rust: peek_mut optim for lazy ancestors
This is one of the two optimizations that are also
present in the Python code: replacing pairs of pop/push
on the BinaryHeap by single updates, hence having it
under the hood maintain its consistency (sift) only once.
On Mozilla central, the measured gain (see details below)
is around 7%.
Creating the PeekMut object by calling peek_mut() right away
instead of peek() first is less efficient (gain is only 4%, stats
not included).
Our interpretation is that its creation has a cost which is vasted
in the cases where it ends by droping the value (Peekmut::pop()
just does self.heap.pop() anyway). On the other hand, the immutable
peek() is very fast: it's just taking a reference in the
underlying vector.
The Python version still has another optimization:
if parent(current) == current-1, then the heap doesn't need
to maintain its consistency, since we already know that
it's bigger than all the others in the heap.
Rust's BinaryHeap doesn't allow us to mutate its biggest
element with no housekeeping, but we tried it anyway, with a
copy of the BinaryHeap implementation with a dedicaded added
method: it's not worth the technical debt in our opinion
(we measured only a further 1.6% improvement).
One possible explanation would be that the sift is really fast
anyway in that case, whereas it's not in the case of Python,
because it's at least partly done in slow Python code.
Still it's possible that replacing BinaryHeap by something more
dedicated to discrete ordered types could be faster.
Measurements on mozilla-central:
Three runs of 'hg perfancestors' on the parent changeset:
Moyenne des médianes: 0.100587
! wall 0.100062 comb 0.100000 user 0.100000 sys 0.000000 (best of 98)
! wall 0.135804 comb 0.130000 user 0.130000 sys 0.000000 (max of 98)
! wall 0.102864 comb 0.102755 user 0.099286 sys 0.003469 (avg of 98)
! wall 0.101486 comb 0.110000 user 0.110000 sys 0.000000 (median of 98)
! wall 0.096804 comb 0.090000 user 0.090000 sys 0.000000 (best of 100)
! wall 0.132235 comb 0.130000 user 0.120000 sys 0.010000 (max of 100)
! wall 0.100258 comb 0.100300 user 0.096000 sys 0.004300 (avg of 100)
! wall 0.098384 comb 0.100000 user 0.100000 sys 0.000000 (median of 100)
! wall 0.099925 comb 0.100000 user 0.100000 sys 0.000000 (best of 98)
! wall 0.133518 comb 0.140000 user 0.130000 sys 0.010000 (max of 98)
! wall 0.102381 comb 0.102449 user 0.098265 sys 0.004184 (avg of 98)
! wall 0.101891 comb 0.090000 user 0.090000 sys 0.000000 (median of 98)
Mean of the medians: 0.100587
On the present changeset:
! wall 0.091344 comb 0.090000 user 0.090000 sys 0.000000 (best of 100)
! wall 0.122728 comb 0.120000 user 0.110000 sys 0.010000 (max of 100)
! wall 0.093268 comb 0.093300 user 0.089300 sys 0.004000 (avg of 100)
! wall 0.092567 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)
! wall 0.093294 comb 0.080000 user 0.080000 sys 0.000000 (best of 100)
! wall 0.144887 comb 0.150000 user 0.140000 sys 0.010000 (max of 100)
! wall 0.097708 comb 0.097700 user 0.093400 sys 0.004300 (avg of 100)
! wall 0.094980 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)
! wall 0.091262 comb 0.090000 user 0.080000 sys 0.010000 (best of 100)
! wall 0.123772 comb 0.130000 user 0.120000 sys 0.010000 (max of 100)
! wall 0.093188 comb 0.093200 user 0.089300 sys 0.003900 (avg of 100)
! wall 0.092364 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)
Mean of the medians is 0.0933
Differential Revision: https://phab.mercurial-scm.org/D5358
This test tries to exercise the ssh functionality with a dummy script
$ checknewrepo()
> {
> name=$1
> if [ -d "$name"/.hg/store ]; then
> echo store created
> fi
> if [ -f "$name"/.hg/00changelog.i ]; then
> echo 00changelog.i created
> fi
> cat "$name"/.hg/requires
> }
creating 'local'
$ hg init local
$ checknewrepo local
store created
00changelog.i created
dotencode
fncache
generaldelta
revlogv1
store
testonly-simplestore (reposimplestore !)
$ echo this > local/foo
$ hg ci --cwd local -A -m "init"
adding foo
test custom revlog chunk cache sizes
$ hg --config format.chunkcachesize=0 log -R local -pv
abort: revlog chunk cache size 0 is not greater than 0!
[255]
$ hg --config format.chunkcachesize=1023 log -R local -pv
abort: revlog chunk cache size 1023 is not a power of 2!
