Prevent newly added sync status records from being deleted and process them incrementally

Frameworks/Account/CloudKit/CloudKitSendStatusOperation.swift

@@ -16,6 +16,7 @@ import SyncDatabase
 class CloudKitSendStatusOperation: MainThreadOperation {
 	
 	private var log = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "CloudKit")
+	private let blockSize = 300
 	
 	// MainThreadOperation
 	public var isCanceled = false
@@ -41,50 +42,60 @@ class CloudKitSendStatusOperation: MainThreadOperation {
 	func run() {
 		os_log(.debug, log: log, "Sending article statuses...")
 		
-		database.selectForProcessing { result in
+		if showProgress {
+			
+			database.selectPendingCount() { result in
+				switch result {
+				case .success(let count):
+					let ticks = count / self.blockSize
+					self.refreshProgress?.addToNumberOfTasksAndRemaining(ticks)
+					self.selectForProcessing()
+				case .failure(let databaseError):
+					os_log(.error, log: self.log, "Send status count pending error: %@.", databaseError.localizedDescription)
+					self.operationDelegate?.cancelOperation(self)
+				}
+			}
+			
+		} else {
+			
+			selectForProcessing()
+			
+		}
+		
+	}
+	
+}
+
+private extension CloudKitSendStatusOperation {
+	
+	func selectForProcessing() {
+		database.selectForProcessing(limit: blockSize) { result in
+			switch result {
+			case .success(let syncStatuses):
 				
-			func processStatuses(_ syncStatuses: [SyncStatus]) {
 				guard syncStatuses.count > 0 else {
+					if self.showProgress {
+						self.refreshProgress?.completeTask()
+					}
 					os_log(.debug, log: self.log, "Done sending article statuses.")
 					self.operationDelegate?.operationDidComplete(self)
 					return
 				}
 				
-				let group = DispatchGroup()
-				let syncStatusChunks = syncStatuses.chunked(into: 300)
-				
-				if self.showProgress {
-					self.refreshProgress?.addToNumberOfTasksAndRemaining(syncStatusChunks.count)
+				self.processStatuses(syncStatuses) {
+					self.selectForProcessing()
 				}
 				
-				for syncStatusChunk in syncStatusChunks {
-					group.enter()
-					self.sendArticleStatusChunk(syncStatuses: syncStatusChunk) {
-						group.leave()
-					}
-				}
-				
-				group.notify(queue: DispatchQueue.global(qos: .background)) {
-					os_log(.debug, log: self.log, "Done sending article statuses.")
-					DispatchQueue.main.async {
-						self.operationDelegate?.operationDidComplete(self)
-					}
-				}
-				
-			}
-
-			switch result {
-			case .success(let syncStatuses):
-				processStatuses(syncStatuses)
 			case .failure(let databaseError):
+				
 				os_log(.error, log: self.log, "Send status error: %@.", databaseError.localizedDescription)
 				self.operationDelegate?.cancelOperation(self)
+				
 			}
 		}
-		
 	}
 	
-	func sendArticleStatusChunk(syncStatuses: [SyncStatus], completion: @escaping () -> Void) {
+	func processStatuses(_ syncStatuses: [SyncStatus], completion: @escaping () -> Void) {
 		guard let account = account, let articlesZone = articlesZone else {
 			completion()
 			return
@@ -107,7 +118,8 @@ class CloudKitSendStatusOperation: MainThreadOperation {
 					switch result {
 					case .success:
 						self.database.deleteSelectedForProcessing(syncStatuses.map({ $0.articleID })) { _ in
-							if self.showProgress {
+							// Don't clear the last one since we might have had additional ticks added
+							if self.showProgress && self.refreshProgress?.numberRemaining ?? 0 > 1 {
 								self.refreshProgress?.completeTask()
 							}
 							os_log(.debug, log: self.log, "Done sending article status block...")

Frameworks/SyncDatabase/SyncDatabase.swift

@@ -36,8 +36,8 @@ public struct SyncDatabase {
 		try syncStatusTable.insertStatuses(statuses)
 	}
 	
-	public func selectForProcessing(completion: @escaping SyncStatusesCompletionBlock) {
-		return syncStatusTable.selectForProcessing(completion)
+	public func selectForProcessing(limit: Int? = nil, completion: @escaping SyncStatusesCompletionBlock) {
+		return syncStatusTable.selectForProcessing(limit: limit, completion: completion)
 	}
 
 	public func selectPendingCount(completion: @escaping DatabaseIntCompletionBlock) {

Frameworks/SyncDatabase/SyncStatusTable.swift

@@ -20,7 +20,7 @@ struct SyncStatusTable: DatabaseTable {
 		self.queue = queue
 	}
 
-	func selectForProcessing(_ completion: @escaping SyncStatusesCompletionBlock) {
+	func selectForProcessing(limit: Int?, completion: @escaping SyncStatusesCompletionBlock) {
 		queue.runInTransaction { databaseResult in
 			var statuses = Set<SyncStatus>()
 			var error: DatabaseError?
@@ -29,7 +29,10 @@ struct SyncStatusTable: DatabaseTable {
 				let updateSQL = "update syncStatus set selected = true"
 				database.executeUpdate(updateSQL, withArgumentsIn: nil)
 
-				let selectSQL = "select * from syncStatus where selected == true"
+				var selectSQL = "select * from syncStatus where selected == true"
+				if let limit = limit {
+					selectSQL = "\(selectSQL) limit \(limit)"
+				}
 				if let resultSet = database.executeQuery(selectSQL, withArgumentsIn: nil) {
 					statuses = resultSet.mapToSet(self.statusWithRow)
 				}
@@ -135,7 +138,7 @@ struct SyncStatusTable: DatabaseTable {
 			func makeDatabaseCall(_ database: FMDatabase) {
 				let parameters = articleIDs.map { $0 as AnyObject }
 				let placeholders = NSString.rs_SQLValueList(withPlaceholders: UInt(articleIDs.count))!
-				let deleteSQL = "delete from syncStatus where articleID in \(placeholders)"
+				let deleteSQL = "delete from syncStatus where selected = true and articleID in \(placeholders)"
 				database.executeUpdate(deleteSQL, withArgumentsIn: parameters)
 			}