Tag broadcasted events with UUID and hop

When API have mutual dependencies, leading to
loops in dependecies, broadcasting an event
never ends because of the loop (see SPEC-2625).

To avoid that weird flood of events, a unic
identifier (UUID) is attached to broadcasted
event and a tiny memory records previously
broadcasted events to avoid re-sending an
already sent event.

The size of the memory can be set using the
macro variable EVENT_BROADCAST_MEMORY_COUNT
whose default value is 8. It can be reduced
to 0.

An other mecanism is added to limit the count
of hops that a broadcasted event can do. That
count can be set using the macro variable
EVENT_BROADCAST_HOP_MAX whose default value
is 10.

Bug-AGL: SPEC-2625

Change-Id: I29550a8a5c8f5e2ffb20edc3330357a1e870c0e2
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/afb-proto-ws.h b/src/afb-proto-ws.h
index 312984a4..506960ea 100644
--- a/src/afb-proto-ws.h
+++ b/src/afb-proto-ws.h
@@ -29,6 +29,8 @@ struct afb_proto_ws;
 struct afb_proto_ws_call;
 struct afb_proto_ws_describe;
 
+typedef unsigned char afb_proto_ws_uuid_t[16];
+
 struct afb_proto_ws_client_itf
 {
 	/* can't be NULL */
@@ -40,7 +42,7 @@ struct afb_proto_ws_client_itf
 	void (*on_event_subscribe)(void *closure, void *request, const char *event_name, int event_id);
 	void (*on_event_unsubscribe)(void *closure, void *request, const char *event_name, int event_id);
 	void (*on_event_push)(void *closure, const char *event_name, int event_id, struct json_object *data);
-	void (*on_event_broadcast)(void *closure, const char *event_name, struct json_object *data);
+	void (*on_event_broadcast)(void *closure, const char *event_name, struct json_object *data, const afb_proto_ws_uuid_t uuid, uint8_t hop);
 };
 
 struct afb_proto_ws_server_itf
@@ -70,7 +72,7 @@ extern int afb_proto_ws_client_describe(struct afb_proto_ws *protows, void (*cal
 extern int afb_proto_ws_server_event_create(struct afb_proto_ws *protows, const char *event_name, int event_id);
 extern int afb_proto_ws_server_event_remove(struct afb_proto_ws *protows, const char *event_name, int event_id);
 extern int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *event_name, int event_id, struct json_object *data);
-extern int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data);
+extern int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data, const afb_proto_ws_uuid_t uuid, uint8_t hop);
 
 extern void afb_proto_ws_call_addref(struct afb_proto_ws_call *call);
 extern void afb_proto_ws_call_unref(struct afb_proto_ws_call *call);