Decoder: check for duplicate register() calls in common backend code

Future implementations might call decoders' start() routine several
times, which makes them call register() again. It's desirable that the
common backend code copes with this condition, such that (the multitude
of) decoder implementations need not work around a specific constraint.

1 files changed, 29 insertions, 1 deletions

diff --git a/type_decoder.c b/type_decoder.c
index 7c71132..06842f9 100644
--- a/type_decoder.c
+++ b/type_decoder.c
@@ -361,6 +361,9 @@ static PyObject *Decoder_register(PyObject *self, PyObject *args,
 	char *proto_id, *meta_name, *meta_descr;
 	char *keywords[] = {"output_type", "proto_id", "meta", NULL};
 	PyGILState_STATE gstate;
+	gboolean is_meta;
+	GSList *l;
+	struct srd_pd_output *cmp;
 
 	gstate = PyGILState_Ensure();
 
@@ -383,7 +386,8 @@ static PyObject *Decoder_register(PyObject *self, PyObject *args,
 	}
 
 	/* Check if the meta value's type is supported. */
-	if (output_type == SRD_OUTPUT_META) {
+	is_meta = output_type == SRD_OUTPUT_META;
+	if (is_meta) {
 		if (meta_type_py == &PyLong_Type)
 			meta_type_gv = G_VARIANT_TYPE_INT64;
 		else if (meta_type_py == &PyFloat_Type)
@@ -394,6 +398,30 @@ static PyObject *Decoder_register(PyObject *self, PyObject *args,
 		}
 	}
 
+	srd_dbg("Instance %s checking registration type %d for %s.",
+		di->inst_id, output_type, proto_id);
+	pdo = NULL;
+	for (l = di->pd_output; l; l = l->next) {
+		cmp = l->data;
+		if (cmp->output_type != output_type)
+			continue;
+		if (strcmp(cmp->proto_id, proto_id) != 0)
+			continue;
+		if (is_meta && cmp->meta_type != meta_type_gv)
+			continue;
+		if (is_meta && strcmp(cmp->meta_name, meta_name) != 0)
+			continue;
+		if (is_meta && strcmp(cmp->meta_descr, meta_descr) != 0)
+			continue;
+		pdo = cmp;
+		break;
+	}
+	if (pdo) {
+		py_new_output_id = Py_BuildValue("i", pdo->pdo_id);
+		PyGILState_Release(gstate);
+		return py_new_output_id;
+	}
+
 	srd_dbg("Instance %s creating new output type %d for %s.",
 		di->inst_id, output_type, proto_id);