From 04e41cf702e12d8cc54b1a6d387ad47dfa394765 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Wed, 2 May 2007 17:38:37 +0000
Subject: [PATCH] improved connection queue handling slightly. Will require
 further improvements

---
 include/libtorrent/torrent.hpp |  4 +++-
 src/policy.cpp                 |  5 +++--
 src/torrent.cpp                | 19 ++++++++++++++-----
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/include/libtorrent/torrent.hpp b/include/libtorrent/torrent.hpp
index c71480da1..0dde2dcd9 100755
--- a/include/libtorrent/torrent.hpp
+++ b/include/libtorrent/torrent.hpp
@@ -199,7 +199,7 @@ namespace libtorrent
 		tcp::endpoint const& get_interface() const { return m_net_interface; }
 		
 		void connect_to_url_seed(std::string const& url);
-		peer_connection& connect_to_peer(policy::peer* peerinfo);
+		peer_connection* connect_to_peer(policy::peer* peerinfo);
 
 		void set_ratio(float ratio)
 		{ assert(ratio >= 0.0f); m_ratio = ratio; }
@@ -247,6 +247,8 @@ namespace libtorrent
 		// decreased in the piece_picker
 		void remove_peer(peer_connection* p);
 
+		bool want_more_peers() const;
+
 		peer_connection* connection_for(tcp::endpoint const& a)
 		{
 			peer_iterator i = m_connections.find(a);
diff --git a/src/policy.cpp b/src/policy.cpp
index 6e524d1ba..001a3ef0c 100755
--- a/src/policy.cpp
+++ b/src/policy.cpp
@@ -1201,7 +1201,7 @@ namespace libtorrent
 	{
 		INVARIANT_CHECK;
 
-		if(m_torrent->num_peers() >= m_torrent->m_connections_quota.given)
+		if (!m_torrent->want_more_peers())
 			return false;
 		
 		bool succeed = false;
@@ -1223,7 +1223,8 @@ namespace libtorrent
 		try
 		{
 			assert(!p->connection);
-			p->connection = &m_torrent->connect_to_peer(&*p);
+			p->connection = m_torrent->connect_to_peer(&*p);
+			if (p->connection == 0) return false;
 			assert(p->connection);
 			p->connection->add_stat(p->prev_amount_download, p->prev_amount_upload);
 			p->prev_amount_download = 0;
diff --git a/src/torrent.cpp b/src/torrent.cpp
index fe6497dc1..72255806c 100755
--- a/src/torrent.cpp
+++ b/src/torrent.cpp
@@ -1877,9 +1877,12 @@ namespace libtorrent
 		}
 	}
 
-	peer_connection& torrent::connect_to_peer(policy::peer* peerinfo)
+	peer_connection* torrent::connect_to_peer(policy::peer* peerinfo)
 	{
 		INVARIANT_CHECK;
+
+		if (!want_more_peers()) return 0;
+
 		tcp::endpoint const& a(peerinfo->ip);
 		if (m_ses.m_ip_filter.access(a.address()) & ip_filter::blocked)
 		{
@@ -1888,11 +1891,10 @@ namespace libtorrent
 				m_ses.m_alerts.post_alert(peer_blocked_alert(a.address()
 					, "peer connection blocked by IP filter"));
 			}
-			throw protocol_error(a.address().to_string() + " blocked by ip filter");
+			return 0;
 		}
 
-		if (m_connections.find(a) != m_connections.end())
-			throw protocol_error("already connected to peer");
+		if (m_connections.find(a) != m_connections.end()) return 0;
 
 		boost::shared_ptr<socket_type> s
 			= instantiate_connection(m_ses.m_io_service, m_ses.peer_proxy());
@@ -1941,7 +1943,7 @@ namespace libtorrent
 			throw;
 		}
 		if (c->is_disconnecting()) throw protocol_error("failed to connect");
-		return *c;
+		return c.get();
 	}
 
 	void torrent::set_metadata(entry const& metadata)
@@ -2036,6 +2038,13 @@ namespace libtorrent
 #endif
 	}
 
+	bool torrent::want_more_peers() const
+	{
+		return m_connections.size() < m_connections_quota.given
+			&& m_ses.m_half_open.size() < m_ses.m_half_open_limit;
+	}
+
+
 	void torrent::disconnect_all()
 	{
 		session_impl::mutex_t::scoped_lock l(m_ses.m_mutex);