start adapting engine to persistent interprocessing

pom.xml

@@ -125,7 +125,7 @@
 		<!-- NB: Deploy releases to the SciJava Maven repository. -->
 		<releaseProfiles>sign,deploy-to-scijava</releaseProfiles>
 
-		<dl-modelrunner.version>0.5.8</dl-modelrunner.version>
+		<dl-modelrunner.version>0.5.10-SNAPSHOT</dl-modelrunner.version>
 		<tensorflow-core.version>0.2.0</tensorflow-core.version>
 	</properties>
 

src/main/java/io/bioimage/modelrunner/tensorflow/v2/api020/JavaWorker.java

@@ -0,0 +1,150 @@
+package io.bioimage.modelrunner.tensorflow.v2.api020;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Scanner;
+
+import io.bioimage.modelrunner.apposed.appose.Types;
+import io.bioimage.modelrunner.apposed.appose.Service.RequestType;
+import io.bioimage.modelrunner.apposed.appose.Service.ResponseType;
+
+public class JavaWorker {
+
+	private static LinkedHashMap<String, Object> tasks = new LinkedHashMap<String, Object>();
+
+	private final String uuid;
+
+	private final Tensorflow2Interface ti;
+
+	private boolean cancelRequested = false;
+
+	public static void main(String[] args) {
+
+    	try(Scanner scanner = new Scanner(System.in)){
+    		Tensorflow2Interface ti;
+    		try {
+				ti = new Tensorflow2Interface(false);
+			} catch (IOException | URISyntaxException e) {
+				return;
+			}
+
+            while (true) {
+            	String line;
+                try {
+                    if (!scanner.hasNextLine()) break;
+                    line = scanner.nextLine().trim();
+                } catch (Exception e) {
+                    break;
+                }
+
+                if (line.isEmpty()) break;
+                Map<String, Object> request = Types.decode(line);
+                String uuid = (String) request.get("task");
+                String requestType = (String) request.get("requestType");
+
+                if (requestType.equals(RequestType.EXECUTE.toString())) {
+                	String script = (String) request.get("script");
+                	Map<String, Object> inputs = (Map<String, Object>) request.get("inputs");
+                	JavaWorker task = new JavaWorker(uuid, ti);
+                	tasks.put(uuid, task);
+                	task.start(script, inputs);
+                } else if (requestType.equals(RequestType.CANCEL.toString())) {
+                	JavaWorker task = (JavaWorker) tasks.get(uuid);
+                	if (task == null) {
+                		System.err.println("No such task: " + uuid);
+                		continue;
+                	}
+                	task.cancelRequested = true;
+                } else {
+                	break;
+                }
+            }
+    	}
+
+	}
+
+	private JavaWorker(String uuid, Tensorflow2Interface ti) {
+		this.uuid = uuid;
+		this.ti = ti;
+	}
+
+	private void executeScript(String script, Map<String, Object> inputs) {
+		Map<String, Object> binding = new LinkedHashMap<String, Object>();
+		binding.put("task", this);
+		if (inputs != null)
+			binding.putAll(binding);
+
+		this.reportLaunch();
+		try {
+			if (script.equals("loadModel")) {
+				ti.loadModel((String) inputs.get("modelFolder"), null);
+			} else if (script.equals("inference")) {
+				ti.runFromShmas((List<String>) inputs.get("inputs"), (List<String>) inputs.get("outputs"));
+			} else if (script.equals("close")) {
+				ti.closeModel();
+			}
+		} catch(Exception ex) {
+			this.fail(Types.stackTrace(ex));
+			return;
+		}
+		this.reportCompletion();
+	}
+
+	private void start(String script, Map<String, Object> inputs) {
+		new Thread(() -> executeScript(script, inputs), "Appose-" + this.uuid).start();
+	}
+
+	private void reportLaunch() {
+		respond(ResponseType.LAUNCH, null);
+	}
+
+	private void reportCompletion() {
+		respond(ResponseType.COMPLETION, null);
+	}
+
+	private void update(String message, Integer current, Integer maximum) {
+		LinkedHashMap<String, Object> args = new LinkedHashMap<String, Object>();
+
+		if (message != null)
+			args.put("message", message);
+
+		if (current != null)
+			args.put("current", current);
+
+		if (maximum != null)
+			args.put("maximum", maximum);
+		this.respond(ResponseType.UPDATE, args);
+	}
+
+	private void respond(ResponseType responseType, Map<String, Object> args) {
+		Map<String, Object> response = new HashMap<String, Object>();
+		response.put("task", uuid);
+		response.put("responseType", responseType);
+		if (args != null)
+			response.putAll(args);
+		try {
+			System.out.println(Types.encode(response));
+			System.out.flush();
+		} catch(Exception ex) {
+			this.fail(Types.stackTrace(ex.getCause()));
+		}
+	}
+
+	private void cancel() {
+		this.respond(ResponseType.CANCELATION, null);
+	}
+
+	private void fail(String error) {
+		Map<String, Object> args = null;
+		if (error != null) {
+			args = new HashMap<String, Object>();
+			args.put("error", error);
+		}
+        respond(ResponseType.FAILURE, args);
+	}
+
+}