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
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ mkdir dir
$ mkdir dir/src
$ cd dir/src
$ for x in `$TESTDIR/seq.py 20`; do echo $x > "f$x"; hg add "f$x"; hg commit -m "Commit src $x"; done
$ cd ..
$ mkdir tests
$ cd tests
$ for x in `$TESTDIR/seq.py 20`; do echo $x > "t$x"; hg add "t$x"; hg commit -m "Commit test $x"; done
$ cd ../../..
narrow clone a file, f10
$ hg clone --narrow ssh://user@dummy/master narrow --noupdate --include "dir/src/f10"
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 1 changes to 1 files
new changesets *:* (glob)
$ cd narrow
$ cat .hg/requires | grep -v generaldelta
dotencode
fncache
narrowhg-experimental
revlogv1
store
testonly-simplestore (reposimplestore !)
$ hg tracked
I path:dir/src/f10
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ find * | sort
dir
dir/src
dir/src/f10
$ cat dir/src/f10
10
$ cd ..
narrow clone a directory, tests/, except tests/t19
$ hg clone --narrow ssh://user@dummy/master narrowdir --noupdate --include "dir/tests/" --exclude "dir/tests/t19"
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 19 changes to 19 files
new changesets *:* (glob)
$ cd narrowdir
$ hg tracked
I path:dir/tests
X path:dir/tests/t19
$ hg update
19 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ find * | sort
dir
dir/tests
dir/tests/t1
dir/tests/t10
dir/tests/t11
dir/tests/t12
dir/tests/t13
dir/tests/t14
dir/tests/t15
dir/tests/t16
dir/tests/t17
dir/tests/t18
dir/tests/t2
dir/tests/t20
dir/tests/t3
dir/tests/t4
dir/tests/t5
dir/tests/t6
dir/tests/t7
dir/tests/t8
dir/tests/t9
$ cd ..
narrow clone everything but a directory (tests/)
$ hg clone --narrow ssh://user@dummy/master narrowroot --noupdate --exclude "dir/tests"
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 20 changes to 20 files
new changesets *:* (glob)
$ cd narrowroot
$ hg tracked
I path:.
X path:dir/tests
$ hg update
20 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ find * | sort
dir
dir/src
dir/src/f1
dir/src/f10
dir/src/f11
dir/src/f12
dir/src/f13
dir/src/f14
dir/src/f15
dir/src/f16
dir/src/f17
dir/src/f18
dir/src/f19
dir/src/f2
dir/src/f20
dir/src/f3
dir/src/f4
dir/src/f5
dir/src/f6
dir/src/f7
dir/src/f8
dir/src/f9
$ cd ..
Testing the --narrowspec flag to clone
$ cat >> narrowspecs <<EOF
> %include foo
> [include]
> path:dir/tests/
> path:dir/src/f12
> EOF
$ hg clone ssh://user@dummy/master specfile --narrowspec narrowspecs
reading narrowspec from '$TESTTMP/narrowspecs'
abort: cannot specify other files using '%include' in narrowspec
[255]
$ cat > narrowspecs <<EOF
> [include]
> path:dir/tests/
> path:dir/src/f12
> EOF
$ hg clone ssh://user@dummy/master specfile --narrowspec narrowspecs
reading narrowspec from '$TESTTMP/narrowspecs'
requesting all changes
adding changesets
adding manifests
adding file changes
added 40 changesets with 21 changes to 21 files
new changesets 681085829a73:26ce255d5b5d
updating to branch default
21 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd specfile
$ hg tracked
I path:dir/src/f12
I path:dir/tests
$ cd ..