Work on defining new direct broadcast multicast algorithm.

node/MulticastTopology.cpp

@@ -0,0 +1,88 @@
+/*
+ * ZeroTier One - Global Peer to Peer Ethernet
+ * Copyright (C) 2011-2014  ZeroTier Networks LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * --
+ *
+ * ZeroTier may be used and distributed under the terms of the GPLv3, which
+ * are available at: http://www.gnu.org/licenses/gpl-3.0.html
+ *
+ * If you would like to embed ZeroTier into a commercial application or
+ * redistribute it in a modified binary form, please contact ZeroTier Networks
+ * LLC. Start here: http://www.zerotier.com/
+ */
+
+#include <algorithm>
+
+#include "Constants.hpp"
+#include "MulticastTopology.hpp"
+#include "Topology.hpp"
+
+namespace ZeroTier {
+
+MulticastTopology::MulticastTopology()
+{
+}
+
+MulticastTopology::~MulticastTopology()
+{
+}
+
+void MulticastTopology::clean(const Topology &topology)
+{
+	uint64_t now = Utils::now();
+
+	for(std::map< MulticastGroup,std::vector<MulticastGroupMember> >::iterator mm(_members.begin());mm!=_members.end();) {
+		std::vector<MulticastGroupMember>::iterator reader(mm->second.begin());
+		std::vector<MulticastGroupMember>::iterator writer(mm->second.begin());
+		unsigned long count = 0;
+		while (reader != mm->second.end()) {
+			if ((now - reader->timestamp) < ZT_MULTICAST_LIKE_EXPIRE) {
+				*writer = *reader;
+
+				/* We sort in ascending order of most recent relevant activity. For peers we've learned
+				 * about by direct LIKEs, we do this in order of their own activity. For indirectly
+				 * acquired peers we do this minus a constant to place these categorically below directly
+				 * learned peers. For peers with no active Peer record, we use the time we last learned
+				 * about them minus one day (a large constant) to put these at the bottom of the list.
+				 * List is sorted in ascending order of rank and multicasts are sent last-to-first. */
+				if (writer->learnedFrom) {
+					SharedPtr<Peer> p(topology.getPeer(writer->learnedFrom));
+					if (p)
+						writer->rank = p->lastUnicastFrame() - ZT_MULTICAST_LIKE_EXPIRE;
+					else writer->rank = writer->timestamp - 86400000;
+				} else {
+					SharedPtr<Peer> p(topology.getPeer(writer->address));
+					if (p)
+						writer->rank = p->lastUnicastFrame();
+					else writer->rank = writer->timestamp - 86400000;
+				}
+
+				++writer;
+				++count;
+			}
+			++reader;
+		}
+
+		if (count) {
+			mm->second.resize(count);
+			std::sort(mm->second.begin(),mm->second.end()); // sorts in ascending order of rank
+			++mm;
+		} else _members.erase(mm++);
+	}
+}
+
+} // namespace ZeroTier