Optimized `UUID::fromString()` and `UUID::toString()` in stout. Rather than using `std::istringstream` and `std::ostringstream`, instead use the facilities provided by Boost's UUID for input and output respectively. This improves a simple benchmark that uses `fromString()` and `toString()` by ~7x.
Review: https://reviews.apache.org/r/48694/ Project: http://git-wip-us.apache.org/repos/asf/mesos/repo Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/a853cc23 Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/a853cc23 Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/a853cc23 Branch: refs/heads/master Commit: a853cc238757066b16090f571c54e4a114a6db69 Parents: dc002e9 Author: Neil Conway <neil.con...@gmail.com> Authored: Thu Jul 21 13:35:17 2016 -0700 Committer: Anand Mazumdar <an...@apache.org> Committed: Thu Jul 21 13:35:17 2016 -0700 ---------------------------------------------------------------------- 3rdparty/stout/include/stout/uuid.hpp | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/mesos/blob/a853cc23/3rdparty/stout/include/stout/uuid.hpp ---------------------------------------------------------------------- diff --git a/3rdparty/stout/include/stout/uuid.hpp b/3rdparty/stout/include/stout/uuid.hpp index a384022..e638d45 100644 --- a/3rdparty/stout/include/stout/uuid.hpp +++ b/3rdparty/stout/include/stout/uuid.hpp @@ -15,10 +15,10 @@ #include <assert.h> -#include <sstream> #include <string> #include <boost/uuid/random_generator.hpp> +#include <boost/uuid/string_generator.hpp> #include <boost/uuid/uuid.hpp> #include <boost/uuid/uuid_io.hpp> @@ -71,9 +71,11 @@ public: static UUID fromString(const std::string& s) { - boost::uuids::uuid uuid; - std::istringstream in(s); - in >> uuid; + // NOTE: We don't use THREAD_LOCAL for the `string_generator` + // (unlike for the `random_generator` above), because it is cheap + // to construct one each time. + boost::uuids::string_generator gen; + boost::uuids::uuid uuid = gen(s); return UUID(uuid); } @@ -85,9 +87,7 @@ public: std::string toString() const { - std::ostringstream out; - out << *this; - return out.str(); + return to_string(*this); } private:
