org.apache.pig.scripting.jython.JythonUtils Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.pig.scripting.jython;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.data.BagFactory;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.DataByteArray;
import org.apache.pig.data.DefaultBagFactory;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;
import org.python.core.Py;
import org.python.core.PyDictionary;
import org.python.core.PyFloat;
import org.python.core.PyInteger;
import org.python.core.PyList;
import org.python.core.PyLong;
import org.python.core.PyNone;
import org.python.core.PyObject;
import org.python.core.PyString;
import org.python.core.PyTuple;
public class JythonUtils {
private static TupleFactory tupleFactory = TupleFactory.getInstance();
private static BagFactory bagFactory = DefaultBagFactory.getInstance();
@SuppressWarnings("unchecked")
public static Object pythonToPig(PyObject pyObject) throws ExecException {
try {
Object javaObj = null;
// Add code for all supported pig types here
// Tuple, bag, map, int, long, float, double, chararray, bytearray
if (pyObject instanceof PyTuple) {
PyTuple pyTuple = (PyTuple) pyObject;
Object[] tuple = new Object[pyTuple.size()];
int i = 0;
for (PyObject tupleObject : pyTuple.getArray()) {
tuple[i++] = pythonToPig(tupleObject);
}
javaObj = tupleFactory.newTuple(Arrays.asList(tuple));
} else if (pyObject instanceof PyList) {
DataBag list = bagFactory.newDefaultBag();
for (PyObject bagTuple : ((PyList) pyObject).asIterable()) {
// In jython, list need not be a bag of tuples, as it is in case of pig
// So we fail with cast exception if we dont find tuples inside bag
// This is consistent with java udf (bag should be filled with tuples)
list.add((Tuple) pythonToPig(bagTuple));
}
javaObj = list;
} else if (pyObject instanceof PyDictionary) {
Map map = Py.tojava(pyObject, Map.class);
Map newMap = new HashMap();
for (Map.Entry entry : map.entrySet()) {
if (entry.getValue() instanceof PyObject) {
newMap.put(entry.getKey(), pythonToPig((PyObject) entry.getValue()));
} else {
// Jython sometimes uses directly the java class: for example for integers
newMap.put(entry.getKey(), entry.getValue());
}
}
javaObj = newMap;
} else if (pyObject instanceof PyLong) {
javaObj = pyObject.__tojava__(Long.class);
} else if (pyObject instanceof PyInteger) {
javaObj = pyObject.__tojava__(Integer.class);
} else if (pyObject instanceof PyFloat) {
// J(P)ython is loosely typed, supports only float type,
// hence we convert everything to double to save precision
javaObj = pyObject.__tojava__(Double.class);
} else if (pyObject instanceof PyString) {
javaObj = pyObject.__tojava__(String.class);
} else if (pyObject instanceof PyNone) {
return null;
} else {
javaObj = pyObject.__tojava__(byte[].class);
// if we successfully converted to byte[]
if(javaObj instanceof byte[]) {
javaObj = new DataByteArray((byte[])javaObj);
}
else {
throw new ExecException("Non supported pig datatype found, cast failed: "+(pyObject==null?null:pyObject.getClass().getName()));
}
}
if(javaObj.equals(Py.NoConversion)) {
throw new ExecException("Cannot cast into any pig supported type: "+(pyObject==null?null:pyObject.getClass().getName()));
}
return javaObj;
} catch (Exception e) {
throw new ExecException("Cannot convert jython type ("+(pyObject==null?null:pyObject.getClass().getName())+") to pig datatype "+ e, e);
}
}
public static PyObject pigToPython(Object object) {
if (object instanceof Tuple) {
return pigTupleToPyTuple((Tuple) object);
} else if (object instanceof DataBag) {
PyList list = new PyList();
for (Tuple bagTuple : (DataBag) object) {
list.add(pigTupleToPyTuple(bagTuple));
}
return list;
} else if (object instanceof Map) {
PyDictionary newMap = new PyDictionary();
for (Map.Entry entry : ((Map) object).entrySet()) {
newMap.put(entry.getKey(), pigToPython(entry.getValue()));
}
return newMap;
} else if (object instanceof DataByteArray) {
return Py.java2py(((DataByteArray) object).get());
} else {
return Py.java2py(object);
}
}
public static PyTuple pigTupleToPyTuple(Tuple tuple) {
PyObject[] pyTuple = new PyObject[tuple.size()];
int i = 0;
for (Object object : tuple.getAll()) {
pyTuple[i++] = pigToPython(object);
}
return new PyTuple(pyTuple);
}
}