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.
bundle w/o type option
$ hg init t1
$ hg init t2
$ cd t1
$ echo blablablablabla > file.txt
$ hg ci -Ama
adding file.txt
$ hg log | grep summary
summary: a
$ hg bundle ../b1 ../t2
searching for changes
1 changesets found
$ cd ../t2
$ hg pull ../b1
pulling from ../b1
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
$ hg up
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log | grep summary
summary: a
$ cd ..
test bundle types
$ for t in "None" "bzip2" "gzip" "none-v2" "v2" "v1" "gzip-v1"; do
> echo % test bundle type $t
> hg init t$t
> cd t1
> hg bundle -t $t ../b$t ../t$t
> cut -b 1-6 ../b$t | head -n 1
> cd ../t$t
> hg debugbundle ../b$t
> echo
> cd ..
> done
% test bundle type None
searching for changes
1 changesets found
HG10UN
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
% test bundle type bzip2
searching for changes
1 changesets found
HG10BZ
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
% test bundle type gzip
searching for changes
1 changesets found
HG10GZ
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
% test bundle type none-v2
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: {}
changegroup -- "{'version': '02'}"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
% test bundle type v2
searching for changes
1 changesets found
HG20\x00\x00 (esc)
Stream params: {'Compression': 'BZ'}
changegroup -- "{'version': '02'}"
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
% test bundle type v1
searching for changes
1 changesets found
HG10BZ
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
% test bundle type gzip-v1
searching for changes
1 changesets found
HG10GZ
c35a0f9217e65d1fdb90c936ffa7dbe679f83ddf
test garbage file
$ echo garbage > bgarbage
$ hg init tgarbage
$ cd tgarbage
$ hg pull ../bgarbage
pulling from ../bgarbage
abort: ../bgarbage: not a Mercurial bundle
[255]
$ cd ..
test invalid bundle type
$ cd t1
$ hg bundle -a -t garbage ../bgarbage
abort: garbage is not a recognized bundle specification
(see "hg help bundle" for supported values for --type)
[255]
$ cd ..