[255]
$ hg --config format.chunkcachesize=1024 log -R local -pv
changeset: 0:08b9e9f63b32
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: foo
description:
init
diff -r 000000000000 -r 08b9e9f63b32 foo
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/foo Thu Jan 01 00:00:00 1970 +0000
@@ -0,0 +1,1 @@
+this
creating repo with format.usestore=false
$ hg --config format.usestore=false init old
$ checknewrepo old
generaldelta
revlogv1
testonly-simplestore (reposimplestore !)
creating repo with format.usefncache=false
$ hg --config format.usefncache=false init old2
$ checknewrepo old2
store created
00changelog.i created
generaldelta
revlogv1
store
testonly-simplestore (reposimplestore !)
creating repo with format.dotencode=false
$ hg --config format.dotencode=false init old3
$ checknewrepo old3
store created
00changelog.i created
fncache
generaldelta
revlogv1
store
testonly-simplestore (reposimplestore !)
creating repo with format.dotencode=false
$ hg --config format.generaldelta=false --config format.usegeneraldelta=false init old4
$ checknewrepo old4
store created
00changelog.i created
dotencode
fncache
revlogv1
store
testonly-simplestore (reposimplestore !)
test failure
$ hg init local
abort: repository local already exists!
[255]
init+push to remote2
$ hg init -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
$ hg incoming -R remote2 local
comparing with local
changeset: 0:08b9e9f63b32
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: init
$ hg push -R local -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote2
pushing to ssh://user@dummy/remote2
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
clone to remote1
$ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
The largefiles extension doesn't crash
$ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remotelf --config extensions.largefiles=
The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)
The fsmonitor extension is incompatible with the largefiles extension and has been disabled. (fsmonitor !)
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
init to existing repo
$ hg init -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/remote1
abort: repository remote1 already exists!
abort: could not create remote repo!
[255]
clone to existing repo
$ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote1
abort: repository remote1 already exists!
abort: could not create remote repo!
[255]
output of dummyssh
$ cat dummylog
Got arguments 1:user@dummy 2:hg init remote2
Got arguments 1:user@dummy 2:hg -R remote2 serve --stdio
Got arguments 1:user@dummy 2:hg -R remote2 serve --stdio
Got arguments 1:user@dummy 2:hg init remote1
Got arguments 1:user@dummy 2:hg -R remote1 serve --stdio
Got arguments 1:user@dummy 2:hg init remotelf
Got arguments 1:user@dummy 2:hg -R remotelf serve --stdio
Got arguments 1:user@dummy 2:hg init remote1
Got arguments 1:user@dummy 2:hg init remote1
comparing repositories
$ hg tip -q -R local
0:08b9e9f63b32
$ hg tip -q -R remote1
0:08b9e9f63b32
$ hg tip -q -R remote2
0:08b9e9f63b32
check names for repositories (clashes with URL schemes, special chars)
$ for i in bundle file hg http https old-http ssh static-http "with space"; do
> printf "hg init \"$i\"... "
> hg init "$i"
> test -d "$i" -a -d "$i/.hg" && echo "ok" || echo "failed"
> done
hg init "bundle"... ok
hg init "file"... ok
hg init "hg"... ok
hg init "http"... ok
hg init "https"... ok
hg init "old-http"... ok
hg init "ssh"... ok
hg init "static-http"... ok
hg init "with space"... ok
#if eol-in-paths
/* " " is not a valid name for a directory on Windows */
$ hg init " "
$ test -d " "
$ test -d " /.hg"
#endif
creating 'local/sub/repo'
$ hg init local/sub/repo
$ checknewrepo local/sub/repo
store created
00changelog.i created
dotencode
fncache
generaldelta
revlogv1
store
testonly-simplestore (reposimplestore !)
prepare test of init of url configured from paths
$ echo '[paths]' >> $HGRCPATH
$ echo "somewhere = `pwd`/url from paths" >> $HGRCPATH
$ echo "elsewhere = `pwd`/another paths url" >> $HGRCPATH
init should (for consistency with clone) expand the url
$ hg init somewhere
$ checknewrepo "url from paths"
store created
00changelog.i created
dotencode
fncache
generaldelta
revlogv1
store
testonly-simplestore (reposimplestore !)
verify that clone also expand urls
$ hg clone somewhere elsewhere
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ checknewrepo "another paths url"
store created
00changelog.i created
dotencode
fncache
generaldelta
revlogv1
store
testonly-simplestore (reposimplestore !)
clone bookmarks
$ hg -R local bookmark test
$ hg -R local bookmarks
* test 0:08b9e9f63b32
$ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" local ssh://user@dummy/remote-bookmarks
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
exporting bookmark test
$ hg -R remote-bookmarks bookmarks
test 0:08b9e9f63b32