Merge pull request #1891 from Westacular/1870_Change_NSURLSessionConfiguration

Add ability to change NSURLSessionConfiguration used by SDWebImageDownloader

SDWebImage/SDWebImageDownloader.h

@@ -119,6 +119,15 @@ typedef SDHTTPHeadersDictionary * _Nullable (^SDWebImageDownloaderHeadersFilterB
 @property (assign, nonatomic) NSTimeInterval downloadTimeout;
 
 
+/**
+ * The configuration in use by the internal NSURLSession.
+ * Mutating this object directly has no effect.
+ *
+ * @see createNewSessionWithConfiguration:
+ */
+@property (readonly, nonatomic, nonnull) NSURLSessionConfiguration *sessionConfiguration;
+
+
 /**
  * Changes download operations execution order. Default value is `SDWebImageDownloaderFIFOExecutionOrder`.
  */
@@ -230,4 +239,14 @@ typedef SDHTTPHeadersDictionary * _Nullable (^SDWebImageDownloaderHeadersFilterB
  */
 - (void)cancelAllDownloads;
 
+/**
+ * Forces SDWebImageDownloader to create and use a new NSURLSession that is
+ * initialized with the given configuration.
+ * *Note*: All existing download operations in the queue will be cancelled.
+ * *Note*: `timeoutIntervalForRequest` is going to be overwritten.
+ *
+ * @param sessionConfiguration The configuration to use for the new NSURLSession
+ */
+- (void)createNewSessionWithConfiguration:(nonnull NSURLSessionConfiguration *)sessionConfiguration;
+
 @end

SDWebImage/SDWebImageDownloader.m

@@ -84,20 +84,30 @@
         _barrierQueue = dispatch_queue_create("com.hackemist.SDWebImageDownloaderBarrierQueue", DISPATCH_QUEUE_CONCURRENT);
         _downloadTimeout = 15.0;
 
-        sessionConfiguration.timeoutIntervalForRequest = _downloadTimeout;
-
-        /**
-         *  Create the session for this task
-         *  We send nil as delegate queue so that the session creates a serial operation queue for performing all delegate
-         *  method calls and completion handler calls.
-         */
-        self.session = [NSURLSession sessionWithConfiguration:sessionConfiguration
-                                                     delegate:self
-                                                delegateQueue:nil];
+        [self createNewSessionWithConfiguration:sessionConfiguration];
     }
     return self;
 }
 
+- (void)createNewSessionWithConfiguration:(NSURLSessionConfiguration *)sessionConfiguration {
+    [self cancelAllDownloads];
+
+    if (self.session) {
+        [self.session invalidateAndCancel];
+    }
+
+    sessionConfiguration.timeoutIntervalForRequest = self.downloadTimeout;
+
+    /**
+     *  Create the session for this task
+     *  We send nil as delegate queue so that the session creates a serial operation queue for performing all delegate
+     *  method calls and completion handler calls.
+     */
+    self.session = [NSURLSession sessionWithConfiguration:sessionConfiguration
+                                                 delegate:self
+                                            delegateQueue:nil];
+}
+
 - (void)dealloc {
     [self.session invalidateAndCancel];
     self.session = nil;
@@ -131,6 +141,10 @@
     return _downloadQueue.maxConcurrentOperationCount;
 }
 
+- (NSURLSessionConfiguration *)sessionConfiguration {
+    return self.session.configuration;
+}
+
 - (void)setOperationClass:(nullable Class)operationClass {
     if (operationClass && [operationClass isSubclassOfClass:[NSOperation class]] && [operationClass conformsToProtocol:@protocol(SDWebImageDownloaderOperationInterface)]) {
         _operationClass = operationClass;