[tmp/jakarta-migration.git] /

/*
 * (C) Copyright 2006-2010 Nuxeo SAS (http://nuxeo.com/) and contributors.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public License
 * (LGPL) version 2.1 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * Contributors:
 *     bstefanescu, jcarsique
 *
 * $Id$
 */

package org.collectionspace.services.nuxeo.client.java;

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;
import java.security.Principal;

import org.collectionspace.services.common.repository.RepositoryInstanceWrapperAdvice;
import org.collectionspace.services.config.tenant.RepositoryDomainType;

import org.nuxeo.ecm.core.api.repository.Repository;
import org.nuxeo.ecm.core.api.CoreInstance;
import org.nuxeo.ecm.core.api.CoreSession;
import org.nuxeo.ecm.core.api.NuxeoPrincipal;
import org.nuxeo.ecm.core.api.SystemPrincipal;
import org.nuxeo.ecm.core.api.repository.RepositoryManager;
import org.nuxeo.runtime.api.Framework;
import org.nuxeo.runtime.transaction.TransactionHelper;

import javax.transaction.TransactionManager;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.aop.framework.ProxyFactory;

/**
 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
 *
 */
public final class NuxeoClientEmbedded {

        private Logger logger = LoggerFactory.getLogger(NuxeoClientEmbedded.class);
        
    private final HashMap<String, CoreSessionInterface> repositoryInstances;

    private RepositoryManager repositoryMgr;

    private static final NuxeoClientEmbedded instance = new NuxeoClientEmbedded();
        
    /**
     * Constructs a new NuxeoClient. NOTE: Using {@link #getInstance()} instead
     * of this constructor is recommended.
     */
    private NuxeoClientEmbedded() {
        repositoryInstances = new HashMap<String, CoreSessionInterface>();
    }
    
    public static NuxeoClientEmbedded getInstance() {
        return instance;
    }

    public synchronized void tryDisconnect() throws Exception {
        doDisconnect();
    }

    private void doDisconnect() throws Exception {
        // close the open Nuxeo repository sessions if any
        Iterator<Entry<String, CoreSessionInterface>> it = repositoryInstances.entrySet().iterator();
        while (it.hasNext()) {
            Entry<String, CoreSessionInterface> repo = it.next();
            try {
                repo.getValue().close();
            } catch (Exception e) {
                logger.debug("Error while trying to close " + repo, e);
            }
            it.remove();
        }

        repositoryMgr = null;
    }

    public RepositoryManager getRepositoryManager() throws Exception {
        if (repositoryMgr == null) {
            repositoryMgr = Framework.getService(RepositoryManager.class);
        }
        return repositoryMgr;
    }

    /**
     * Gets the repositories available on the connected server.
     *
     * @return the repositories
     */
    public Repository[] getRepositories() throws Exception {
        Collection<Repository> repos = getRepositoryManager().getRepositories();
        return repos.toArray(new Repository[repos.size()]);
    }

    public Repository getDefaultRepository() throws Exception {
        return getRepositoryManager().getDefaultRepository();
    }

    public Repository getRepository(String name) throws Exception {
        return getRepositoryManager().getRepository(name);
    }

    /*
     * Open a Nuxeo repo session using the passed in repoDomain and use the default tx timeout period
     */
    public CoreSessionInterface openRepository(RepositoryDomainType repoDomain) throws Exception {
        return openRepository(repoDomain.getRepositoryName(), -1);
    }
    
    /*
     * Open a Nuxeo repo session using the passed in repoDomain and use the default tx timeout period
     */
    public CoreSessionInterface openRepository(String repoName) throws Exception {
        return openRepository(repoName, -1);
    }    

    public CoreSessionInterface openRepository(String repoName, int timeoutSeconds) throws Exception {
        CoreSessionInterface result = null;
        
        //
        // If the called passed in a custom timeout setting, use it to configure Nuxeo's transaction manager.
        //
        if (timeoutSeconds > 0) {
                TransactionManager transactionMgr = TransactionHelper.lookupTransactionManager();
                transactionMgr.setTransactionTimeout(timeoutSeconds);
                if (logger.isInfoEnabled()) {
                        logger.info(String.format("Changing current request's transaction timeout period to %d seconds",
                                        timeoutSeconds));
                }
        }
        
        //
        // Start a new Nuxeo transaction
        //
        boolean startedTransaction = false;
        if (TransactionHelper.isTransactionActive() == false) {
                startedTransaction = TransactionHelper.startTransaction();
                if (startedTransaction == false) {
                        String errMsg = "Could not start a Nuxeo transaction with the TransactionHelper class.";
                        logger.error(errMsg);
                        throw new Exception(errMsg);
                }
        } else {
                logger.warn("A request to start a new transaction was made, but a transaction is already open.");
        }
        
