Added the stopWithError() method to Streamer class

Author: smistad

source/FAST/Algorithms/ImagePatch/PatchGenerator.cpp

@@ -310,10 +310,7 @@ void PatchGenerator::generateStream() {
         if(!previousPatch) {
             // No patches have been created
             reportInfo() << "No patches were generated." << reportEnd();
-            frameAdded(); // Unlock blocking execute()
-            for(const auto& channel : mOutputConnections[0]) {
-                channel.lock()->stop("No patches were created by the PatchGenerator");
-            }
+            stopWithError("No patches were created by the PatchGenerator");
         } else {
             previousPatch->setLastFrame(getNameOfClass());
             previousPatch->setFrameData("streaming", "yes"); // Since we are not propagating frame data, we have to set this
@@ -326,12 +323,7 @@ void PatchGenerator::generateStream() {
         }
     } catch(std::exception &e) {
         // Exception happened in thread. Stop pipeline, and propagate error message.
-        for(auto item : mOutputConnections) {
-            for(auto output : item.second) {
-                output.lock()->stop(e.what());
-            }
-        }
-        frameAdded(); // To unlock if happens before first frame
+        stopWithError(e.what());
     }
 }
 

source/FAST/Algorithms/ImagePatch/Tests.cpp

@@ -82,6 +82,30 @@ TEST_CASE("Patch generator with no patches", "[fast][PatchGenerator]") {
     REQUIRE(counter == 0);
 }
 
+
+TEST_CASE("Patch generator throws exception in thread", "[fast][PatchGenerator]") {
+    auto importer = WholeSlideImageImporter::create(Config::getTestDataPath() + "/WSI/CMU-1.svs");
+    auto wsi = importer->runAndGetOutputData<ImagePyramid>();
+
+    auto segmentation = Image::create(512, 512, TYPE_UINT8, 1);
+    segmentation->fill(0); // Empty segmentation will mean no patches
+    const int width = 256;
+    const int height = 256;
+    // Level 4 doesn't exist in this image pyramid, thus it will trigger an exception
+    auto generator = PatchGenerator::create(width, height, 1, 4)
+            ->connect(importer)
+            ->connect(1, segmentation);
+    auto stream = DataStream(generator);
+    int counter = 0;
+    CHECK_THROWS(
+            while(!stream.isDone()) {
+                auto image = stream.getNextFrame<Image>();
+                ++counter;
+            }
+    );
+    REQUIRE(counter == 0);
+}
+
 TEST_CASE("Patch generator on 3D image", "[fast][PatchGenerator]") {
     auto importer = ImageFileImporter::create(Config::getTestDataPath() + "/CT/CT-Thorax.mhd");
     auto image = importer->runAndGetOutputData<Image>();

source/FAST/Python/Tests/test_data_stream_object.py

@@ -3,7 +3,7 @@
 import pytest
 
 
-def test_data_stream_empty():
+def test_data_stream_empty_generator():
     importer = fast.WholeSlideImageImporter.create(fast.Config.getTestDataPath() + '/WSI/CMU-1.svs')
 
     segmentation = fast.TissueSegmentation.create(False).connect(importer).runAndGetOutputData()
@@ -14,7 +14,19 @@ def test_data_stream_empty():
     with pytest.raises(RuntimeError):
         for image in fast.DataStream(generator):
             counter += 1
-    assert(counter == 0)
+    assert counter == 0
+
+
+def test_data_stream_empty_file_streamer():
+    streamer = fast.ImageFileStreamer \
+        .create(fast.Config.getTestDataPath() + "/US/Heart/ApicalFourChamber/US-2D_#.mhd",)
+    streamer.setStartNumber(200) # Incorrect start number, will result in no frames
+
+    counter = 0
+    with pytest.raises(RuntimeError):
+        for image in fast.DataStream(streamer):
+            counter += 1
+    assert counter == 0
 
 
 def test_data_stream_single():

source/FAST/Streamers/FileStreamer.cpp

@@ -100,6 +100,9 @@ void FileStreamer::setFilenameFormats(std::vector<std::string> strs) {
 }
 
 void FileStreamer::generateStream() {
+    if(getNrOfFrames() == 0) {
+        stopWithError("No frames were created by the FileStreamer");
+    }
 
     // Read timestamp file if available
     std::ifstream timestampFile;

source/FAST/Streamers/Streamer.cpp

@@ -101,4 +101,13 @@ void Streamer::stopPipeline() {
     ProcessObject::stopPipeline();
 }
 
+void Streamer::stopWithError(std::string message, int outputPort) {
+    frameAdded(); // Unlock blocking execute()
+    if(outputPort < 0)
+        outputPort = 0;
+    for(const auto& channel : mOutputConnections[outputPort]) {
+        channel.lock()->stop();
+    }
+}
+
 }

source/FAST/Streamers/Streamer.hpp

@@ -48,6 +48,8 @@ class FAST_EXPORT Streamer : public ProcessObject {
          */
         virtual void stop();
 
+        virtual void stopWithError(std::string message, int outputPort = -1);
+
         virtual bool isStopped();
 
         virtual void setMaximumNrOfFrames(int maximumNrOfFrames);