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 no-windows
Prepare
$ hg init a
$ echo a > a/a
$ hg -R a ci -A -m a
adding a
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Test that raising an exception in the release function doesn't cause the lock to choke
$ cat > testlock.py << EOF
> from mercurial import error, registrar
>
> cmdtable = {}
> command = registrar.command(cmdtable)
>
> def acquiretestlock(repo, releaseexc):
> def unlock():
> if releaseexc:
> raise error.Abort(b'expected release exception')
> l = repo._lock(repo.vfs, b'testlock', False, unlock, None, b'test lock')
> return l
>
> @command(b'testlockexc')
> def testlockexc(ui, repo):
> testlock = acquiretestlock(repo, True)
> try:
> testlock.release()
> finally:
> try:
> testlock = acquiretestlock(repo, False)
> except error.LockHeld:
> raise error.Abort(b'lockfile on disk even after releasing!')
> testlock.release()
> EOF
$ cat >> $HGRCPATH << EOF
> [extensions]
> testlock=$TESTTMP/testlock.py
> EOF
$ hg -R b testlockexc
abort: expected release exception
[255]
One process waiting for another
$ SYNC_FILE_LOCKED="$TESTTMP/sync-file-locked"
$ export SYNC_FILE_LOCKED
$ SYNC_FILE_TRYING_LOCK="$TESTTMP/sync-file-trying-lock"
$ export SYNC_FILE_TRYING_LOCK
$ cat << EOF > locker.sh
> $RUNTESTDIR/testlib/wait-on-file 10 $SYNC_FILE_TRYING_LOCK $SYNC_FILE_LOCKED;
> EOF
$ cat << EOF > waiter.sh
> $RUNTESTDIR/testlib/wait-on-file 10 $SYNC_FILE_LOCKED;
> EOF
$ clean_sync() {
> rm -f "$SYNC_FILE_LOCKED"
> rm -f "$SYNC_FILE_TRYING_LOCK"
> }
$ clean_sync
$ echo b > b/b
$ hg -R b ci -A -m b \
> --config hooks.precommit="sh $TESTTMP/locker.sh" \
> > stdout &
$ hg -R b up -q \
> --config ui.timeout.warn=0 \
> --config hooks.pre-update="sh $TESTTMP/waiter.sh" \
> --config devel.lock-wait-sync-file="$SYNC_FILE_TRYING_LOCK" \
> > preup-stdout 2> preup-stderr
$ wait
$ cat preup-stdout
$ cat preup-stderr
waiting for lock on working directory of b held by process '*' on host '*' (glob)
got lock after * seconds (glob)
$ cat stdout
adding b
On processs waiting on another, warning after a long time.
$ clean_sync
$ echo b > b/c
$ hg -R b ci -A -m b \
> --config hooks.precommit="sh $TESTTMP/locker.sh" \
> > stdout &
$ hg -R b up -q \
> --config hooks.pre-update="sh $TESTTMP/waiter.sh" \
> --config devel.lock-wait-sync-file="$SYNC_FILE_TRYING_LOCK" \
> --config ui.timeout.warn=250 \
> > preup-stdout 2> preup-stderr
$ wait
$ cat preup-stdout
$ cat preup-stderr
$ cat stdout
adding c
On processs waiting on another, warning disabled.
$ clean_sync
$ echo b > b/d
$ hg -R b ci -A -m b \
> --config hooks.precommit="sh $TESTTMP/locker.sh" \
> > stdout &
$ hg -R b up -q \
> --config hooks.pre-update="sh $TESTTMP/waiter.sh" \
> --config devel.lock-wait-sync-file="$SYNC_FILE_TRYING_LOCK" \
> --config ui.timeout.warn=-1 \
> > preup-stdout 2>preup-stderr
$ wait
$ cat preup-stdout
$ cat preup-stderr
$ cat stdout
adding d
check we still print debug output
On processs waiting on another, warning after a long time (debug output on)
$ clean_sync
$ echo b > b/e
$ hg -R b ci -A -m b \
> --config hooks.precommit="sh $TESTTMP/locker.sh" \
> > stdout &
$ hg -R b up \
> --config hooks.pre-update="sh $TESTTMP/waiter.sh" \
> --config devel.lock-wait-sync-file="$SYNC_FILE_TRYING_LOCK" \
> --config ui.timeout.warn=250 --debug \
> > preup-stdout 2>preup-stderr
$ wait
$ cat preup-stdout
running hook pre-update: sh $TESTTMP/waiter.sh
waiting for lock on working directory of b held by process '*' on host '*' (glob)
got lock after * seconds (glob)
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat preup-stderr
$ cat stdout
adding e
On processs waiting on another, warning disabled, (debug output on)
$ clean_sync
$ echo b > b/f
$ hg -R b ci -A -m b \
> --config hooks.precommit="sh $TESTTMP/locker.sh" \
> > stdout &
$ hg -R b up \
> --config hooks.pre-update="sh $TESTTMP/waiter.sh" \
> --config devel.lock-wait-sync-file="$SYNC_FILE_TRYING_LOCK" \
> --config ui.timeout.warn=-1 --debug\
> > preup-stdout 2>preup-stderr
$ wait
$ cat preup-stdout
running hook pre-update: sh $TESTTMP/waiter.sh
waiting for lock on working directory of b held by process '*' on host '*' (glob)
got lock after * seconds (glob)
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat preup-stderr
$ cat stdout
adding f
Pushing to a local read-only repo that can't be locked
$ chmod 100 a/.hg/store
$ hg -R b push a
pushing to a
searching for changes
abort: could not lock repository a: $EACCES$
[20]
$ chmod 700 a/.hg/store