From: Christian Grothoff <christian@grothoff.org>
Date: Sat, 17 Apr 2010 21:16:41 +0000 (+0000)
Subject: proper HELLO merging
X-Git-Tag: initial-import-from-subversion-38251~22104
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=967418d0b309a8efb8d552ced8359bfe2d444e45;p=oweals%2Fgnunet.git

proper HELLO merging
---

diff --git a/TODO b/TODO
index b7b1441b7..bca489b25 100644
--- a/TODO
+++ b/TODO
@@ -1,17 +1,14 @@
 0.9.0pre1:
-* PEERINFO:
+* PEERINFO: [CG]
   - trust: need *fast* way to check/update trust in peers
            (async peerinfo would not be right; certainly not with the current API)
-* TOPOLOGY:
-  - check if new HELLO learned is different from old HELLO
-    before resetting entire state!
-  - needs more testing (especially F2F topology)
+* TOPOLOGY: [CG]
   - needs to re-try connecting after disconnect (currently, it
     initially triggers a connection request, but if that connection
     fails / goes down, it does not retry in a timely fashion;
-    cause seems to be the 'blacklist_after_attempt' being set to 1h,
+    cause seems to be the 'greylist_after_attempt' being set to 1h,
     which is rather long -- and should probably be adjusted based on
-    the number of connections / known peers)
+    the number of connections / known peers & use some form of back-off)
   - If the topology daemon crashes, peers that were put on the
     blacklist with transport will never be removed from it (until
     transport service dies); we should use the blacklist notification
@@ -24,9 +21,7 @@
      a minor issue; OTOH, we might want to be more explicit about
      allowing/forbidding connects on pre-connect to avoid 
      entering connect attempts to just be blacklisted shortly afterwards).
-* DATASTORE:
-  - API lacks cancellation methods (needed? or is disconnect enough?)
-  - may also want to integrate request queuing here instead of gnunet-service-fs_drq.c 
+  - needs more testing (especially F2F topology)
 * FS: [CG]
   - support recursive download even if filename is NULL and we hence
     do not generate files on disk (use temp_filename)
@@ -180,10 +175,6 @@
 Optimizations:
 * TCP:
   - should use hash map to look up sessions
-* PEERINFO:
-  - api creates many, many short-lived TCP connections; either some
-    clients should use the API differently or we need to change the
-    API to enable re-use of connections to the service
 * STATISTICS:
   - should use BIO instead of mmap
 * TRANSPORT:
@@ -196,7 +187,7 @@ Optimizations:
   - should use hash map to look up Neighbours
 * HOSTLIST:
   - 'server' uses 'GNUNET_PEERINFO_iterate', should probably switch to notification API
-    (for more instant / up-to-date hostlists at lower cost) [OPTIMIZATION]
+    (for more instant / up-to-date hostlists at lower cost)
 * DATASTORE (?):
   - check for duplicates on insertion (currently, same content is frequently
     stored again [seen with KBLOCKS and SBLOCKS]!)
diff --git a/src/topology/gnunet-daemon-topology.c b/src/topology/gnunet-daemon-topology.c
index 3aa518fa1..3a2a421d4 100644
--- a/src/topology/gnunet-daemon-topology.c
+++ b/src/topology/gnunet-daemon-topology.c
@@ -1016,6 +1016,8 @@ consider_for_advertising (const struct GNUNET_HELLO_Message *hello)
 {
   int have_address;
   struct GNUNET_PeerIdentity pid;
+  struct GNUNET_TIME_Absolute dt;
+  struct GNUNET_HELLO_Message *nh;
   struct Peer *peer;
   uint16_t size;
 
@@ -1034,17 +1036,36 @@ consider_for_advertising (const struct GNUNET_HELLO_Message *hello)
   peer = GNUNET_CONTAINER_multihashmap_get (peers,
 					    &pid.hashPubKey);
   if (peer == NULL)
-    peer = make_peer (&pid, hello, GNUNET_NO);
+    {
+      peer = make_peer (&pid, hello, GNUNET_NO);
+    }
+  else if (peer->hello != NULL)
+    {
+      dt = GNUNET_HELLO_equals (peer->hello,
+				hello,
+				GNUNET_TIME_absolute_get());
+      if (dt.value == GNUNET_TIME_UNIT_FOREVER_ABS.value)
+	return; /* nothing new here */
+    }
 #if DEBUG_TOPOLOGY
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 	      "Found `%s' from peer `%s' for advertising\n",
 	      "HELLO",
 	      GNUNET_i2s (&pid));
 #endif 
-  size = GNUNET_HELLO_size (hello);
-  GNUNET_free_non_null (peer->hello);
-  peer->hello = GNUNET_malloc (size);
-  memcpy (peer->hello, hello, size);
+  if (peer->hello != NULL)
+    {
+      nh = GNUNET_HELLO_merge (peer->hello,
+			       hello);
+      GNUNET_free (peer->hello);
+      peer->hello = nh;
+    }
+  else
+    {
+      size = GNUNET_HELLO_size (hello);
+      peer->hello = GNUNET_malloc (size);
+      memcpy (peer->hello, hello, size);
+    }
   if (peer->filter != NULL)
     GNUNET_CONTAINER_bloomfilter_free (peer->filter);
   setup_filter (peer);