Add NSURLSession delegation to http_file_source.mm (#16321)

platform/darwin/include/mbgl/interface/native_apple_interface.h

@@ -2,12 +2,16 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+@class MGLNativeNetworkManager;
+
 @protocol MGLNativeNetworkDelegate <NSObject>
 
 @optional
 
 - (NSString *)skuToken;
 
+- (NSURLSession *)sessionForNetworkManager:(MGLNativeNetworkManager *)networkManager;
+
 @required
 
 - (NSURLSessionConfiguration *)sessionConfiguration;

platform/darwin/src/http_file_source.mm

@@ -249,10 +249,27 @@ std::unique_ptr<AsyncRequest> HTTPFileSource::request(const Resource& resource,
         if (isTile) {
             [MGLNativeNetworkManager.sharedManager startDownloadEvent:url.relativePath type:@"tile"];
         }
-        
-        request->task = [impl->session
+
+        __block NSURLSession *session;
+
+        // Use the delegate's session if there is one, otherwise use the one that
+        // was created when this class was constructed.
+        MGLNativeNetworkManager *networkManager = MGLNativeNetworkManager.sharedManager;
+        if ([networkManager.delegate respondsToSelector:@selector(sessionForNetworkManager:)]) {
+            session = [networkManager.delegate sessionForNetworkManager:networkManager];
+        }
+
+        if (!session) {
+            session = impl->session;
+        }
+
+        assert(session);
+
+        request->task = [session
             dataTaskWithRequest:req
               completionHandler:^(NSData* data, NSURLResponse* res, NSError* error) {
+                session = nil;
+            
                 if (error && [error code] == NSURLErrorCancelled) {
                     [MGLNativeNetworkManager.sharedManager cancelDownloadEventForResponse:res];
                     return;

platform/darwin/src/native_apple_interface.m

@@ -13,61 +13,65 @@ static MGLNativeNetworkManager *instance = nil;
     return instance;
 }
 
-- (NSURLSessionConfiguration *)sessionConfiguration {
-    if (_delegate && [_delegate respondsToSelector:@selector(sessionConfiguration)]) {
-        return [_delegate sessionConfiguration];
-    }
-    // For testing. Since we get a `nil` return when SDK is modualar, we use this for testing requests.
-    // Same as `[MGLNetworkConfiguration defaultSessionConfiguration]` in `MGLNetworkConfiguration.m`.
-    return [self testSessionConfiguration];
-}
-
-- (NSURLSessionConfiguration *)testSessionConfiguration {
++ (NSURLSessionConfiguration *)testSessionConfiguration {
     NSURLSessionConfiguration* sessionConfiguration = [NSURLSessionConfiguration defaultSessionConfiguration];
-    
+
     sessionConfiguration.timeoutIntervalForResource = 30;
     sessionConfiguration.HTTPMaximumConnectionsPerHost = 8;
     sessionConfiguration.requestCachePolicy = NSURLRequestReloadIgnoringLocalCacheData;
     sessionConfiguration.URLCache = nil;
-    
+
     return sessionConfiguration;
 }
 
+#pragma mark - Optionals
+
 - (NSString *)skuToken {
-    if(_delegate && [_delegate respondsToSelector:@selector(skuToken)]) {
-        return [_delegate skuToken];
+    if([self.delegate respondsToSelector:@selector(skuToken)]) {
+        return [self.delegate skuToken];
     }
     return nil;
 }
 
-- (void)startDownloadEvent:(NSString *)event type:(NSString *)type {
-    if (_delegate && [_delegate respondsToSelector:@selector(startDownloadEvent:type:)]) {
-        [_delegate startDownloadEvent:event type:type];
+#pragma mark - Required
+
+- (NSURLSessionConfiguration *)sessionConfiguration {
+    NSURLSessionConfiguration *configuration = [_delegate sessionConfiguration];
+
+    if (!configuration) {
+        // TODO: Remove
+        NSLog(@"Using testSessionConfiguration");
+
+        // For testing. Since we get a `nil` return when SDK is modular, we use
+        // this for testing requests.
+        // Same as `[MGLNetworkConfiguration defaultSessionConfiguration]` in
+        // `MGLNetworkConfiguration.m`.
+        configuration = [MGLNativeNetworkManager testSessionConfiguration];
     }
+
+    return configuration;
+}
+
+- (void)startDownloadEvent:(NSString *)event type:(NSString *)type {
+    [self.delegate startDownloadEvent:event type:type];
 }
 
 - (void)cancelDownloadEventForResponse:(NSURLResponse *)response {
-    if (_delegate && [_delegate respondsToSelector:@selector(cancelDownloadEventForResponse:)]) {
-        return [_delegate cancelDownloadEventForResponse:response];
-    }
+    [self.delegate cancelDownloadEventForResponse:response];
 }
 
 - (void)stopDownloadEventForResponse:(NSURLResponse *)response {
-    if (_delegate && [_delegate respondsToSelector:@selector(stopDownloadEventForResponse:)]) {
-        return [_delegate stopDownloadEventForResponse:response];
-    }
+    [self.delegate stopDownloadEventForResponse:response];
 }
 
-- (void)debugLog:(NSString *)format, ...{
-    if (_delegate && [_delegate respondsToSelector:@selector(debugLog:)]) {
-        return [_delegate debugLog:format];
-    }
+- (void)debugLog:(NSString *)format, ... {
+    // TODO: Replace with existing mbgl logging handling.
+    [self.delegate debugLog:format];
 }
 
-- (void)errorLog:(NSString *)format, ...{
-    if (_delegate && [_delegate respondsToSelector:@selector(errorLog:)]) {
-        return [_delegate errorLog:format];
-    }
+- (void)errorLog:(NSString *)format, ... {
+    // TODO: Replace with existing mbgl logging handling.
+    [self.delegate errorLog:format];
 }
 
 @end