Merge pull request #1654 from Wondermall/session-configuration

Allow to specify NSURLSessionConfiguration for SDWebImageDownloader

SDWebImage/SDWebImageDownloader.h

@@ -149,6 +149,13 @@ typedef SDHTTPHeadersDictionary * _Nullable (^SDWebImageDownloaderHeadersFilterB
  */
 @property (nonatomic, copy, nullable) SDWebImageDownloaderHeadersFilterBlock headersFilter;
 
+/**
+ * Creates an instance of a downloader with specified session configuration.
+ * *Note*: `timeoutIntervalForRequest` is going to be overwritten.
+ * @return new instance of downloader class
+ */
+- (nonnull instancetype)initWithSessionConfiguration:(nullable NSURLSessionConfiguration *)sessionConfiguration NS_DESIGNATED_INITIALIZER;
+
 /**
  * Set a value for a HTTP header to be appended to each download HTTP request.
  *

SDWebImage/SDWebImageDownloader.m

@@ -64,6 +64,10 @@
 }
 
 - (nonnull instancetype)init {
+    return [self initWithSessionConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
+}
+
+- (nonnull instancetype)initWithSessionConfiguration:(nullable NSURLSessionConfiguration *)sessionConfiguration {
     if ((self = [super init])) {
         _operationClass = [SDWebImageDownloaderOperation class];
         _shouldDecompressImages = YES;
@@ -80,15 +84,14 @@
         _barrierQueue = dispatch_queue_create("com.hackemist.SDWebImageDownloaderBarrierQueue", DISPATCH_QUEUE_CONCURRENT);
         _downloadTimeout = 15.0;
 
-        NSURLSessionConfiguration *sessionConfig = [NSURLSessionConfiguration defaultSessionConfiguration];
-        sessionConfig.timeoutIntervalForRequest = _downloadTimeout;
+        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:sessionConfig
+        self.session = [NSURLSession sessionWithConfiguration:sessionConfiguration
                                                      delegate:self
                                                 delegateQueue:nil];
     }