use auto iterator having more simple code and good performence

Signed-off-by: dingdangzhang <boqian.zy@alibaba-inc.com>

diff --git a/src/msg/async/AsyncConnection.cc b/src/msg/async/AsyncConnection.cc
index fa3c76725ea9a27e80d5c1313d9dde743034259c..a1f72c1366a1cbc5fbb16514d83f37bcd2bb1c86 100644 (file)
--- a/src/msg/async/AsyncConnection.cc
+++ b/src/msg/async/AsyncConnection.cc
@@ -2240,9 +2240,8 @@ ssize_t AsyncConnection::write_message(Message *m, bufferlist& bl, bool more)
                              << " off " << header.data_off << dendl;
 
   if ((bl.length() <= ASYNC_COALESCE_THRESHOLD) && (bl.buffers().size() > 1)) {
-    std::list<buffer::ptr>::const_iterator pb;
-    for (pb = bl.buffers().begin(); pb != bl.buffers().end(); ++pb) {
-      outcoming_bl.append((char*)pb->c_str(), pb->length());
+    for (const auto &pb : bl.buffers()) {
+      outcoming_bl.append((char*)pb.c_str(), pb.length());
     }
   } else {
     outcoming_bl.claim_append(bl);