scmutil: speed up relativization of paths when it's a no-op
authorValentin Gatien-Baron <valentin.gatienbaron@gmail.com>
Tue, 26 May 2020 07:03:11 -0400
changeset 44917 5d8ae9248a70
parent 44916 e607099d8b93
child 44918 15e26cc0e2c6
scmutil: speed up relativization of paths when it's a no-op Running commands from the root is commmon, in particular for automation. Running `hg files > /tmp/a` from the root of mozilla-central on linux: before: real 0m1,510s user 0m1,387s sys 0m0,090s after: real 0m1,266s user 0m1,165s sys 0m0,073s (there are 280k paths, so this was costing ~1us per path somehow) Differential Revision: https://phab.mercurial-scm.org/D8585
mercurial/scmutil.py
--- a/mercurial/scmutil.py	Mon May 18 16:00:26 2020 -0400
+++ b/mercurial/scmutil.py	Tue May 26 07:03:11 2020 -0400
@@ -803,9 +803,12 @@
 
     if relative:
         cwd = repo.getcwd()
-        pathto = repo.pathto
-        return lambda f: pathto(f, cwd)
-    elif repo.ui.configbool(b'ui', b'slash'):
+        if cwd != b'':
+            # this branch is correct when cwd == b'', ie cwd = repo root,
+            # but it's slower
+            pathto = repo.pathto
+            return lambda f: pathto(f, cwd)
+    if repo.ui.configbool(b'ui', b'slash'):
         return lambda f: f
     else:
         return util.localpath