Fix bug introduced by multi-engine feature

Change-Id: I17d3db91e878adbdaad193b1e435850329e0f930

api/src/main/java/ai/djl/engine/Engine.java

@@ -93,6 +93,17 @@ public static Engine getInstance() {
  return getEngine(System.getProperty("ai.djl.default_engine", DEFAULT_ENGINE));
  }
 
+ /**
+ * Returns if the specified engine is available.
+ *
+ * @param engineName the name of Engine to check
+ * @return {@code true} if the specified engine is available
+ * @see EngineProvider
+ */
+ public static boolean hasEngine(String engineName) {
+ return ALL_ENGINES.containsKey(engineName);
+ }
+
  /**
  * Returns the {@code Engine} with the given name.
  *

api/src/main/java/ai/djl/repository/zoo/BaseModelLoader.java

@@ -104,47 +104,32 @@ public <S, T> ZooModel<S, T> loadModel(Criteria<S, T> criteria)
  Path modelPath = repository.getResourceDirectory(artifact);
 
  // Check if the engine is specified in Criteria, use it if it is.
- // Otherwise check the modelzoo supported engine and grab the first engine in the list.
+ // Otherwise check the modelzoo supported engine and grab a random engine in the list.
  // Otherwise if none of them is specified or model zoo is null, go to default engine.
-
  String engine = criteria.getEngine();
- if (engine == null || engine.isEmpty()) {
- if (modelZoo != null) {
- engine = Engine.getInstance().getEngineName();
- if (!modelZoo.getSupportedEngines().contains(engine)) {
- engine = modelZoo.getSupportedEngines().iterator().next();
+ if (engine == null && modelZoo != null) {
+ String defaultEngine = Engine.getInstance().getEngineName();
+ for (String supportedEngine : modelZoo.getSupportedEngines()) {
+ if (supportedEngine.equals(defaultEngine)) {
+ engine = supportedEngine;
+ break;
+ } else if (Engine.hasEngine(supportedEngine)) {
+ engine = supportedEngine;
  }
  }
- }
-
- try {
- Model model = createModel(Device.defaultDevice(), artifact, arguments, engine);
- model.load(modelPath, artifact.getName(), criteria.getOptions());
- return new ZooModel<>(model, translator);
- } catch (IllegalArgumentException e) {
-
- if (e.getMessage().contains("Deep learning engine not found:")) {
- StringBuilder errorMsg = new StringBuilder(200);
-
- errorMsg.append("Your Criteria Filters: ");
- errorMsg.append(criteria.getFilters().toString());
-
- errorMsg.append(", Under Model Zoo: ");
- errorMsg.append((modelZoo == null) ? "null" : modelZoo.getClass().toString());
-
- errorMsg.append(", Is using Engine: ");
- errorMsg.append(
- (engine == null || engine.isEmpty())
- ? Engine.getInstance().getEngineName()
- : engine);
- errorMsg.append(
- ", But the engine could not be found, "
- + "please try adding the dependency engine to the gradle file");
-
- throw new UnsupportedOperationException(errorMsg.toString(), e);
+ if (engine == null) {
+ throw new ModelNotFoundException(
+ "No supported engine available for model zoo: "
+ + modelZoo.getGroupId());
  }
- throw e;
  }
+ if (engine != null && !Engine.hasEngine(engine)) {
+ throw new ModelNotFoundException(engine + " is not supported.");
+ }
+
+ Model model = createModel(Device.defaultDevice(), artifact, arguments, engine);
+ model.load(modelPath, artifact.getName(), criteria.getOptions());
+ return new ZooModel<>(model, translator);
  } finally {
  if (progress != null) {
  progress.end();
@@ -167,11 +152,6 @@ protected Model createModel(
  return Model.newInstance(device, engine);
  }
 
- protected Model createModel(Device device, Artifact artifact, Map<String, Object> arguments)
- throws IOException {
- return Model.newInstance(device);
- }
-
  /**
  * Returns the first artifact that matches a given criteria.
  *

api/src/main/java/ai/djl/repository/zoo/ModelZoo.java

@@ -107,8 +107,7 @@ static <I, O> ZooModel<I, O> loadModel(Criteria<I, O> criteria)
 
  Set<String> supportedEngine = zoo.getSupportedEngines();
  String engine = criteria.getEngine();
-
- if (engine != null && !engine.isEmpty() && !supportedEngine.contains(engine)) {
+ if (engine != null && !supportedEngine.contains(engine)) {
  continue;
  }
 

integration/src/main/java/ai/djl/integration/tests/model_zoo/classification/ResnetTest.java

