51 lines
2 KiB
Swift
51 lines
2 KiB
Swift
import Foundation
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final class DownloadManager {
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static let shared = DownloadManager()
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private let urlSession: URLSession
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private let downloadQueue = DispatchQueue(label: "com.example.downloadQueue")
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private var activeDownloads = Set<URL>()
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init() {
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let configuration = URLSessionConfiguration.default
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urlSession = URLSession(configuration: configuration)
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}
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func enqueueDownload(from url: URL, to localUrl: URL, completion: @escaping (Error?) -> Void) {
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downloadQueue.async {
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if self.activeDownloads.contains(url) {
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print("Download for this file is already in queue.")
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return
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}
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self.activeDownloads.insert(url)
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let task = self.urlSession.downloadTask(with: url) { tempLocalUrl, _, error in
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self.downloadQueue.async {
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self.activeDownloads.remove(url)
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if let tempLocalUrl = tempLocalUrl, error == nil {
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do {
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let destinationDirectory = localUrl.deletingLastPathComponent()
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if !FileManager.default.fileExists(atPath: destinationDirectory.path) {
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try FileManager.default.createDirectory(at: destinationDirectory, withIntermediateDirectories: true, attributes: nil)
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}
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if FileManager.default.fileExists(atPath: localUrl.path) {
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try FileManager.default.removeItem(at: localUrl)
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}
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try FileManager.default.moveItem(at: tempLocalUrl, to: localUrl)
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completion(nil)
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} catch let writeError {
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completion(writeError)
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}
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} else {
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completion(error)
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}
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}
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}
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task.resume()
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}
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}
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}
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