transaction: allow registering a temporary transaction file
During the transaction, files may be created to store or expose data
involved in the transaction (eg: changelog index data are written in
a 'changelog.i.a' for hooks). But we do not have an official way to
record such file creation and make sure they are cleaned up. The lack
of clean-up is currently okay because there is a single file involved
and a single producer/consumer.
However, as we want to expose more data (bookmarks, phases, obsmarker)
we need something more solid. The 'backupentries' mechanism could
handle that. Temporary files can be encoded as a backup of nothing
'('', <temporarypath>)'. We "need" to attach it to the same mechanism
as we use to be able to use temporary transaction files outside of
.'store/' and 'backupentries' is expected to gain such feature.
This changeset makes it clear that we should rename 'backupentries' to
something more generic.
#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 cmdutil, error, util
>
> cmdtable = {}
> command = cmdutil.command(cmdtable)
>
> def acquiretestlock(repo, releaseexc):
> def unlock():
> if releaseexc:
> raise util.Abort('expected release exception')
> l = repo._lock(repo.vfs, 'testlock', False, unlock, None, 'test lock')
> return l
>
> @command('testlockexc')
> def testlockexc(ui, repo):
> testlock = acquiretestlock(repo, True)
> try:
> testlock.release()
> finally:
> try:
> testlock = acquiretestlock(repo, False)
> except error.LockHeld:
> raise util.Abort('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
$ cat > hooks.py << EOF
> import time
> def sleepone(**x): time.sleep(1)
> def sleephalf(**x): time.sleep(0.5)
> EOF
$ echo b > b/b
$ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
$ hg -R b up -q --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf"
waiting for lock on working directory of b held by '*:*' (glob)
got lock after ? seconds (glob)
warning: ignoring unknown working parent d2ae7f538514!
$ wait
$ cat stdout
adding b
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: Permission denied
[255]
$ chmod 700 a/.hg/store