com.splout.db.hazelcast.TablespaceVersionStore.java Source code

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Here is the source code for com.splout.db.hazelcast.TablespaceVersionStore.java

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package com.splout.db.hazelcast;

/*
 * #%L
 * Splout SQL Server
 * %%
 * Copyright (C) 2012 Datasalt Systems S.L.
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * #L%
 */

import com.google.common.io.Files;
import com.hazelcast.core.MapLoader;
import com.hazelcast.core.MapStore;
import com.splout.db.common.JSONSerDe;
import com.splout.db.common.JSONSerDe.JSONSerDeException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.codehaus.jackson.type.TypeReference;

import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.*;

/**
 * A Hazelcast MapLoader and MapStore that saves each map key/value in a file named "key" that contains "value" as a string (JSON).
 * Saves data for CoordinationStructures.VERSIONS_BEING_SERVED
 */
public class TablespaceVersionStore
        implements MapLoader<String, Map<String, Long>>, MapStore<String, Map<String, Long>> {

    private final static Log log = LogFactory.getLog(TablespaceVersionStore.class);

    private File folder;
    private final static Charset UTF8 = Charset.forName("UTF-8");

    public TablespaceVersionStore(String baseFolder) {
        File folder = new File(baseFolder);
        if (!folder.exists()) {
            folder.mkdirs();
        }
        this.folder = folder;
    }

    @Override
    public void delete(String key) {
        File file = getKeyFile(key);
        if (file.exists()) {
            file.delete();
        }
    }

    @Override
    public void deleteAll(Collection<String> keys) {
        for (String key : keys) {
            delete(key);
        }
    }

    @Override
    public void store(String key, Map<String, Long> value) {
        log.info("Store: " + key + " value: " + value);
        try {
            /**
             * Save value as UTF8 String in a File
             */
            Files.write(JSONSerDe.ser(value).getBytes(UTF8), getKeyFile(key));
        } catch (IOException e) {
            throw new RuntimeException(e);
        } catch (JSONSerDeException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void storeAll(Map<String, Map<String, Long>> keyValues) {
        for (Map.Entry<String, Map<String, Long>> keyValue : keyValues.entrySet()) {
            store(keyValue.getKey(), keyValue.getValue());
        }
    }

    @Override
    public Map<String, Long> load(String key) {
        //      log.info("Load: " + key);
        try {
            /**
             * Load value from a String in a File
             */
            Map<String, Long> map = readValues(getKeyFile(key));
            //         log.info("Load to return: " + map);
            return map;
        } catch (IOException e) {
            throw new RuntimeException(e);
        } catch (JSONSerDeException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public Map<String, Map<String, Long>> loadAll(Collection<String> keys) {
        //     log.info("Load all: " + keys);
        Map<String, Map<String, Long>> toReturn = new HashMap<String, Map<String, Long>>();
        for (String key : keys) {
            Map<String, Long> result = load(key);
            toReturn.put(key, result);
        }
        //     log.info("Load all to return: " + toReturn);
        return toReturn;
    }

    @Override
    public Set<String> loadAllKeys() {
        //      log.info("Load all keys:");
        File[] files = folder.listFiles();
        if (files == null) {
            return null;
        }
        Set<String> keys = new HashSet<String>();
        for (File file : files) {
            keys.add(file.getName());
        }
        //     log.info("Load all keys to return: " + keys);
        return keys;
    }

    // --------------------------------- //

    protected File getKeyFile(String key) {
        return new File(folder, key);
    }

    public final static TypeReference<Map<String, Long>> MAP_STRING_LONG_TYPE_REF = new TypeReference<Map<String, Long>>() {

    };

    protected Map<String, Long> readValues(File file) throws JSONSerDeException, IOException {
        if (file.exists()) {
            return JSONSerDe.deSer(Files.toString(file, UTF8), MAP_STRING_LONG_TYPE_REF);
        } else {
            return null;
        }
    }
}