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.
This test makes sure that we don't mark a file as merged with its ancestor
when we do a merge.
$ cat <<EOF > merge
> import sys, os
> print "merging for", os.path.basename(sys.argv[1])
> EOF
$ HGMERGE="python ../merge"; export HGMERGE
Creating base:
$ hg init a
$ cd a
$ echo 1 > foo
$ echo 1 > bar
$ echo 1 > baz
$ echo 1 > quux
$ hg add foo bar baz quux
$ hg commit -m "base"
$ cd ..
$ hg clone a b
updating to branch default
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
Creating branch a:
$ cd a
$ echo 2a > foo
$ echo 2a > bar
$ hg commit -m "branch a"
Creating branch b:
$ cd ..
$ cd b
$ echo 2b > foo
$ echo 2b > baz
$ hg commit -m "branch b"
We shouldn't have anything but n state here:
$ hg debugstate --nodates | grep -v "^n"
[1]
Merging:
$ hg pull ../a
pulling from ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 2 changes to 2 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge -v
resolving manifests
getting bar
merging foo
merging for foo
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ echo 2m > foo
$ echo 2b > baz
$ echo new > quux
$ hg ci -m "merge"
main: we should have a merge here:
$ hg debugindex --changelog
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 73 ..... 0 cdca01651b96 000000000000 000000000000 (re)
1 73 68 ..... 1 f6718a9cb7f3 cdca01651b96 000000000000 (re)
2 141 68 ..... 2 bdd988058d16 cdca01651b96 000000000000 (re)
3 209 66 ..... 3 d8a521142a3c f6718a9cb7f3 bdd988058d16 (re)
log should show foo and quux changed:
$ hg log -v -r tip
changeset: 3:d8a521142a3c
tag: tip
parent: 1:f6718a9cb7f3
parent: 2:bdd988058d16
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: foo quux
description:
merge
foo: we should have a merge here:
$ hg debugindex foo
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 3 ..... 0 b8e02f643373 000000000000 000000000000 (re)
1 3 4 ..... 1 2ffeddde1b65 b8e02f643373 000000000000 (re)
2 7 4 ..... 2 33d1fb69067a b8e02f643373 000000000000 (re)
3 11 4 ..... 3 aa27919ee430 2ffeddde1b65 33d1fb69067a (re)
bar: we should not have a merge here:
$ hg debugindex bar
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 3 ..... 0 b8e02f643373 000000000000 000000000000 (re)
1 3 4 ..... 2 33d1fb69067a b8e02f643373 000000000000 (re)
baz: we should not have a merge here:
$ hg debugindex baz
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 3 ..... 0 b8e02f643373 000000000000 000000000000 (re)
1 3 4 ..... 1 2ffeddde1b65 b8e02f643373 000000000000 (re)
quux: we should not have a merge here:
$ hg debugindex quux
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 3 ..... 0 b8e02f643373 000000000000 000000000000 (re)
1 3 5 ..... 3 6128c0f33108 b8e02f643373 000000000000 (re)
Manifest entries should match tips of all files:
$ hg manifest --debug
33d1fb69067a0139622a3fa3b7ba1cdb1367972e 644 bar
2ffeddde1b65b4827f6746174a145474129fa2ce 644 baz
aa27919ee4303cfd575e1fb932dd64d75aa08be4 644 foo
6128c0f33108e8cfbb4e0824d13ae48b466d7280 644 quux
Everything should be clean now:
$ hg status
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 4 changesets, 10 total revisions
$ cd ..