org.cryptomator.ui.settings.SettingsProvider.java Source code

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Here is the source code for org.cryptomator.ui.settings.SettingsProvider.java

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/*******************************************************************************
 * Copyright (c) 2016 Sebastian Stenzel and others.
 * This file is licensed under the terms of the MIT license.
 * See the LICENSE.txt file for more info.
 *
 * Contributors:
 *     Sebastian Stenzel - initial API and implementation
 *******************************************************************************/
package org.cryptomator.ui.settings;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.FileSystem;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.Objects;
import java.util.Optional;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Provider;
import javax.inject.Singleton;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.SystemUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.databind.ObjectMapper;

@Singleton
public class SettingsProvider implements Provider<Settings> {

    private static final Logger LOG = LoggerFactory.getLogger(SettingsProvider.class);
    private static final Path DEFAULT_SETTINGS_PATH;
    private static final long SAVE_DELAY_MS = 1000;

    static {
        final FileSystem fs = FileSystems.getDefault();
        if (SystemUtils.IS_OS_WINDOWS) {
            DEFAULT_SETTINGS_PATH = fs.getPath(SystemUtils.USER_HOME, "AppData/Roaming/Cryptomator/settings.json");
        } else if (SystemUtils.IS_OS_MAC_OSX) {
            DEFAULT_SETTINGS_PATH = fs.getPath(SystemUtils.USER_HOME,
                    "Library/Application Support/Cryptomator/settings.json");
        } else {
            DEFAULT_SETTINGS_PATH = fs.getPath(SystemUtils.USER_HOME, ".Cryptomator/settings.json");
        }
    }

    private final ObjectMapper objectMapper;
    private final ScheduledExecutorService saveScheduler = Executors.newSingleThreadScheduledExecutor();
    private final AtomicReference<ScheduledFuture<?>> scheduledSaveCmd = new AtomicReference<>();

    @Inject
    public SettingsProvider(@Named("VaultJsonMapper") ObjectMapper objectMapper) {
        this.objectMapper = objectMapper;
    }

    private Path getSettingsPath() throws IOException {
        final String settingsPathProperty = System.getProperty("cryptomator.settingsPath");
        return Optional.ofNullable(settingsPathProperty).filter(StringUtils::isNotBlank).map(this::replaceHomeDir)
                .map(FileSystems.getDefault()::getPath).orElse(DEFAULT_SETTINGS_PATH);
    }

    private String replaceHomeDir(String path) {
        if (path.startsWith("~/")) {
            return SystemUtils.USER_HOME + path.substring(1);
        } else {
            return path;
        }
    }

    @Override
    public Settings get() {
        final Settings settings = new Settings(this::scheduleSave);
        try {
            final Path settingsPath = getSettingsPath();
            final InputStream in = Files.newInputStream(settingsPath, StandardOpenOption.READ);
            objectMapper.readerForUpdating(settings).readValue(in);
            LOG.info("Settings loaded from " + settingsPath);
        } catch (IOException e) {
            LOG.info("Failed to load settings, creating new one.");
        }
        return settings;
    }

    private void scheduleSave(Settings settings) {
        if (settings == null) {
            return;
        }
        ScheduledFuture<?> saveCmd = saveScheduler.schedule(() -> {
            this.save(settings);
        }, SAVE_DELAY_MS, TimeUnit.MILLISECONDS);
        ScheduledFuture<?> previousSaveCmd = scheduledSaveCmd.getAndSet(saveCmd);
        if (previousSaveCmd != null) {
            previousSaveCmd.cancel(false);
        }
    }

    private void save(Settings settings) {
        Objects.requireNonNull(settings);
        try {
            final Path settingsPath = getSettingsPath();
            Files.createDirectories(settingsPath.getParent());
            final OutputStream out = Files.newOutputStream(settingsPath, StandardOpenOption.WRITE,
                    StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.CREATE);
            objectMapper.writeValue(out, settings);
            LOG.info("Settings saved to " + settingsPath);
        } catch (IOException e) {
            LOG.error("Failed to save settings.", e);
        }
    }

}