water.udf.JythonCFuncLoader Maven / Gradle / Ivy
package water.udf;
import org.python.core.PySystemState;
/**
* Custom function loader, which can instantiate
* functions written in Python.
*
* The provider internally uses Jython.
*
* Note: Jython caches the loaded python programs. That means
* changing underlying function definition (i.e, Python code) is not
* reflected!
*/
public class JythonCFuncLoader extends CFuncLoader {
@Override
public String getLang() {
return "python";
}
@Override
public F load(String jfuncName, Class targetKlazz, ClassLoader classLoader) {
int idxLastDot = jfuncName.lastIndexOf('.');
String module = jfuncName.substring(0, idxLastDot);
String clsName = jfuncName.substring(idxLastDot+1);
PySystemState pySystemState = new PySystemState();
ClassLoader savedCtxCl = Thread.currentThread().getContextClassLoader();
try {
Thread.currentThread().setContextClassLoader(classLoader);
return new JythonObjectFactory(pySystemState, targetKlazz, module, clsName).createObject();
} finally {
Thread.currentThread().setContextClassLoader(savedCtxCl);
}
}
}