/*
* eXist Open Source Native XML Database
* Copyright (C) 2014 The eXist Project
* http://exist-db.org
*
* This program 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 2
* 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.exist.mongodb.xquery.mongodb.collection;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.MapReduceCommand.OutputType;
import com.mongodb.MapReduceOutput;
import com.mongodb.MongoClient;
import com.mongodb.MongoCommandException;
import com.mongodb.MongoException;
import com.mongodb.util.JSON;
import com.mongodb.util.JSONParseException;
import java.util.Locale;
import org.exist.dom.QName;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_COLLECTION;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_DATABASE;
import static org.exist.mongodb.shared.FunctionDefinitions.PARAMETER_MONGODB_CLIENT;
import org.exist.mongodb.shared.MongodbClientStore;
import org.exist.mongodb.xquery.MongodbModule;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.StringValue;
import org.exist.xquery.value.Type;
import org.exist.xquery.value.ValueSequence;
/**
* Function to execute map-reduce on Mongo
*
* @author Dannes Wessels
*/
public class MapReduce extends BasicFunction {
private static final String MAP_REDUCE = "map-reduce";
public static final String PARAM_MAP = "map";
public static final String DESCR_MAP = "A JavaScript function that associates or \"maps\" a value with a key and emits the key and value pair.";
public static final FunctionParameterSequenceType PARAMETER_MAP
= new FunctionParameterSequenceType(PARAM_MAP, Type.STRING, Cardinality.ONE, DESCR_MAP);
public static final String PARAM_REDUCE = "reduce";
public static final String DESCR_REDUCE = "A JavaScript function that \"reduces\" to a single object all the values associated with a particular key.";
public static final FunctionParameterSequenceType PARAMETER_REDUCE
= new FunctionParameterSequenceType(PARAM_REDUCE, Type.STRING, Cardinality.ONE, DESCR_REDUCE);
public static final String PARAM_OUTPUT_TARGET = "output-target";
public static final String DESCR_OUTPUT_TARGET = "Specifies the location of the result of the map-reduce operation (optional), empty-sequence if want to use temp collection";
public static final FunctionParameterSequenceType PARAMETER_OUTPUT_TARGET
= new FunctionParameterSequenceType(PARAM_OUTPUT_TARGET, Type.STRING, Cardinality.ZERO_OR_ONE, DESCR_OUTPUT_TARGET);
public static final String PARAM_OUTPUT_TYPE = "output-type";
public static final String DESCR_OUTPUT_TYPE = "Specifies the option for outputting the results of a map-reduce operation. Available values: "
+ "replace,merge,reduce,inline. Empty sequence defaults to inline.";
public static final FunctionParameterSequenceType PARAMETER_OUTPUT_TYPE
= new FunctionParameterSequenceType(PARAM_OUTPUT_TYPE, Type.STRING, Cardinality.ZERO_OR_ONE, DESCR_OUTPUT_TYPE);
public static final String PARAM_MR_QUERY = "query";
public static final String DESCR_MR_QUERY = "Specifies the selection criteria using query operators for determining the documents input to the map function.";
public static final FunctionParameterSequenceType PARAMETER_MR_QUERY
= new FunctionParameterSequenceType(PARAM_MR_QUERY, Type.STRING, Cardinality.ZERO_OR_ONE, DESCR_MR_QUERY);
public final static FunctionSignature signatures[] = {
new FunctionSignature(
new QName(MAP_REDUCE, MongodbModule.NAMESPACE_URI, MongodbModule.PREFIX), "Allows you to run map-reduce aggregation operations "
+ "over a collection. Runs the command in REPLACE output mode (saves to named collection)..",
new SequenceType[]{
PARAMETER_MONGODB_CLIENT, PARAMETER_DATABASE, PARAMETER_COLLECTION, PARAMETER_MAP, PARAMETER_REDUCE, PARAMETER_OUTPUT_TARGET, PARAMETER_OUTPUT_TYPE, PARAMETER_MR_QUERY},
new FunctionReturnSequenceType(Type.STRING, Cardinality.ZERO_OR_ONE, "The results of this map reduce operation formatted as JSON")
),
};
public MapReduce(XQueryContext context, FunctionSignature signature) {
super(context, signature);
}
@Override
public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
try {
// Verify clientid and get client
String mongodbClientId = args[0].itemAt(0).getStringValue();
MongodbClientStore.getInstance().validate(mongodbClientId);
MongoClient client = MongodbClientStore.getInstance().get(mongodbClientId);
// Get parameters
String dbname = args[1].itemAt(0).getStringValue();
String collection = args[2].itemAt(0).getStringValue();
String map = args[3].itemAt(0).getStringValue();
String reduce = args[4].itemAt(0).getStringValue();
// output-target can have value null
String outputTarget = args[5].isEmpty()
? null
: args[5].itemAt(0).getStringValue();
OutputType outputType = args[6].isEmpty()
? OutputType.INLINE
: OutputType.valueOf( args[6].itemAt(0).getStringValue().toUpperCase(Locale.US) );
DBObject query = (BasicDBObject) JSON.parse(args[7].itemAt(0).getStringValue());
// Get collection in database
DB db = client.getDB(dbname);
DBCollection dbcol = db.getCollection(collection);
// Execute query
MapReduceOutput output = dbcol.mapReduce(map, reduce, outputTarget, outputType,query);
// Parse results
Sequence retVal = new ValueSequence();
for (DBObject result : output.results()) {
retVal.add(new StringValue(result.toString()));
}
return retVal;
} catch(JSONParseException ex){
LOG.error(ex.getMessage());
throw new XPathException(this, MongodbModule.MONG0004, ex.getMessage());
} catch (XPathException ex) {
LOG.error(ex.getMessage(), ex);
throw new XPathException(this, ex.getMessage(), ex);
} catch (MongoCommandException ex) {
LOG.error(ex.getMessage(), ex);
throw new XPathException(this, MongodbModule.MONG0005, ex.getMessage());
} catch (MongoException ex) {
LOG.error(ex.getMessage(), ex);
throw new XPathException(this, MongodbModule.MONG0002, ex.getMessage());
} catch (Throwable ex) {
LOG.error(ex.getMessage(), ex);
throw new XPathException(this, MongodbModule.MONG0003, ex.getMessage());
}
}
}