Move the operation queue from Account to ArticlesDatabase, which is the rightful owner.

Frameworks/Account/Account.swift

@@ -231,14 +231,6 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 		return delegate.refreshProgress
 	}
 
-	private var operationQueue = MainThreadOperationQueue()
-	private enum OperationName {
-		static let FetchAllUnreadCounts = "FetchAllUnreadCounts"
-		static let FetchFeedUnreadCount = "FetchFeedUnreadCount"
-		static let FetchUnreadCountsForFeeds = "FetchUnreadCountsForFeeds"
-	}
-	private static let discardableOperationNames = [OperationName.FetchAllUnreadCounts, OperationName.FetchFeedUnreadCount, OperationName.FetchUnreadCountsForFeeds]
-	
 	init?(dataFolder: String, type: AccountType, accountID: String, transport: Transport? = nil) {
 		switch type {
 		case .onMyMac:
@@ -422,9 +414,7 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 	}
 	
 	public func suspendDatabase() {
-		operationQueue.suspend()
-		cancelDiscardableOperations()
-		database.suspend()
+		database.cancelAndSuspend()
 		save()
 		metadataFile.suspend()
 		webFeedMetadataFile.suspend()
@@ -436,7 +426,6 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 	public func resumeDatabaseAndDelegate() {
 		database.resume()
 		delegate.resume()
-		operationQueue.resume()
 	}
 
 	/// Reload OPML, etc.
@@ -460,12 +449,6 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 		delegate.accountWillBeDeleted(self)
 	}
 
-	public func cancelDiscardableOperations() {
-		for operationName in Self.discardableOperationNames {
-			operationQueue.cancelOperations(named: operationName)
-		}
-	}
-	
 	func loadOPMLItems(_ items: [RSOPMLItem], parentFolder: Folder?) {
 		var feedsToAdd = Set<WebFeed>()
 
@@ -1242,43 +1225,34 @@ private extension Account {
 			fetchUnreadCounts(feeds, completion)
 		}
 		else {
-			fetchAllUnreadCounts()
+			fetchAllUnreadCounts(completion)
 		}
 	}
 
 	func fetchUnreadCount(_ feed: WebFeed, _ completion: VoidCompletionBlock?) {
-		let operation = database.createFetchFeedUnreadCountOperation(feedID: feed.webFeedID)
-		operation.name = OperationName.FetchFeedUnreadCount
-		operation.completionBlock = { operation in
-			let fetchOperation = operation as! FetchFeedUnreadCountOperation
-			if let unreadCount = fetchOperation.unreadCount {
+		database.fetchUnreadCount(feed.webFeedID) { result in
+			if let unreadCount = try? result.get() {
 				feed.unreadCount = unreadCount
 			}
 			completion?()
 		}
-
-		operationQueue.add(operation)
 	}
 
 	func fetchUnreadCounts(_ feeds: Set<WebFeed>, _ completion: VoidCompletionBlock?) {
-		let feedIDs = feeds.map { $0.webFeedID }
-		let operation = database.createFetchUnreadCountsForFeedsOperation(feedIDs: Set(feedIDs))
-		operation.name = OperationName.FetchUnreadCountsForFeeds
-		operation.completionBlock = { operation in
-			let fetchOperation = operation as! FetchUnreadCountsForFeedsOperation
-			if let unreadCountDictionary = fetchOperation.unreadCountDictionary {
+		let webFeedIDs = Set(feeds.map { $0.webFeedID })
+		database.fetchUnreadCounts(for: webFeedIDs) { result in
+			if let unreadCountDictionary = try? result.get() {
 				self.processUnreadCounts(unreadCountDictionary: unreadCountDictionary, feeds: feeds)
 			}
 			completion?()
 		}
-
-		operationQueue.add(operation)
 	}
 
-	func fetchAllUnreadCounts() {
+	func fetchAllUnreadCounts(_ completion: VoidCompletionBlock? = nil) {
 		fetchingAllUnreadCounts = true
-		database.fetchAllUnreadCounts { (result) in
+		database.fetchAllUnreadCounts { result in
 			guard let unreadCountDictionary = try? result.get() else {
+				completion?()
 				return
 			}
 			self.processUnreadCounts(unreadCountDictionary: unreadCountDictionary, feeds: self.flattenedWebFeeds())
@@ -1290,6 +1264,7 @@ private extension Account {
 				self.isUnreadCountsInitialized = true
 				self.postUnreadCountDidInitializeNotification()
 			}
+			completion?()
 		}
 	}
 

Frameworks/ArticlesDatabase/ArticlesDatabase.swift

@@ -149,6 +149,26 @@ public final class ArticlesDatabase {
 		operationQueue.add(operation)
 	}
 
