util: lower water mark when removing nodes after cost limit reached
See the inline comment for the reasoning here. This is a pretty
common strategy for garbage collectors, other cache-like primtives.
The performance impact is substantial:
$ hg perflrucachedict --size 4 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 100
! inserts w/ cost limit
! wall 1.659181 comb 1.650000 user 1.650000 sys 0.000000 (best of 7)
! wall 1.722122 comb 1.720000 user 1.720000 sys 0.000000 (best of 6)
! mixed w/ cost limit
! wall 1.139955 comb 1.140000 user 1.140000 sys 0.000000 (best of 9)
! wall 1.182513 comb 1.180000 user 1.180000 sys 0.000000 (best of 9)
$ hg perflrucachedict --size 1000 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 10000
! inserts
! wall 0.679546 comb 0.680000 user 0.680000 sys 0.000000 (best of 15)
! sets
! wall 0.825147 comb 0.830000 user 0.830000 sys 0.000000 (best of 13)
! inserts w/ cost limit
! wall 25.105273 comb 25.080000 user 25.080000 sys 0.000000 (best of 3)
! wall 1.724397 comb 1.720000 user 1.720000 sys 0.000000 (best of 6)
! mixed
! wall 0.807096 comb 0.810000 user 0.810000 sys 0.000000 (best of 13)
! mixed w/ cost limit
! wall 12.104470 comb 12.070000 user 12.070000 sys 0.000000 (best of 3)
! wall 1.190563 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
$ hg perflrucachedict --size 1000 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 10000 --mixedgetfreq 90
! inserts
! wall 0.711177 comb 0.710000 user 0.710000 sys 0.000000 (best of 14)
! sets
! wall 0.846992 comb 0.850000 user 0.850000 sys 0.000000 (best of 12)
! inserts w/ cost limit
! wall 25.963028 comb 25.960000 user 25.960000 sys 0.000000 (best of 3)
! wall 2.184311 comb 2.180000 user 2.180000 sys 0.000000 (best of 5)
! mixed
! wall 0.728256 comb 0.730000 user 0.730000 sys 0.000000 (best of 14)
! mixed w/ cost limit
! wall 3.174256 comb 3.170000 user 3.170000 sys 0.000000 (best of 4)
! wall 0.773186 comb 0.770000 user 0.770000 sys 0.000000 (best of 13)
$ hg perflrucachedict --size 100000 --gets 1000000 --sets 1000000 --mixed 1000000 --mixedgetfreq 90 --costlimit 5000000
! gets
! wall 1.191368 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
! wall 1.195304 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
! inserts
! wall 0.950995 comb 0.950000 user 0.950000 sys 0.000000 (best of 11)
! inserts w/ cost limit
! wall 1.589732 comb 1.590000 user 1.590000 sys 0.000000 (best of 7)
! sets
! wall 1.094941 comb 1.100000 user 1.090000 sys 0.010000 (best of 9)
! mixed
! wall 0.936420 comb 0.940000 user 0.930000 sys 0.010000 (best of 10)
! mixed w/ cost limit
! wall 0.882780 comb 0.870000 user 0.870000 sys 0.000000 (best of 11)
This puts us ~2x slower than caches without cost accounting. And for
read-heavy workloads (the prime use cases for caches), performance is
nearly identical.
In the worst case (pure write workloads with cost accounting enabled),
we're looking at ~1.5us per insert on large caches. That seems "fast
enough."
Differential Revision: https://phab.mercurial-scm.org/D4505
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(b'hook %s\\n' % repo[b'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
Test that pending on transaction without changegroup see the normal changegroup(
(issue4609)
$ cat <<EOF > parent/.hg/hgrc
> [hooks]
> pretxnchangegroup=
> pretxnclose = hg tip -T "tip: {node|short}\n"
> [phases]
> publishing=False
> EOF
setup
$ cd parent
$ echo a > a
$ hg add a
$ hg commit -m a
tip: cb9a9f314b8b
actual test
$ hg phase --public .
tip: cb9a9f314b8b