/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2007-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotools.data.ogr;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.geotools.data.EmptyFeatureReader;
import org.geotools.data.FeatureReader;
import org.geotools.data.FilteringFeatureReader;
import org.geotools.data.Query;
import org.geotools.data.ReTypeFeatureReader;
import org.geotools.data.store.ContentEntry;
import org.geotools.data.store.ContentFeatureSource;
import org.geotools.data.store.ContentFeatureStore;
import org.geotools.factory.Hints;
import org.geotools.feature.simple.SimpleFeatureTypeBuilder;
import org.geotools.filter.FilterAttributeExtractor;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.opengis.feature.FeatureVisitor;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.feature.type.AttributeDescriptor;
import org.opengis.feature.type.GeometryDescriptor;
import org.opengis.filter.Filter;
import org.opengis.filter.sort.SortBy;
import org.opengis.filter.sort.SortOrder;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import com.vividsolutions.jts.geom.CoordinateSequenceFactory;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;
/**
* FeatureSource for the OGR store, based on the {@link ContentFeatureStore} framework
*
* @author Andrea Aime - GeoSolutions
* @source $URL$
*/
@SuppressWarnings("rawtypes")
class OGRFeatureSource extends ContentFeatureSource {
OGR ogr;
public OGRFeatureSource(ContentEntry entry, Query query, OGR ogr) {
super(entry, query);
this.ogr = ogr;
}
@Override
public OGRDataStore getDataStore() {
return (OGRDataStore) super.getDataStore();
}
@Override
protected ReferencedEnvelope getBoundsInternal(Query query) throws IOException {
CoordinateReferenceSystem crs = getSchema().getCoordinateReferenceSystem();
// we need to know how much we can translate of the filter (the translator will also
// simplify the filter)
OGRFilterTranslator filterTx = new OGRFilterTranslator(getSchema(), query.getFilter());
if (Filter.EXCLUDE.equals(filterTx.getFilter())) {
// empty results
return new ReferencedEnvelope(crs);
} else if (!filterTx.isFilterFullySupported()) {
return null;
} else {
// encodable, we then encode and get the bounds
Object dataSource = null;
Object layer = null;
try {
// grab the layer
String typeName = getEntry().getTypeName();
dataSource = getDataStore().openOGRDataSource(false);
layer = getDataStore().openOGRLayer(dataSource, typeName);
// filter it
setLayerFilters(layer, filterTx);
Object extent = ogr.LayerGetExtent(layer);
if (extent == null) {
return null;
}
return ogr.toEnvelope(extent, crs);
} finally {
ogr.LayerRelease(layer);
ogr.DataSourceRelease(dataSource);
}
}
}
/**
* Sets the spatial filter and attribute filter on the specified layer
*
* @param layer
* @param filterTx
* @throws IOException
*/
private void setLayerFilters(Object layer, OGRFilterTranslator filterTx) throws IOException {
Geometry spatialFilter = filterTx.getSpatialFilter();
if (spatialFilter != null) {
Object ogrGeometry = new GeometryMapper.WKB(new GeometryFactory(), ogr)
.parseGTGeometry(spatialFilter);
ogr.LayerSetSpatialFilter(layer, ogrGeometry);
}
String attFilter = filterTx.getAttributeFilter();
if (attFilter != null) {
ogr.LayerSetAttributeFilter(layer, attFilter);
}
}
@Override
protected int getCountInternal(Query query) throws IOException {
// check how much we can encode
OGRFilterTranslator filterTx = new OGRFilterTranslator(getSchema(), query.getFilter());
if (Filter.EXCLUDE.equals(filterTx.getFilter())) {
return 0;
} else if (!filterTx.isFilterFullySupported()) {
// too expensive then
return -1;
} else {
// encode and count
Object dataSource = null;
Object layer = null;
try {
// grab the layer
String typeName = getEntry().getTypeName();
dataSource = getDataStore().openOGRDataSource(false);
layer = getDataStore().openOGRLayer(dataSource, typeName);
// filter it
setLayerFilters(layer, filterTx);
return (int) ogr.LayerGetFeatureCount(layer);
} finally {
ogr.LayerRelease(layer);
ogr.DataSourceRelease(dataSource);
}
}
}
@Override
protected FeatureReader<SimpleFeatureType, SimpleFeature> getReaderInternal(Query query)
throws IOException {
return getReaderInternal(null, null, query);
}
protected FeatureReader<SimpleFeatureType, SimpleFeature> getReaderInternal(Object dataSource,
Object layer, Query query) throws IOException {
// check how much we can encode
