localrepo: create new function for instantiating a local repo object
Today, there is a single local repository class - localrepository. Its
__init__ is responsible for loading the .hg/requires file and taking
different actions depending on what is present.
In addition, extensions may define a "reposetup" function that
monkeypatches constructed repository instances, often by implementing
a derived type and changing the __class__ of the repo instance.
Work around alternate storage backends and partial clone has made it
clear to me that shoehorning all this logic into __init__ and operating
on an existing instance is too convoluted. For example, localrepository
assumes revlog storage and swapping in non-revlog storage requires
overriding e.g. file() to return something that isn't a revlog. I've
authored various patches that either:
a) teach various methods (like file()) about different states and
taking the appropriate code path at run-time
b) create methods/attributes/callables used for instantiating things
and populating these in __init__
"a" incurs run-time performance penalties and makes code more
complicated since various functions have a bunch of "if storage is X"
branches.
"b" makes localrepository quickly explode in complexity.
My plan for tackling this problem is to make the local repository type
more dynamic. Instead of a static localrepository class/type that
supports all of the local repository configurations (revlogs vs other,
revlogs with ellipsis, revlog v1 versus revlog v2, etc), we'll
dynamically construct a type providing the implementations that are
needed for the repository on disk, derived from the .hg/requires file
and configuration options. The constructed repository type will be
specialized and methods won't need to be taught about different
implementations nor overloaded.
We may also leverage this functionality for building types that don't
implement all attributes. For example, the "intents" feature allows
commands to declare that they are read only. By dynamically
constructing a repository type, we could return a repository instance
with no attributes related to mutating the repository. This could
include things like a "changelog" property implementation that doesn't
check whether it needs to invalidate the hidden revisions set on every
access.
This commit establishes a function for building a local repository
instance. Future commits will start moving functionality from
localrepository.__init__ to this function. Then we'll start dynamically
changing the returned type depending on options that are present.
This change may seem radical. But it should be fully compatible with
the reposetup() model - at least for now.
Differential Revision: https://phab.mercurial-scm.org/D4563
#require no-chg
$ hg init repo
$ cd repo
$ echo foo > foo
$ hg ci -qAm 'add foo'
$ echo >> foo
$ hg ci -m 'change foo'
$ hg up -qC 0
$ echo bar > bar
$ hg ci -qAm 'add bar'
$ hg log
changeset: 2:effea6de0384
tag: tip
parent: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add bar
changeset: 1:ed1b79f46b9a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ cd ..
Test pullbundle functionality
$ cd repo
$ cat <<EOF > .hg/hgrc
> [server]
> pullbundle = True
> [extensions]
> blackbox =
> EOF
$ hg bundle --base null -r 0 .hg/0.hg
1 changesets found
$ hg bundle --base 0 -r 1 .hg/1.hg
1 changesets found
$ hg bundle --base 1 -r 2 .hg/2.hg
1 changesets found
$ cat <<EOF > .hg/pullbundles.manifest
> 2.hg BUNDLESPEC=none-v2 heads=effea6de0384e684f44435651cb7bd70b8735bd4 bases=bbd179dfa0a71671c253b3ae0aa1513b60d199fa
> 1.hg BUNDLESPEC=bzip2-v2 heads=ed1b79f46b9a29f5a6efa59cf12fcfca43bead5a bases=bbd179dfa0a71671c253b3ae0aa1513b60d199fa
> 0.hg BUNDLESPEC=gzip-v2 heads=bbd179dfa0a71671c253b3ae0aa1513b60d199fa
> EOF
$ hg --config blackbox.track=debug --debug serve -p $HGPORT2 -d --pid-file=../repo.pid
listening at http://*:$HGPORT2/ (bound to $LOCALIP:$HGPORT2) (glob) (?)
$ cat ../repo.pid >> $DAEMON_PIDS
$ cd ..
$ hg clone -r 0 http://localhost:$HGPORT2/ repo.pullbundle
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets bbd179dfa0a7 (1 drafts)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo.pullbundle
$ hg pull -r 1
pulling from http://localhost:$HGPORT2/
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets ed1b79f46b9a (1 drafts)
(run 'hg update' to get a working copy)
$ hg pull -r 2
pulling from http://localhost:$HGPORT2/
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets effea6de0384 (1 drafts)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ cd ..
$ killdaemons.py
$ grep 'sending pullbundle ' repo/.hg/blackbox.log
* sending pullbundle "0.hg" (glob)
* sending pullbundle "1.hg" (glob)
* sending pullbundle "2.hg" (glob)
$ rm repo/.hg/blackbox.log
Test pullbundle functionality for incremental pulls
$ cd repo
$ hg --config blackbox.track=debug --debug serve -p $HGPORT2 -d --pid-file=../repo.pid
listening at http://*:$HGPORT2/ (bound to $LOCALIP:$HGPORT2) (glob) (?)
$ cat ../repo.pid >> $DAEMON_PIDS
$ cd ..
$ hg clone http://localhost:$HGPORT2/ repo.pullbundle2
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets bbd179dfa0a7:ed1b79f46b9a (3 drafts)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ killdaemons.py
$ grep 'sending pullbundle ' repo/.hg/blackbox.log
* sending pullbundle "0.hg" (glob)
* sending pullbundle "2.hg" (glob)
* sending pullbundle "1.hg" (glob)
$ rm repo/.hg/blackbox.log
Test recovery from misconfigured server sending no new data
$ cd repo
$ cat <<EOF > .hg/pullbundles.manifest
> 0.hg heads=ed1b79f46b9a29f5a6efa59cf12fcfca43bead5a bases=bbd179dfa0a71671c253b3ae0aa1513b60d199fa
> 0.hg heads=bbd179dfa0a71671c253b3ae0aa1513b60d199fa
> EOF
$ hg --config blackbox.track=debug --debug serve -p $HGPORT2 -d --pid-file=../repo.pid
listening at http://*:$HGPORT2/ (bound to $LOCALIP:$HGPORT2) (glob) (?)
$ cat ../repo.pid >> $DAEMON_PIDS
$ cd ..
$ hg clone -r 0 http://localhost:$HGPORT2/ repo.pullbundle3
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets bbd179dfa0a7 (1 drafts)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo.pullbundle3
$ hg pull -r 1
pulling from http://localhost:$HGPORT2/
searching for changes
adding changesets
adding manifests
adding file changes
added 0 changesets with 0 changes to 1 files
abort: 00changelog.i@ed1b79f46b9a: no node!
[255]
$ cd ..
$ killdaemons.py
$ grep 'sending pullbundle ' repo/.hg/blackbox.log
* sending pullbundle "0.hg" (glob)
* sending pullbundle "0.hg" (glob)
$ rm repo/.hg/blackbox.log