TaskQueue

TaskQueue.swift

final class TaskQueue: Sendable {
    private actor TaskQueueActor {
        private var blocks = [() async -> Void]()
        private var currentTask: Task<Void, Never>?
        
        func addBlock(priority: TaskPriority? = nil, block: @escaping @Sendable () async -> Void) {
            blocks.append(block)
            next(priority: priority)
        }
        
        func next(priority: TaskPriority? = nil) {
            guard currentTask == nil, !blocks.isEmpty else { return }
            
            let block = blocks.removeFirst()
            currentTask = Task(priority: priority) {
                await block()
                currentTask = nil
                next(priority: priority)
            }
        }
    }
    
    private let taskQueueActor = TaskQueueActor()
    
    func dispatch(
        priority: TaskPriority? = nil,
        immediately: Bool = false,
        block: @escaping @Sendable () async -> Void
    ) {
        Task(priority: priority) {
            await taskQueueActor.addBlock(priority: priority, block: block)
        }
    }
}