OGRFilterTranslator filterTx = new OGRFilterTranslator(getSchema(), query.getFilter());
if (Filter.EXCLUDE.equals(filterTx.getFilter())) {
return new EmptyFeatureReader<SimpleFeatureType, SimpleFeature>(getSchema());
}
// encode and count
boolean cleanup = false;
try {
// grab the data source
String typeName = getEntry().getTypeName();
if (dataSource == null) {
dataSource = getDataStore().openOGRDataSource(false);
cleanup = true;
}
// extract the post filter
Filter postFilter = null;
if (!filterTx.isFilterFullySupported()) {
postFilter = filterTx.getPostFilter();
}
// prepare the target schema
SimpleFeatureType sourceSchema = getSchema();
SimpleFeatureType querySchema = sourceSchema;
SimpleFeatureType targetSchema = sourceSchema;
String[] properties = query.getPropertyNames();
if (properties != null && properties.length > 0) {
targetSchema = SimpleFeatureTypeBuilder.retype(sourceSchema, properties);
querySchema = targetSchema;
// if we have a post filter we have to include in the queried features also the
// attribute needed to evaluate the post-filter
if (postFilter != null) {
Set<String> queriedAttributes = new HashSet<String>(Arrays.asList(properties));
FilterAttributeExtractor extraAttributeExtractor = new FilterAttributeExtractor();
postFilter.accept(extraAttributeExtractor, null);
Set<String> extraAttributeSet = new HashSet<String>(
extraAttributeExtractor.getAttributeNameSet());
extraAttributeSet.removeAll(queriedAttributes);
if (extraAttributeSet.size() > 0) {
String[] queryProperties = new String[properties.length
+ extraAttributeSet.size()];
System.arraycopy(properties, 0, queryProperties, 0, properties.length);
String[] extraAttributes = (String[]) extraAttributeSet
.toArray(new String[extraAttributeSet.size()]);
System.arraycopy(extraAttributes, 0, queryProperties, properties.length,
extraAttributes.length);
querySchema = SimpleFeatureTypeBuilder
.retype(sourceSchema, queryProperties);
}
}
}
// build the layer query and execute it
if (layer == null) {
// We only need ExecuteSQL if the user specified sorting
if (query.getSortBy() == null || query.getSortBy().length == 0) {
layer = ogr.DataSourceGetLayerByName(dataSource, getSchema().getTypeName());
setLayerFilters(layer, filterTx);
}
// build the layer query and execute it
else {
Object driver = ogr.DataSourceGetDriver(dataSource);
String driverName = ogr.DriverGetName(driver);
ogr.DriverRelease(driver);
boolean isNonOgrSql = doesDriverUseNonOgrSql(driverName);
String fidColumnName = "FID";
if (isNonOgrSql) {
boolean needsFid = false;
for (SortBy sort : query.getSortBy()) {
if(SortBy.NATURAL_ORDER.equals(sort)|| SortBy.REVERSE_ORDER.equals(sort)) {
needsFid = true;
break;
}
}
if (needsFid) {
layer = ogr.DataSourceGetLayerByName(dataSource, getSchema().getTypeName());
fidColumnName = ogr.LayerGetFIDColumnName(layer);
ogr.LayerRelease(layer);
if (fidColumnName == null) {
throw new IOException("Cannot do natural order without an FID column!");
}
}
}
String sql = getLayerSql(querySchema == sourceSchema ? null : querySchema,
filterTx.getAttributeFilter(), query.getSortBy(), isNonOgrSql, fidColumnName);
Object spatialFilterPtr = null;
Geometry spatialFilter = filterTx.getSpatialFilter();
if (spatialFilter != null) {
spatialFilterPtr = new GeometryMapper.WKB(new GeometryFactory(), ogr)
.parseGTGeometry(spatialFilter);
}
layer = ogr.DataSourceExecuteSQL(dataSource, sql, spatialFilterPtr);
if (layer == null) {
throw new IOException("Failed to query the source layer with SQL: " + sql);
}
}
} else {
setLayerFilters(layer, filterTx);
// would be nice, but it's not really working...
// setIgnoredFields(layer, querySchema, sourceSchema);
}
// see if we have a geometry factory to use
GeometryFactory gf = getGeometryFactory(query);
// build the reader
FeatureReader<SimpleFeatureType, SimpleFeature> reader = new OGRFeatureReader(
dataSource, layer, querySchema, sourceSchema, gf, ogr);
cleanup = false;
// do we have to post-filter?
if (!filterTx.isFilterFullySupported()) {
reader = new FilteringFeatureReader<SimpleFeatureType, SimpleFeature>(reader,
filterTx.getPostFilter());
if (targetSchema != querySchema) {
reader = new ReTypeFeatureReader(reader, targetSchema);
}
}
return reader;
} finally {
if (cleanup) {
ogr.LayerRelease(layer);
ogr.DataSourceRelease(dataSource);
}
}
}
private boolean doesDriverUseNonOgrSql(String driverName) {
// Is this a database driver where the SQL is passed directly?
