spectral created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.
REVISION SUMMARY
This has some mild performance benefits. I'm looking into a pathological case
where one of our `hg log` invocations takes several seconds, and according to
hyperfine this reduces the wall time of the entire operation (running in chg)
from:
Time (mean ± σ): 7.390 s ± 0.106 s [User: 7.058 s, System: 0.271 s]
Range (min … max): 7.300 s … 7.625 s
to:
Time (mean ± σ): 7.046 s ± 0.091 s [User: 6.714 s, System: 0.279 s]
Range (min … max): 6.916 s … 7.169 s
Note: the log command is slow due to an issue in our custom stuff executing
`repo[<arg>]` 298,800 times. This performance improvement is likely not
noticeable during normal operation, but I don't feel like it's making the code
more difficult to understand, and every small bit helps.
REPOSITORY
rHG Mercurial
BRANCH
default
REVISION DETAIL
https://phab.mercurial-scm.org/D9022
AFFECTED FILES
mercurial/localrepo.py
CHANGE DETAILS
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1570,7 +1570,7 @@
def _quick_access_changeid_wc(self):
# also fast path access to the working copy parents
# however, only do it for filter that ensure wc is visible.
- quick = {}
+ quick = self._quick_access_changeid_null.copy()
cl = self.unfiltered().changelog
for node in self.dirstate.parents():
if node == nullid:
@@ -1609,11 +1609,9 @@
This contains a list of symbol we can recognise right away without
further processing.
"""
- mapping = self._quick_access_changeid_null
if self.filtername in repoview.filter_has_wc:
- mapping = mapping.copy()
- mapping.update(self._quick_access_changeid_wc)
- return mapping
+ return self._quick_access_changeid_wc
+ return self._quick_access_changeid_null
def __getitem__(self, changeid):
# dealing with special cases
To: spectral, #hg-reviewers
Cc: mercurial-patches, mercurial-devel
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