GameStarter.java

/*
 * Copyright 2016 MovingBlocks
 *
 * 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.
 */

package org.terasology.launcher.game;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.terasology.launcher.util.FileUtils;
import org.terasology.launcher.util.JavaHeapSize;
import org.terasology.launcher.util.LogLevel;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public final class GameStarter {

    private static final Logger logger = LoggerFactory.getLogger(GameStarter.class);

    private static final int PROCESS_START_SLEEP_TIME = 5000;

    private Thread gameThread;

    public GameStarter() {
    }

    public boolean isRunning() {
        return (gameThread != null) && gameThread.isAlive();
    }

    public void dispose() {
        if (gameThread != null) {
            gameThread.interrupt();
        }
        gameThread = null;
    }

    public boolean startGame(TerasologyGameVersion gameVersion, File gameDataDirectory, JavaHeapSize maxHeapSize,
                             JavaHeapSize initialHeapSize, List<String> userJavaParameters, List<String> userGameParameters, LogLevel logLevel) {
        if (isRunning()) {
            logger.warn("The game can not be started because another game is already running! '{}'", gameThread);
            return false;
        }

        final List<String> javaParameters = createJavaParameters(maxHeapSize, initialHeapSize, userJavaParameters, logLevel);
        final List<String> processParameters = createProcessParameters(gameVersion, gameDataDirectory, javaParameters, userGameParameters);

        return startProcess(gameVersion, processParameters);
    }

    private List<String> createJavaParameters(JavaHeapSize maxHeapSize, JavaHeapSize initialHeapSize, List<String> userJavaParameters, LogLevel logLevel) {
        final List<String> javaParameters = new ArrayList<>();
        if (initialHeapSize.isUsed()) {
            javaParameters.add("-Xms" + initialHeapSize.getSizeParameter());
        }
        if (maxHeapSize.isUsed()) {
            javaParameters.add("-Xmx" + maxHeapSize.getSizeParameter());
        }
        if (!logLevel.isDefault()) {
            javaParameters.add("-DlogOverrideLevel=" + logLevel.name());
        }
        javaParameters.addAll(userJavaParameters);
        return javaParameters;
    }

    private List<String> createProcessParameters(TerasologyGameVersion gameVersion, File gameDataDirectory, List<String> javaParameters,
                                                 List<String> gameParameters) {
        final List<String> processParameters = new ArrayList<>();
        processParameters.add("java");
        processParameters.addAll(javaParameters);
        processParameters.add("-jar");
        processParameters.add(gameVersion.getGameJar().getName());
        processParameters.add("-homedir=" + gameDataDirectory.getPath());
        processParameters.addAll(gameParameters);

        return processParameters;
    }

    private boolean startProcess(TerasologyGameVersion gameVersion, List<String> processParameters) {
        final ProcessBuilder pb = new ProcessBuilder(processParameters);
        pb.redirectErrorStream(true);
        pb.directory(gameVersion.getInstallationPath());
        logger.debug("Starting game process with '{}' in '{}' for '{}'", processParameters, gameVersion.getInstallationPath(), gameVersion);
        try {
            final Process p = pb.start();

            gameThread = new Thread(new GameRunner(p));
            gameThread.setName("game" + gameVersion.getBuildNumber());
            gameThread.start();

            Thread.sleep(PROCESS_START_SLEEP_TIME);

            if (!gameThread.isAlive()) {
                final int exitValue = p.waitFor();
                logger.warn("The game was stopped early. It returns with the exit value '{}'.", exitValue);
                return false;
            } else {
                logger.info("The game is successfully launched.");
            }
        } catch (InterruptedException | IOException | RuntimeException e) {
            logger.error("The game could not be started due to an error! Parameters '{}' for '{}'!", processParameters, gameVersion, e);
            return false;
        }
        return true;
    }
}