refactor: remove ExecutorService dependency from script compilation and initialization logic (#2517)

Author: predic8

core/src/main/java/com/predic8/membrane/core/interceptor/groovy/GroovyInterceptor.java

@@ -56,7 +56,7 @@ public EnumSet<Flow> getAppliedFlow() {
     @Override
     protected void initInternal() {
         try {
-            script = new GroovyLanguageSupport().compileScript(router.getBackgroundInitializer(), null, src);
+            script = new GroovyLanguageSupport().compileScript(null, src);
         } catch (MultipleCompilationErrorsException e) {
             logGroovyError(e);
             throw new ConfigurationException("Error in Groovy script initialization.",e);

core/src/main/java/com/predic8/membrane/core/interceptor/javascript/LanguageAdapter.java

@@ -91,7 +91,7 @@ public static LanguageAdapter instance(Router router) {
     }
 
     public Function<Map<String, Object>, Object> compileScript(String script) {
-        return languageSupport.compileScript(router.getBackgroundInitializer(), getClassLoader(), prepareScript(script));
+        return languageSupport.compileScript(getClassLoader(), prepareScript(script));
     }
 
     private @Nullable ClassLoader getClassLoader() {

core/src/main/java/com/predic8/membrane/core/lang/LanguageSupport.java

@@ -15,11 +15,10 @@
 package com.predic8.membrane.core.lang;
 
 import java.util.*;
-import java.util.concurrent.*;
 import java.util.function.*;
 
 public interface LanguageSupport {
 
-	Function<Map<String, Object>, Object> compileScript(ExecutorService executorService, ClassLoader classLoader, String script);
+	Function<Map<String, Object>, Object> compileScript(ClassLoader classLoader, String script);
 
 }

core/src/main/java/com/predic8/membrane/core/lang/ScriptExecutorPool.java

@@ -26,9 +26,9 @@ public abstract class ScriptExecutorPool<T, R> implements Function<Map<String, O
 	private static final int concurrency = Runtime.getRuntime().availableProcessors() * 2;
 	final ArrayBlockingQueue<T> scripts = new ArrayBlockingQueue<>(concurrency);
 
-	public void init(ExecutorService executorService) {
+	public void init() {
 		scripts.add(createOneScript());
-		executorService.execute(() -> {
+		Thread.ofVirtual().start(() -> {
 			try {
 				for (int i = 1; i < concurrency; i++)
 					scripts.add(createOneScript());

core/src/main/java/com/predic8/membrane/core/lang/groovy/GroovyExchangeExpression.java

@@ -39,7 +39,7 @@ public GroovyExchangeExpression(Interceptor interceptor, String source) {
         super(source);
         this.router = interceptor.getRouter();
         try {
-            script = new GroovyLanguageSupport().compileScript(router.getBackgroundInitializer(), null, source);
+            script = new GroovyLanguageSupport().compileScript( null, source);
         } catch (MultipleCompilationErrorsException e) {
             throw new ConfigurationException("Cannot compile Groovy Script.",e);
         }

core/src/main/java/com/predic8/membrane/core/lang/groovy/GroovyLanguageSupport.java

@@ -27,9 +27,9 @@ private abstract static class GroovyScriptExecutorPool<R> extends
 	ScriptExecutorPool<Script, R> {
 		private final String groovyCode;
 
-		private GroovyScriptExecutorPool(ExecutorService executorService, String expression) {
+		private GroovyScriptExecutorPool(String expression) {
 			this.groovyCode = expression;
-			init(executorService);
+			init();
 		}
 
 		@Override
@@ -56,8 +56,8 @@ private static Binding getBinding(Map<String, Object> parameters) {
 	private static final GroovyShell shell = new GroovyShell();
 
 	@Override
-	public Function<Map<String, Object>, Object> compileScript(ExecutorService executorService, ClassLoader classLoader, String script) {
-		return new GroovyScriptExecutorPool<>(executorService, addImports(script)) {
+	public Function<Map<String, Object>, Object> compileScript(ClassLoader classLoader, String script) {
+		return new GroovyScriptExecutorPool<>(addImports(script)) {
 			@Override
 			public Object apply(Map<String, Object> parameters) {
 				return this.execute(parameters);

core/src/main/java/com/predic8/membrane/core/lang/javascript/GraalVMJavascriptSupport.java

@@ -38,9 +38,9 @@ private abstract static class GraalVMJavascriptExecutorPool<R> extends ScriptExe
 
         private final String javascriptCode;
 
-        private GraalVMJavascriptExecutorPool(ExecutorService executorService, String expression) {
+        private GraalVMJavascriptExecutorPool(String expression) {
             this.javascriptCode = expression;
-            init(executorService);
+            init();
         }
 
         @Override
@@ -79,11 +79,11 @@ protected Source createOneScript() {
     }
 
     @Override
-    public Function<Map<String, Object>, Object> compileScript(ExecutorService executorService, ClassLoader cl, String script) {
-        return new GraalVMJavascriptSupport.GraalVMJavascriptExecutorPool<>(executorService, script) {
+    public Function<Map<String, Object>, Object> compileScript(ClassLoader cl, String script) {
+        return new GraalVMJavascriptSupport.GraalVMJavascriptExecutorPool<>(script) {
             @Override
             public Object apply(Map<String, Object> parameters) {
-                return this.execute(parameters);
+                return execute(parameters);
             }
         };
     }

core/src/main/java/com/predic8/membrane/core/lang/javascript/RhinoJavascriptLanguageSupport.java

@@ -35,14 +35,14 @@ private abstract static class JavascriptScriptExecutorPool<R> extends ScriptExec
         protected final ScriptEngineManager sce;
         protected final static String javascriptEngineName = "rhino";
 
-        private JavascriptScriptExecutorPool(ExecutorService executorService, ClassLoader classLoader, String expression) {
+        private JavascriptScriptExecutorPool(ClassLoader classLoader, String expression) {
             this.javascriptCode = expression;
 
             // The ScriptEngineManager should search the engine in the classloader of the router
             // otherwise the engine will not be found
             sce = new ScriptEngineManager(classLoader);
 
-            init(executorService);
+            init();
         }
 
         @Override
@@ -67,8 +67,8 @@ protected ScriptEngine createOneScript() {
     }
 
     @Override
-    public Function<Map<String, Object>, Object> compileScript(ExecutorService executorService, ClassLoader classLoader, String script) {
-        return new JavascriptScriptExecutorPool<>(executorService, classLoader, script) {
+    public Function<Map<String, Object>, Object> compileScript(ClassLoader classLoader, String script) {
+        return new JavascriptScriptExecutorPool<>(classLoader, script) {
             @Override
             public Object apply(Map<String, Object> parameters) {
                 return this.execute(parameters);