// List from bottom of http://www.gdal.org/ogr/ogr_sql.html (Non-OGR SQL)
List<String> databaseDriverNames = Arrays.asList(
"MYSQL", "POSTGRESQL","POSTGIS", "PG", "ORACLE", "OCI", "SQLITE",
"ODBC", "ESRI PERSONAL GEODATABASE", "PGEO","MS SQL SPATIAL",
"MSSQLSPATIAL"
);
return databaseDriverNames.contains(driverName.toUpperCase());
}
void setIgnoredFields(Object layer, SimpleFeatureType querySchema,
SimpleFeatureType sourceSchema) throws IOException {
if (ogr.LayerCanIgnoreFields(layer)) {
List<String> ignoredFields = new ArrayList<String>();
ignoredFields.add("OGR_STYLE");
// if no geometry, skip it
if (querySchema.getGeometryDescriptor() == null) {
ignoredFields.add("OGR_GEOMETRY");
}
// process all other attributes
for (AttributeDescriptor ad : sourceSchema.getAttributeDescriptors()) {
if (!(ad instanceof GeometryDescriptor)) {
String name = ad.getLocalName();
if (querySchema.getDescriptor(name) == null) {
ignoredFields.add(name);
}
}
}
if (ignoredFields.size() > 0) {
// the list should be NULL terminated
ignoredFields.add(null);
String[] ignoredFieldsArr = (String[]) ignoredFields
.toArray(new String[ignoredFields.size()]);
ogr.CheckError(ogr.LayerSetIgnoredFields(layer, ignoredFieldsArr));
}
}
}
private String getLayerSql(SimpleFeatureType targetSchema, String attributeFilter,
SortBy[] sortBy, boolean isNonOgrSql, String fidColumnName) {
StringBuilder sb = new StringBuilder();
// list only the non geometry attributes
// select attributes
sb.append("SELECT ");
if (!isNonOgrSql) {
sb.append("FID, ");
}
if (targetSchema == null) {
sb.append("* ");
} else {
for (AttributeDescriptor attribute : targetSchema.getAttributeDescriptors()) {
if(attribute instanceof GeometryDescriptor) {
continue;
} else {
sb.append(attribute.getLocalName()).append(", ");
}
}
sb.setLength(sb.length() - 2);
sb.append(" ");
}
sb.append("FROM ").append("'").append(getSchema().getTypeName()).append("' ");
// attribute filter
if (attributeFilter != null) {
sb.append("WHERE ").append(attributeFilter);
}
// order by
if (sortBy != null && sortBy.length > 0) {
sb.append("ORDER BY ");
for (SortBy sort : sortBy) {
if (sort == SortBy.NATURAL_ORDER) {
sb.append(fidColumnName).append(", ");
} else if (sort == SortBy.REVERSE_ORDER) {
sb.append(fidColumnName).append(" DESC, ");
} else {
sb.append(sort.getPropertyName().getPropertyName());
if (sort.getSortOrder() == SortOrder.DESCENDING) {
sb.append(" DESC");
}
sb.append(", ");
}
}
sb.setLength(sb.length() - 2);
}
return sb.toString();
}
GeometryFactory getGeometryFactory(Query query) {
Hints hints = query.getHints();
GeometryFactory gf = null;
if (hints != null) {
gf = (GeometryFactory) hints.get(Hints.JTS_GEOMETRY_FACTORY);
if (gf == null) {
// look for a coordinate sequence factory
CoordinateSequenceFactory csFactory = (CoordinateSequenceFactory) hints
.get(Hints.JTS_COORDINATE_SEQUENCE_FACTORY);
if (csFactory != null) {
gf = new GeometryFactory(csFactory);
}
}
}
if (gf == null) {
gf = new GeometryFactory();
}
return gf;
}
@Override
protected SimpleFeatureType buildFeatureType() throws IOException {
String typeName = getEntry().getTypeName();
String namespaceURI = getDataStore().getNamespaceURI();
Object dataSource = null;
Object layer = null;
try {
// grab the layer definition
dataSource = getDataStore().openOGRDataSource(false);
layer = getDataStore().openOGRLayer(dataSource, typeName);
// map to geotools feature type
return new FeatureTypeMapper(ogr).getFeatureType(layer, typeName, namespaceURI);
} finally {
ogr.LayerRelease(layer);
ogr.DataSourceRelease(dataSource);
}
}
@Override
protected boolean canFilter() {
return true;
}
@Override
protected boolean canRetype() {
return true;
}
@Override
protected boolean canSort() {
return true;
}
@Override
protected boolean handleVisitor(Query query, FeatureVisitor visitor) throws IOException {
return super.handleVisitor(query, visitor);
}
}