martinvonz created this revision. Herald added a reviewer: hg-reviewers. Herald added a subscriber: mercurial-patches.
REVISION SUMMARY It's wasteful to call `splitlines()` and only get the first line from it. However, Python doesn't seem to provide a built-in way of doing just one split based on the set of bytes used by `splitlines()`. As a workaround, we do an initial split on just LF and then call `splitlines()` on the result. Thanks to Joerg for this suggestion. I didn't bother to also split on CR, so users with old Windows editors (or repos created by such editors) will not get this performance improvement. REPOSITORY rHG Mercurial BRANCH default REVISION DETAIL https://phab.mercurial-scm.org/D12413 AFFECTED FILES mercurial/utils/stringutil.py CHANGE DETAILS diff --git a/mercurial/utils/stringutil.py b/mercurial/utils/stringutil.py --- a/mercurial/utils/stringutil.py +++ b/mercurial/utils/stringutil.py @@ -687,6 +687,10 @@ def firstline(text): """Return the first line of the input""" + # Try to avoid running splitlines() on the whole string + i = text.find(b'\n') + if i != -1: + text = text[:i] try: return text.splitlines()[0] except IndexError: To: martinvonz, #hg-reviewers Cc: mercurial-patches, mercurial-devel _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
