Refactor handling of an SPDP-republish event

Signed-off-by: Erik Boasson <eb@ilities.com>

src/core/ddsi/src/q_xevent.c

@@ -959,6 +959,42 @@ static void handle_xevk_acknack (UNUSED_ARG (struct nn_xpack *xp), struct xevent
   resched_xevent_if_earlier (ev, add_duration_to_mtime (tnow, 100 * T_MILLISECOND));
 }
 
+static bool resend_spdp_sample_by_guid_key (struct writer *wr, const nn_guid_t *guid, struct proxy_reader *prd)
+{
+  /* Look up data in (transient-local) WHC by key value -- FIXME: clearly
+   a slightly more efficient and elegant way of looking up the key value
+   is to be preferred */
+  bool sample_found;
+  nn_plist_t ps;
+  nn_plist_init_empty (&ps);
+  ps.present |= PP_PARTICIPANT_GUID;
+  ps.participant_guid = *guid;
+  struct nn_xmsg *mpayload = nn_xmsg_new (gv.xmsgpool, &guid->prefix, 0, NN_XMSG_KIND_DATA);
+  nn_plist_addtomsg (mpayload, &ps, ~(uint64_t)0, ~(uint64_t)0);
+  nn_xmsg_addpar_sentinel (mpayload);
+  nn_plist_fini (&ps);
+  struct ddsi_plist_sample plist_sample;
+  nn_xmsg_payload_to_plistsample (&plist_sample, PID_PARTICIPANT_GUID, mpayload);
+  struct ddsi_serdata *sd = ddsi_serdata_from_sample (gv.plist_topic, SDK_KEY, &plist_sample);
+  struct whc_borrowed_sample sample;
+  nn_xmsg_free (mpayload);
+
+  os_mutexLock (&wr->e.lock);
+  sample_found = whc_borrow_sample_key (wr->whc, sd, &sample);
+  if (sample_found)
+  {
+    /* Claiming it is new rather than a retransmit so that the rexmit
+     limiting won't kick in.  It is best-effort and therefore the
+     updating of the last transmitted sequence number won't take
+     place anyway.  Nor is it necessary to fiddle with heartbeat
+     control stuff. */
+    enqueue_sample_wrlock_held (wr, sample.seq, sample.plist, sample.serdata, prd, 1);
+    whc_return_sample(wr->whc, &sample, false);
+  }
+  os_mutexUnlock (&wr->e.lock);
+  ddsi_serdata_unref (sd);
+  return sample_found;
+}
 
 static void handle_xevk_spdp (UNUSED_ARG (struct nn_xpack *xp), struct xevent *ev, nn_mtime_t tnow)
 {
@@ -966,10 +1002,7 @@ static void handle_xevk_spdp (UNUSED_ARG (struct nn_xpack *xp), struct xevent *e
   struct participant *pp;
   struct proxy_reader *prd;
   struct writer *spdp_wr;
-  struct whc_borrowed_sample sample;
+  bool do_write;
-#ifndef NDEBUG
-  bool sample_found;
-#endif
 
   if ((pp = ephash_lookup_participant_guid (&ev->u.spdp.pp_guid)) == NULL)
   {
@@ -994,62 +1027,22 @@ static void handle_xevk_spdp (UNUSED_ARG (struct nn_xpack *xp), struct xevent *e
     /* memset is for tracing output */
     memset (&ev->u.spdp.dest_proxypp_guid_prefix, 0, sizeof (ev->u.spdp.dest_proxypp_guid_prefix));
     prd = NULL;
+    do_write = true;
   }
   else
   {
     nn_guid_t guid;
     guid.prefix = ev->u.spdp.dest_proxypp_guid_prefix;
     guid.entityid.u = NN_ENTITYID_SPDP_BUILTIN_PARTICIPANT_READER;
-    if ((prd = ephash_lookup_proxy_reader_guid (&guid)) == NULL)
+    prd = ephash_lookup_proxy_reader_guid (&guid);
-    {
+    do_write = (prd != NULL);
+    if (!do_write)
       DDS_TRACE("xmit spdp: no proxy reader %x:%x:%x:%x\n", PGUID (guid));
-      goto skip;
-    }
   }
 
-  /* Look up data in (transient-local) WHC by key value -- FIXME: clearly
+  if (do_write && !resend_spdp_sample_by_guid_key (spdp_wr, &ev->u.spdp.pp_guid, prd))
-     a slightly more efficient and elegant way of looking up the key value
-     is to be preferred */
-  nn_plist_t ps;
-  nn_plist_init_empty (&ps);
-  ps.present |= PP_PARTICIPANT_GUID;
-  ps.participant_guid = ev->u.spdp.pp_guid;
-  struct nn_xmsg *mpayload = nn_xmsg_new (gv.xmsgpool, &ev->u.spdp.pp_guid.prefix, 0, NN_XMSG_KIND_DATA);
-  nn_plist_addtomsg (mpayload, &ps, ~(uint64_t)0, ~(uint64_t)0);
-  nn_xmsg_addpar_sentinel (mpayload);
-  nn_plist_fini (&ps);
-  struct ddsi_plist_sample plist_sample;
-  nn_xmsg_payload_to_plistsample (&plist_sample, PID_PARTICIPANT_GUID, mpayload);
-  struct ddsi_serdata *sd = ddsi_serdata_from_sample (gv.plist_topic, SDK_KEY, &plist_sample);
-  nn_xmsg_free (mpayload);
-
-  os_mutexLock (&spdp_wr->e.lock);
-  if (whc_borrow_sample_key (spdp_wr->whc, sd, &sample))
   {
-    /* Claiming it is new rather than a retransmit so that the rexmit
-       limiting won't kick in.  It is best-effort and therefore the
-       updating of the last transmitted sequence number won't take
-       place anyway.  Nor is it necessary to fiddle with heartbeat
-       control stuff. */
-    enqueue_sample_wrlock_held (spdp_wr, sample.seq, sample.plist, sample.serdata, prd, 1);
-    whc_return_sample(spdp_wr->whc, &sample, false);
 #ifndef NDEBUG
-    sample_found = true;
-#endif
-  }
-#ifndef NDEBUG
-  else
-  {
-    sample_found = false;
-  }
-#endif
-  os_mutexUnlock (&spdp_wr->e.lock);
-
-  ddsi_serdata_unref (sd);
-
-#ifndef NDEBUG
-  if (!sample_found)
-  {
     /* If undirected, it is pp->spdp_xevent, and that one must never
        run into an empty WHC unless it is already marked for deletion.
 
@@ -1072,10 +1065,9 @@ static void handle_xevk_spdp (UNUSED_ARG (struct nn_xpack *xp), struct xevent *e
       DDS_TRACE("xmit spdp: suppressing early spdp response from %x:%x:%x:%x to %x:%x:%x:%x\n",
                 PGUID (pp->e.guid), PGUIDPREFIX (ev->u.spdp.dest_proxypp_guid_prefix), NN_ENTITYID_PARTICIPANT);
     }
-  }
 #endif
+  }
 
- skip:
   if (ev->u.spdp.directed)
   {
     /* Directed events are used to send SPDP packets to newly