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 cvs
This is https://bz.mercurial-scm.org/1148
and https://bz.mercurial-scm.org/1447
$ cvscall()
> {
> cvs -f "$@" > /dev/null
> }
$ cat <<EOF >> $HGRCPATH
> [extensions]
> convert =
> [convert]
> cvsps.cache = 0
> EOF
create cvs repository
$ mkdir cvsrepo
$ cd cvsrepo
$ CVSROOT=`pwd`
$ export CVSROOT
$ CVS_OPTIONS=-f
$ export CVS_OPTIONS
$ cd ..
$ rmdir cvsrepo
$ cvscall -q -d "$CVSROOT" init
Create a new project
$ mkdir src
$ cd src
$ echo "1" > a
$ echo "1" > b
$ cvscall import -m "init" src v0 r0 | sort
$ cd ..
$ cvscall co src
cvs checkout: Updating src
$ cd src
Branch the project
$ cvscall tag -b BRANCH
cvs tag: Tagging .
$ cvscall up -r BRANCH > /dev/null
cvs update: Updating .
Modify file a, then b, then a
$ sleep 1
$ echo "2" > a
$ cvscall ci -m "mod a"
cvs commit: Examining .
$ echo "2" > b
$ cvscall ci -m "mod b"
cvs commit: Examining .
$ sleep 1
$ echo "3" > a
$ cvscall ci -m "mod a again"
cvs commit: Examining .
Convert
$ cd ..
$ hg convert src
assuming destination src-hg
initializing destination src-hg repository
connecting to $TESTTMP/cvsrepo
scanning source...
collecting CVS rlog
7 log entries
creating changesets
5 changeset entries
sorting...
converting...
4 Initial revision
3 init
2 mod a
1 mod b
0 mod a again
updating tags
Check the result
$ hg -R src-hg log -G --template '{rev} ({branches}) {desc} files: {files}\n'
o 5 () update tags files: .hgtags
|
| o 4 (BRANCH) mod a again files: a
| |
| o 3 (BRANCH) mod b files: b
| |
| o 2 (BRANCH) mod a files: a
| |
| o 1 (v0) init files:
|/
o 0 () Initial revision files: a b
issue 1447
$ cvscall()
> {
> cvs -f "$@" > /dev/null
> sleep 1
> }
$ cvsci()
> {
> cvs -f ci "$@" >/dev/null
> sleep 1
> }
$ cvscall -Q -d `pwd`/cvsmaster2 init
$ cd cvsmaster2
$ CVSROOT=`pwd`
$ export CVSROOT
$ mkdir foo
$ cd ..
$ cvscall -Q co -d cvswork2 foo
$ cd cvswork2
$ echo foo > a.txt
$ echo bar > b.txt
$ cvscall -Q add a.txt b.txt
$ cvsci -m "Initial commit"
cvs commit: Examining .
$ echo foo > b.txt
$ cvsci -m "Fix b on HEAD"
cvs commit: Examining .
$ echo bar > a.txt
$ cvsci -m "Small fix in a on HEAD"
cvs commit: Examining .
$ cvscall -Q tag -b BRANCH
$ cvscall -Q up -P -rBRANCH
$ echo baz > b.txt
$ cvsci -m "Change on BRANCH in b"
cvs commit: Examining .
$ hg debugcvsps -x --parents foo
collecting CVS rlog
5 log entries
creating changesets
4 changeset entries
---------------------
PatchSet 1
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Log:
Initial commit
Members:
a.txt:INITIAL->1.1
b.txt:INITIAL->1.1
---------------------
PatchSet 2
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Branchpoints: BRANCH
Parent: 1
Log:
Fix b on HEAD
Members:
b.txt:1.1->1.2
---------------------
PatchSet 3
Date: * (glob)
Author: * (glob)
Branch: HEAD
Tag: (none)
Branchpoints: BRANCH
Parent: 2
Log:
Small fix in a on HEAD
Members:
a.txt:1.1->1.2
---------------------
PatchSet 4
Date: * (glob)
Author: * (glob)
Branch: BRANCH
Tag: (none)
Parent: 3
Log:
Change on BRANCH in b
Members:
b.txt:1.2->1.2.2.1
$ cd ..