localrepo: introduce a `_quick_access_changeid` property
Having faster access to `null` is cute… but limited. We want to speedup access
to more useful revision, like `.`. We start with turning the fast path for
`null` into something more generic.
Differential Revision: https://phab.mercurial-scm.org/D7488
--- a/mercurial/localrepo.py Sun Nov 17 08:50:21 2019 +0100
+++ b/mercurial/localrepo.py Sat Nov 23 16:52:44 2019 -0800
@@ -1514,6 +1514,19 @@
narrowspec.save(self, newincludes, newexcludes)
self.invalidate(clearfilecache=True)
+ @util.propertycache
+ def _quick_access_changeid(self):
+ """an helper dictionnary for __getitem__ calls
+
+ This contains a list of symbol we can recognise right away without
+ further processing.
+ """
+ return {
+ b'null': (nullrev, nullid),
+ nullrev: (nullrev, nullid),
+ nullid: (nullrev, nullid),
+ }
+
def __getitem__(self, changeid):
# dealing with special cases
if changeid is None:
@@ -1531,8 +1544,10 @@
]
# dealing with some special values
- if changeid == b'null' or changeid == nullrev or changeid == nullid:
- return context.changectx(self, nullrev, nullid, maybe_filtered=False)
+ quick_access = self._quick_access_changeid.get(changeid)
+ if quick_access is not None:
+ rev, node = quick_access
+ return context.changectx(self, rev, node, maybe_filtered=False)
if changeid == b'tip':
node = self.changelog.tip()
rev = self.changelog.rev(node)