hg: support for auto sharing stores when cloning
Many 3rd party consumers of Mercurial have created wrappers to
essentially perform clone+share as a single operation. This is
especially popular in automated processes like continuous integration
systems. The Jenkins CI software and Mozilla's Firefox release
automation infrastructure have both implemented custom code that
effectively perform clone+share. The common use case here is that
clients want to obtain N>1 checkouts while minimizing disk space and
network requirements. Furthermore, they often don't care that a clone
is an exact mirror of a remote: they are simply looking to obtain
checkouts of specific revisions.
When multiple third parties implement a similar feature, it's a good
sign that the feature is worth adding to the core product. This patch
adds support for an easy-to-use clone+share feature.
The internal "clone" function now accepts options to control auto
sharing during clone. When the auto share mode is active, a store will
be created/updated under the base directory specified and a new
repository pointing to the shared store will be created at the path
specified by the user.
The share extension has grown the ability to pass these options into
the clone command/function.
No command line options for this feature are added because we don't
feel the feature will be popular enough to warrant their existence.
There are two modes for auto share mode. In the default mode, the shared
repo is derived from the first changeset (rev 0) in the remote
repository. This enables related repositories existing at different URLs
to automatically use the same storage. In environments that operate
several repositories (separate repo for branch/head/bookmark or separate
repo per user), this has the potential to drastically reduce storage
and network requirements. In the other mode, the name is derived from the
remote's path/URL.
#require killdaemons
$ hgserve() {
> hg serve -a localhost -p $HGPORT1 -d --pid-file=hg.pid \
> -E errors.log -v $@ > startup.log
> # Grepping hg serve stdout would hang on Windows
> grep -v 'listening at' startup.log
> cat hg.pid >> "$DAEMON_PIDS"
> }
$ hg init a
$ hg --encoding utf-8 -R a branch æ
marked working directory as branch \xc3\xa6 (esc)
(branches are permanent and global, did you want a bookmark?)
$ echo foo > a/foo
$ hg -R a ci -Am foo
adding foo
$ hgserve -R a --config web.push_ssl=False --config web.allow_push=* --encoding latin1
$ hg --encoding utf-8 clone http://localhost:$HGPORT1 b
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
updating to branch \xc3\xa6 (esc)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg --encoding utf-8 -R b log
changeset: 0:867c11ce77b8
branch: \xc3\xa6 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: foo
$ echo bar >> b/foo
$ hg -R b ci -m bar
$ hg --encoding utf-8 -R b push
pushing to http://localhost:$HGPORT1/
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
$ hg -R a --encoding utf-8 log
changeset: 1:58e7c90d67cb
branch: \xc3\xa6 (esc)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: bar
changeset: 0:867c11ce77b8
branch: \xc3\xa6 (esc)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: foo
$ killdaemons.py hg.pid
verify 7e7d56fe4833 (encoding fallback in branchmap to maintain compatibility with 1.3.x)
$ cat <<EOF > oldhg
> import sys
> from mercurial import ui, hg, commands
>
> class StdoutWrapper(object):
> def __init__(self, stdout):
> self._file = stdout
>
> def write(self, data):
> if data == '47\n':
> # latin1 encoding is one %xx (3 bytes) shorter
> data = '44\n'
> elif data.startswith('%C3%A6 '):
> # translate to latin1 encoding
> data = '%%E6 %s' % data[7:]
> self._file.write(data)
>
> def __getattr__(self, name):
> return getattr(self._file, name)
>
> sys.stdout = StdoutWrapper(sys.stdout)
> sys.stderr = StdoutWrapper(sys.stderr)
>
> myui = ui.ui()
> repo = hg.repository(myui, 'a')
> commands.serve(myui, repo, stdio=True, cmdserver=False)
> EOF
$ echo baz >> b/foo
$ hg -R b ci -m baz
$ hg push -R b -e 'python oldhg' ssh://dummy/ --encoding latin1
pushing to ssh://dummy/
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files