PoC for JSR223 script-engine (#149)

Signed-off-by: Thomas Darimont <[email protected]>

pom.xml

@@ -43,6 +43,7 @@
     <module>wasi</module>
     <module>wasm-corpus</module>
     <module>cli</module>
+    <module>scriptengine</module>
   </modules>
 
   <scm>

scriptengine/pom.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.dylibso.chicory</groupId>
+    <artifactId>chicory</artifactId>
+    <version>999-SNAPSHOT</version>
+  </parent>
+  <artifactId>scriptengine</artifactId>
+  <name>Chicory - JSR 223 Script Engine</name>
+  <description>WebAssembly Script Engine</description>
+  <dependencies>
+    <dependency>
+      <groupId>com.dylibso.chicory</groupId>
+      <artifactId>runtime</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
+    </dependency>
+
+    <dependency>
+      <!-- generates meta-inf services file for script engine -->
+      <groupId>com.google.auto.service</groupId>
+      <artifactId>auto-service</artifactId>
+      <version>1.1.1</version>
+      <scope>provided</scope>
+      <optional>true</optional>
+    </dependency>
+  </dependencies>
+</project>

scriptengine/src/main/java/com/dylibso/chicory/scriptengine/ChicoryScriptEngine.java

@@ -0,0 +1,102 @@
+package com.dylibso.chicory.scriptengine;
+
+import com.dylibso.chicory.runtime.Module;
+import com.dylibso.chicory.wasm.types.Value;
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.util.Base64;
+import java.util.Objects;
+import javax.script.Bindings;
+import javax.script.ScriptContext;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineFactory;
+import javax.script.ScriptException;
+import javax.script.SimpleBindings;
+
+public class ChicoryScriptEngine implements ScriptEngine {
+
+    @Override
+    public Object eval(String script, ScriptContext context) throws ScriptException {
+        return null;
+    }
+
+    @Override
+    public Object eval(Reader reader, ScriptContext context) throws ScriptException {
+        return null;
+    }
+
+    @Override
+    public Object eval(String script) throws ScriptException {
+        return eval(script, (ScriptContext) null);
+    }
+
+    @Override
+    public Object eval(Reader reader) throws ScriptException {
+        return eval(reader, (ScriptContext) null);
+    }
+
+    @Override
+    public Object eval(String script, Bindings bindings) throws ScriptException {
+        return eval(new StringReader(script), bindings);
+    }
+
+    @Override
+    public Object eval(Reader reader, Bindings bindings) throws ScriptException {
+
+        StringWriter sw = new StringWriter();
+        try {
+            reader.transferTo(sw);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+
+        byte[] wasmBytes =
+                Base64.getDecoder().decode(Objects.requireNonNull(sw.toString(), "script"));
+
+        int arg0 = ((Integer) bindings.get("arg0")).intValue();
+        String func = (String) bindings.get("func");
+
+        var module = Module.builder(wasmBytes).build();
+        var instance = module.instantiate();
+        var iterFact = instance.export(func);
+        var result = iterFact.apply(Value.i32(arg0))[0].asInt();
+
+        return result;
+    }
+
+    @Override
+    public void put(String key, Object value) {}
+
+    @Override
+    public Object get(String key) {
+        return null;
+    }
+
+    @Override
+    public Bindings getBindings(int scope) {
+        return null;
+    }
+
+    @Override
+    public void setBindings(Bindings bindings, int scope) {}
+
+    @Override
+    public Bindings createBindings() {
+        return new SimpleBindings();
+    }
+
+    @Override
+    public ScriptContext getContext() {
+        return null;
+    }
+
+    @Override
+    public void setContext(ScriptContext context) {}
+
+    @Override
+    public ScriptEngineFactory getFactory() {
+        return null;
+    }
+}

scriptengine/src/main/java/com/dylibso/chicory/scriptengine/ChicoryScriptEngineFactory.java

@@ -0,0 +1,70 @@
+package com.dylibso.chicory.scriptengine;
+
+import com.google.auto.service.AutoService;
+import java.util.List;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineFactory;
+
+@AutoService(ScriptEngineFactory.class)
+public class ChicoryScriptEngineFactory implements ScriptEngineFactory {
+
+    @Override
+    public String getEngineName() {
+        return "Chicory ScriptEngine";
+    }
+
+    @Override
+    public String getEngineVersion() {
+        return getClass().getPackage().getImplementationVersion();
+    }
+
+    @Override
+    public List<String> getExtensions() {
+        return List.of("wasm");
+    }
+
+    @Override
+    public List<String> getMimeTypes() {
+        return List.of("application/wasm");
+    }
+
+    @Override
+    public List<String> getNames() {
+        return List.of("chicory");
+    }
+
+    @Override
+    public String getLanguageName() {
+        return "WebAssembly";
+    }
+
+    @Override
+    public String getLanguageVersion() {
+        return "1.0";
+    }
+
+    @Override
+    public Object getParameter(String key) {
+        return null;
+    }
+
+    @Override
+    public String getMethodCallSyntax(String obj, String m, String... args) {
+        return "";
+    }
+
+    @Override
+    public String getOutputStatement(String toDisplay) {
+        return "";
+    }
+
+    @Override
+    public String getProgram(String... statements) {
+        return "";
+    }
+
+    @Override
+    public ScriptEngine getScriptEngine() {
+        return new ChicoryScriptEngine();
+    }
+}

scriptengine/src/test/java/com/dylibso/chicory/scriptengine/ChicoryScriptEngineTest.java

@@ -0,0 +1,45 @@
+package com.dylibso.chicory.scriptengine;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Base64;
+import javax.script.Bindings;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class ChicoryScriptEngineTest {
+
+    ScriptEngineManager engines;
+
+    @BeforeEach
+    public void init() {
+        engines = new ScriptEngineManager();
+    }
+
+    @Test
+    public void scriptEngineLookupByName() {
+        Assertions.assertNotNull(engines.getEngineByName("chicory"));
+    }
+
+    @Test
+    public void scriptEngineLookupByExtension() {
+        Assertions.assertNotNull(engines.getEngineByExtension("wasm"));
+    }
+
+    @Test
+    public void simpleEval() throws Exception {
+        ScriptEngine engine = engines.getEngineByExtension("wasm");
+        byte[] wasmBytes =
+                Files.readAllBytes(
+                        Path.of("../wasm-corpus/src/test/resources/compiled/iterfact.wat.wasm"));
+        String wasmBase64 = Base64.getEncoder().encodeToString(wasmBytes);
+        Bindings bindings = engine.createBindings();
+        bindings.put("arg0", 5);
+        bindings.put("func", "iterFact");
+        Object result = engine.eval(wasmBase64, bindings);
+        Assertions.assertEquals(120, result);
+    }
+}