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
#testcases abortcommand abortflag
#testcases continuecommand continueflag
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}:{phase} '{desc}' {branches}\n"
> EOF
#if abortflag
$ cat >> $HGRCPATH <<EOF
> [alias]
> abort = rebase --abort
> EOF
#endif
#if continueflag
$ cat >> $HGRCPATH <<EOF
> [alias]
> continue = rebase --continue
> EOF
#endif
$ hg init a
$ cd a
$ touch .hg/rebasestate
$ hg sum
parent: -1:000000000000 tip (empty repository)
branch: default
commit: (clean)
update: (current)
abort: .hg/rebasestate is incomplete
[255]
$ rm .hg/rebasestate
$ echo c1 > common
$ hg add common
$ hg ci -m C1
$ echo c2 >> common
$ hg ci -m C2
$ echo c3 >> common
$ hg ci -m C3
$ hg up -q -C 1
$ echo l1 >> extra
$ hg add extra
$ hg ci -m L1
created new head
$ sed -e 's/c2/l2/' common > common.new
$ mv common.new common
$ hg ci -m L2
$ hg phase --force --secret 2
$ hg tglog
@ 4:draft 'L2'
|
o 3:draft 'L1'
|
| o 2:secret 'C3'
|/
o 1:draft 'C2'
|
o 0:draft 'C1'
Conflicting rebase:
$ hg rebase -s 3 -d 2
rebasing 3:3163e20567cc "L1"
rebasing 4:46f0b057b5c0 tip "L2"
merging common
warning: conflicts while merging common! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
Insert unsupported advisory merge record:
$ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -x
$ hg debugmergestate
local (dest): 3e046f2ecedb793b97ed32108086edd1a162f8bc
other (source): 46f0b057b5c061d276b91491c22151f78698abd2
file: common (state "u")
local path: common (hash 94c8c21d08740f5da9eaa38d1f175c592692f0d1, flags "")
ancestor path: common (node de0a666fdd9c1a0b0698b90d85064d8bd34f74b6)
other path: common (node 2f6411de53677f6f1048fef5bf888d67a342e0a5)
extra: ancestorlinknode = 3163e20567cc93074fbb7a53c8b93312e59dbf2c
extra: merged = yes
$ hg resolve -l
U common
Insert unsupported mandatory merge record:
$ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -X
$ hg debugmergestate
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
$ hg resolve -l
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
$ hg resolve -ma
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
Abort (should clear out unsupported merge state):
#if abortcommand
when in dry-run mode
$ hg abort --dry-run
rebase in progress, will be aborted
#endif
$ hg abort
saved backup bundle to $TESTTMP/a/.hg/strip-backup/3e046f2ecedb-6beef7d5-backup.hg
rebase aborted
$ hg debugmergestate
no merge state found
$ hg tglog
@ 4:draft 'L2'
|
o 3:draft 'L1'
|
| o 2:secret 'C3'
|/
o 1:draft 'C2'
|
o 0:draft 'C1'
Test safety for inconsistent rebase state, which may be created (and
forgotten) by Mercurial earlier than 2.7. This emulates Mercurial
earlier than 2.7 by renaming ".hg/rebasestate" temporarily.
$ hg rebase -s 3 -d 2
rebasing 3:3163e20567cc "L1"
rebasing 4:46f0b057b5c0 tip "L2"
merging common
warning: conflicts while merging common! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ mv .hg/rebasestate .hg/rebasestate.back
$ hg update --quiet --clean 2
$ hg --config extensions.mq= strip --quiet "destination()"
$ mv .hg/rebasestate.back .hg/rebasestate
$ hg continue
abort: cannot continue inconsistent rebase
(use "hg rebase --abort" to clear broken state)
[255]
$ hg summary | grep '^rebase: '
rebase: (use "hg rebase --abort" to clear broken state)
$ hg abort
rebase aborted (no revision is removed, only broken state is cleared)
$ cd ..
Construct new repo:
$ hg init b
$ cd b
$ echo a > a
$ hg ci -Am A
adding a
$ echo b > b
$ hg ci -Am B
adding b
$ echo c > c
$ hg ci -Am C
adding c
$ hg up -q 0
$ echo b > b
$ hg ci -Am 'B bis'
adding b
created new head
$ echo c1 > c
$ hg ci -Am C1
adding c
$ hg phase --force --secret 1
$ hg phase --public 1
Rebase and abort without generating new changesets:
$ hg tglog
@ 4:draft 'C1'
|
o 3:draft 'B bis'
|
| o 2:secret 'C'
| |
| o 1:public 'B'
|/
o 0:public 'A'
$ hg rebase -b 4 -d 2
rebasing 3:a6484957d6b9 "B bis"
note: not rebasing 3:a6484957d6b9 "B bis", its destination already has all its changes
rebasing 4:145842775fec tip "C1"
merging c
warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg tglog
% 4:draft 'C1'
|
o 3:draft 'B bis'
|
| @ 2:secret 'C'
| |
| o 1:public 'B'
|/
o 0:public 'A'
$ hg rebase -a
rebase aborted
$ hg tglog
@ 4:draft 'C1'
|
o 3:draft 'B bis'
|
| o 2:secret 'C'
| |
| o 1:public 'B'
|/
o 0:public 'A'
$ cd ..
rebase abort should not leave working copy in a merge state if tip-1 is public
(issue4082)
$ hg init abortpublic
$ cd abortpublic
$ echo a > a && hg ci -Aqm a
$ hg book master
$ hg book foo
$ echo b > b && hg ci -Aqm b
$ hg up -q master
$ echo c > c && hg ci -Aqm c
$ hg phase -p -r .
