common/buffer_seastar: reserve the packet slots in ctor

for better performance, and simpler this way

Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/src/common/buffer_seastar.cc b/src/common/buffer_seastar.cc
index 8d77cf8f6b6708637d0c18ce34aff606625943ee..7d0e98e379a9a8a9939a0a157fd9b9d2a2239bd4 100644 (file)
--- a/src/common/buffer_seastar.cc
+++ b/src/common/buffer_seastar.cc
@@ -74,8 +74,7 @@ ptr::operator seastar::temporary_buffer<char>() &&
 
 list::operator seastar::net::packet() &&
 {
-  seastar::net::packet p;
-  p.reserve(_num);
+  seastar::net::packet p(_num);
   for (auto& ptr : _buffers) {
     // append each ptr as a temporary_buffer
     p = seastar::net::packet(std::move(p), std::move(ptr));