introduced failcount and retry time settings for peers

include/libtorrent/session_settings.hpp

@@ -58,6 +58,8 @@ namespace libtorrent
 			, urlseed_pipeline_size(5)
 			, file_pool_size(40)
 			, allow_multiple_connections_per_ip(false)
+			, max_failcount(3)
+			, min_reconnect_time(60)
 #ifndef TORRENT_DISABLE_DHT
 			, use_dht_as_fallback(true)
 #endif
@@ -154,6 +156,14 @@ namespace libtorrent
 		// IP address. true will allow it.
 		bool allow_multiple_connections_per_ip;
 
+		// the number of times we can fail to connect to a peer
+		// before we stop retrying it.
+		int max_failcount;
+		
+		// the number of seconds to wait to reconnect to a peer.
+		// this time is multiplied with the failcount.
+		int min_reconnect_time;
+
 #ifndef TORRENT_DISABLE_DHT
 		// while this is true, the dht will note be used unless the
 		// tracker is online

src/policy.cpp

@@ -513,9 +513,9 @@ namespace libtorrent
 		ptime now = time_now();
 		ptime ptime(now);
 		iterator candidate = m_peers.end();
-		
-		// TODO: take failcount into account
-		// TODO: have a minimum time before retrying
+
+		int max_failcount = m_torrent->settings().max_failcount;
+		int min_reconnect_time = m_torrent->settings().min_reconnect_time;
 
 		for (iterator i = m_peers.begin();
 			i != m_peers.end(); ++i)
@@ -524,6 +524,9 @@ namespace libtorrent
 			if (i->banned) continue;
 			if (i->type == peer::not_connectable) continue;
 			if (i->seed && m_torrent->is_seed()) continue;
+			if (i->failcount >= max_failcount) continue;
+			if (now - i->connected < seconds(i->failcount * min_reconnect_time))
+				continue;
 
 			assert(i->connected <= now);
 
@@ -1005,6 +1008,13 @@ namespace libtorrent
 				// for some reason.
 				i->ip = remote;
 				i->source |= src;
+				
+				// if this peer has failed before, decrease the
+				// counter to allow it another try, since somebody
+				// else is appearantly able to connect to it
+				// if it comes from the DHT it might be stale though
+				if (i->failcount > 0 && src != peer_info::dht)
+					--i->failcount;
 
 				if (flags & 0x02) i->seed = true;
 
@@ -1214,9 +1224,6 @@ namespace libtorrent
 		catch (std::exception& e)
 		{
 			++p->failcount;
-			// TODO: make this costumizable
-			if (p->failcount > 3)
-				m_peers.erase(p);
 		}
 		return false;
 	}
@@ -1241,7 +1248,6 @@ namespace libtorrent
 
 //		assert(c.is_disconnecting());
 		bool unchoked = false;
-		bool erase = false;
 
 		iterator i = std::find_if(
 			m_peers.begin()
@@ -1261,8 +1267,7 @@ namespace libtorrent
 
 		if (c.failed())
 		{
-			// TODO: make 3 customizable
-			if (++i->failcount > 3) erase = true;
+			++i->failcount;
 			i->connected = time_now();
 		}
 
@@ -1278,9 +1283,6 @@ namespace libtorrent
 		i->prev_amount_download += c.statistics().total_payload_download();
 		i->prev_amount_upload += c.statistics().total_payload_upload();
 
-		if (erase)
-			m_peers.erase(i);
-
 		if (unchoked)
 		{
 			// if the peer that is diconnecting is unchoked