Changed SPDY's ip connection pooling logic to only add the used IP,

net/spdy/spdy_session_pool.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/spdy/spdy_session_pool.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/values.h"
 #include "net/base/address_list.h"
@@ skipping 132 matching lines @@
   if (!list)
     list = AddSessionList(host_port_proxy_pair);
   DCHECK(list->empty());
   list->push_back(*spdy_session);
 
   net_log.AddEvent(
       NetLog::TYPE_SPDY_SESSION_POOL_IMPORTED_SESSION_FROM_SOCKET,
       make_scoped_refptr(new NetLogSourceParameter(
           "session", (*spdy_session)->net_log().source())));
 
+  // We have a new session.  Lookup the IP address for this session so that we
+  // can match future Sessions (potentially to different domains) which can
+  // potentially be pooled with this one. Because GetPeerAddress() reports the
+  // proxy's address instead of the origin server, check to see if this is a
+  // direct connection.
+  if (g_enable_ip_pooling  && host_port_proxy_pair.second.is_direct()) {
+    AddressList addresses;
+    if (connection->socket()->GetPeerAddress(&addresses) == OK) {
+      const addrinfo* address = addresses.head();
+      AddAlias(address, host_port_proxy_pair);

[wtc, 2011/07/19 22:12:36]

Nit: you can just pass addresses.head() to AddAlias and
remove the curly braces around the inner if statement.

[ramant (doing other things), 2011/07/25 23:36:06]

Done.

+    }
+  }
+
   // Now we can initialize the session with the SSL socket.
   return (*spdy_session)->InitializeWithSocket(connection, is_secure,
                                                certificate_error_code);
 }
 
 bool SpdySessionPool::HasSession(
     const HostPortProxyPair& host_port_proxy_pair) const {
   if (GetSessionList(host_port_proxy_pair))
     return true;
 
@@ skipping 132 matching lines @@
   return *single_domain_pair;
 }
 
 SpdySessionPool::SpdySessionList*
     SpdySessionPool::AddSessionList(
         const HostPortProxyPair& host_port_proxy_pair) {
   const HostPortProxyPair& pair = NormalizeListPair(host_port_proxy_pair);
   DCHECK(sessions_.find(pair) == sessions_.end());
   SpdySessionPool::SpdySessionList* list = new SpdySessionList();
   sessions_[pair] = list;
-
-  // We have a new session.  Lookup the IP addresses for this session so that
-  // we can match future Sessions (potentially to different domains) which can
-  // potentially be pooled with this one.
-  if (g_enable_ip_pooling) {
-    AddressList addresses;
-    if (LookupAddresses(host_port_proxy_pair, &addresses))
-      AddAliases(addresses, host_port_proxy_pair);
-  }
-
   return list;
 }
 
 SpdySessionPool::SpdySessionList*
     SpdySessionPool::GetSessionList(
         const HostPortProxyPair& host_port_proxy_pair) const {
   const HostPortProxyPair& pair = NormalizeListPair(host_port_proxy_pair);
   SpdySessionsMap::const_iterator it = sessions_.find(pair);
   if (it != sessions_.end())
     return it->second;
@@ skipping 19 matching lines @@
   resolve_info.set_only_use_cached_response(true);
   int rv = resolver_->Resolve(resolve_info,
                               addresses,
                               NULL,
                               NULL,
                               net::BoundNetLog());
   DCHECK_NE(ERR_IO_PENDING, rv);
   return rv == OK;
 }
 
-void SpdySessionPool::AddAliases(const AddressList& addresses,
-                                 const HostPortProxyPair& pair) {
-  // Note:  it is possible to think of strange overlapping sets of ip addresses
-  // for hosts such that a new session can override the alias for an IP
-  // address that was previously aliased to a different host.  This is probably
-  // undesirable, but seemingly unlikely and complicated to fix.
-  //    Example:
-  //      host1 = 1.1.1.1, 1.1.1.4
-  //      host2 = 1.1.1.4, 1.1.1.5
-  //      host3 = 1.1.1.3, 1.1.1.5
-  //      Creating session1 (to host1), creates an alias for host2 to host1.
-  //      Creating session2 (to host3), overrides the alias for host2 to host3.
-
-  const addrinfo* address = addresses.head();
-  while (address) {
-    IPEndPoint endpoint;
-    endpoint.FromSockAddr(address->ai_addr, address->ai_addrlen);
-    aliases_[endpoint] = pair;
-    address = address->ai_next;
-  }
+void SpdySessionPool::AddAlias(const addrinfo* address,
+                               const HostPortProxyPair& pair) {
+  DCHECK(g_enable_ip_pooling);
+  DCHECK(address);
+  IPEndPoint endpoint;
+  endpoint.FromSockAddr(address->ai_addr, address->ai_addrlen);
+  aliases_[endpoint] = pair;
 }
 
 void SpdySessionPool::RemoveAliases(const HostPortProxyPair& pair) {
   // Walk the aliases map, find references to this pair.
   // TODO(mbelshe):  Figure out if this is too expensive.
   SpdyAliasMap::iterator alias_it = aliases_.begin();
   while (alias_it != aliases_.end()) {
     if (HostPortProxyPairsAreEqual(alias_it->second, pair)) {
       aliases_.erase(alias_it);
       alias_it = aliases_.begin();  // Iterator was invalidated.
@@ skipping 38 matching lines @@
       delete list;
       RemoveAliases(old_map.begin()->first);
       old_map.erase(old_map.begin()->first);
     }
   }
   DCHECK(sessions_.empty());
   DCHECK(aliases_.empty());
 }
 
 }  // namespace net