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

Signed-off-by: José Bollo <jose.bollo@iot.bzh>
Change-Id: I45877583dbf478a79d405c3650880a5579ac1f9e

1 files changed, 4 insertions, 1 deletions

diff --git a/src/afb-evt.h b/src/afb-evt.h
index 423bd552..02693e9c 100644
--- a/src/afb-evt.h
+++ b/src/afb-evt.h
@@ -17,6 +17,8 @@
 
 #pragma once
 
+#include "uuid.h"
+
 struct afb_event_x1;
 struct afb_event_x2;
 struct afb_evtid;
@@ -27,7 +29,7 @@ struct afb_evt_listener;
 struct afb_evt_itf
 {
 	void (*push)(void *closure, const char *event, int evtid, struct json_object *object);
-	void (*broadcast)(void *closure, const char *event, struct json_object *object);
+	void (*broadcast)(void *closure, const char *event, struct json_object *object, const uuid_binary_t uuid, uint8_t hop);
 	void (*add)(void *closure, const char *event, int evtid);
 	void (*remove)(void *closure, const char *event, int evtid);
 };
@@ -35,6 +37,7 @@ struct afb_evt_itf
 extern struct afb_evt_listener *afb_evt_listener_create(const struct afb_evt_itf *itf, void *closure);
 
 extern int afb_evt_broadcast(const char *event, struct json_object *object);
+extern int afb_evt_rebroadcast(const char *event, struct json_object *object, const  uuid_binary_t uuid, uint8_t hop);
 
 extern struct afb_evt_listener *afb_evt_listener_addref(struct afb_evt_listener *listener);
 extern void afb_evt_listener_unref(struct afb_evt_listener *listener);