$ hg up -q foo
$ echo C > c && hg ci -Aqm C
$ hg log -G --template "{rev} {desc} {bookmarks}"
@ 3 C foo
|
| o 2 c master
| |
o | 1 b
|/
o 0 a
$ hg rebase -d master -r foo
rebasing 3:6c0f977a22d8 foo tip "C"
merging c
warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg abort
rebase aborted
$ hg log -G --template "{rev} {desc} {bookmarks}"
@ 3 C foo
|
| o 2 c master
| |
o | 1 b
|/
o 0 a
$ cd ..
Make sure we don't clobber changes in the working directory when the
user has somehow managed to update to a different revision (issue4009)
$ hg init noupdate
$ cd noupdate
$ hg book @
$ echo original > a
$ hg add a
$ hg commit -m a
$ echo x > b
$ hg add b
$ hg commit -m b1
$ hg up 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
(leaving bookmark @)
$ hg book foo
$ echo y > b
$ hg add b
$ hg commit -m b2
created new head
$ hg rebase -d @ -b foo --tool=internal:fail
rebasing 2:070cf4580bb5 foo tip "b2"
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ mv .hg/rebasestate ./ # so we're allowed to hg up like in mercurial <2.6.3
$ hg up -C 0 # user does other stuff in the repo
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ mv rebasestate .hg/ # user upgrades to 2.7
$ echo new > a
$ hg up 1 # user gets an error saying to run hg rebase --abort
abort: rebase in progress
(use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
[20]
$ cat a
new
$ hg abort
rebase aborted
$ cat a
new
$ cd ..
test aborting an interrupted series (issue5084)
$ hg init interrupted
$ cd interrupted
$ touch base
$ hg add base
$ hg commit -m base
$ touch a
$ hg add a
$ hg commit -m a
$ echo 1 > a
$ hg commit -m 1
$ touch b
$ hg add b
$ hg commit -m b
$ echo 2 >> a
$ hg commit -m c
$ touch d
$ hg add d
$ hg commit -m d
$ hg co -q 1
$ hg rm a
$ hg commit -m no-a
created new head
$ hg co 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log -G --template "{rev} {desc} {bookmarks}"
o 6 no-a
|
| o 5 d
| |
| o 4 c
| |
| o 3 b
| |
| o 2 1
|/
o 1 a
|
@ 0 base
$ hg --config extensions.n=$TESTDIR/failfilemerge.py rebase -s 3 -d tip
rebasing 3:3a71550954f1 "b"
rebasing 4:e80b69427d80 "c"
abort: ^C
[255]
New operations are blocked with the correct state message
$ find .hg -name '*state' -prune | sort
.hg/dirstate
.hg/merge/state
.hg/rebasestate
.hg/undo.backup.dirstate
.hg/undo.dirstate
.hg/updatestate
$ hg rebase -s 3 -d tip
abort: rebase in progress
(use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
[20]
$ hg up .
abort: rebase in progress
(use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
[20]
$ hg up -C .
abort: rebase in progress
(use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
[20]
$ hg graft 3
abort: rebase in progress
(use 'hg rebase --continue', 'hg rebase --abort', or 'hg rebase --stop')
[20]
$ hg abort
saved backup bundle to $TESTTMP/interrupted/.hg/strip-backup/3d8812cf300d-93041a90-backup.hg
rebase aborted
$ hg log -G --template "{rev} {desc} {bookmarks}"
o 6 no-a
|
| o 5 d
| |
| o 4 c
| |
| o 3 b
| |
| o 2 1
|/
o 1 a
|
@ 0 base
$ hg summary
parent: 0:df4f53cec30a
base
branch: default
commit: (clean)
update: 6 new changesets (update)
phases: 7 draft
$ cd ..
On the other hand, make sure we *do* clobber changes whenever we
haven't somehow managed to update the repo to a different revision
during a rebase (issue4661)
$ hg ini yesupdate
$ cd yesupdate
$ echo "initial data" > foo.txt
$ hg add
adding foo.txt
$ hg ci -m "initial checkin"
$ echo "change 1" > foo.txt
$ hg ci -m "change 1"
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo "conflicting change 1" > foo.txt
$ hg ci -m "conflicting 1"
created new head
$ echo "conflicting change 2" > foo.txt
$ hg ci -m "conflicting 2"
$ hg rebase -d 1 --tool 'internal:fail'
rebasing 2:e4ea5cdc9789 "conflicting 1"
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg abort
rebase aborted
$ hg summary
parent: 3:b16646383533 tip
conflicting 2
branch: default
commit: (clean)
update: 1 new changesets, 2 branch heads (merge)
phases: 4 draft
$ cd ..
test aborting a rebase succeeds after rebasing with skipped commits onto a
public changeset (issue4896)
$ hg init succeedonpublic
$ cd succeedonpublic
$ echo 'content' > root
$ hg commit -A -m 'root' -q
set up public branch
$ echo 'content' > disappear
$ hg commit -A -m 'disappear public' -q
commit will cause merge conflict on rebase
$ echo '' > root
$ hg commit -m 'remove content public' -q
$ hg phase --public
setup the draft branch that will be rebased onto public commit
$ hg up -r 0 -q
$ echo 'content' > disappear
commit will disappear
$ hg commit -A -m 'disappear draft' -q
$ echo 'addedcontADDEDentadded' > root
commit will cause merge conflict on rebase
$ hg commit -m 'add content draft' -q
$ hg rebase -d 'public()' --tool :merge -q
note: not rebasing 3:0682fd3dabf5 "disappear draft", its destination already has all its changes
warning: conflicts while merging root! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg abort
rebase aborted
$ cd ..