Simplify decompressobj parser

Author: rhpvorderman

src/isal/isal_zlib.c

@@ -906,41 +906,23 @@ PyDoc_STRVAR(isal_zlib_decompressobj__doc__,
 "    dictionary as used by the compressor that produced the input data.");
 
 #define ISAL_ZLIB_DECOMPRESSOBJ_METHODDEF    \
-    {"decompressobj", (PyCFunction)(void(*)(void))isal_zlib_decompressobj, METH_FASTCALL|METH_KEYWORDS, isal_zlib_decompressobj__doc__}
+    {"decompressobj", (PyCFunction)(void(*)(void))isal_zlib_decompressobj, METH_VARARGS|METH_KEYWORDS, isal_zlib_decompressobj__doc__}
 
 static PyObject *
-isal_zlib_decompressobj(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+isal_zlib_decompressobj(PyObject *module, PyObject *args, PyObject *kwargs)
 {
     PyObject *return_value = NULL;
-    static const char * const _keywords[] = {"wbits", "zdict", NULL};
-    static _PyArg_Parser _parser = {NULL, _keywords, "decompressobj", 0};
-    PyObject *argsbuf[2];
-    Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 0;
+    char *keywords[] = {"wbits", "zdict", NULL};
+    char *format = "|iO:decompressobj";
     int wbits = ISAL_DEF_MAX_HIST_BITS;
     PyObject *zdict = NULL;
 
-    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 0, 2, 0, argsbuf);
-    if (!args) {
-        goto exit;
-    }
-    if (!noptargs) {
-        goto skip_optional_pos;
-    }
-    if (args[0]) {
-        wbits = _PyLong_AsInt(args[0]);
-        if (wbits == -1 && PyErr_Occurred()) {
-            goto exit;
-        }
-        if (!--noptargs) {
-            goto skip_optional_pos;
-        }
+    if (!PyArg_ParseTupleAndKeywords(
+            args, kwargs, format, keywords,
+            &wbits, &zdict)) {
+        return NULL;
     }
-    zdict = args[1];
-skip_optional_pos:
-    return_value = isal_zlib_decompressobj_impl(module, wbits, zdict);
-
-exit:
-    return return_value;
+    return isal_zlib_decompressobj_impl(module, wbits, zdict);
 }
 
 PyDoc_STRVAR(isal_zlib_Compress_compress__doc__,