streamclone: support for producing and consuming stream clone bundles
Up to this point, stream clones only existed as a dynamically generated
data format produced and consumed during streaming clones. In order to
support this efficient cloning format with the clone bundles feature, we
need a more formal, on disk representation of the streaming clone data.
This patch introduces a new "bundle" type for streaming clones. Unlike
existing bundles, it does not contain changegroup data. It does,
however, share the same concepts like the 4 byte header which identifies
the type of data that follows and the 2 byte abbreviation for
compression types (of which only "UN" is currently supported).
The new bundle format is essentially the existing stream clone version 1
data format with some headers at the beginning.
Content negotiation at stream clone request time checked for repository
format/requirements compatibility before initiating a stream clone. We
can't do active content negotiation when using clone bundles. So, we put
this set of requirements inside the payload so consumers have a built-in
mechanism for checking compatibility before reading and applying lots of
data. Of course, we will also advertise this requirements set in clone
bundles. But that's for another patch.
We currently don't have a mechanism to produce and consume this new
bundle format. This will be implemented in upcoming patches.
It's worth noting that if a legacy client attempts to `hg unbundle` a
stream clone bundle (with the "HGS1" header), it will abort with:
"unknown bundle version S1," which seems appropriate.
#require cvs
$ filterpath()
> {
> eval "$@" | sed "s:$CVSROOT:*REPO*:g"
> }
$ cvscall()
> {
> cvs -f "$@"
> }
output of 'cvs ci' varies unpredictably, so discard most of it
-- just keep the part that matters
$ cvsci()
> {
> cvs -f ci -f "$@" > /dev/null
> }
$ hgcat()
> {
> hg --cwd src-hg cat -r tip "$1"
> }
$ echo "[extensions]" >> $HGRCPATH
$ echo "convert = " >> $HGRCPATH
create cvs repository
$ mkdir cvsmaster
$ cd cvsmaster
$ CVSROOT=`pwd`
$ export CVSROOT
$ CVS_OPTIONS=-f
$ export CVS_OPTIONS
$ cd ..
$ rmdir cvsmaster
$ filterpath cvscall -Q -d "$CVSROOT" init
checkout #1: add foo.txt
$ cvscall -Q checkout -d cvsworktmp .
$ cd cvsworktmp
$ mkdir foo
$ cvscall -Q add foo
$ cd foo
$ echo foo > foo.txt
$ cvscall -Q add foo.txt
$ cvsci -m "add foo.txt" foo.txt
$ cd ../..
$ rm -rf cvsworktmp
checkout #2: create MYBRANCH1 and modify foo.txt on it
$ cvscall -Q checkout -d cvswork foo
$ cd cvswork
$ cvscall -q rtag -b -R MYBRANCH1 foo
$ cvscall -Q update -P -r MYBRANCH1
$ echo bar > foo.txt
$ cvsci -m "bar" foo.txt
$ echo baz > foo.txt
$ cvsci -m "baz" foo.txt
create MYBRANCH1_2 and modify foo.txt some more
$ cvscall -q rtag -b -R -r MYBRANCH1 MYBRANCH1_2 foo
$ cvscall -Q update -P -r MYBRANCH1_2
$ echo bazzie > foo.txt
$ cvsci -m "bazzie" foo.txt
create MYBRANCH1_1 and modify foo.txt yet again
$ cvscall -q rtag -b -R MYBRANCH1_1 foo
$ cvscall -Q update -P -r MYBRANCH1_1
$ echo quux > foo.txt
$ cvsci -m "quux" foo.txt
merge MYBRANCH1 to MYBRANCH1_1
$ filterpath cvscall -Q update -P -jMYBRANCH1
rcsmerge: warning: conflicts during merge
RCS file: *REPO*/foo/foo.txt,v
retrieving revision 1.1
retrieving revision 1.1.2.2
Merging differences between 1.1 and 1.1.2.2 into foo.txt
carefully placed sleep to dodge cvs bug (optimization?) where it
sometimes ignores a "commit" command if it comes too fast (the -f
option in cvsci seems to work for all the other commits in this
script)
$ sleep 1
$ echo xyzzy > foo.txt
$ cvsci -m "merge1+clobber" foo.txt
#if unix-permissions
return to trunk and merge MYBRANCH1_2
$ cvscall -Q update -P -A
$ filterpath cvscall -Q update -P -jMYBRANCH1_2
RCS file: *REPO*/foo/foo.txt,v
retrieving revision 1.1
retrieving revision 1.1.2.2.2.1
Merging differences between 1.1 and 1.1.2.2.2.1 into foo.txt
$ cvsci -m "merge2" foo.txt
$ REALCVS=`which cvs`
$ echo "for x in \$*; do if [ \"\$x\" = \"rlog\" ]; then echo \"RCS file: $CVSROOT/foo/foo.txt,v\"; cat \"$TESTDIR/test-convert-cvsnt-mergepoints.rlog\"; exit 0; fi; done; $REALCVS \$*" > ../cvs
$ chmod +x ../cvs
$ PATH=..:${PATH} hg debugcvsps --parents foo
collecting CVS rlog
7 log entries
creating changesets
7 changeset entries
---------------------
PatchSet 1
Date: * (glob)
Author: user
Branch: HEAD
Tag: (none)
Branchpoints: MYBRANCH1, MYBRANCH1_1
Log:
foo.txt
Members:
foo.txt:INITIAL->1.1
---------------------
PatchSet 2
Date: * (glob)
Author: user
Branch: MYBRANCH1
Tag: (none)
Parent: 1
Log:
bar
Members:
foo.txt:1.1->1.1.2.1
---------------------
PatchSet 3
Date: * (glob)
Author: user
Branch: MYBRANCH1
Tag: (none)
Branchpoints: MYBRANCH1_2
Parent: 2
Log:
baz
Members:
foo.txt:1.1.2.1->1.1.2.2
---------------------
PatchSet 4
Date: * (glob)
Author: user
Branch: MYBRANCH1_1
Tag: (none)
Parent: 1
Log:
quux
Members:
foo.txt:1.1->1.1.4.1
---------------------
PatchSet 5
Date: * (glob)
Author: user
Branch: MYBRANCH1_2
Tag: (none)
Parent: 3
Log:
bazzie
Members:
foo.txt:1.1.2.2->1.1.2.2.2.1
---------------------
PatchSet 6
Date: * (glob)
Author: user
Branch: HEAD
Tag: (none)
Parents: 1,5
Log:
merge
Members:
foo.txt:1.1->1.2
---------------------
PatchSet 7
Date: * (glob)
Author: user
Branch: MYBRANCH1_1
Tag: (none)
Parents: 4,3
Log:
merge
Members:
foo.txt:1.1.4.1->1.1.4.2
#endif
$ cd ..