From: Kefu Chai <kchai@redhat.com>
Date: Mon, 11 Mar 2019 13:38:21 +0000 (+0800)
Subject: crimson/os: use transparent comparator in xattr
X-Git-Tag: v15.0.0~186^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=c78b36d3a377c4be6967deb656b9c7cfe859340d;p=ceph.git

crimson/os: use transparent comparator in xattr

so we don't need to allocate a temporary string for looking up OI or SS
attribute

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

diff --git a/src/crimson/os/cyan_object.h b/src/crimson/os/cyan_object.h
index 6846b1a4dc5f..4806589daa95 100644
--- a/src/crimson/os/cyan_object.h
+++ b/src/crimson/os/cyan_object.h
@@ -16,7 +16,9 @@ struct Object : public boost::intrusive_ref_counter<
   using bufferlist = ceph::bufferlist;
 
   bufferlist data;
-  std::map<std::string,bufferptr> xattr;
+  // use transparent comparator for better performance, see
+  // https://en.cppreference.com/w/cpp/utility/functional/less_void
+  std::map<std::string,bufferptr,std::less<>> xattr;
   bufferlist omap_header;
   std::map<std::string,bufferlist> omap;