EvalScala.java

/*
 * Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. licenses this file to you 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.
 */

package org.wso2.siddhi.extension.script;

import org.wso2.siddhi.annotation.Extension;
import org.wso2.siddhi.core.exception.ExecutionPlanCreationException;
import org.wso2.siddhi.core.exception.ExecutionPlanRuntimeException;
import org.wso2.siddhi.core.function.Script;
import org.wso2.siddhi.query.api.definition.Attribute;
import scala.Function1;

@Extension(
        name = "scala",
        namespace = "script",
        description = ""
)
public class EvalScala implements Script {

    private Function1<Object[], Object> scalaFunction;
    private Attribute.Type returnType;
    private String functionName;

    public EvalScala() {

    }

    public void init(String name, String body) {
        this.functionName = name;
        if (returnType == null) {
            throw new ExecutionPlanCreationException("Cannot find the return type of the function " + functionName);
        }
        ScalaEvaluationEngine scalaEvaluationEngine = new ScalaEvaluationEngine();
        try {
            scalaFunction = scalaEvaluationEngine.eval("data: (Array[Any]) =>  {\n" + body + "\n}");
        } catch (Exception e) {
            throw new ExecutionPlanCreationException("Compilation Failure of the Scala Function " + name, e);
        }
    }

    @Override
    public Object eval(String name, Object[] arg) {
        try {
            return scalaFunction.apply(arg);
        } catch (Exception e) {
            throw new ExecutionPlanRuntimeException("Error while evaluating function " + name, e);
        }
    }

    @Override
    public Attribute.Type getReturnType() {
        return returnType;
    }

    @Override
    public void setReturnType(Attribute.Type returnType) {
        this.returnType = returnType;
    }
}