diff options
author | José Bollo <jose.bollo@iot.bzh> | 2019-07-16 23:39:27 +0200 |
---|---|---|
committer | Jose Bollo <jose.bollo@iot.bzh> | 2019-07-18 15:38:02 +0200 |
commit | 6dfeafe7e4fa582b3db3f950136bc97f8611fc6d (patch) | |
tree | 62386661fe495dd8992260c89e09757326450edc /src/afb-proto-ws.c | |
parent | 5b5968815dc672467f40ed6b49f05a590bdb8b4d (diff) |
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>
Diffstat (limited to 'src/afb-proto-ws.c')
-rw-r--r-- | src/afb-proto-ws.c | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/src/afb-proto-ws.c b/src/afb-proto-ws.c index 2781ff09..fb8628db 100644 --- a/src/afb-proto-ws.c +++ b/src/afb-proto-ws.c @@ -560,11 +560,12 @@ static void client_on_event_unsubscribe(struct afb_proto_ws *protows, struct rea /* receives broadcasted events */ static void client_on_event_broadcast(struct afb_proto_ws *protows, struct readbuf *rb) { - const char *event_name; + const char *event_name, *uuid; + char hop; struct json_object *object; - if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object)) - protows->client_itf->on_event_broadcast(protows->closure, event_name, object); + if (protows->client_itf->on_event_broadcast && readbuf_string(rb, &event_name, NULL) && readbuf_object(rb, &object) && (uuid = readbuf_get(rb, 16)) && readbuf_char(rb, &hop)) + protows->client_itf->on_event_broadcast(protows->closure, event_name, object, (unsigned char*)uuid, (uint8_t)hop); else ERROR("Ignoring broadcast of event"); } @@ -909,9 +910,9 @@ static int server_event_send(struct afb_proto_ws *protows, char order, const cha int rc; if (writebuf_char(&wb, order) - && (order == CHAR_FOR_EVT_BROADCAST || writebuf_uint32(&wb, event_id)) + && writebuf_uint32(&wb, event_id) && writebuf_string(&wb, event_name) - && (order == CHAR_FOR_EVT_ADD || order == CHAR_FOR_EVT_DEL || writebuf_object(&wb, data))) { + && (order != CHAR_FOR_EVT_PUSH || writebuf_object(&wb, data))) { pthread_mutex_lock(&protows->mutex); rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count); pthread_mutex_unlock(&protows->mutex); @@ -936,9 +937,26 @@ int afb_proto_ws_server_event_push(struct afb_proto_ws *protows, const char *eve return server_event_send(protows, CHAR_FOR_EVT_PUSH, event_name, event_id, data); } -int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data) +int afb_proto_ws_server_event_broadcast(struct afb_proto_ws *protows, const char *event_name, struct json_object *data, const unsigned char uuid[16], uint8_t hop) { - return server_event_send(protows, CHAR_FOR_EVT_BROADCAST, event_name, 0, data); + struct writebuf wb = { .count = 0 }; + int rc; + + if (!hop--) + return 0; + + if (writebuf_char(&wb, CHAR_FOR_EVT_BROADCAST) + && writebuf_string(&wb, event_name) + && writebuf_object(&wb, data) + && writebuf_put(&wb, uuid, 16) + && writebuf_char(&wb, (char)hop)) { + pthread_mutex_lock(&protows->mutex); + rc = afb_ws_binary_v(protows->ws, wb.iovec, wb.count); + pthread_mutex_unlock(&protows->mutex); + if (rc >= 0) + return 0; + } + return -1; } /*****************************************************/ |