msg/async/ProtocolV1: avoid unnecessary bufferlist::swap.

Currently, for MOSDOpRely it don't prepare in func send_message.
So no need do swap for empty bufferlist.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>

diff --git a/src/msg/async/ProtocolV1.cc b/src/msg/async/ProtocolV1.cc
index 2c7121a9c80dea0d23ee196843959f0a8d8cdd74..9f6160d7ef0844bda6a637a147b7a50e969825be 100644 (file)
--- a/src/msg/async/ProtocolV1.cc
+++ b/src/msg/async/ProtocolV1.cc
@@ -1304,7 +1304,10 @@ Message *ProtocolV1::_get_next_outgoing(bufferlist *bl) {
     ceph_assert(!it->second.empty());
     list<pair<bufferlist, Message *> >::iterator p = it->second.begin();
     m = p->second;
-    if (bl) bl->swap(p->first);
+    if (p->first.length() && bl) {
+      assert(bl->length() == 0);
+      bl->swap(p->first);
+    }
     it->second.erase(p);
     if (it->second.empty()) out_q.erase(it->first);
   }