me.tfeng.toolbox.dust.JsEnginePool.java Source code

Introduction

Here is the source code for me.tfeng.toolbox.dust.JsEnginePool.java

Source

/**
 * Copyright 2016 Thomas Feng
 * <p>
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE
 * file distributed with this work for additional information regarding copyright ownership.  The ASF 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 me.tfeng.toolbox.dust;

import java.util.concurrent.ConcurrentLinkedQueue;

import com.fasterxml.jackson.databind.JsonNode;
import com.google.common.collect.Queues;

import me.tfeng.toolbox.spring.Startable;

/**
 * @author Thomas Feng (huining.feng@gmail.com)
 */
public class JsEnginePool extends JsEngineConfig implements Startable {

    private EngineType engineType = EngineType.NASHORN;

    private volatile ConcurrentLinkedQueue<JsEngine> engines;

    private int size = 5;

    public EngineType getEngineType() {
        return engineType;
    }

    public int getSize() {
        return size;
    }

    @Override
    public void onStart() throws Throwable {
        ConcurrentLinkedQueue engines = Queues.newConcurrentLinkedQueue();
        for (int i = 0; i < size; i++) {
            engines.offer(createEngine());
        }
        this.engines = engines;
    }

    @Override
    public void onStop() throws Throwable {
        engines.forEach(JsEngine::destroy);
    }

    public String render(String template, JsonNode data) throws Exception {
        JsEngine engine = engines.poll();
        try {
            return engine.render(template, data);
        } finally {
            engines.offer(engine);
        }
    }

    public void setEngineType(EngineType engineType) {
        this.engineType = engineType;
    }

    public void setSize(int size) {
        this.size = size;
    }

    private JsEngine createEngine() throws Exception {
        JsEngine engine;
        switch (engineType) {
        case NASHORN:
            engine = new NashornEngine(this);
            break;
        case NODE:
            engine = new NodeEngine(this);
            break;
        default:
            throw new RuntimeException("Unknown engine type " + engineType);
        }

        engine.initialize();
        return engine;
    }
}