net.sf.aguacate.script.InternalScriptCoupling Maven / Gradle / Ivy

Go to download
package net.sf.aguacate.script;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import net.sf.aguacate.script.spi.JavascriptInternalScriptFactory;
import net.sf.aguacate.util.resource.ResourceLocator;
import net.sf.aguacate.util.resource.impl.ResourceLocatorClassImpl;
import net.sf.aguacate.util.resource.impl.ResourceLocatorFileImpl;

public final class InternalScriptCoupling {

	private static final Logger LOGGER = LogManager.getLogger(InternalScriptCoupling.class);

	private static final String DIRECTORY_DATASOURCE = "DIRECTORY_DATASOURCE";

	private static final ResourceLocator LOCATOR;

	private static final InternalScriptFactory FACTORY;

	private static Map cache;

	static {
		FACTORY = new JavascriptInternalScriptFactory();
		String temp = System.getProperty(DIRECTORY_DATASOURCE);
		if (temp == null || temp.isEmpty()) {
			temp = System.getenv(DIRECTORY_DATASOURCE);
			if (temp == null || temp.isEmpty()) {
				LOGGER.info("No " + DIRECTORY_DATASOURCE + " defined, using default");
				LOCATOR = new ResourceLocatorClassImpl(InternalScriptCoupling.class);
			} else {
				LOGGER.info("using " + DIRECTORY_DATASOURCE + " (env): {}", temp);
				LOCATOR = new ResourceLocatorFileImpl(temp);
			}
		} else {
			LOGGER.info("using " + DIRECTORY_DATASOURCE + " (prop): {}", temp);
			LOCATOR = new ResourceLocatorFileImpl(temp);
		}
		cache = Collections.emptyMap();
	}

	private InternalScriptCoupling() {
	}

	public static final InternalScript load(String scriptName) {
		InternalScript result = cache.get(scriptName);
		if (result == null) {
			synchronized (InternalScriptCoupling.class) {
				result = cache.get(scriptName);
				if (result == null) {
					Map temp = new HashMap<>(cache);
					result = load0(scriptName);
					temp.put(scriptName, result);
					cache = temp;
				}
			}
		}
		return result;
	}

	static InternalScript load0(String scriptName) {
		String filename = scriptName.concat(".js");
		LOGGER.debug(filename);
		try {
			InputStream inputStream = LOCATOR.open(filename);
			if (inputStream == null) {
				return null;
			} else {
				Reader reader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
				try {
					return FACTORY.build(reader);
				} finally {
					try {
						reader.close();
					} catch (IOException e) {
						LOGGER.warn("On closing resource", e);
					}
				}
			}
		} catch (IOException e) {
			throw new IllegalStateException(filename, e);
		}
	}

}