Files
letro-ios/ElementX/Sources/Services/Background/UIKitBackgroundTask.swift
2022-07-27 16:06:40 +03:00

97 lines
2.7 KiB
Swift

//
// UIKitBackgroundTask.swift
// ElementX
//
// Created by Ismail on 28.06.2022.
// Copyright © 2022 Element. All rights reserved.
//
import Foundation
import UIKit
/// UIKitBackgroundTask is a concrete implementation of BackgroundTaskProtocol using UIApplication background task.
class UIKitBackgroundTask: BackgroundTaskProtocol {
let name: String
var isRunning: Bool {
identifier != .invalid
}
let isReusable: Bool
let expirationHandler: BackgroundTaskExpirationHandler?
var elapsedTime: TimeInterval {
Date().timeIntervalSince(startDate) * 1000
}
private let application: ApplicationProtocol
private var identifier: UIBackgroundTaskIdentifier = .invalid
private var useCounter = 0
private let startDate = Date()
/// Initializes and starts a new background task
/// - Parameters:
/// - name: name
/// - isReusable: flag indicating the task is reusable
/// - application: application instance
/// - expirationHandler: expiration handler
init?(name: String,
isReusable: Bool,
application: ApplicationProtocol,
expirationHandler: BackgroundTaskExpirationHandler?) {
self.name = name
self.isReusable = isReusable
self.application = application
self.expirationHandler = expirationHandler
// attempt to start
identifier = application.beginBackgroundTask(withName: name) { [weak self] in
guard let self = self else { return }
self.expirationHandler?(self)
}
if identifier == .invalid {
MXLog.verbose("[UIKitBackgroundTask] Do not start background task: \(name), as OS declined")
// call expiration handler immediately
expirationHandler?(self)
return nil
}
if isReusable {
// creation itself is a use
reuse()
}
MXLog.verbose("[UIKitBackgroundTask] Start background task #\(identifier.rawValue) - \(name)")
}
func reuse() {
guard isReusable else {
return
}
useCounter += 1
}
func stop() {
if isReusable {
useCounter -= 1
if useCounter <= 0 {
endTask()
}
} else {
endTask()
}
}
private func endTask() {
if identifier != .invalid {
MXLog.verbose("[UIKitBackgroundTask] End background task #\(identifier.rawValue) - \(name) after \(readableElapsedTime)")
application.endBackgroundTask(identifier)
identifier = .invalid
}
}
private var readableElapsedTime: String {
String(format: "%.3fms", elapsedTime)
}
}