/Operations/FeedlySyncAllOperation.swift

@@ -94,10 +94,9 @@ final class FeedlySyncAllOperation: FeedlyOperation {
 		os_log(.debug, log: log, "Cancelling sync %{public}@", syncUUID.uuidString)
 		self.operationQueue.cancelAllOperations()
 		
-		syncCompletionHandler?(.failure(URLError(.cancelled)))
+		super.cancel()
-		syncCompletionHandler = nil
 		
-		self.didFinish()
+		didFinish()
 	}
 	
 	override func main() {

Frameworks/Account/Feedly/Operations/FeedlySyncStarredArticlesOperation.swift

@@ -96,13 +96,15 @@ final class FeedlySyncStarredArticlesOperation: FeedlyOperation, FeedlyOperation
 	}
 	
 	override func cancel() {
+		os_log(.debug, log: log, "Canceling sync starred articles")
 		operationQueue.cancelAllOperations()
 		super.cancel()
+		didFinish()
 	}
 	
 	override func main() {
 		guard !isCancelled else {
-			didFinish()
+			// override of cancel calls didFinish().
 			return
 		}
 		
@@ -110,6 +112,11 @@ final class FeedlySyncStarredArticlesOperation: FeedlyOperation, FeedlyOperation
 	}
 	
 	func feedlyGetStreamContentsOperation(_ operation: FeedlyGetStreamContentsOperation, didGetContentsOf stream: FeedlyStream) {
+		guard !isCancelled else {
+			os_log(.debug, log: log, "Cancelled starred stream contents for %@", stream.id)
+			return
+		}
+		
 		entryProvider.addEntries(from: operation)
 		os_log(.debug, log: log, "Collecting %i items from %@", stream.items.count, stream.id)
 		

Frameworks/Account/Feedly/Operations/FeedlySyncStreamContentsOperation.swift

@@ -42,13 +42,15 @@ final class FeedlySyncStreamContentsOperation: FeedlyOperation, FeedlyOperationD
 	}
 	
 	override func cancel() {
+		os_log(.debug, log: log, "Canceling sync stream contents")
 		operationQueue.cancelAllOperations()
 		super.cancel()
+		didFinish()
 	}
 	
 	override func main() {
 		guard !isCancelled else {
-			didFinish()
+			// override of cancel calls didFinish().
 			return
 		}
 		
@@ -92,6 +94,11 @@ final class FeedlySyncStreamContentsOperation: FeedlyOperation, FeedlyOperationD
 	}
 	
 	func feedlyGetStreamContentsOperation(_ operation: FeedlyGetStreamContentsOperation, didGetContentsOf stream: FeedlyStream) {
+		guard !isCancelled else {
+			os_log(.debug, log: log, "Cancelled requesting page for %@", resource.id)
+			return
+		}
+		
 		os_log(.debug, log: log, "Ingesting %i items from %@", stream.items.count, stream.id)
 		
 		guard let continuation = stream.continuation else {

Frameworks/Account/Feedly/Operations/FeedlySyncUnreadStatusesOperation.swift

@@ -77,13 +77,15 @@ final class FeedlySyncUnreadStatusesOperation: FeedlyOperation, FeedlyOperationD
 	}
 	
 	override func cancel() {
+		os_log(.debug, log: log, "Canceling sync unread statuses")
 		operationQueue.cancelAllOperations()
 		super.cancel()
+		didFinish()
 	}
 	
 	override func main() {
 		guard !isCancelled else {
-			didFinish()
+			// override of cancel calls didFinish().
 			return
 		}
 		
@@ -91,6 +93,11 @@ final class FeedlySyncUnreadStatusesOperation: FeedlyOperation, FeedlyOperationD
 	}
 	
 	func feedlyGetStreamIdsOperation(_ operation: FeedlyGetStreamIdsOperation, didGet streamIds: FeedlyStreamIds) {
+		guard !isCancelled else {
+			os_log(.debug, log: log, "Cancelled unread stream ids.")
+			return
+		}
+		
 		os_log(.debug, log: log, "Collecting %i unread article ids from %@", streamIds.ids.count, resource.id)
 		unreadEntryIdsProvider.addEntryIds(from: operation)