+	/// Fetch unread count for a single feed.
+	public func fetchUnreadCount(_ webFeedID: String, _ completion: @escaping SingleUnreadCountCompletionBlock) {
+		let operation = FetchFeedUnreadCountOperation(webFeedID: webFeedID, databaseQueue: queue, cutoffDate: articlesTable.articleCutoffDate)
+		operation.completionBlock = { operation in
+			let fetchOperation = operation as! FetchFeedUnreadCountOperation
+			completion(fetchOperation.result)
+		}
+		operationQueue.add(operation)
+	}
+
+	/// Fetch non-zero unread counts for given webFeedIDs.
+	public func fetchUnreadCounts(for webFeedIDs: Set<String>, _ completion: @escaping UnreadCountDictionaryCompletionBlock) {
+		let operation = FetchUnreadCountsForFeedsOperation(webFeedIDs: webFeedIDs, databaseQueue: queue, cutoffDate: articlesTable.articleCutoffDate)
+		operation.completionBlock = { operation in
+			let fetchOperation = operation as! FetchUnreadCountsForFeedsOperation
+			completion(fetchOperation.result)
+		}
+		operationQueue.add(operation)
+	}
+
 	public func fetchUnreadCountForToday(for webFeedIDs: Set<String>, completion: @escaping SingleUnreadCountCompletionBlock) {
 		fetchUnreadCount(for: webFeedIDs, since: todayCutoffDate(), completion: completion)
 	}
@@ -199,33 +219,25 @@ public final class ArticlesDatabase {
 		articlesTable.createStatusesIfNeeded(articleIDs, completion)
 	}
 
-	// MARK: - Operations
-
-	public func cancelOperations() {
-		operationQueue.cancelAllOperations()
-	}
-
-	/// Create an operation that fetches the unread count for a single given feedID.
-	public func createFetchFeedUnreadCountOperation(feedID: String) -> FetchFeedUnreadCountOperation {
-		return FetchFeedUnreadCountOperation(feedID: feedID, databaseQueue: queue, cutoffDate: articlesTable.articleCutoffDate)
-	}
-
-	/// Create an operation that fetches unread counts for a number of feedIDs.
-	public func createFetchUnreadCountsForFeedsOperation(feedIDs: Set<String>) -> FetchUnreadCountsForFeedsOperation {
-		return FetchUnreadCountsForFeedsOperation(feedIDs: feedIDs, databaseQueue: queue, cutoffDate: articlesTable.articleCutoffDate)
-	}
-
 	// MARK: - Suspend and Resume (for iOS)
 
+	/// Cancel current operations and close the database.
+	public func cancelAndSuspend() {
+		cancelOperations()
+		suspend()
+	}
+
 	/// Close the database and stop running database calls.
 	/// Any pending calls will complete first.
 	public func suspend() {
+		operationQueue.suspend()
 		queue.suspend()
 	}
 
 	/// Open the database and allow for running database calls again.
 	public func resume() {
 		queue.resume()
+		operationQueue.resume()
 	}
 
 	// MARK: - Caches
@@ -272,4 +284,10 @@ private extension ArticlesDatabase {
 		// 24 hours previous. This is used by the Today smart feed, which should not actually empty out at midnight.
 		return Date(timeIntervalSinceNow: -(60 * 60 * 24)) // This does not need to be more precise.
 	}
+
+	// MARK: - Operations
+
+	func cancelOperations() {
+		operationQueue.cancelAllOperations()
+	}
 }

Frameworks/ArticlesDatabase/Operations/FetchAllUnreadCountsOperation.swift

@@ -12,7 +12,7 @@ import RSDatabase
 
 public final class FetchAllUnreadCountsOperation: MainThreadOperation {
 
-	public var result: UnreadCountDictionaryCompletionResult = .failure(.isSuspended)
+	var result: UnreadCountDictionaryCompletionResult = .failure(.isSuspended)
 
 	// MainThreadOperation
 	public var isCanceled = false

Frameworks/ArticlesDatabase/Operations/FetchFeedUnreadCountOperation.swift

@@ -13,8 +13,7 @@ import RSDatabase
 /// Fetch the unread count for a single feed.
 public final class FetchFeedUnreadCountOperation: MainThreadOperation {
 
-	public var unreadCount: Int?
-	public let feedID: String
+	var result: SingleUnreadCountResult = .failure(.isSuspended)
 
 	// MainThreadOperation
 	public var isCanceled = false
@@ -25,9 +24,10 @@ public final class FetchFeedUnreadCountOperation: MainThreadOperation {
 
 	private let queue: DatabaseQueue
 	private let cutoffDate: Date
+	private let webFeedID: String
 
