Merge pull request #471 from lf-lang/custom-serializer

Custom Serialization in Python Target

python/include/pythontarget.h

@@ -185,6 +185,29 @@ PyObject* convert_C_action_to_py(void* action);
  */
 PyObject* get_python_function(string module, string class, int instance_id, string func);
 
+/**
+ * Load the Serializer class from package name
+ * @param package_name Name of the python package to load
+ * @return Initialized Serializer class
+ */
+PyObject* load_serializer(string package_name);
+
+/**
+ * Serialize Python object to a bytes object using external serializer
+ * @param obj The Python object to serialize
+ * @param custom_serializer The custom Serializer class
+ * @return Serialized Python bytes object
+ */
+PyObject* custom_serialize(PyObject* obj, PyObject* custom_serializer);
+
+/**
+ * Deserialize Python object from a bytes object using external serializer
+ * @param serialized_pyobject The serialized bytes Python object
+ * @param custom_serializer The custom Serializer class
+ * @return Deserialized Python object
+ */
+PyObject* custom_deserialize(PyObject* serialized_pyobject, PyObject* custom_serializer);
+
 /*
  * The Python runtime will call this function to initialize the module.
  * The name of this function is dynamically generated to follow

python/lib/pythontarget.c

@@ -695,3 +695,58 @@ PyObject* get_python_function(string module, string class, int instance_id, stri
   PyGILState_Release(gstate);
   return Py_None;
 }
+
+PyObject* load_serializer(string package_name) {
+  // import package_name
+  PyObject* pName = PyUnicode_DecodeFSDefault(package_name);
+  PyObject* pModule = PyImport_Import(pName);
+  Py_DECREF(pName);
+  if (PyErr_Occurred())
+    PyErr_Print();
+  if (pModule == NULL)
+    lf_print_error_and_exit("Could not load the custom serializer package '%s'.", package_name);
+  // Get the Serializer class
+  PyObject* SerializerClass = PyObject_GetAttrString(pModule, "Serializer");
+  if (PyErr_Occurred())
+    PyErr_Print();
+  if (SerializerClass == NULL)
+    lf_print_error_and_exit("Could not find class 'Serializer' in module '%s'.", package_name);
+  // Instanciate and initialize Serializer class
+  PyObject* custom_serializer = PyObject_CallObject(SerializerClass, NULL);
+  if (PyErr_Occurred())
+    PyErr_Print();
+  if (custom_serializer == NULL)
+    lf_print_error_and_exit("Could not instantiate class 'Serializer' in module '%s'.", package_name);
+  lf_print_log("Successfully loaded custom serializer package '%s'.\n", package_name);
+  return custom_serializer;
+}
+
+PyObject* custom_serialize(PyObject* obj, PyObject* custom_serializer) {
+  if (custom_serializer == NULL)
+    lf_print_error_and_exit("Serializer is null.");
+  PyObject* serializer_serialize = PyObject_GetAttrString(custom_serializer, "serialize");
+  PyObject* args = PyTuple_Pack(1, obj);
+  PyObject* serialized_pyobject = PyObject_CallObject(serializer_serialize, args);
+  Py_XDECREF(serializer_serialize);
+  Py_XDECREF(args);
+  if (PyErr_Occurred())
+    PyErr_Print();
+  if (serialized_pyobject == NULL)
+    lf_print_error_and_exit("Could not serialize object.");
+  return serialized_pyobject;
+}
+
+PyObject* custom_deserialize(PyObject* serialized_pyobject, PyObject* custom_serializer) {
+  if (custom_serializer == NULL)
+    lf_print_error_and_exit("Serializer is null.");
+  PyObject* serializer_deserialize = PyObject_GetAttrString(custom_serializer, "deserialize");
+  PyObject* args = PyTuple_Pack(1, serialized_pyobject);
+  PyObject* deserialized_obj = PyObject_CallObject(serializer_deserialize, args);
+  Py_XDECREF(serializer_deserialize);
+  Py_XDECREF(args);
+  if (PyErr_Occurred())
+    PyErr_Print();
+  if (deserialized_obj == NULL)
+    lf_print_error_and_exit("Could not deserialize deserialized_obj.");
+  return deserialized_obj;
+}