streamclone: define first iteration of version 2 of stream format
(This patch is based on a first draft from Gregory Szorc, with deeper rework)
Version 1 of the stream clone format was invented many years ago and suffers
from a few deficiencies:
1) Filenames are stored in store-encoded (on filesystem) form rather than in
their internal form. This makes future compatibility with new store
filename encodings more difficult.
2) File entry "headers" consist of a newline of the file name followed by the
string file size. Converting strings to integers is avoidable overhead. We
can't store filenames with newlines (manifests have this limitation as
well, so it isn't a major concern). But the big concern here is the
necessity for readline(). Scanning for newlines means reading ahead and
that means extra buffer allocations and slicing (in Python) and this makes
performance suffer.
3) Filenames aren't compressed optimally. Filenames should be compressed well
since there is a lot of repeated data. However, since they are scattered
all over the stream (with revlog data in between), they typically fall
outside the window size of the compressor and don't compress.
4) It can only exchange stored based content, being able to exchange caches
too would be nice.
5) It is limited to a stream-based protocol and isn't suitable for an on-disk
format for general repository reading because the offset of individual file
entries requires scanning the entire file to find file records.
As part of enabling streaming clones to work in bundle2, #2 proved to have a
significant negative impact on performance. Since bundle2 provides the
opportunity to start fresh, Gregory Szorc figured he would take the
opportunity to invent a new streaming clone data format.
The new format devised in this series addresses #1, #2, and #4. It punts on #3
because it was complex without yielding a significant gain and on #5 because
devising a new store format that "packs" multiple revlogs into a single
"packed revlog" is massive scope bloat. However, this v2 format might be
suitable for streaming into a "packed revlog" with minimal processing. If it
works, great. If not, we can always invent stream format when it is needed.
This patch only introduces the bases of the format. We'll get it usable through
bundle2 first, then we'll extend the format in future patches to bring it to its
full potential (especially #4).
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
> tglogp = log -G --template "{rev}: {node|short} {phase} '{desc}' {branches}\n"
> EOF
$ hg init a
$ cd a
$ echo A > A
$ hg ci -Am A
adding A
$ echo B > B
$ hg ci -Am B
adding B
$ echo C >> A
$ hg ci -m C
$ hg up -q -C 0
$ echo D >> A
$ hg ci -m D
created new head
$ echo E > E
$ hg ci -Am E
adding E
$ cd ..
Changes during an interruption - continue:
$ hg clone -q -u . a a1
$ cd a1
$ hg tglog
@ 4: ae36e8e3dfd7 'E'
|
o 3: 46b37eabc604 'D'
|
| o 2: 965c486023db 'C'
| |
| o 1: 27547f69f254 'B'
|/
o 0: 4a2df7238c3b 'A'
Rebasing B onto E:
$ hg rebase -s 1 -d 4
rebasing 1:27547f69f254 "B"
rebasing 2:965c486023db "C"
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
Force a commit on C during the interruption:
$ hg up -q -C 2 --config 'extensions.rebase=!'
$ echo 'Extra' > Extra
$ hg add Extra
$ hg ci -m 'Extra' --config 'extensions.rebase=!'
Force this commit onto secret phase
$ hg phase --force --secret 6
$ hg tglogp
@ 6: deb5d2f93d8b secret 'Extra'
|
| o 5: 45396c49d53b draft 'B'
| |
| o 4: ae36e8e3dfd7 draft 'E'
| |
| o 3: 46b37eabc604 draft 'D'
| |
o | 2: 965c486023db draft 'C'
| |
o | 1: 27547f69f254 draft 'B'
|/
o 0: 4a2df7238c3b draft 'A'
Resume the rebasing:
$ hg rebase --continue
already rebased 1:27547f69f254 "B" as 45396c49d53b
rebasing 2:965c486023db "C"
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
Solve the conflict and go on:
$ echo 'conflict solved' > A
$ rm A.orig
$ hg resolve -m A
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase --continue
already rebased 1:27547f69f254 "B" as 45396c49d53b
rebasing 2:965c486023db "C"
warning: orphaned descendants detected, not stripping 27547f69f254, 965c486023db
$ hg tglogp
o 7: d2d25e26288e draft 'C'
|
| o 6: deb5d2f93d8b secret 'Extra'
| |
o | 5: 45396c49d53b draft 'B'
| |
@ | 4: ae36e8e3dfd7 draft 'E'
| |
o | 3: 46b37eabc604 draft 'D'
| |
| o 2: 965c486023db draft 'C'
| |
| o 1: 27547f69f254 draft 'B'
|/
o 0: 4a2df7238c3b draft 'A'
$ cd ..
