TableTrigger.java

/**
 * OrbisGIS is a java GIS application dedicated to research in GIScience.
 * OrbisGIS is developed by the GIS group of the DECIDE team of the 
 * Lab-STICC CNRS laboratory, see <http://www.lab-sticc.fr/>.
 *
 * The GIS group of the DECIDE team is located at :
 *
 * Laboratoire Lab-STICC – CNRS UMR 6285
 * Equipe DECIDE
 * UNIVERSITÉ DE BRETAGNE-SUD
 * Institut Universitaire de Technologie de Vannes
 * 8, Rue Montaigne - BP 561 56017 Vannes Cedex
 * 
 * OrbisGIS is distributed under GPL 3 license.
 *
 * Copyright (C) 2007-2014 CNRS (IRSTV FR CNRS 2488)
 * Copyright (C) 2015-2017 CNRS (Lab-STICC UMR CNRS 6285)
 *
 * This file is part of OrbisGIS.
 *
 * OrbisGIS is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * OrbisGIS 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 General Public License along with
 * OrbisGIS. If not, see <http://www.gnu.org/licenses/>.
 *
 * For more information, please consult: <http://www.orbisgis.org/>
 * or contact directly:
 * info_at_ orbisgis.org
 */
package org.orbisgis.h2triggersosgi;

import org.h2.api.Trigger;
import org.h2gis.utilities.JDBCUtilities;
import org.h2gis.utilities.TableLocation;
import org.orbisgis.corejdbc.DataManager;
import org.orbisgis.corejdbc.StateEvent;
import org.orbisgis.corejdbc.TableEditEvent;

import javax.swing.*;
import javax.swing.event.TableModelEvent;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicBoolean;

/**
 * Trigger attached to H2 Database
 * @author Nicolas Fortin
 */
public class TableTrigger implements Trigger {
    private DataManager dataManager;
    private String tableIdentifier;
    private boolean update;
    private final Queue<TableEditEvent> editStack = new ConcurrentLinkedQueue<>();
    private final AtomicBoolean stateEventProcessing = new AtomicBoolean(false);
    private int pkColumn = -1;

    public TableTrigger(DataManager dataManager) {
        this.dataManager = dataManager;
    }

    @Override
    public void init(Connection conn, String schemaName, String triggerName, String tableName, boolean before, int type) throws SQLException {
        this.update = type == UPDATE;
        this.tableIdentifier = new TableLocation(schemaName, tableName).toString(true);
        if(!dataManager.hasTableEditListener(tableIdentifier)) {
            try(Statement st = conn.createStatement()) {
                st.execute("DROP TRIGGER IF EXISTS "+triggerName);
            }
            throw new SQLException("This trigger does not exists");
        } else {
            // Fetch primary key column
            pkColumn = JDBCUtilities.getIntegerPrimaryKey(conn, tableIdentifier);
        }
    }

    @Override
    public void fire(Connection conn, Object[] oldRow, Object[] newRow) throws SQLException {
        // Do not fire the event in the H2 thread in order to not raise
        // org.h2.jdbc.JdbcSQLException: Timeout trying to lock table XXX
        int type = TableModelEvent.DELETE;
        if(oldRow == null && newRow != null) {
            type = TableModelEvent.INSERT;
        } else if(oldRow != null && newRow != null) {
            type = TableModelEvent.UPDATE;
        }
        Long pk = null;
        if(pkColumn != -1 && newRow != null && newRow.length > pkColumn - 1 && newRow[pkColumn - 1] instanceof Long) {
            pk = (Long)newRow[pkColumn - 1];
        }
        fireEvent(new TableEditEvent(tableIdentifier, TableModelEvent.ALL_COLUMNS, pk, pk, type));
    }

    @Override
    public void close() throws SQLException {

    }

    @Override
    public void remove() throws SQLException {
        // Do not fire the event in the H2 thread in order to not raise
        // org.h2.jdbc.JdbcSQLException: Timeout trying to lock table XXX
        fireEvent(new TableEditEvent(tableIdentifier, TableModelEvent.ALL_COLUMNS, null, null, TableModelEvent.DELETE));
    }

    private void fireEvent(TableEditEvent evt) {
        editStack.add(evt);
        if(!stateEventProcessing.getAndSet(true)) {
            new TableEditEventProcess(dataManager, editStack, stateEventProcessing).execute();
        }

    }

    private static class TableEditEventProcess extends SwingWorker {
        private final DataManager dataManager;
        private final Queue<TableEditEvent> editStack;
        private final AtomicBoolean stateEventProcessing;
        private static final int TIME_MAX_THREAD_ALIVE = 5000;
        private static final int SLEEP_TIME = 500;

        private TableEditEventProcess(DataManager dataManager, Queue<TableEditEvent> editStack, AtomicBoolean stateEventProcessing) {
            this.dataManager = dataManager;
            this.editStack = editStack;
            this.stateEventProcessing = stateEventProcessing;
        }

        @Override
        public String toString() {
            return "TableEditEventProcess editStack="+editStack.size();
        }

        @Override
        protected Object doInBackground() throws Exception {
            long begin = System.currentTimeMillis();
            try {
                while (!editStack.isEmpty() || System.currentTimeMillis() - begin < TIME_MAX_THREAD_ALIVE) {
                    while (!editStack.isEmpty()) {
                        dataManager.fireTableEditHappened(editStack.remove());
                    }
                    try {
                        Thread.sleep(SLEEP_TIME);
                    } catch (InterruptedException ex) {
                        break;
                    }
                }
            } finally {
                stateEventProcessing.set(false);
            }
            return null;
        }
    }
}