changeset 15496:c1c5b3cc2996 stable

Avoid inefficient seeks in gzfilebuf (bug #37509) * src/zfstream.cc (gzfilebuf::seekoff): Avoid calling gzseek and invalidating buffers when not actually seeking.
author Mike Miller <mtmiller@ieee.org>
date Sat, 06 Oct 2012 11:23:55 -0400
parents d174210ce1ec
children dcd6fa8d3da2
files src/zfstream.cc
diffstat 1 files changed, 5 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/src/zfstream.cc
+++ b/src/zfstream.cc
@@ -473,6 +473,11 @@
       if ((io_mode & std::ios_base::in) && way == std::ios_base::cur)
         computed_off += this->gptr() - this->egptr();
 
+      // Handle tellg/tellp as a special case up front, no need to seek
+      // or invalidate get/put buffers
+      if (off == 0 && way == std::ios_base::cur)
+        return pos_type (gztell (file) + computed_off);
+
       if (way == std::ios_base::beg)
         ret = pos_type (gzseek (file, computed_off, SEEK_SET));
       else if (way == std::ios_base::cur)