Changes during an interruption - abort:
$ hg clone -q -u . a a2
$ cd a2
$ hg tglog
@ 4: ae36e8e3dfd7 'E'
|
o 3: 46b37eabc604 'D'
|
| o 2: 965c486023db 'C'
| |
| o 1: 27547f69f254 'B'
|/
o 0: 4a2df7238c3b 'A'
Rebasing B onto E:
$ hg rebase -s 1 -d 4
rebasing 1:27547f69f254 "B"
rebasing 2:965c486023db "C"
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
Force a commit on B' during the interruption:
$ hg up -q -C 5 --config 'extensions.rebase=!'
$ echo 'Extra' > Extra
$ hg add Extra
$ hg ci -m 'Extra' --config 'extensions.rebase=!'
$ hg tglog
@ 6: 402ee3642b59 'Extra'
|
o 5: 45396c49d53b 'B'
|
o 4: ae36e8e3dfd7 'E'
|
o 3: 46b37eabc604 'D'
|
| o 2: 965c486023db 'C'
| |
| o 1: 27547f69f254 'B'
|/
o 0: 4a2df7238c3b 'A'
Abort the rebasing:
$ hg rebase --abort
warning: new changesets detected on destination branch, can't strip
rebase aborted
$ hg tglog
@ 6: 402ee3642b59 'Extra'
|
o 5: 45396c49d53b 'B'
|
o 4: ae36e8e3dfd7 'E'
|
o 3: 46b37eabc604 'D'
|
| o 2: 965c486023db 'C'
| |
| o 1: 27547f69f254 'B'
|/
o 0: 4a2df7238c3b 'A'
$ cd ..
Changes during an interruption - abort (again):
$ hg clone -q -u . a a3
$ cd a3
$ hg tglogp
@ 4: ae36e8e3dfd7 draft 'E'
|
o 3: 46b37eabc604 draft 'D'
|
| o 2: 965c486023db draft 'C'
| |
| o 1: 27547f69f254 draft 'B'
|/
o 0: 4a2df7238c3b draft 'A'
Rebasing B onto E:
$ hg rebase -s 1 -d 4
rebasing 1:27547f69f254 "B"
rebasing 2:965c486023db "C"
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
Change phase on B and B'
$ hg up -q -C 5 --config 'extensions.rebase=!'
$ hg phase --public 1
$ hg phase --public 5
$ hg phase --secret -f 2
$ hg tglogp
@ 5: 45396c49d53b public 'B'
|
o 4: ae36e8e3dfd7 public 'E'
|
o 3: 46b37eabc604 public 'D'
|
| o 2: 965c486023db secret 'C'
| |
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
Abort the rebasing:
$ hg rebase --abort
warning: can't clean up public changesets 45396c49d53b
rebase aborted
$ hg tglogp
@ 5: 45396c49d53b public 'B'
|
o 4: ae36e8e3dfd7 public 'E'
|
o 3: 46b37eabc604 public 'D'
|
| o 2: 965c486023db secret 'C'
| |
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
Test rebase interrupted by hooks
$ hg up 2
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo F > F
$ hg add F
$ hg ci -m F
$ cd ..
(precommit version)
$ cp -R a3 hook-precommit
$ cd hook-precommit
$ hg rebase --source 2 --dest 5 --tool internal:other --config 'hooks.precommit=hg status | grep "M A"'
rebasing 2:965c486023db "C"
M A
rebasing 6:a0b2430ebfb8 "F" (tip)
abort: precommit hook exited with status 1
[255]
$ hg tglogp
@ 7: 401ccec5e39f secret 'C'
|
| @ 6: a0b2430ebfb8 secret 'F'
| |
o | 5: 45396c49d53b public 'B'
| |
o | 4: ae36e8e3dfd7 public 'E'
| |
o | 3: 46b37eabc604 public 'D'
| |
| o 2: 965c486023db secret 'C'
| |
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
$ hg rebase --continue
already rebased 2:965c486023db "C" as 401ccec5e39f
rebasing 6:a0b2430ebfb8 "F"
saved backup bundle to $TESTTMP/hook-precommit/.hg/strip-backup/965c486023db-aa6250e7-rebase.hg
$ hg tglogp
@ 6: 6e92a149ac6b secret 'F'
|
o 5: 401ccec5e39f secret 'C'
|
o 4: 45396c49d53b public 'B'
|
o 3: ae36e8e3dfd7 public 'E'
|
o 2: 46b37eabc604 public 'D'
|
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
$ cd ..
