alfresco-community-repo/source/java/org/alfresco/repo/domain/hibernate/HibernateUsageDeltaDAO.java

/*
 * Copyright (C) 2005-2010 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Alfresco 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.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */
package org.alfresco.repo.domain.hibernate;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.alfresco.repo.domain.Node;
import org.alfresco.repo.domain.UsageDelta;
import org.alfresco.repo.domain.UsageDeltaDAO;
import org.alfresco.repo.node.db.NodeDaoService;
import org.alfresco.repo.transaction.TransactionalDao;
import org.alfresco.service.cmr.repository.InvalidNodeRefException;
import org.alfresco.service.cmr.repository.NodeRef;
import org.alfresco.util.GUID;
import org.alfresco.util.Pair;
import org.springframework.dao.ConcurrencyFailureException;
import org.springframework.extensions.surf.util.ParameterCheck;
import org.hibernate.Query;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**
 * Hibernate-specific implementation of the persistence-independent <b>Usage Delta</b> DAO interface
 * 
 */
public class HibernateUsageDeltaDAO extends HibernateDaoSupport implements UsageDeltaDAO, TransactionalDao
{
//    private static final String QUERY_GET_DELTAS = "usage.GetDeltas";
    private static final String QUERY_GET_TOTAL_DELTA_SIZE = "usage.GetTotalDeltaSize";
    private static final String QUERY_GET_USAGE_DELTA_NODES = "usage.GetUsageDeltaNodes";
    private static final String QUERY_DELETE_DELTAS_FOR_NODE = "usage.DeleteUsageDeltasForNode";
        
    /** a uuid identifying this unique instance */
    private final String uuid;
    private NodeDaoService nodeDaoService;
    
    public void setNodeDaoService(NodeDaoService nodeDaoService)
    {
        this.nodeDaoService = nodeDaoService;
    }

    /**
     * 
     */
    public HibernateUsageDeltaDAO()
    {
        this.uuid = GUID.generate();
    }

    /**
     * Checks equality by type and uuid
     */
    public boolean equals(Object obj)
    {
        if (obj == null)
        {
            return false;
        }
        else if (!(obj instanceof HibernateUsageDeltaDAO))
        {
            return false;
        }
        HibernateUsageDeltaDAO that = (HibernateUsageDeltaDAO) obj;
        return this.uuid.equals(that.uuid);
    }
    
    /**
     * @see #uuid
     */
    public int hashCode()
    {
        return uuid.hashCode();
    }

    /**
     * NO-OP
     */
    public void beforeCommit()
    {
    }   

    /**
     * Does this <tt>Session</tt> contain any changes which must be
     * synchronized with the store?
     * 
     * @return true => changes are pending
     */
    public boolean isDirty()
    {
        // create a callback for the task
        HibernateCallback callback = new HibernateCallback()
        {
            public Object doInHibernate(Session session)
            {
                return session.isDirty();
            }
        };
        // execute the callback
        return ((Boolean)getHibernateTemplate().execute(callback)).booleanValue();
    }

    /**
     * Just flushes the session
     */
    public void flush()
    {
        getSession().flush();
    }
    
    private Long getNodeIdNotNull(NodeRef nodeRef) throws InvalidNodeRefException
    {
        ParameterCheck.mandatory("nodeRef", nodeRef);
        
        Pair<Long, NodeRef> nodePair = nodeDaoService.getNodePair(nodeRef);
        if (nodePair == null)
        {
            throw new InvalidNodeRefException("Node does not exist: " + nodeRef, nodeRef);
        }
        return nodePair.getFirst();
    }

    public int deleteDeltas(NodeRef nodeRef)
    {
        Long nodeId = getNodeIdNotNull(nodeRef);
        return deleteDeltas(nodeId);
    }
    
    @SuppressWarnings("unchecked")
    public int deleteDeltas(final Long nodeId)
    {
        HibernateCallback callback = new HibernateCallback()
        {
            public Object doInHibernate(Session session)
            {
                Query query = session.getNamedQuery(QUERY_DELETE_DELTAS_FOR_NODE);
                query.setParameter("nodeId", nodeId);
                return query.executeUpdate();
            }
        };
        
        // execute
        Integer delCount = (Integer) getHibernateTemplate().execute(callback);

        return (delCount == null ? 0 : delCount.intValue());
    }
    
    @SuppressWarnings("unchecked")
    private Object[] getTotalDeltaSizeImpl(NodeRef nodeRef)
    {
        final Long nodeId = getNodeIdNotNull(nodeRef);
        HibernateCallback callback = new HibernateCallback()
        {
            public Object doInHibernate(Session session)
            {
                Query query = session.getNamedQuery(QUERY_GET_TOTAL_DELTA_SIZE);
                query.setParameter("nodeId", nodeId);
                query.setReadOnly(true);
                return query.uniqueResult();
            }
        };

        // execute read-only tx
        return (Object[])getHibernateTemplate().execute(callback);
    }

    public long getTotalDeltaSize(NodeRef nodeRef)
    {
        Object[] result = getTotalDeltaSizeImpl(nodeRef);
        Long queryResult = (Long)result[1];
        return (queryResult == null ? 0 : queryResult.longValue());
    }

    /**
     * Guard against deleting deltas committed by another transaction after calculating the delta sum above.
	 * If the expected number of deletes is different from the actual number of deletes then deltas from
	 * another committed transaction are probably being removed.
	 */
    @SuppressWarnings("unchecked")
    public long getAndRemoveTotalDeltaSize(NodeRef nodeRef)
    {
        Object[] result = getTotalDeltaSizeImpl(nodeRef);
        Long queryResult = (Long)result[1];
        Number deltaCount = (Number)result[0];

        long expectedNumDeletes = deltaCount == null ? 0 : deltaCount.intValue();

        int numDeltasRemoved = deleteDeltas(nodeRef);

        if(expectedNumDeletes != numDeltasRemoved) {
            throw new ConcurrencyFailureException("More than expected number of usage delta deletes has occurred for node id "
                    + nodeRef.getId() + " in store " + nodeRef.getStoreRef());
        }

        return (queryResult == null ? 0 : queryResult.longValue());
    }
    
    public void insertDelta(NodeRef usageNodeRef, long deltaSize)
    {
        Long nodeId = getNodeIdNotNull(usageNodeRef);
        Node node = (Node) getHibernateTemplate().get(NodeImpl.class, nodeId);
        
        UsageDelta delta = new UsageDeltaImpl();
        // delta properties
        delta.setNode(node);
        delta.setDeltaSize(deltaSize);

        // Save
        getSession().save(delta);
    }
    
    @SuppressWarnings("unchecked")
    public Set<NodeRef> getUsageDeltaNodes()
    {
        HibernateCallback callback = new HibernateCallback()
        {
            public Object doInHibernate(Session session)
            {
                Query query = session.getNamedQuery(QUERY_GET_USAGE_DELTA_NODES);
                query.setReadOnly(true);
                return query.list();
            }
        };
        // execute read-only tx
        List<Node> queryResults = (List<Node>)getHibernateTemplate().execute(callback);
        Set<NodeRef> results = new HashSet<NodeRef>(queryResults.size(), 1.0F);
        for (Node node : queryResults)
        {
            results.add(node.getNodeRef());
        }
        return results;
    }
}