New async support

Author: MelindaShore

context_util.c

@@ -0,0 +1,69 @@
+#include <Python.h>
+#include <getdns/getdns.h>
+#include <arpa/inet.h>
+#include "pygetdns.h"
+
+
+/*
+ *  Get the address of the Python function object
+ *    being passed in by name to the context
+ *    query methods
+ */
+
+PyObject *
+get_callback(char *py_main, char *callback)
+{
+    PyObject *main_module;
+    PyObject *main_dict;
+    PyObject *callback_func;
+
+    if ((main_module = PyImport_AddModule(py_main)) == 0)  {
+        PyErr_SetString(getdns_error, "No 'main'");
+        return NULL;
+    }
+    main_dict = PyModule_GetDict(main_module);
+    if ((callback_func = PyDict_GetItemString(main_dict, callback)) == 0)  {
+        PyErr_SetString(getdns_error, "callback not found\n");
+        return NULL;
+    }
+    if (!PyCallable_Check(callback_func))  {
+        PyErr_SetString(getdns_error, "The callback function is not runnable");
+        return NULL;
+    }
+    return callback_func;
+}
+
+    
+void
+callback_shim(struct getdns_context *context,
+              getdns_callback_type_t type,
+              struct getdns_dict *response,
+              void *userarg,
+              getdns_transaction_t tid)
+{
+    PyObject *py_callback_type;
+    PyObject *py_result;
+    PyObject *py_tid;
+    PyObject *py_userarg;
+
+    userarg_blob *u = (userarg_blob *)userarg;
+    if ((py_callback_type = PyInt_FromLong((long)type)) == NULL)  {
+        PyObject *err_type, *err_value, *err_traceback;
+        PyErr_Fetch(&err_type, &err_value, &err_traceback);
+        PyErr_Restore(err_type, err_value, err_traceback);
+        return;
+    }
+    if (type == GETDNS_CALLBACK_CANCEL)  {
+        py_result = Py_None;
+        py_tid = Py_None;
+        py_userarg = Py_None;
+    }  else  {
+        py_result = result_create(response);
+        py_tid = PyInt_FromLong((long)tid);
+        if (u->userarg)
+            py_userarg = PyString_FromString(u->userarg);
+        else
+            py_userarg = Py_None;
+    }
+    PyObject_CallFunctionObjArgs(u->callback_func, py_callback_type, py_result, py_userarg, py_tid, NULL);
+}