branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
#require unix-permissions no-root reporevlogstore
$ cat > $TESTTMP/dumpjournal.py <<EOF
> import sys
> for entry in sys.stdin.read().split('\n'):
> if entry:
> print(entry.split('\x00')[0])
> EOF
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=">> $HGRCPATH
$ teststrip() {
> hg -q up -C $1
> echo % before update $1, strip $2
> hg parents
> chmod -$3 $4
> hg strip $2 2>&1 | sed 's/\(bundle\).*/\1/' | sed 's/Permission denied.*\.hg\/store\/\(.*\)/Permission denied \.hg\/store\/\1/'
> echo % after update $1, strip $2
> chmod +$3 $4
> hg verify
> echo % journal contents
> if [ -f .hg/store/journal ]; then
> cat .hg/store/journal | "$PYTHON" $TESTTMP/dumpjournal.py
> else
> echo "(no journal)"
> fi
> if ls .hg/store/journal >/dev/null 2>&1; then
> hg recover --verify
> fi
> ls .hg/strip-backup/* >/dev/null 2>&1 && hg unbundle -q .hg/strip-backup/*
> rm -rf .hg/strip-backup
> }
$ hg init test
$ cd test
$ echo a > a
$ hg -q ci -m "a" -A
$ echo b > b
$ hg -q ci -m "b" -A
$ echo b2 >> b
$ hg -q ci -m "b2" -A
$ echo c > c
$ hg -q ci -m "c" -A
$ teststrip 0 2 w .hg/store/data/b.i
% before update 0, strip 2
changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
saved backup bundle
transaction abort!
failed to truncate data/b.i
rollback failed - please run hg recover
(failure reason: [Errno *] $EACCES$ .hg/store/data/b.i') (glob)
strip failed, backup bundle
abort: $EACCES$ .hg/store/data/b.i'
% after update 0, strip 2
abandoned transaction found - run hg recover
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
b@?: rev 1 points to nonexistent changeset 2
(expected 1)
b@?: 736c29771fba not in manifests
warning: orphan data file 'data/c.i'
not checking dirstate because of previous errors
checked 2 changesets with 3 changes to 2 files
2 warnings encountered!
2 integrity errors encountered!
% journal contents
00changelog.d
00changelog.i
00manifest.i
data/b.i
data/c.i
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 2 changesets with 2 changes to 2 files
$ teststrip 0 2 r .hg/store/data/b.i
% before update 0, strip 2
changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
abort: $EACCES$ .hg/store/data/b.i'
% after update 0, strip 2
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 4 changesets with 4 changes to 3 files
% journal contents
(no journal)
$ teststrip 0 2 w .hg/store/00manifest.i
% before update 0, strip 2
changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
saved backup bundle
transaction abort!
failed to truncate 00manifest.i
rollback failed - please run hg recover
(failure reason: [Errno *] $EACCES$ .hg/store/00manifest.i') (glob)
strip failed, backup bundle
abort: $EACCES$ .hg/store/00manifest.i'
% after update 0, strip 2
abandoned transaction found - run hg recover
checking changesets
checking manifests
manifest@?: rev 2 points to nonexistent changeset 2
manifest@?: 3362547cdf64 not in changesets
manifest@?: rev 3 points to nonexistent changeset 3
manifest@?: 265a85892ecb not in changesets
crosschecking files in changesets and manifests
c@3: in manifest but not in changeset
checking files
b@?: rev 1 points to nonexistent changeset 2
(expected 1)
c@?: rev 0 points to nonexistent changeset 3
not checking dirstate because of previous errors
checked 2 changesets with 4 changes to 3 files
1 warnings encountered!
7 integrity errors encountered!
(first damaged changeset appears to be 3)
% journal contents
00changelog.d
00changelog.i
00manifest.i
data/b.i
data/c.i
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 2 changesets with 2 changes to 2 files
$ cd ..