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The engine API for nosqlbench; Provides the interfaces needed to build internal modules for the nosqlbench core engine

There is a newer version: 5.17.0

package io.nosqlbench.engine.api.scripting;

/*
 * Copyright (c) 2022 nosqlbench
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */


import org.graalvm.polyglot.*;

public class GraalJsEvaluator implements ExprEvaluator {

    private final Class resultType;
    private Context context;
    private Source script;

    public GraalJsEvaluator(Class resultType) {
        this.resultType = resultType;
    }

    private Context getContext() {
        if (context == null) {
            Context.Builder contextSettings = Context.newBuilder("js")
                    .allowHostAccess(HostAccess.ALL)
                    .allowNativeAccess(true)
                    .allowCreateThread(true)
                    .allowIO(true)
                    .allowHostClassLookup(s -> true)
                    .allowHostClassLoading(true)
                    .allowCreateProcess(true)
                    .allowAllAccess(true)
                    .allowEnvironmentAccess(EnvironmentAccess.INHERIT)
                    .allowPolyglotAccess(PolyglotAccess.ALL)
                    .option("js.ecmascript-version", "2020")
                    .option("js.nashorn-compat", "true");
            context = contextSettings.build();
        }
        return context;
    }

    @Override
    public T eval() {
        Value result = getContext().eval(this.script);
        T asType = result.as(resultType);
        return asType;
    }

    @Override
    public ExprEvaluator script(String scriptText) {
        this.script = Source.create("js", scriptText);
        return this;
    }

    @Override
    public ExprEvaluator put(String varName, Object var) {
        getContext().getBindings("js").putMember(varName, var);
        return this;
    }
}