Merge pull request #44 from 3sidedcube/fix/background_download_memory…

…_limits

Adds option to stop background download controller reading to disk

README.md

@@ -1,6 +1,6 @@
 # Thunder Request
 
-[![Build Status](https://travis-ci.org/3sidedcube/ThunderRequest.svg)](https://travis-ci.org/3sidedcube/ThunderRequest) [![Swift 5.1](http://img.shields.io/badge/swift-5.1-brightgreen.svg)](https://swift.org/blog/swift-5-1-released/) [![Apache 2](https://img.shields.io/badge/license-Apache%202-brightgreen.svg)](LICENSE.md)
+[![Build Status](https://travis-ci.org/3sidedcube/ThunderRequest.svg)](https://travis-ci.org/3sidedcube/ThunderRequest) [![Carthage Compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage) [![Swift 5.2](http://img.shields.io/badge/swift-5.2-brightgreen.svg)](https://swift.org/blog/swift-5-2-released/) [![Apache 2](https://img.shields.io/badge/license-Apache%202-brightgreen.svg)](LICENSE.md)
 
 Thunder Request is a Framework used to simplify making http and https web requests.
 

ThunderRequest/BackgroundSessionController.swift

@@ -27,15 +27,21 @@ public class BackgroundRequestController: NSObject, URLSessionDelegate, URLSessi
 
     private var urlSession: URLSession?
 
+    private let readData: Bool
+
     /// Creates a new request controller with a background session configuration identifier passed by the OS.
     ///
     /// - Parameters:
     ///   - identifier: The identifier to re-create the `URLSessionConfiguration` using.
     ///   - responseHandler: A closure called with the response to each background request.
-    ///   - finishHandler: A closure called when all background events have finished.
+    ///   - finishedHandler: A closure called when all background events have finished.
     ///   - queue: The operation queue to call back on.
-    public init(identifier: String, responseHandler: ResponseHandler?, finishedHandler: FinishHandler?, queue: OperationQueue? = nil) {
+    ///   - readDataAutomatically: Setting this to false allows you to stop the downloaded file's data being read from disk.
+    ///   Reading from disk can cause problems with large background downloads as the background Daemon has a ~40mb memory limit
+    ///   before being killed by the OS!
+    public init(identifier: String, responseHandler: ResponseHandler?, finishedHandler: FinishHandler?, readDataAutomatically: Bool = true, queue: OperationQueue? = nil) {
 
+        readData = readDataAutomatically
         self.responseHandler = responseHandler
         self.finishedHandler = finishedHandler
         sessionConfiguration = URLSessionConfiguration.background(withIdentifier: identifier)
@@ -56,7 +62,11 @@ public class BackgroundRequestController: NSObject, URLSessionDelegate, URLSessi
             responseHandler?(downloadTask, nil, nil)
             return
         }
-        let response = RequestResponse(response: taskResponse, data: try? Data(contentsOf: location))
+        var data: Data?
+        if readData {
+            data = try? Data(contentsOf: location)
+        }
+        let response = RequestResponse(response: taskResponse, data: data, fileURL: location)
         responseHandler?(downloadTask, response, nil)
     }
 

ThunderRequest/RequestController+Callbacks.swift

@@ -49,7 +49,7 @@ extension RequestController {
 
         var requestResponse: RequestResponse?
         if let urlResponse = response {
-            requestResponse = RequestResponse(response: urlResponse, data: nil)
+            requestResponse = RequestResponse(response: urlResponse, data: nil, fileURL: fileURL)
         }
 
         transferCompletionHandlers[taskIdentifier]?(requestResponse, fileURL, error)

ThunderRequest/RequestController.swift

@@ -630,7 +630,7 @@ open class RequestController {
                     RequestController.hideApplicationActivityIndicator()
                     var returnResponse: RequestResponse?
                     if let requestResponse = response.response {
-                        returnResponse = RequestResponse(response: requestResponse, data: nil)
+                        returnResponse = RequestResponse(response: requestResponse, data: nil, fileURL: response.downloadURL)
                     }
                     completion?(returnResponse, response.downloadURL, error)
 

ThunderRequest/RequestResponse.swift

@@ -18,6 +18,10 @@ public class RequestResponse {
         return httpResponse?.allHeaderFields
     }
 
+    /// File url the response's data was saved to. This is only present for file downloads and is useful
+    /// to get around the `40mb` memory limit which the Apple background service imposes on background download daemon
+    public let fileURL: URL?
+
     /// Raw data returned from the server
     public let data: Data?
 
@@ -31,10 +35,11 @@ public class RequestResponse {
     /// Initialises a new request response from a given `URLResponse` and `Data`
     /// - Parameter response: The response to populate properties with
     /// - Parameter data: The data that was returned with the response
-    public init(response: URLResponse, data: Data?) {
-        
+    /// - Parameter fileURL: The file url that the responses download was saved to (Only present for download tasks!)
+    public init(response: URLResponse, data: Data?, fileURL: URL? = nil) {
         httpResponse = response as? HTTPURLResponse
         self.data = data
+        self.fileURL = fileURL
     }
 
     /// The status of the HTTP request as an enum