treemanifest: log findrecenttrees time

Summary:
`findrecenttrees` can take very long in my case - it only tests 1280 trees in
30 seconds. Log it so we can get some ideas about how long it takes.

As we're here, teach `util.timefunction` to figure out the `ui` object
automatically.

Reviewed By: xavierd

Differential Revision: D17066278

fbshipit-source-id: 7e59c8683359a7ce8d4e87fde92af36b95d37b2f

edenscm/hgext/treemanifest/__init__.py

@@ -2186,6 +2186,7 @@ def _postpullprefetch(ui, repo):
         repo.prefetchtrees(mfnodes, basemfnodes=basemfnodes)
 
 
+@util.timefunction("findrecenttrees")
 def _findrecenttree(repo, startrev, targetmfnodes):
     cl = repo.changelog
     mfstore = repo.manifestlog.datastore

edenscm/mercurial/util.py

@@ -4310,7 +4310,7 @@ class ring(object):
             return head + tail
 
 
-def timefunction(key, uiposition, uiname):
+def timefunction(key, uiposition=None, uiname=None):
     """A decorator for indicating a function should be timed and logged.
 
     `uiposition` the integer argument number that contains the ui or a reference
@@ -4327,9 +4327,20 @@ def timefunction(key, uiposition, uiname):
 
     def wrapper(func):
         def inner(*args, **kwargs):
-            uiarg = args[uiposition]
+            uiarg = None
+            if uiposition is not None:
+                uiarg = args[uiposition]
             if uiname is not None:
                 uiarg = getattr(uiarg, uiname)
+            if uiarg is None:
+                for arg in list(args) + list(kwargs.values()):
+                    if safehasattr(arg, "timesection"):
+                        uiarg = arg
+                        break
+                    elif safehasattr(arg, "ui"):
+                        uiarg = arg.ui
+                        break
+            assert uiarg
             with uiarg.timesection(key):
                 return func(*args, **kwargs)