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   1 /**
   2  * Copyright (c) 2010-2021 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13
  14 package org.openhab.automation.jsscripting.internal;
  15
  16 import static org.openhab.core.automation.module.script.ScriptEngineFactory.CONTEXT_KEY_ENGINE_IDENTIFIER;
  17 import static org.openhab.core.automation.module.script.ScriptEngineFactory.CONTEXT_KEY_EXTENSION_ACCESSOR;
  18
  19 import java.io.File;
  20 import java.io.IOException;
  21 import java.nio.channels.SeekableByteChannel;
  22 import java.nio.file.FileSystems;
  23 import java.nio.file.OpenOption;
  24 import java.nio.file.Path;
  25 import java.nio.file.attribute.FileAttribute;
  26 import java.util.Set;
  27 import java.util.function.Consumer;
  28 import java.util.function.Function;
  29
  30 import javax.script.ScriptContext;
  31
  32 import org.eclipse.jdt.annotation.NonNullByDefault;
  33 import org.graalvm.polyglot.Context;
  34 import org.openhab.automation.jsscripting.internal.fs.DelegatingFileSystem;
  35 import org.openhab.automation.jsscripting.internal.fs.PrefixedSeekableByteChannel;
  36 import org.openhab.automation.jsscripting.internal.scriptengine.InvocationInterceptingScriptEngineWithInvocable;
  37 import org.openhab.core.OpenHAB;
  38 import org.openhab.core.automation.module.script.ScriptExtensionAccessor;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 import com.oracle.truffle.js.scriptengine.GraalJSScriptEngine;
  43
  44 /**
  45  * GraalJS Script Engine implementation
  46  *
  47  * @author Jonathan Gilbert - Initial contribution
  48  */
  49 public class OpenhabGraalJSScriptEngine extends InvocationInterceptingScriptEngineWithInvocable<GraalJSScriptEngine> {
  50
  51     private static final Logger logger = LoggerFactory.getLogger(OpenhabGraalJSScriptEngine.class);
  52
  53     private static final String REQUIRE_WRAPPER_NAME = "__wraprequire__";
  54     private static final String MODULE_DIR = String.join(File.separator, OpenHAB.getConfigFolder(), "automation", "lib",
  55             "javascript", "personal");
  56
  57     // these fields start as null because they are populated on first use
  58     @NonNullByDefault({})
  59     private String engineIdentifier;
  60     @NonNullByDefault({})
  61     private Consumer<String> scriptDependencyListener;
  62
  63     private boolean initialized = false;
  64
  65     /**
  66      * Creates an implementation of ScriptEngine (& Invocable), wrapping the contained engine, that tracks the script
  67      * lifecycle and provides hooks for scripts to do so too.
  68      */
  69     public OpenhabGraalJSScriptEngine() {
  70         super(null); // delegate depends on fields not yet initialised, so we cannot set it immediately
  71         delegate = GraalJSScriptEngine.create(null,
  72                 Context.newBuilder("js").allowExperimentalOptions(true).allowAllAccess(true)
  73                         .option("js.commonjs-require-cwd", MODULE_DIR).option("js.nashorn-compat", "true") // to ease
  74                                                                                                            // migration
  75                         .option("js.commonjs-require", "true") // enable CommonJS module support
  76                         .fileSystem(new DelegatingFileSystem(FileSystems.getDefault().provider()) {
  77                             @Override
  78                             public SeekableByteChannel newByteChannel(Path path, Set<? extends OpenOption> options,
  79                                     FileAttribute<?>... attrs) throws IOException {
  80                                 if (scriptDependencyListener != null) {
  81                                     scriptDependencyListener.accept(path.toString());
  82                                 }
  83
  84                                 if (path.toString().endsWith(".js")) {
  85                                     return new PrefixedSeekableByteChannel(
  86                                             ("require=" + REQUIRE_WRAPPER_NAME + "(require);").getBytes(),
  87                                             super.newByteChannel(path, options, attrs));
  88                                 } else {
  89                                     return super.newByteChannel(path, options, attrs);
  90                                 }
  91                             }
  92                         }));
  93     }
  94
  95     @Override
  96     protected void beforeInvocation() {
  97         if (initialized) {
  98             return;
  99         }
 100
 101         ScriptContext ctx = delegate.getContext();
 102
 103         // these are added post-construction, so we need to fetch them late
 104         this.engineIdentifier = (String) ctx.getAttribute(CONTEXT_KEY_ENGINE_IDENTIFIER);
 105         if (this.engineIdentifier == null) {
 106             throw new IllegalStateException("Failed to retrieve engine identifier from engine bindings");
 107         }
 108
 109         ScriptExtensionAccessor scriptExtensionAccessor = (ScriptExtensionAccessor) ctx
 110                 .getAttribute(CONTEXT_KEY_EXTENSION_ACCESSOR);
 111         if (scriptExtensionAccessor == null) {
 112             throw new IllegalStateException("Failed to retrieve script extension accessor from engine bindings");
 113         }
 114
 115         scriptDependencyListener = (Consumer<String>) ctx
 116                 .getAttribute("oh.dependency-listener"/* CONTEXT_KEY_DEPENDENCY_LISTENER */);
 117         if (scriptDependencyListener == null) {
 118             logger.warn(
 119                     "Failed to retrieve script script dependency listener from engine bindings. Script dependency tracking will be disabled.");
 120         }
 121
 122         ScriptExtensionModuleProvider scriptExtensionModuleProvider = new ScriptExtensionModuleProvider(
 123                 scriptExtensionAccessor);
 124
 125         Function<Function<Object[], Object>, Function<String, Object>> wrapRequireFn = originalRequireFn -> moduleName -> scriptExtensionModuleProvider
 126                 .locatorFor(delegate.getPolyglotContext(), engineIdentifier).locateModule(moduleName)
 127                 .map(m -> (Object) m).orElseGet(() -> originalRequireFn.apply(new Object[] { moduleName }));
 128
 129         delegate.getBindings(ScriptContext.ENGINE_SCOPE).put(REQUIRE_WRAPPER_NAME, wrapRequireFn);
 130         delegate.put("require", wrapRequireFn.apply((Function<Object[], Object>) delegate.get("require")));
 131
 132         initialized = true;
 133     }
 134 }