remove thrown exception from fetchFile and replaced with corrupted flag in returned MemoryFile

include/openspace/engine/downloadmanager.h

@@ -64,6 +64,7 @@ public:
     struct MemoryFile {
         std::string buffer;
         std::string format;
+        bool corrupted;
     };
 
     using DownloadProgressCallback = std::function<void(const FileFuture&)>;

modules/iswa/rendering/dataplane.cpp

@@ -95,15 +95,15 @@ DataPlane::~DataPlane(){}
 
 bool DataPlane::loadTexture() {
     
+    // if The future is done then get the new dataFile
     if(_futureObject.valid() && DownloadManager::futureReady(_futureObject)){
-        try {
-            _dataFile = _futureObject.get();
-        } catch( std::exception& e ) {
-            LWARNING( "DataPlane future data exception: " + std::string(e.what()) );
+         _dataFile = _futureObject.get();
+
+         if(_dataFile.corrupted)
             return false;
-        }
     }
 
+    // if the buffer in the datafile is empty, do not proceed
     if(_dataFile.buffer.empty())
         return false;
 

modules/iswa/rendering/screenspacecygnet.cpp

@@ -134,26 +134,24 @@ void ScreenSpaceCygnet::updateTexture(){
 
 void ScreenSpaceCygnet::loadTexture() {
 
-    try {
+    DownloadManager::MemoryFile imageFile = _futureImage.get();
 
-        DownloadManager::MemoryFile imageFile = _futureImage.get();
-        std::unique_ptr<ghoul::opengl::Texture> texture = ghoul::io::TextureReader::ref().loadTexture(
-            (void*) imageFile.buffer.c_str(),
-            imageFile.buffer.size(), 
-            imageFile.format);
+    if(imageFile.corrupted)
+        return;
 
-        if (texture) {
-            LDEBUG("Loaded texture from iswa cygnet with id: '" << _cygnetId << "'");
+    std::unique_ptr<ghoul::opengl::Texture> texture = ghoul::io::TextureReader::ref().loadTexture(
+        (void*) imageFile.buffer.c_str(),
+        imageFile.buffer.size(), 
+        imageFile.format);
 
-            texture->uploadTexture();
-            // Textures of planets looks much smoother with AnisotropicMipMap rather than linear
-            texture->setFilter(ghoul::opengl::Texture::FilterMode::Linear);
+    if (texture) {
+        LDEBUG("Loaded texture from iswa cygnet with id: '" << _cygnetId << "'");
 
-            _texture = std::move(texture);
-        }
+        texture->uploadTexture();
+        // Textures of planets looks much smoother with AnisotropicMipMap rather than linear
+        texture->setFilter(ghoul::opengl::Texture::FilterMode::Linear);
 
-    } catch( std::exception& e ) {
-        LWARNING( "ScreenSpaceCygnet futureImage exception: " + std::string(e.what()) );
+        _texture = std::move(texture);
     }
 }
 }

modules/iswa/rendering/textureplane.cpp

@@ -56,13 +56,10 @@ TexturePlane::~TexturePlane(){}
 
 bool TexturePlane::loadTexture() {
 
-    DownloadManager::MemoryFile imageFile;
-    try {
-        imageFile = _futureObject.get();
-    } catch( std::exception& e ) {
-        LWARNING( "Textureplane futureImage exception: " + std::string(e.what()) );
+    DownloadManager::MemoryFile imageFile = _futureObject.get();
+
+    if(imageFile.corrupted)
         return false;
-    }
 
     std::unique_ptr<ghoul::opengl::Texture> texture = ghoul::io::TextureReader::ref().loadTexture(
                                                         (void*) imageFile.buffer.c_str(),

modules/iswa/util/iswamanager.cpp

@@ -203,10 +203,10 @@ std::future<DownloadManager::MemoryFile> ISWAManager::fetchImageCygnet(int id){
     return std::move( DlManager.fetchFile(
             iSWAurl(id, "image"),
             [id](const DownloadManager::MemoryFile& file){
-                LDEBUG("Download to memory finished");
+                LDEBUG("Download to memory finished for image cygnet with id: " + std::to_string(id));
             },
             [id](const std::string& err){
-                LDEBUG("Download to memory was aborted: " + err);
+                LDEBUG("Download to memory was aborted for image cygnet with id "+ std::to_string(id)+": " + err);
             }
         ) );   
 }

src/engine/downloadmanager.cpp

@@ -294,15 +294,19 @@ std::future<DownloadManager::MemoryFile> DownloadManager::fetchFile(
                 }
                 successCallback(file);
                 curl_easy_cleanup(curl);
+                file.corrupted = false;
                 return std::move(file);
             } else {
                 std::string err = curl_easy_strerror(res);
                 errorCallback(err);
                 curl_easy_cleanup(curl);
                 // Throw an error and use try-catch around future.get() call
-                throw std::runtime_error( err );
+                //throw std::runtime_error( err );
+
                 // or set a boolean variable in MemoryFile to determine if it is valid/corrupted or not.
                 // Return MemoryFile even if it is not valid, and check if it is after future.get() call.
+                file.corrupted = true;
+                return std::move(file);
             }
         }
     };