Semaphore.java

/*
 * GovWay - A customizable API Gateway 
 * https://govway.org
 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
 * 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 General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package org.openspcoop2.utils.semaphore;

import java.sql.Connection;

import org.slf4j.Logger;
import org.openspcoop2.utils.TipiDatabase;
import org.openspcoop2.utils.UtilsException;
import org.openspcoop2.utils.id.serial.InfoStatistics;
import org.openspcoop2.utils.jdbc.JDBCUtilities;

/**
 * IDSerialGenerator
 *
 * @author Poli Andrea (apoli@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public class Semaphore {

    private InfoStatistics infoStatistics;
    private SemaphoreEngine engine;
    private TipiDatabase databaseType;
    private Logger log;
    private boolean serializableLevel;
    public Semaphore(InfoStatistics infoStatistics, SemaphoreMapping mapping, SemaphoreConfiguration config, TipiDatabase databaseType, Logger log) throws UtilsException{
        this.infoStatistics = infoStatistics;
        this.engine = new SemaphoreEngine(mapping, config, databaseType, log);
        this.databaseType = databaseType;
        this.log = log;
        this.serializableLevel = config.isSerializableLevel();
    }
    
    public boolean createEmptyLock(Connection conDB, boolean throwExceptionIfExists) throws UtilsException{
        return this.engine.createEmptyLock(conDB, throwExceptionIfExists);  
    }
    
    
    public boolean newLock(Connection con,String details) throws UtilsException {
        return this._engine(con, details, SemaphoreOperationType.NEW);
    }
    public boolean updateLock(Connection con,String details) throws UtilsException {
        return this._engine(con, details, SemaphoreOperationType.UPDATE);
    }
    public boolean releaseLock(Connection con,String details) throws UtilsException {
        return this._engine(con, details, SemaphoreOperationType.RELEASE);
    }
    
    private boolean _engine(Connection con,String details,SemaphoreOperationType tipo) throws UtilsException {

        // Check connessione
        if(con == null){
            throw new UtilsException("Connessione non fornita");
        }
        try{
            if(con.isClosed()){
                throw new UtilsException("Connessione risulta già chiusa");
            }
        }catch(Exception e){
            throw new UtilsException("Test Connessione non riuscito: "+e.getMessage(),e);
        }

        boolean originalConnectionAutocommit = false;
        boolean autoCommitModificato = false;
        try{
            originalConnectionAutocommit = con.getAutoCommit();
        }catch(Exception e){
            throw new UtilsException("Verifica AutoCommit Connessione non riuscito: "+e.getMessage(),e); 
        }
        if(originalConnectionAutocommit==false){
            throw new UtilsException("Lock ["+tipo+"] failed (Non e' possibile fornire una connessione con autocommit disabilitato poiche' l'utility ha necessita' di effettuare operazioni di commit/rollback)");      
        }
        
        int originalConnectionTransactionIsolation = -1;
        boolean transactionIsolationModificato = false;
        try{
            originalConnectionTransactionIsolation = con.getTransactionIsolation();
        }catch(Exception e){
            throw new UtilsException("Lettura livello di isolamento transazione della Connessione non riuscito: "+e.getMessage(),e); 
        }
        
        try{        
            try{                

                //System.out.println("SET TRANSACTION SERIALIZABLE ("+conDB.getTransactionIsolation()+","+conDB.getAutoCommit()+")");
                // Il rollback, non servirebbe, pero le WrappedConnection di JBoss hanno un bug, per cui alcune risorse non vengono rilasciate.
                // Con il rollback tali risorse vengono rilasciate, e poi effettivamente la ConnectionSottostante emette una eccezione.
                try{
                    con.rollback();
                }catch(Exception e){
                    //System.out.println("ROLLBACK ERROR: "+e.getMessage());
                }
                
                if(this.serializableLevel) {
                    JDBCUtilities.setTransactionIsolationSerializable(this.databaseType, con);
                    transactionIsolationModificato = true;
                }
                
                if(originalConnectionAutocommit){
                    con.setAutoCommit(false);
                    autoCommitModificato = true;
                }
                
            } catch(Exception er) {
                this.log.error("Lock ["+tipo+"] failed (impostazione transazione): "+er.getMessage(),er);
                throw new UtilsException("Lock ["+tipo+"] failed (impostazione transazione): "+er.getMessage(),er);     
            }

            return this.engine.lock(con, details, this.infoStatistics, tipo);   

        }
        finally{

            // Ripristino Transazione
            try{
                if(transactionIsolationModificato){
                    con.setTransactionIsolation(originalConnectionTransactionIsolation);
                }
                if(autoCommitModificato){
                    con.setAutoCommit(originalConnectionAutocommit);
                }
            } catch(Exception er) {
                //System.out.println("ERROR UNSET:"+er.getMessage());
                this.log.error("Lock ["+tipo+"] failed (ripristino transazione): "+er.getMessage());
                //throw new UtilsException("Lock ["+tipo+"] failed (ripristino transazione): "+er.getMessage());
            }
        }

    }



}