revlog: skeleton support for version 2 revlogs
There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.
It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.
This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.
An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.
To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.
Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.
There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.
#require cvs
$ cvscall()
> {
> cvs -f "$@"
> }
$ hgcat()
> {
> hg --cwd src-hg cat -r tip "$1"
> }
$ echo "[extensions]" >> $HGRCPATH
$ echo "convert = " >> $HGRCPATH
$ cat > cvshooks.py <<EOF
> def cvslog(ui,repo,hooktype,log):
> print "%s hook: %d entries"%(hooktype,len(log))
>
> def cvschangesets(ui,repo,hooktype,changesets):
> print "%s hook: %d changesets"%(hooktype,len(changesets))
> EOF
$ hookpath=`pwd`
$ cat <<EOF >> $HGRCPATH
> [hooks]
> cvslog = python:$hookpath/cvshooks.py:cvslog
> cvschangesets = python:$hookpath/cvshooks.py:cvschangesets
> EOF
create cvs repository
$ mkdir cvsrepo
$ cd cvsrepo
$ CVSROOT=`pwd`
$ export CVSROOT
$ CVS_OPTIONS=-f
$ export CVS_OPTIONS
$ cd ..
$ rmdir cvsrepo
$ cvscall -q -d "$CVSROOT" init
create source directory
$ mkdir src-temp
$ cd src-temp
$ echo a > a
$ mkdir b
$ cd b
$ echo c > c
$ cd ..
import source directory
$ cvscall -q import -m import src INITIAL start
N src/a
N src/b/c
No conflicts created by this import
$ cd ..
checkout source directory
$ cvscall -q checkout src
U src/a
U src/b/c
commit a new revision changing b/c
$ cd src
$ sleep 1
$ echo c >> b/c
$ cvscall -q commit -mci0 . | grep '<--'
$TESTTMP/cvsrepo/src/b/c,v <-- *c (glob)
$ cd ..
convert fresh repo and also check localtimezone option
NOTE: This doesn't check all time zones -- it merely determines that
the configuration option is taking effect.
An arbitrary (U.S.) time zone is used here. TZ=US/Hawaii is selected
since it does not use DST (unlike other U.S. time zones) and is always
a fixed difference from UTC.
$ TZ=US/Hawaii hg convert --config convert.localtimezone=True src src-hg
initializing destination src-hg repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
5 log entries
cvslog hook: 5 entries
creating changesets
3 changeset entries
cvschangesets hook: 3 changesets
sorting...
converting...
2 Initial revision
1 ci0
0 import
updating tags
$ hgcat a
a
$ hgcat b/c
c
c
convert fresh repo with --filemap
$ echo include b/c > filemap
$ hg convert --filemap filemap src src-filemap
initializing destination src-filemap repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
5 log entries
cvslog hook: 5 entries
creating changesets
3 changeset entries
cvschangesets hook: 3 changesets
sorting...
converting...
2 Initial revision
1 ci0
0 import
filtering out empty revision
repository tip rolled back to revision 1 (undo convert)
updating tags
$ hgcat b/c
c
c
$ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
2 update tags files: .hgtags
1 ci0 files: b/c
0 Initial revision files: b/c
convert full repository (issue1649)
$ cvscall -q -d "$CVSROOT" checkout -d srcfull "." | grep -v CVSROOT
U srcfull/src/a
U srcfull/src/b/c
$ ls srcfull
CVS
CVSROOT
src
$ hg convert srcfull srcfull-hg \
> | grep -v 'log entries' | grep -v 'hook:' \
> | grep -v '^[0-3] .*' # filter instable changeset order
initializing destination srcfull-hg repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
creating changesets
4 changeset entries
sorting...
converting...
updating tags
$ hg cat -r tip --cwd srcfull-hg src/a
a
$ hg cat -r tip --cwd srcfull-hg src/b/c
c
c
commit new file revisions
$ cd src
$ echo a >> a
$ echo c >> b/c
$ cvscall -q commit -mci1 . | grep '<--'
$TESTTMP/cvsrepo/src/a,v <-- a
$TESTTMP/cvsrepo/src/b/c,v <-- *c (glob)
$ cd ..
convert again
$ TZ=US/Hawaii hg convert --config convert.localtimezone=True src src-hg
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
7 log entries
cvslog hook: 7 entries
creating changesets
4 changeset entries
cvschangesets hook: 4 changesets
sorting...
converting...
0 ci1
$ hgcat a
a
a
$ hgcat b/c
c
c
c
convert again with --filemap
$ hg convert --filemap filemap src src-filemap
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
7 log entries
cvslog hook: 7 entries
creating changesets
4 changeset entries
cvschangesets hook: 4 changesets
sorting...
converting...
0 ci1
$ hgcat b/c
c
c
c
$ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
3 ci1 files: b/c
2 update tags files: .hgtags
1 ci0 files: b/c
0 Initial revision files: b/c
commit branch
$ cd src
$ cvs -q update -r1.1 b/c
U b/c
$ cvs -q tag -b branch
T a
T b/c
$ cvs -q update -r branch > /dev/null
$ sleep 1
$ echo d >> b/c
$ cvs -q commit -mci2 . | grep '<--'
$TESTTMP/cvsrepo/src/b/c,v <-- *c (glob)
$ cd ..
convert again
$ TZ=US/Hawaii hg convert --config convert.localtimezone=True src src-hg
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
8 log entries
cvslog hook: 8 entries
creating changesets
5 changeset entries
cvschangesets hook: 5 changesets
sorting...
converting...
