support deepcopy & copy

src/fastpb/template/module.jinjacc

@@ -203,6 +203,23 @@ namespace {
       return PyString_FromStringAndSize(result.data(), result.length());
   }
 
+  PyObject *
+  {{ message.name }}_Copy({{ message.name }}* self)
+  {
+      {{ message.name }}* cloned = NULL;
+      Py_BEGIN_ALLOW_THREADS
+      cloned = ({{ message.name }}*){{ message.name }}_new(&{{ message.name }}Type, NULL, NULL);
+      cloned->protobuf->CopyFrom(*self->protobuf);
+      Py_END_ALLOW_THREADS
+      return (PyObject*)cloned;
+  }
+
+  PyObject *
+  {{ message.name }}_DeepCopy({{ message.name }}* self, PyObject* /*memo*/)
+  {
+      return {{ message.name }}_Copy(self);
+  }
+
 
   PyObject *
   {{ message.name }}_ParseFromString({{ message.name }}* self, PyObject *value)
@@ -658,6 +675,12 @@ namespace {
       {"ParseMany", (PyCFunction){{ message.name }}_ParseMany, METH_VARARGS | METH_CLASS,
        "Parses many protocol buffers of this type from a string."
       },
+      {"__copy__", (PyCFunction){{ message.name }}_DeepCopy, METH_NOARGS,
+       "copy a pb message."
+      },
+      {"__deepcopy__", (PyCFunction){{ message.name }}_DeepCopy, METH_O,
+       "deep copy a pb message."
+      },
       {NULL}  // Sentinel
   };
 

src/fastpb/template/test.jinjapy

@@ -54,6 +54,13 @@ class Test_{{ file.package.replace('.', '_') }}(unittest.TestCase):
     {% for field in message.field %}
     self.assertEquals(pb.{{ field.name }}, pb2.{{ field.name }})
     {% endfor %}
+
+    pb3 = copy.deepcopy(pb)
+
+    {% for field in message.field %}
+    self.assertEquals(pb.{{ field.name }}, pb3.{{ field.name }})
+    {% endfor %}
+
   {% endfor %}
 {% endfor %}