-	init(feedID: String, databaseQueue: DatabaseQueue, cutoffDate: Date) {
-		self.feedID = feedID
+	init(webFeedID: String, databaseQueue: DatabaseQueue, cutoffDate: Date) {
+		self.webFeedID = webFeedID
 		self.queue = databaseQueue
 		self.cutoffDate = cutoffDate
 	}
@@ -54,7 +54,7 @@ private extension FetchFeedUnreadCountOperation {
 	func fetchUnreadCount(_ database: FMDatabase) {
 		let sql = "select count(*) from articles natural join statuses where feedID=? and read=0 and userDeleted=0 and (starred=1 or dateArrived>?);"
 
-		guard let resultSet = database.executeQuery(sql, withArgumentsIn: [feedID, cutoffDate]) else {
+		guard let resultSet = database.executeQuery(sql, withArgumentsIn: [webFeedID, cutoffDate]) else {
 			informOperationDelegateOfCompletion()
 			return
 		}
@@ -64,7 +64,8 @@ private extension FetchFeedUnreadCountOperation {
 		}
 
 		if resultSet.next() {
-			unreadCount = resultSet.long(forColumnIndex: 0)
+			let unreadCount = resultSet.long(forColumnIndex: 0)
+			result = .success(unreadCount)
 		}
 		resultSet.close()
 

Frameworks/ArticlesDatabase/Operations/FetchUnreadCountsForFeedsOperation.swift

@@ -13,8 +13,7 @@ import RSDatabase
 /// Fetch the unread counts for a number of feeds.
 public final class FetchUnreadCountsForFeedsOperation: MainThreadOperation {
 
-	public var unreadCountDictionary: UnreadCountDictionary?
-	public let feedIDs: Set<String>
+	var result: UnreadCountDictionaryCompletionResult = .failure(.isSuspended)
 
 	// MainThreadOperation
 	public var isCanceled = false
@@ -25,9 +24,10 @@ public final class FetchUnreadCountsForFeedsOperation: MainThreadOperation {
 
 	private let queue: DatabaseQueue
 	private let cutoffDate: Date
+	private let webFeedIDs: Set<String>
 
-	init(feedIDs: Set<String>, databaseQueue: DatabaseQueue, cutoffDate: Date) {
-		self.feedIDs = feedIDs
+	init(webFeedIDs: Set<String>, databaseQueue: DatabaseQueue, cutoffDate: Date) {
+		self.webFeedIDs = webFeedIDs
 		self.queue = databaseQueue
 		self.cutoffDate = cutoffDate
 	}
@@ -52,11 +52,11 @@ public final class FetchUnreadCountsForFeedsOperation: MainThreadOperation {
 private extension FetchUnreadCountsForFeedsOperation {
 
 	func fetchUnreadCounts(_ database: FMDatabase) {
-		let placeholders = NSString.rs_SQLValueList(withPlaceholders: UInt(feedIDs.count))!
+		let placeholders = NSString.rs_SQLValueList(withPlaceholders: UInt(webFeedIDs.count))!
 		let sql = "select distinct feedID, count(*) from articles natural join statuses where feedID in \(placeholders) and read=0 and userDeleted=0 and (starred=1 or dateArrived>?) group by feedID;"
 
 		var parameters = [Any]()
-		parameters += Array(feedIDs) as [Any]
+		parameters += Array(webFeedIDs) as [Any]
 		parameters += [cutoffDate] as [Any]
 
 		guard let resultSet = database.executeQuery(sql, withArgumentsIn: parameters) else {
@@ -64,11 +64,12 @@ private extension FetchUnreadCountsForFeedsOperation {
 			return
 		}
 		if isCanceled {
+			resultSet.close()
 			informOperationDelegateOfCompletion()
 			return
 		}
 
-		var d = UnreadCountDictionary()
+		var unreadCountDictionary = UnreadCountDictionary()
 		while resultSet.next() {
 			if isCanceled {
 				resultSet.close()
@@ -77,12 +78,12 @@ private extension FetchUnreadCountsForFeedsOperation {
 			}
 			let unreadCount = resultSet.long(forColumnIndex: 1)
 			if let webFeedID = resultSet.string(forColumnIndex: 0) {
-				d[webFeedID] = unreadCount
+				unreadCountDictionary[webFeedID] = unreadCount
 			}
 		}
 		resultSet.close()
 
-		unreadCountDictionary = d
+		result = .success(unreadCountDictionary)
 		informOperationDelegateOfCompletion()
 	}
 }