        //
        // From the repository name that the caller passed in, get an instance of Nuxeo's Repository class.
        // The Repository class is just a metadata description of the repository.
        //
        Repository repository;
        if (repoName != null) {
                repository = getRepositoryManager().getRepository(repoName);
        } else {
                repository = getRepositoryManager().getDefaultRepository();
                logger.warn(String.format("Using default repository '%s' because no name was specified.", repository.getName()));
        }
        
        //
        // Using the Repository class, get a Spring AOP proxied instance.  We use Spring AOP to "wrap" all calls to the
        // Nuxeo repository so we can check for network related failures and perform a series of retries.
        //
        if (repository != null) {
            result = getCoreSessionWrapper(repository);
                logger.trace(String.format("A new transaction was started on thread '%d' : %s.",
                                Thread.currentThread().getId(), startedTransaction ? "true" : "false"));
                logger.trace(String.format("Added a new repository instance to our repo list.  Current count is now: %d",
                                repositoryInstances.size()));
        } else {
                String errMsg = String.format("Could not open a session to the Nuxeo repository='%s'", repoName);
                logger.error(errMsg);
                throw new Exception(errMsg);
        }       
        
        
        return result;
    }
    
    //
    // Returns a proxied interface to a Nuxeo repository instance.  Our proxy uses Spring AOP to
    // wrap each call to the Nuxeo repo with code that catches network related errors/exceptions and
    // re-attempts the calls to see if it recovers.
    //
    private CoreSessionInterface getAOPProxy(CoreSession repositoryInstance) {
        CoreSessionInterface result = null;
        
        try {
                        ProxyFactory factory = new ProxyFactory(new CoreSessionWrapper(repositoryInstance));
                        factory.addAdvice(new RepositoryInstanceWrapperAdvice());
                        factory.setExposeProxy(true);
                        result = (CoreSessionInterface)factory.getProxy();
        } catch (Exception e) {
                logger.error("Could not create AOP proxy for: " + CoreSessionWrapper.class.getName(), e);
        }
        
        return result;
    }
    
        private Principal getSystemPrincipal() {
                NuxeoPrincipal principal = new SystemPrincipal(null);
                return principal;
        }

    /*
     * From the Repository object (a description of the repository), get repository instance wrapper.  Our wrapper
     * will using the Spring AOP mechanism to intercept all calls to the repository.  We will wrap all the calls to the
     * Nuxeo repository and check for network related failures.  We will retry all calls to the Nuxeo repo that fail because
     * of network erros.
     */
    private CoreSessionInterface getCoreSessionWrapper(Repository repository) throws Exception {
        CoreSessionInterface result = null;
                
        CoreSession coreSession  = CoreInstance.openCoreSession(repository.getName(), getSystemPrincipal());  // A Nuxeo repo instance handler proxy
        
        if (coreSession != null) {
                result = this.getAOPProxy(coreSession);  // This is our AOP proxy
                if (result != null) {
                        String key = result.getSessionId();
                        repositoryInstances.put(key, result);
                } else {
                        String errMsg = String.format("Could not instantiate a Spring AOP proxy for class '%s'.",
                                        CoreSessionWrapper.class.getName());
                        logger.error(errMsg);
                        throw new Exception(errMsg);
                }
        } else {
                String errMsg = String.format("Could not create a new repository instance for '%s' repository.", repository.getName());
                logger.error(errMsg);
                throw new Exception(errMsg);
        }
        
        return result;
    }

    public void releaseRepository(CoreSessionInterface repoSession) throws Exception {
        String key = repoSession.getSessionId();
        String name = repoSession.getRepositoryName();

        try {
                repoSession.save();
                repoSession.close();
        } catch (Exception e) {
                String errMsg = String.format("Possible data loss.  Could not save and/or close the Nuxeo repository name = '%s'.",
                                name);
                logger.error(errMsg, e);
                throw e;
        } finally {
                CoreSessionInterface wasRemoved = repositoryInstances.remove(key);
            if (logger.isTraceEnabled()) {
                if (wasRemoved != null) {
                        logger.trace("Removed a repository instance from our repo list.  Current count is now: "
                                        + repositoryInstances.size());
                } else {
                        logger.trace("Could not remove a repository instance from our repo list.  Current count is now: "
                                        + repositoryInstances.size());
                }
            }
            if (TransactionHelper.isTransactionActiveOrMarkedRollback() == true) {
                TransactionHelper.commitOrRollbackTransaction();
                logger.trace(String.format("Transaction closed on thread '%d'", Thread.currentThread().getId()));
            }
        }
    }    
}