0 ci2
$ hgcat b/c
c
d
convert again with --filemap
$ TZ=US/Hawaii hg convert --config convert.localtimezone=True --filemap filemap src src-filemap
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
8 log entries
cvslog hook: 8 entries
creating changesets
5 changeset entries
cvschangesets hook: 5 changesets
sorting...
converting...
0 ci2
$ hgcat b/c
c
d
$ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
4 ci2 files: b/c
3 ci1 files: b/c
2 update tags files: .hgtags
1 ci0 files: b/c
0 Initial revision files: b/c
commit a new revision with funny log message
$ cd src
$ sleep 1
$ echo e >> a
$ cvscall -q commit -m'funny
> ----------------------------
> log message' . | grep '<--' |\
> sed -e 's:.*src/\(.*\),v.*:checking in src/\1,v:g'
checking in src/a,v
commit new file revisions with some fuzz
$ sleep 1
$ echo f >> a
$ cvscall -q commit -mfuzzy . | grep '<--'
$TESTTMP/cvsrepo/src/a,v <-- a
$ sleep 4 # the two changes will be split if fuzz < 4
$ echo g >> b/c
$ cvscall -q commit -mfuzzy . | grep '<--'
$TESTTMP/cvsrepo/src/b/c,v <-- *c (glob)
$ cd ..
convert again
$ TZ=US/Hawaii hg convert --config convert.cvsps.fuzz=2 --config convert.localtimezone=True src src-hg
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
11 log entries
cvslog hook: 11 entries
creating changesets
8 changeset entries
cvschangesets hook: 8 changesets
sorting...
converting...
2 funny
1 fuzzy
0 fuzzy
$ hg -R src-hg log -G --template '{rev} ({branches}) {desc} date: {date|date} files: {files}\n'
o 8 (branch) fuzzy date: * -1000 files: b/c (glob)
|
o 7 (branch) fuzzy date: * -1000 files: a (glob)
|
o 6 (branch) funny
| ----------------------------
| log message date: * -1000 files: a (glob)
o 5 (branch) ci2 date: * -1000 files: b/c (glob)
o 4 () ci1 date: * -1000 files: a b/c (glob)
|
o 3 () update tags date: * +0000 files: .hgtags (glob)
|
| o 2 (INITIAL) import date: * -1000 files: (glob)
| |
o | 1 () ci0 date: * -1000 files: b/c (glob)
|/
o 0 () Initial revision date: * -1000 files: a b/c (glob)
testing debugcvsps
$ cd src
$ hg debugcvsps --fuzz=2 -x >/dev/null
commit a new revision changing a and removing b/c
$ cvscall -q update -A
U a
U b/c
$ sleep 1
$ echo h >> a
$ cvscall -Q remove -f b/c
$ cvscall -q commit -mci | grep '<--'
$TESTTMP/cvsrepo/src/a,v <-- a
$TESTTMP/cvsrepo/src/b/c,v <-- *c (glob)
update and verify the cvsps cache
$ hg debugcvsps --fuzz=2 -u
collecting CVS rlog
13 log entries
cvslog hook: 13 entries
creating changesets
11 changeset entries
cvschangesets hook: 11 changesets
---------------------
PatchSet 1
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Branchpoints: INITIAL
Log:
Initial revision
Members:
a:INITIAL->1.1
---------------------
PatchSet 2
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Branchpoints: INITIAL, branch
Log:
Initial revision
Members:
b/c:INITIAL->1.1
---------------------
PatchSet 3
Date: * (glob)
Author: * (glob)
Branch: INITIAL
Tag: start
Log:
import
Members:
a:1.1->1.1.1.1
b/c:1.1->1.1.1.1
---------------------
PatchSet 4
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Log:
ci0
Members:
b/c:1.1->1.2
---------------------
PatchSet 5
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Branchpoints: branch
Log:
ci1
Members:
a:1.1->1.2
---------------------
PatchSet 6
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Log:
ci1
Members:
b/c:1.2->1.3
---------------------
PatchSet 7
Date: * (glob)
Author: * (glob)
Branch: branch
Tag: (none)
Log:
ci2
Members:
b/c:1.1->1.1.2.1
---------------------
PatchSet 8
Date: * (glob)
Author: * (glob)
Branch: branch
Tag: (none)
Log:
funny
----------------------------
log message
Members:
a:1.2->1.2.2.1
---------------------
PatchSet 9
Date: * (glob)
Author: * (glob)
Branch: branch
Tag: (none)
Log:
fuzzy
Members:
a:1.2.2.1->1.2.2.2
---------------------
PatchSet 10
Date: * (glob)
Author: * (glob)
Branch: branch
Tag: (none)
Log:
fuzzy
Members:
b/c:1.1.2.1->1.1.2.2
---------------------
PatchSet 11
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Log:
ci
Members:
a:1.2->1.3
b/c:1.3->1.4(DEAD)
$ cd ..