@@ -18,6 +18,7 @@
 import ai.djl.basicmodelzoo.BasicModelZoo;
 import ai.djl.basicmodelzoo.cv.classification.ResNetV1;
 import ai.djl.inference.Predictor;
+import ai.djl.integration.util.TestUtils;
 import ai.djl.modality.Classifications;
 import ai.djl.modality.cv.Image;
 import ai.djl.ndarray.NDArray;
@@ -45,6 +46,7 @@
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
+import org.testng.SkipException;
 import org.testng.annotations.Test;
 
 public class ResnetTest {
@@ -143,6 +145,9 @@ public void testLoadTrain()
 
  private ZooModel<Image, Classifications> getModel()
  throws IOException, ModelNotFoundException, MalformedModelException {
+ if (!TestUtils.isMxnet()) {
+ throw new SkipException("Resnet50-cifar10 model only available in MXNet");
+ }
 
  Criteria<Image, Classifications> criteria =
  Criteria.builder()

integration/src/main/java/ai/djl/integration/tests/model_zoo/object_detection/SingleShotDetectionTest.java

@@ -19,6 +19,7 @@
 import ai.djl.basicdataset.PikachuDetection;
 import ai.djl.basicmodelzoo.BasicModelZoo;
 import ai.djl.inference.Predictor;
+import ai.djl.integration.util.TestUtils;
 import ai.djl.modality.cv.Image;
 import ai.djl.modality.cv.ImageFactory;
 import ai.djl.modality.cv.MultiBoxDetection;
@@ -49,6 +50,7 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import org.testng.Assert;
+import org.testng.SkipException;
 import org.testng.annotations.Test;
 
 public class SingleShotDetectionTest {
@@ -129,6 +131,9 @@ private TrainingConfig setupTrainingConfig() {
 
  private ZooModel<Image, DetectedObjects> getModel()
  throws IOException, ModelNotFoundException, MalformedModelException {
+ if (!TestUtils.isMxnet()) {
+ throw new SkipException("SSD-pikachu model only available in MXNet");
+ }
 
  Criteria<Image, DetectedObjects> criteria =
  Criteria.builder()

model-zoo/src/main/java/ai/djl/basicmodelzoo/cv/classification/MlpModelLoader.java

@@ -107,7 +107,8 @@ public ZooModel<Image, Classifications> loadModel(
 
  /** {@inheritDoc} */
  @Override
- protected Model createModel(Device device, Artifact artifact, Map<String, Object> arguments) {
+ protected Model createModel(
+ Device device, Artifact artifact, Map<String, Object> arguments, String engine) {
  int width = ((Double) arguments.getOrDefault("width", 28d)).intValue();
  int height = ((Double) arguments.getOrDefault("height", 28d)).intValue();
  int input = width * height;
@@ -119,7 +120,7 @@ protected Model createModel(Device device, Artifact artifact, Map<String, Object
  .mapToInt(Double::intValue)
  .toArray();
 
- Model model = Model.newInstance(device);
+ Model model = Model.newInstance(device, engine);
  model.setBlock(new Mlp(input, output, hidden));
  return model;
  }

model-zoo/src/main/java/ai/djl/basicmodelzoo/cv/classification/ResNetModelLoader.java

@@ -131,6 +131,7 @@ private Block resnetBlock(Map<String, Object> arguments) {
  return blockBuilder.build();
  }
 
+ /** {@inheritDoc} */
  @Override
  protected Model createModel(
  Device device, Artifact artifact, Map<String, Object> arguments, String engine) {
@@ -139,14 +140,6 @@ protected Model createModel(
  return model;
  }
 
- /** {@inheritDoc} */
- @Override
- protected Model createModel(Device device, Artifact artifact, Map<String, Object> arguments) {
- Model model = Model.newInstance(device);
- model.setBlock(resnetBlock(arguments));
- return model;
- }
-
  private static final class FactoryImpl implements TranslatorFactory<Image, Classifications> {
 
  /** {@inheritDoc} */

model-zoo/src/main/java/ai/djl/basicmodelzoo/cv/object_detection/ssd/SingleShotDetectionModelLoader.java

@@ -163,14 +163,6 @@ protected Model createModel(
  return model;
  }
 
- /** {@inheritDoc} */
- @Override
- protected Model createModel(Device device, Artifact artifact, Map<String, Object> arguments) {
- Model model = Model.newInstance(device);
- model.setBlock(customSSDBlock(arguments));
- return model;
- }
-
  private static final class FactoryImpl implements TranslatorFactory<Image, DetectedObjects> {
 
  /** {@inheritDoc} */

mxnet/mxnet-model-zoo/src/main/java/ai/djl/mxnet/zoo/nlp/embedding/GloveWordEmbeddingModelLoader.java

@@ -95,14 +95,6 @@ protected Model createModel(
  return customGloveBlock(model, artifact, arguments);
  }
 
- /** {@inheritDoc} */
- @Override
- protected Model createModel(Device device, Artifact artifact, Map<String, Object> arguments)
- throws IOException {
- Model model = Model.newInstance(device);
- return customGloveBlock(model, artifact, arguments);
- }
-
  /** {@inheritDoc} */
  @Override
  public ZooModel<NDList, NDList> loadModel(