bisect: avoid copying ancestor list for non-merge commits
During a bisection, hg needs to compute a list of all ancestors for every
candidate commit. This is accomplished via a bottom-up traversal of the set of
candidates, during which each revision's ancestor list is populated using the
ancestor list of its parent(s). Previously, this involved copying the entire
list, which could be very long in if the bisection range was large.
To help improve this, we can observe that each candidate commit is visited
exactly once, at which point its ancestor list is copied into its children's
lists and then dropped. In the case of non-merge commits, a commit's ancestor
list consists exactly of its parent's list plus itself. This means that we can
trivially reuse the parent's existing list for one of its non-merge children,
which avoids copying entirely if that commit is the parent's only child. This
makes bisections over linear ranges of commits much faster.
During some informal testing in the large publicly-available `mozilla-central`
repository, this noticeably sped up bisections over large ranges of history:
Setup:
$ cd mozilla-central
$ hg bisect --reset
$ hg bisect --good 0
$ hg log -r tip -T '{rev}\n'
628417
Test:
$ time hg bisect --bad tip --noupdate
Before:
real 3m35.927s
user 3m35.553s
sys 0m0.319s
After:
real 1m41.142s
user 1m40.810s
sys 0m0.285s
$ cat <<EOF >> $HGRCPATH
> [ui]
> interactive = true
> EOF
$ hg init repo
$ cd repo
$ echo foo > foo
$ hg ci -qAm 'add foo'
$ echo >> foo
$ hg ci -m 'change foo'
$ hg up -qC 0
$ echo bar > bar
$ hg ci -qAm 'add bar'
$ hg log
changeset: 2:effea6de0384
tag: tip
parent: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add bar
changeset: 1:ed1b79f46b9a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ cd ..
don't show "(+1 heads)" message when pulling closed head
$ hg clone -q repo repo2
$ hg clone -q repo2 repo3
$ cd repo2
$ hg up -q 0
$ echo hello >> foo
$ hg ci -mx1
created new head
$ hg ci -mx2 --close-branch
$ cd ../repo3
$ hg heads -q --closed
2:effea6de0384
1:ed1b79f46b9a
$ hg pull --confirm << EOF
> n
> EOF
pulling from $TESTTMP/repo2
searching for changes
adding changesets
adding manifests
adding file changes
adding 2 changesets with 1 changes to 1 files
new changesets 8c900227dd5d:00cfe9073916
accept incoming changes (yn)? n
transaction abort!
rollback completed
abort: user aborted
[255]
$ hg pull --config pull.confirm=true << EOF
> n
> EOF
pulling from $TESTTMP/repo2
searching for changes
adding changesets
adding manifests
adding file changes
adding 2 changesets with 1 changes to 1 files
new changesets 8c900227dd5d:00cfe9073916
accept incoming changes (yn)? n
transaction abort!
rollback completed
abort: user aborted
[255]
$ hg pull --confirm << EOF
> y
> EOF
pulling from $TESTTMP/repo2
searching for changes
adding changesets
adding manifests
adding file changes
adding 2 changesets with 1 changes to 1 files
new changesets 8c900227dd5d:00cfe9073916
accept incoming changes (yn)? y
added 2 changesets with 1 changes to 1 files
new changesets 8c900227dd5d:00cfe9073916
(run 'hg update' to get a working copy)
$ hg heads -q --closed
4:00cfe9073916
2:effea6de0384
1:ed1b79f46b9a
pull--confirm config option should be ignored if HGPLAIN is set
$ HGPLAIN=1 hg pull --config pull.confirm=True
pulling from $TESTTMP/repo2
searching for changes
no changes found
$ cd ..
$ hg init copy
$ cd copy
Pull a missing revision:
$ hg pull -qr missing ../repo
abort: unknown revision 'missing'
[10]
Pull multiple revisions with update:
$ hg pull -qu -r 0 -r 1 ../repo
$ hg -q parents
0:bbd179dfa0a7
$ hg rollback
repository tip rolled back to revision -1 (undo pull)
working directory now based on revision -1
$ hg pull -qr 0 ../repo
$ hg log
changeset: 0:bbd179dfa0a7
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ hg pull -qr 1 ../repo
$ hg log
changeset: 1:ed1b79f46b9a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
This used to abort: received changelog group is empty:
$ hg pull -qr 1 ../repo
Test race condition with -r and -U (issue4707)
We pull '-U -r <name>' and the name change right after/during the changegroup emission.
We use http because http is better is our racy-est option.
$ echo babar > ../repo/jungle
$ cat <<EOF > ../repo/.hg/hgrc
> [hooks]
> outgoing.makecommit = hg ci -Am 'racy commit'; echo committed in pull-race
> EOF
$ hg serve -R ../repo -p $HGPORT2 -d --pid-file=../repo.pid
$ cat ../repo.pid >> $DAEMON_PIDS
$ hg pull --rev default --update http://localhost:$HGPORT2/
pulling from http://localhost:$HGPORT2/
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets effea6de0384
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log -G
@ changeset: 2:effea6de0384
| tag: tip
| parent: 0:bbd179dfa0a7
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: add bar
|
| o changeset: 1:ed1b79f46b9a
|/ user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: change foo
|
o changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ cd ..
$ killdaemons.py