Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * This program 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.

 *

 * 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, write to the Free Software Foundation, Inc., 51

 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us at info AT

 * gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.fmap.dal.store.jdbc2.impl;

import java.util.ArrayList;

import java.util.List;

import java.util.NoSuchElementException;

import org.apache.commons.collections.CollectionUtils;

import org.apache.commons.lang3.BooleanUtils;

import org.apache.commons.lang3.StringUtils;

import org.gvsig.fmap.dal.DataTypes;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.fmap.dal.feature.FeatureQuery;

import org.gvsig.fmap.dal.feature.FeatureQueryOrder.FeatureQueryOrderMember;

import org.gvsig.fmap.dal.feature.FeatureType;

import org.gvsig.fmap.dal.feature.spi.AbstractFeatureSetProvider;

import org.gvsig.fmap.dal.feature.spi.AbstractFeatureStoreProvider;

import org.gvsig.fmap.dal.store.jdbc.JDBCStoreParameters;

import org.gvsig.fmap.dal.store.jdbc2.JDBCHelper;

import org.gvsig.fmap.dal.store.jdbc2.JDBCStoreProvider;

import org.gvsig.fmap.dal.store.jdbc2.JDBCUtils;

import org.gvsig.fmap.dal.store.jdbc2.OperationsFactory;

import org.gvsig.fmap.dal.store.jdbc2.ResulSetControler;

import org.gvsig.fmap.dal.store.jdbc2.ResulSetControler.ResultSetEntry;

import org.gvsig.fmap.dal.store.jdbc2.spi.operations.TableIsEmptyOperation;

import org.gvsig.fmap.dal.store.jdbc2.spi.operations.ResultSetForSetProviderOperation;

import org.gvsig.fmap.dal.store.jdbc2.spi.operations.CountOperation;

import org.gvsig.tools.evaluator.Evaluator;

import org.gvsig.tools.evaluator.EvaluatorFieldsInfo;

import org.gvsig.tools.exception.BaseException;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

public class JDBCSetProvider extends AbstractFeatureSetProvider {

    final static protected Logger LOGGER = LoggerFactory.getLogger(JDBCSetProvider.class);

    private class EmptyJDBCIterator extends JDBCIterator {

        protected EmptyJDBCIterator(JDBCStoreProvider store) throws DataException {

            super(store, null, null, null);

        }

        @Override

        protected boolean internalHasNext() {

            return false;

        }

        @Override

        protected Object internalNext() {

            throw new NoSuchElementException();

        }

        @Override

        protected void doDispose() throws BaseException {

            // nothing to do

        }

    }

    protected Long size = null;

    protected Boolean isEmpty = null;

    protected List<ResultSetEntry> resultSets;

    private int defaultFetchSize = 1000;

    public JDBCSetProvider(

            AbstractFeatureStoreProvider store,

            JDBCHelper helper,

            FeatureQuery query,

            FeatureType featureType

    ) throws DataException {

        super(store, query, featureType);

        this.resultSets = new ArrayList<>();

    }

    /**

     * @return the defaultFetchSize

     */

    public int getDefaultFetchSize() {

        return defaultFetchSize;

    }

    /**

     * @param defaultFetchSize the defaultFetchSize to set

     */

    public void setDefaultFetchSize(int defaultFetchSize) {

        this.defaultFetchSize = defaultFetchSize;

    }

//    @Override

//    protected JDBCStoreProvider getStore() {

//        return (JDBCStoreProvider) super.getStore();

//    }

    protected JDBCStoreProvider getJDBCStore() {

//        Corregido el problema en AbstractFeatureSetProvider, de que getStore

//        debe ser un FeatureStoreProvider y no un AbstractFeatureStoreProvider

//        este metodo debe desaparecer y quedar el getStore de arriba que esta

//          comentarizado

        return (JDBCStoreProvider) super.getStore();

    }    

    protected JDBCHelper getHelper() {

        return this.getJDBCStore().getHelper();

    }

    protected OperationsFactory getOperations() {

        return this.getHelper().getOperations();

    }

    @Override

    public boolean canIterateFromIndex() {

        return this.getHelper().supportOffsetInSelect();

    }

    @Override

    public boolean canFilter() {

        // No podemos filtrar si:

        // - Hay una subquery especificada en los parametros 

        // - Si no soportamos geometrias y hay un filtro espacial.

        //

        if (this.getHelper().useSubquery()) {

            return false;

        }

        if( this.getHelper().hasSpatialFunctions() ) {

            // Como soportamos filtros espaciales, podremos hacer cualquier

            // filtro que se especifique, sea alfanumerico o espacial.

            return true;

        }

        // No se soportan filtros espaciales.

        // Si se esta filtrando por un campo Geometria, retornamos false

        Evaluator filter = getQuery().getFilter();

        if (filter == null) {

            return true;

        }

        String sql = filter.getSQL();

        if (StringUtils.isEmpty(sql)) {

            return true;

        }

        EvaluatorFieldsInfo fInfo = filter.getFieldsInfo();

        if (fInfo == null ) {

            return true;

        }

        String[] names = fInfo.getFieldNames();

        if (  names == null) {

            return true;

        }

        for (String name : names) {

            int type = this.getFeatureType()

                .getAttributeDescriptor(name)

                .getType();

            if( type == DataTypes.GEOMETRY ) {

                return false;

            }

        }

        return true;

    }

    @Override

    public boolean canOrder() {

        // No podemos ordenar si:

        // - Hay una subquery especificada en los parametros 

        // - Si no soportamos geometrias y hay un filtro espacial.

