com.qwazr.graph.GraphManager.java Source code

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Here is the source code for com.qwazr.graph.GraphManager.java

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/**
 * Copyright 2015-2016 Emmanuel Keller / QWAZR
 * <p>
 * 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
 * <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 com.qwazr.graph;

import com.qwazr.cluster.client.ClusterMultiClient;
import com.qwazr.cluster.manager.ClusterManager;
import com.qwazr.database.store.DatabaseException;
import com.qwazr.database.store.Table;
import com.qwazr.database.store.Tables;
import com.qwazr.graph.model.GraphDefinition;
import com.qwazr.utils.LockUtils;
import com.qwazr.utils.json.DirectoryJsonManager;
import com.qwazr.utils.server.ServerException;
import org.apache.commons.io.FileUtils;

import javax.ws.rs.core.Response.Status;
import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ExecutorService;

public class GraphManager extends DirectoryJsonManager<GraphDefinition> {

    public final static String SERVICE_NAME_GRAPH = "graph";

    private final LockUtils.ReadWriteLock rwl = new LockUtils.ReadWriteLock();

    static GraphManager INSTANCE = null;

    public File directory;

    final ExecutorService executorService;

    private final Map<String, GraphInstance> graphMap;

    public synchronized static Class<? extends GraphServiceInterface> load(ExecutorService executorService,
            File dataDirectory) throws IOException {
        if (INSTANCE != null)
            throw new IOException("Already loaded");
        File graphDirectory = new File(dataDirectory, SERVICE_NAME_GRAPH);
        if (!graphDirectory.exists())
            graphDirectory.mkdir();
        try {
            INSTANCE = new GraphManager(executorService, graphDirectory);
            for (String name : INSTANCE.nameSet())
                INSTANCE.addNewInstance(name, INSTANCE.get(name));
            return GraphServiceImpl.class;
        } catch (ServerException | DatabaseException e) {
            throw new RuntimeException(e);
        }
    }

    public static GraphManager getInstance() {
        if (INSTANCE == null)
            throw new RuntimeException("The graph service is not enabled");
        return INSTANCE;
    }

    private GraphManager(ExecutorService executorService, File directory) throws ServerException, IOException {
        super(directory, GraphDefinition.class);
        this.executorService = executorService;
        this.directory = directory;
        graphMap = new HashMap<String, GraphInstance>();
    }

    private GraphInstance addNewInstance(String graphName, GraphDefinition graphDef)
            throws IOException, ServerException, DatabaseException {
        File dbDirectory = new File(directory, graphName);
        if (!dbDirectory.exists())
            dbDirectory.mkdir();
        Table table = Tables.getInstance(dbDirectory, true);
        GraphInstance graphInstance = new GraphInstance(graphName, table, graphDef);
        graphInstance.checkFields();
        graphMap.put(graphName, graphInstance);
        return graphInstance;
    }

    public GraphInstance getGraphInstance(String graphName) throws ServerException {
        rwl.r.lock();
        try {
            GraphInstance graphInstance = graphMap.get(graphName);
            if (graphInstance == null)
                throw new ServerException(Status.NOT_FOUND, "Graph instance not found");
            return graphInstance;
        } finally {
            rwl.r.unlock();
        }
    }

    @Override
    public Set<String> nameSet() {
        return super.nameSet();
    }

    @Override
    public GraphDefinition get(String name) throws IOException {
        return super.get(name);
    }

    public void createUpdateGraph(String graphName, GraphDefinition graphDef)
            throws IOException, ServerException, DatabaseException {
        rwl.w.lock();
        try {
            super.set(graphName, graphDef);
            graphMap.remove(graphName);
            addNewInstance(graphName, graphDef);
        } finally {
            rwl.w.unlock();
        }
    }

    @Override
    public GraphDefinition delete(String graphName) throws ServerException, IOException {
        rwl.w.lock();
        try {
            GraphDefinition graphDef = super.delete(graphName);
            File dbDirectory = new File(directory, graphName);
            Table table = Tables.getInstance(dbDirectory, false);
            if (table != null)
                table.close();
            FileUtils.deleteDirectory(dbDirectory);
            graphMap.remove(graphName);
            return graphDef;
        } catch (DatabaseException e) {
            throw new ServerException(e);
        } finally {
            rwl.w.unlock();
        }
    }

    GraphMultiClient getMultiClient(int msTimeOut) throws URISyntaxException {
        ClusterMultiClient clusterClient = ClusterManager.INSTANCE.getClusterClient();
        if (clusterClient == null)
            return null;
        return new GraphMultiClient(executorService,
                clusterClient.getActiveNodesByService(SERVICE_NAME_GRAPH, null), msTimeOut);
    }
}