branchcache: write branchmap in subset inheritance order
This way, we can guarantee a valid subset has been written before touching the
branchmap of another filter.
This is especially useful as we are bout to start deleting outdated branchmap
file.
--- a/mercurial/branchmap.py Fri Mar 08 15:06:54 2024 +0100
+++ b/mercurial/branchmap.py Fri Mar 08 15:50:15 2024 +0100
@@ -166,7 +166,10 @@
def write_delayed(self, repo):
unfi = repo.unfiltered()
- for filtername, cache in self._per_filter.items():
+ for filtername in repoviewutil.get_ordered_subset():
+ cache = self._per_filter.get(filtername)
+ if cache is None:
+ continue
if cache._delayed:
if filtername is None:
repo = unfi
--- a/mercurial/utils/repoviewutil.py Fri Mar 08 15:06:54 2024 +0100
+++ b/mercurial/utils/repoviewutil.py Fri Mar 08 15:50:15 2024 +0100
@@ -6,6 +6,7 @@
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
+from .. import error
### Nearest subset relation
# Nearest subset of filter X is a filter Y so that:
@@ -21,3 +22,30 @@
b'served': b'immutable',
b'immutable': b'base',
}
+
+
+def get_ordered_subset():
+ """return a list of subset name from dependencies to dependents"""
+ _unfinalized = set(subsettable.values())
+ ordered = []
+
+ # the subset table is expected to be small so we do the stupid N² version
+ # of the algorithm
+ while _unfinalized:
+ this_level = []
+ for candidate in _unfinalized:
+ dependency = subsettable.get(candidate)
+ if dependency not in _unfinalized:
+ this_level.append(candidate)
+
+ if not this_level:
+ msg = "cyclic dependencies in repoview subset %r"
+ msg %= subsettable
+ raise error.ProgrammingError(msg)
+
+ this_level.sort(key=lambda x: x if x is not None else '')
+
+ ordered.extend(this_level)
+ _unfinalized.difference_update(this_level)
+
+ return ordered