tests/test-pending.t

performance: speedup computation of extinct revisions

In their current state, revset calls can be very costly, as we test
predicates on the entire repository.

This change drops revset calls in favor of direct testing of the phase
of changesets.

Performance test on my Mercurial checkout
- 19857 total changesets,
- 1584 obsolete changesets,
- 13310 obsolescence markers.

Before:
  ! extinct
  ! wall 0.015124

After:
  ! extinct
  ! wall 0.009424

Performance test on a Mozilla central checkout:
- 117293 total changesets,
- 1 obsolete changeset,
- 1 obsolescence marker.

Before:
  ! extinct
  ! wall 0.032844

After:
  ! extinct
  ! wall 0.000066

Verify that pending changesets are seen by pretxn* hooks but not by other
processes that access the destination repo while the hooks are running.

The hooks (python and external) both reject changesets after some think time,
during which another process runs pull.  Each hook creates a file ('notify') to
indicate to the controlling process that it is running; the process removes the
file to indicate the hook can terminate.

init env vars

  $ d=`pwd`
  $ maxwait=20

utility to run the test - start a push in the background and run pull

  $ dotest() {
  >     rm -f notify
  >     printf 'push '; hg -R child-push tip --template '{node}\n'
  >     hg -R child-push -q push > push.out 2>&1 &
  > 
  >     # wait for hook to create the notify file
  >     i=$maxwait
  >     while [ ! -f notify -a $i != 0 ]; do
  >         sleep 1
  >         i=`expr $i - 1`
  >     done
  > 
  >     # run pull
  >     hg -R child-pull -q pull
  >     rc=$?
  > 
  >     # tell hook to finish; notify should exist.
  >     rm notify
  >     wait
  > 
  >     cat push.out
  >     printf 'pull '; hg -R child-pull tip --template '{node}\n'
  >     return $rc
  > }

python hook

  $ cat <<EOF > reject.py
  > import os, time
  > from mercurial import ui, localrepo
  > def rejecthook(ui, repo, hooktype, node, **opts):
  >     ui.write('hook %s\\n' % repo['tip'].hex())
  >     # create the notify file so caller knows we're running
  >     fpath = os.path.join('$d', 'notify')
  >     f = open(fpath, 'w')
  >     f.close()
  >     # wait for ack - caller should delete the notify file
  >     i = $maxwait
  >     while os.path.exists(fpath) and i > 0:
  >         time.sleep(1)
  >         i -= 1
  >     return True # reject the changesets
  > EOF

external hook

  $ cat <<EOF > reject.sh
  > printf 'hook '; hg tip --template '{node}\\n'
  > # create the notify file so caller knows we're running
  > fpath=$d/notify
  > touch \$fpath
  > # wait for ack - caller should delete the notify file
  > i=$maxwait
  > while [ -f \$fpath -a \$i != 0 ]; do
  >     sleep 1
  >     i=\`expr \$i - 1\`
  > done
  > exit 1 # reject the changesets
  > EOF

create repos

  $ hg init parent
  $ hg clone -q parent child-push
  $ hg clone -q parent child-pull
  $ echo a > child-push/a
  $ hg -R child-push add child-push/a
  $ hg -R child-push commit -m a -d '1000000 0'

test python hook

  $ cat <<EOF > parent/.hg/hgrc
  > [extensions]
  > reject = $d/reject.py
  > [hooks]
  > pretxnchangegroup = python:reject.rejecthook
  > EOF

  $ dotest
  push 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
  hook 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
  transaction abort!
  rollback completed
  abort: pretxnchangegroup hook failed
  pull 0000000000000000000000000000000000000000

test external hook

  $ cat <<EOF > parent/.hg/hgrc
  > [hooks]
  > pretxnchangegroup = sh $d/reject.sh
  > EOF

  $ dotest
  push 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
  hook 29b62aeb769fdf78d8d9c5f28b017f76d7ef824b
  transaction abort!
  rollback completed
  abort: pretxnchangegroup hook exited with status 1
  pull 0000000000000000000000000000000000000000