        //

        if (this.getHelper().useSubquery()) {

            return false;

        }

        if( this.getHelper().hasSpatialFunctions() ) {

            // Como soportamos filtros espaciales, podremos hacer cualquier

            // filtro que se especifique, sea alfanumerico o espacial.

            return true;

        }

        FeatureQuery query = getQuery();

        if (!query.hasOrder()) {

            return true;

        }

        for( FeatureQueryOrderMember member : query.getOrder().members() ) {

            if (member.hasEvaluator()) {

                String sql = member.getEvaluator().getSQL();

                if ( StringUtils.isEmpty(sql) ) {

                    return false;

                }

            }            

        }

        return true;

    }

    public ResulSetControler getResulSetControler() {

        return this.getHelper().getResulSetControler();

    }

    @Override

    protected void doDispose() throws BaseException {

        if( ! CollectionUtils.isEmpty(this.resultSets) ) {

            for( ResultSetEntry resulset : this.resultSets ) {

               JDBCUtils.closeQuietly(resulset);

            }

        }

        size = null;

        isEmpty = null;

    }

    protected int getFetchSize() {

        long pageSize = -1;

        if (getQuery() != null) {

            pageSize = getQuery().getPageSize();

            pageSize = pageSize > Integer.MAX_VALUE ? Integer.MAX_VALUE : pageSize;

        }

        return (pageSize > 0 ? (int) pageSize : defaultFetchSize);

    }

    @Override

    public long getSize() throws DataException {

        if (size == null) {

            JDBCStoreParameters params = this.getJDBCStore().getParameters();

            String filtersql = null;

            Evaluator filter = this.getQuery().getFilter();

            if( filter != null ) {

                filtersql = filter.getSQL();

            }

            CountOperation selectCount = this.getOperations().createCount(

                    this.getOperations().createTableReference(params),

                    params.getBaseFilter(), 

                    filtersql

            );

            size = (Long) selectCount.perform();              

        }

        return size;

    }

    @Override

    public boolean isEmpty() throws DataException {

        if (this.isEmpty == null) {

            if (this.size == null) {

                JDBCStoreParameters params = this.getJDBCStore().getParameters();

                String filtersql = null;

                Evaluator filter = this.getQuery().getFilter();

                if( filter != null ) {

                    filtersql = filter.getSQL();

                }

                TableIsEmptyOperation isEmpty_ = this.getOperations().createTableIsEmpty(

                        this.getOperations().createTableReference(params),

                        params.getBaseFilter(), 

                        filtersql

                );

                this.isEmpty = (Boolean) isEmpty_.perform();   

            } else {

                this.isEmpty = (this.size < 1);

            }

        }

        return isEmpty;

    }

    protected JDBCIterator createFastIterator(long index) throws DataException {

        return createFastIterator(index, 0);

    }

    @Override

    protected JDBCIterator createFastIterator(long index, long elements) throws DataException {

        if( BooleanUtils.isTrue(isEmpty) ) {

            return new EmptyJDBCIterator(this.getJDBCStore());

        }

        JDBCStoreParameters params = this.getJDBCStore().getParameters();

        FeatureType storeType = this.getStore()

                .getStoreServices()

                .getProviderFeatureType(this.getFeatureType().getId());

        ResultSetForSetProviderOperation createResultSet 

            = getOperations().createResultSetForSetProvider(

                    this.getOperations().createTableReference(params),

                    params.getBaseFilter(), 

                    params.getBaseOrder(), 

                    this.getQuery(), 

                    storeType, 

                    this.getFeatureType(), 

                    elements, 

                    index, 

                    this.getDefaultFetchSize()

            );

        ResultSetEntry resultSetEntry = (ResultSetEntry) createResultSet.perform();

        this.resultSets.add(resultSetEntry);

        return new JDBCFastIterator(

                this.getJDBCStore(), 

                this, 

                this.getFeatureType(),

                resultSetEntry

        );

    }

    @Override

    protected JDBCIterator createIterator(long index) throws DataException {

        return createIterator(index, -1);

    }

    @Override

    protected JDBCIterator createIterator(long index, long elements) throws DataException {

        if( BooleanUtils.isTrue(isEmpty) ) {

            return new EmptyJDBCIterator(this.getJDBCStore());

        }

        JDBCStoreParameters params = this.getJDBCStore().getParameters();

        FeatureType storeType = this.getStore()

                .getStoreServices()

                .getProviderFeatureType(this.getFeatureType().getId());

        ResultSetForSetProviderOperation createResultSet 

            = getOperations().createResultSetForSetProvider(

                    this.getOperations().createTableReference(params),

                    params.getBaseFilter(), 

                    params.getBaseOrder(), 

                    this.getQuery(), 

                    storeType, 

                    this.getFeatureType(), 

                    elements, 

                    index, 

                    this.getDefaultFetchSize()

            );

        ResultSetEntry resultSetEntry = (ResultSetEntry) createResultSet.perform();

        this.resultSets.add(resultSetEntry);

        return new JDBCIterator(

                this.getJDBCStore(), 

                this, 

                this.getFeatureType(),

                resultSetEntry

        );

    }

}