81 lines
2.4 KiB
Swift
81 lines
2.4 KiB
Swift
/*
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The MIT License (MIT)
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Copyright (c) 2015-present Badoo Trading Limited.
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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import Foundation
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public typealias TaskClosure = (_ completion: @escaping () -> Void) -> Void
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public protocol SerialTaskQueueProtocol {
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func addTask(_ task: @escaping TaskClosure)
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func start()
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func stop()
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func flushQueue()
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var isEmpty: Bool { get }
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var isStopped: Bool { get }
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}
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public final class SerialTaskQueue: SerialTaskQueueProtocol {
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public private(set) var isBusy = false
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public private(set) var isStopped = true
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private var tasksQueue = [TaskClosure]()
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public init() {}
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public func addTask(_ task: @escaping TaskClosure) {
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self.tasksQueue.append(task)
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self.maybeExecuteNextTask()
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}
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public func start() {
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self.isStopped = false
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self.maybeExecuteNextTask()
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}
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public func stop() {
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self.isStopped = true
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}
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public func flushQueue() {
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self.tasksQueue.removeAll()
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}
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public var isEmpty: Bool {
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return self.tasksQueue.isEmpty
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}
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private func maybeExecuteNextTask() {
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if !self.isStopped && !self.isBusy {
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if !self.isEmpty {
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let firstTask = self.tasksQueue.removeFirst()
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self.isBusy = true
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firstTask({ [weak self] () -> Void in
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self?.isBusy = false
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self?.maybeExecuteNextTask()
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})
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}
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}
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}
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}
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