(pretxncommit version)
$ cp -R a3 hook-pretxncommit
$ cd hook-pretxncommit
#if windows
$ NODE="%HG_NODE%"
#else
$ NODE="\$HG_NODE"
#endif
$ hg rebase --source 2 --dest 5 --tool internal:other --config "hooks.pretxncommit=hg log -r $NODE | grep \"summary: C\""
rebasing 2:965c486023db "C"
summary: C
rebasing 6:a0b2430ebfb8 "F" (tip)
transaction abort!
rollback completed
abort: pretxncommit hook exited with status 1
[255]
$ hg tglogp
@ 7: 401ccec5e39f secret 'C'
|
| @ 6: a0b2430ebfb8 secret 'F'
| |
o | 5: 45396c49d53b public 'B'
| |
o | 4: ae36e8e3dfd7 public 'E'
| |
o | 3: 46b37eabc604 public 'D'
| |
| o 2: 965c486023db secret 'C'
| |
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
$ hg rebase --continue
already rebased 2:965c486023db "C" as 401ccec5e39f
rebasing 6:a0b2430ebfb8 "F"
saved backup bundle to $TESTTMP/hook-pretxncommit/.hg/strip-backup/965c486023db-aa6250e7-rebase.hg
$ hg tglogp
@ 6: 6e92a149ac6b secret 'F'
|
o 5: 401ccec5e39f secret 'C'
|
o 4: 45396c49d53b public 'B'
|
o 3: ae36e8e3dfd7 public 'E'
|
o 2: 46b37eabc604 public 'D'
|
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
$ cd ..
(pretxnclose version)
$ cp -R a3 hook-pretxnclose
$ cd hook-pretxnclose
$ hg rebase --source 2 --dest 5 --tool internal:other --config 'hooks.pretxnclose=hg log -r tip | grep "summary: C"'
rebasing 2:965c486023db "C"
summary: C
rebasing 6:a0b2430ebfb8 "F" (tip)
transaction abort!
rollback completed
abort: pretxnclose hook exited with status 1
[255]
$ hg tglogp
@ 7: 401ccec5e39f secret 'C'
|
| @ 6: a0b2430ebfb8 secret 'F'
| |
o | 5: 45396c49d53b public 'B'
| |
o | 4: ae36e8e3dfd7 public 'E'
| |
o | 3: 46b37eabc604 public 'D'
| |
| o 2: 965c486023db secret 'C'
| |
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
$ hg rebase --continue
already rebased 2:965c486023db "C" as 401ccec5e39f
rebasing 6:a0b2430ebfb8 "F"
saved backup bundle to $TESTTMP/hook-pretxnclose/.hg/strip-backup/965c486023db-aa6250e7-rebase.hg
$ hg tglogp
@ 6: 6e92a149ac6b secret 'F'
|
o 5: 401ccec5e39f secret 'C'
|
o 4: 45396c49d53b public 'B'
|
o 3: ae36e8e3dfd7 public 'E'
|
o 2: 46b37eabc604 public 'D'
|
| o 1: 27547f69f254 public 'B'
|/
o 0: 4a2df7238c3b public 'A'
$ cd ..
Make sure merge state is cleaned up after a no-op rebase merge (issue5494)
$ hg init repo
$ cd repo
$ echo a > a
$ hg commit -qAm base
$ echo b >> a
$ hg commit -qm b
$ hg up '.^'
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo c >> a
$ hg commit -qm c
$ hg rebase -s 1 -d 2 --noninteractive
rebasing 1:fdaca8533b86 "b"
merging a
warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
$ echo a > a
$ echo c >> a
$ hg resolve --mark a
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase --continue
rebasing 1:fdaca8533b86 "b"
note: rebase of 1:fdaca8533b86 created no changes to commit
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/fdaca8533b86-7fd70513-rebase.hg
$ hg resolve --list
$ test -f .hg/merge
[1]