view tests/test-lock-badness.t @ 38486:4c0683655599

namespaces: let namespaces override singlenode() definition

Some namespaces have multiple nodes per name (meaning that their
namemap() returns multiple nodes). One such namespace is the "topics"
namespace (from the evolve repo). We also have our own internal
namespace at Google (for review units) that has multiple nodes per
name. These namespaces may not want to use the default "pick highest
revnum" resolution that we currently use when resolving a name to a
single node. As an example, they may decide that `hg co <name>` should
check out a commit that's last in some sense even if an earlier commit
had just been amended and thus had a higher revnum [1]. This patch
gives the namespace the option to continue to return multiple nodes
and to override how the best node is picked. Allowing namespaces to
override that may also be useful as an optimization (it may be cheaper
for the namespace to find just that node).

I have been arguing (in D3715) for using all the nodes returned from
namemap() when resolving the symbol to a revset, so e.g. `hg log -r
stable` would resolve to *all* nodes on stable, not just the one with
the highest revnum (except that I don't actually think we should
change it for the branch namespace because of BC). Most people seem
opposed to that. If we decide not to do it, I think we can deprecate
the namemap() function in favor of the new singlenode() (I find it
weird to have namespaces, like the branch namespace, where namemap()
isn't nodemap()'s inverse). I therefore think this patch makes sense
regardless of what we decide on that issue.


 [1] Actually, even the branch namespace would have wanted to override
     singlenode() if it had supported multiple nodes. That's because
     closes branch heads are mostly ignored, so "hg co default" will
     not check out the highest-revnum node if that's a closed head.

Differential Revision: https://phab.mercurial-scm.org/D3852

#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

  $ 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" \
  > > 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.

  $ echo b > b/c
  $ 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" \
  > --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.

  $ echo b > b/d
  $ 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" \
  > --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)

  $ echo b > b/e
  $ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
  $ hg -R b up --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf" \
  > --config ui.timeout.warn=250 --debug\
  > > preup-stdout 2>preup-stderr
  $ wait
  $ cat preup-stdout
  calling hook pre-update: hghook_pre-update.sleephalf
  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)

  $ echo b > b/f
  $ hg -R b ci -A -m b --config hooks.precommit="python:`pwd`/hooks.py:sleepone" > stdout &
  $ hg -R b up --config hooks.pre-update="python:`pwd`/hooks.py:sleephalf" \
  > --config ui.timeout.warn=-1 --debug\
  > > preup-stdout 2>preup-stderr
  $ wait
  $ cat preup-stdout
  calling hook pre-update: hghook_pre-update.sleephalf
  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: Permission denied
  [255]

  $ chmod 700 a/.hg/store