/* (c) 2014 Open Source Geospatial Foundation - all rights reserved
* (c) 2001 - 2013 OpenPlans
* This code is licensed under the GPL 2.0 license, available at the root
*/
package org.geoserver.filter.function;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.geoserver.catalog.Catalog;
import org.geotools.factory.CommonFactoryFinder;
import org.geotools.feature.NameImpl;
import org.geotools.filter.FunctionFactory;
import org.geotools.util.logging.Logging;
import org.opengis.feature.type.Name;
import org.opengis.filter.FilterFactory;
import org.opengis.filter.capability.FunctionName;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.Function;
import org.opengis.filter.expression.Literal;
/**
* Factory for the functions that do query the GeoServer catalog as well as the support ones used to
* mix them into larger filters
*
* @author Andrea Aime - GeoSolutions
*/
public class QueryLayerFunctionFactory implements FunctionFactory {
static final Name COLLECT_GEOMETRIES = new NameImpl("collectGeometries");
static final Name QUERY_COLLECTION = new NameImpl("queryCollection");
static final Name QUERY_SINGLE = new NameImpl("querySingle");
static final Logger LOGGER = Logging.getLogger(QueryLayerFunctionFactory.class);
List<FunctionName> functionNames;
Catalog catalog;
int maxFeatures = 1000;
long maxCoordinates = 1024 * 1024 / 28; // this results 1MB of Coordinate object max
public QueryLayerFunctionFactory() {
FilterFactory ff = CommonFactoryFinder.getFilterFactory(null);
List<FunctionName> names = new ArrayList<FunctionName>();
names.add(ff.functionName(QUERY_SINGLE, -1)); // 2 or 3 args
names.add(ff.functionName(QUERY_COLLECTION, -1)); // 2 or 3 args
names.add(ff.functionName(COLLECT_GEOMETRIES, 1));
functionNames = Collections.unmodifiableList(names);
}
public long getMaxFeatures() {
return maxFeatures;
}
/**
* Sets the max number of features returned by a free query
*
* @param maxFeatures
*/
public void setMaxFeatures(int maxFeatures) {
if (maxFeatures <= 0) {
throw new IllegalArgumentException("The max features retrieved by a query layer "
+ "function must be a positive number");
}
this.maxFeatures = maxFeatures;
}
/**
* Sets the maximum number of coordinates to be collected, a non positive value implies no limit
*
* @param maxCoordinates
*/
public void setMaxCoordinates(long maxCoordinates) {
this.maxCoordinates = maxCoordinates;
}
/**
* Initializes the catalog reference, without it the factory won't generate any function
*
* @param catalog
*/
public void setCatalog(Catalog catalog) {
this.catalog = catalog;
}
public Function function(String name, List<Expression> args, Literal fallback) {
return function(new NameImpl(name), args, fallback);
}
@Override
public Function function(Name name, List<Expression> args, Literal fallback) {
if (!isInitialized()) {
return null;
}
if (QUERY_SINGLE.equals(name)) {
return new QueryFunction(QUERY_SINGLE, catalog, args, fallback, true, 1);
} else if (QUERY_COLLECTION.equals(name)) {
return new QueryFunction(QUERY_COLLECTION, catalog, args, fallback, false, maxFeatures);
} else if(COLLECT_GEOMETRIES.equals(name)) {
return new CollectGeometriesFunction(COLLECT_GEOMETRIES, args, fallback, maxCoordinates);
} else {
return null;
}
}
public List<FunctionName> getFunctionNames() {
if (isInitialized()) {
return functionNames;
} else {
return Collections.emptyList();
}
}
private boolean isInitialized() {
if (catalog == null) {
LOGGER.log(Level.INFO, "Looking for functions but the catalog still "
+ "has not been set into QueryLayerFunctionFactory");
return false;
} else {
return true;
}
}
}