revlog: change generaldelta delta parent heuristic
The old generaldelta heuristic was "if p1 (or p2) was closer than the last full text,
use it, otherwise use prev". This was problematic when a repo contained multiple
branches that were very different. If commits to branch A were pushed, and the
last full text was branch B, it would generate a fulltext. Then if branch B was
pushed, it would generate another fulltext. The problem is that the last
fulltext (and delta'ing against `prev` in general) has no correlation with the
contents of the incoming revision, and therefore will always have degenerate
cases.
According to the blame, that algorithm was chosen to minimize the chain length.
Since there is already code that protects against that (the delta-vs-fulltext
code), and since it has been improved since the original generaldelta algorithm
went in (2011), I believe the chain length criteria will still be preserved.
The new algorithm always diffs against p1 (or p2 if it's closer), unless the
resulting delta will fail the delta-vs-fulltext check, in which case we delta
against prev.
Some before and after stats on manifest.d size.
internal large repo
old heuristic - 2.0 GB
new heuristic - 1.2 GB
mozilla-central
old heuristic - 242 MB
new heuristic - 261 MB
The regression in mozilla central is due to the new heuristic choosing p2r as
the delta when it's closer to the tip. Switching the algorithm to always prefer
p1r brings the size back down (242 MB). This is result of the way in which
mozilla does merges and pushes, and the result could easily swing the other
direction in other repos (depending on if they merge X into Y or Y into X), but
will never be as degenerate as before.
I future patch will address the regression by introducing an optional, even more
aggressive delta heuristic which will knock the mozilla manifest size down
dramatically.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: '{desc}' bookmarks: {bookmarks}\n"
> EOF
Create a repo with several bookmarks
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am A
adding a
$ echo b > b
$ hg ci -Am B
adding b
$ hg book 'X'
$ hg book 'Y'
$ echo c > c
$ hg ci -Am C
adding c
$ hg book 'Z'
$ hg up -q 0
$ echo d > d
$ hg ci -Am D
adding d
created new head
$ hg book W
$ hg tglog
@ 3: 'D' bookmarks: W
|
| o 2: 'C' bookmarks: Y Z
| |
| o 1: 'B' bookmarks: X
|/
o 0: 'A' bookmarks:
Move only rebased bookmarks
$ cd ..
$ hg clone -q a a1
$ cd a1
$ hg up -q Z
Test deleting divergent bookmarks from dest (issue3685)
$ hg book -r 3 Z@diverge
... and also test that bookmarks not on dest or not being moved aren't deleted
$ hg book -r 3 X@diverge
$ hg book -r 0 Y@diverge
$ hg tglog
o 3: 'D' bookmarks: W X@diverge Z@diverge
|
| @ 2: 'C' bookmarks: Y Z
| |
| o 1: 'B' bookmarks: X
|/
o 0: 'A' bookmarks: Y@diverge
$ hg rebase -s Y -d 3
rebasing 2:49cb3485fa0c "C" (Y Z)
saved backup bundle to $TESTTMP/a1/.hg/strip-backup/49cb3485fa0c-126f3e97-backup.hg (glob)
$ hg tglog
@ 3: 'C' bookmarks: Y Z
|
o 2: 'D' bookmarks: W X@diverge
|
| o 1: 'B' bookmarks: X
|/
o 0: 'A' bookmarks: Y@diverge
Do not try to keep active but deleted divergent bookmark
$ cd ..
$ hg clone -q a a4
$ cd a4
$ hg up -q 2
$ hg book W@diverge
$ hg rebase -s W -d .
rebasing 3:41acb9dca9eb "D" (tip W)
saved backup bundle to $TESTTMP/a4/.hg/strip-backup/41acb9dca9eb-b35a6a63-backup.hg (glob)
$ hg bookmarks
W 3:0d3554f74897
X 1:6c81ed0049f8
Y 2:49cb3485fa0c
Z 2:49cb3485fa0c
Keep bookmarks to the correct rebased changeset
$ cd ..
$ hg clone -q a a2
$ cd a2
$ hg up -q Z
$ hg rebase -s 1 -d 3
rebasing 1:6c81ed0049f8 "B" (X)
rebasing 2:49cb3485fa0c "C" (Y Z)
saved backup bundle to $TESTTMP/a2/.hg/strip-backup/6c81ed0049f8-a687065f-backup.hg (glob)
$ hg tglog
@ 3: 'C' bookmarks: Y Z
|
o 2: 'B' bookmarks: X
|
o 1: 'D' bookmarks: W
|
o 0: 'A' bookmarks:
Keep active bookmark on the correct changeset
$ cd ..
$ hg clone -q a a3
$ cd a3
$ hg up -q X
$ hg rebase -d W
rebasing 1:6c81ed0049f8 "B" (X)
rebasing 2:49cb3485fa0c "C" (Y Z)
saved backup bundle to $TESTTMP/a3/.hg/strip-backup/6c81ed0049f8-a687065f-backup.hg (glob)
$ hg tglog
o 3: 'C' bookmarks: Y Z
|
@ 2: 'B' bookmarks: X
|
o 1: 'D' bookmarks: W
|
o 0: 'A' bookmarks:
$ hg bookmarks
W 1:41acb9dca9eb
* X 2:e926fccfa8ec
Y 3:3d5fa227f4b5
Z 3:3d5fa227f4b5
rebase --continue with bookmarks present (issue3802)
$ hg up 2
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(leaving bookmark X)
$ echo 'C' > c
$ hg add c
$ hg ci -m 'other C'
created new head
$ hg up 3
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg rebase
rebasing 3:3d5fa227f4b5 "C" (Y Z)
merging c
warning: conflicts during merge.
merging c incomplete! (edit conflicts, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
$ echo 'c' > c
$ hg resolve --mark c
(no more unresolved files)
$ hg rebase --continue
rebasing 3:3d5fa227f4b5 "C" (Y Z)
saved backup bundle to $TESTTMP/a3/.hg/strip-backup/3d5fa227f4b5-c6ea2371-backup.hg (glob)
$ hg tglog
@ 4: 'C' bookmarks: Y Z
|
o 3: 'other C' bookmarks:
|
o 2: 'B' bookmarks: X
|
o 1: 'D' bookmarks: W
|
o 0: 'A' bookmarks:
ensure that bookmarks given the names of revset functions can be used
as --rev arguments (issue3950)
$ hg update -q 3
$ echo bimble > bimble
$ hg add bimble
$ hg commit -q -m 'bisect'
$ echo e >> bimble
$ hg ci -m bisect2
$ echo e >> bimble
$ hg ci -m bisect3
$ hg book bisect
$ hg update -q Y
$ hg rebase -r '"bisect"^^::"bisect"^' -r bisect -d Z
rebasing 5:345c90f326a4 "bisect"
rebasing 6:f677a2907404 "bisect2"
rebasing 7:325c16001345 "bisect3" (tip bisect)
saved backup bundle to $TESTTMP/a3/.hg/strip-backup/345c90f326a4-b4840586-backup.hg (glob)