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/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepo ()
> {
> hg init r
> cd r
> for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> }
$ initrepo
log before edit
$ hg log --graph
@ changeset: 5:652413bf663e
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
edit the history
$ hg histedit 177f92b77385 --commands - 2>&1 << EOF | fixbundle
> drop 177f92b77385 c
> pick e860deea161a e
> pick 652413bf663e f
> pick 055a42cdd887 d
> EOF
log after edit
$ hg log --graph
@ changeset: 4:f518305ce889
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 3:a4f7421b80f7
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:ee283cb5f2d5
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Check histedit_source
$ hg log --debug --rev f518305ce889
changeset: 4:f518305ce889c07cb5bd05522176d75590ef3324
tag: tip
phase: draft
parent: 3:a4f7421b80f79fcc59fff01bcbf4a53d127dd6d3
parent: -1:0000000000000000000000000000000000000000
manifest: 4:d3d4f51c157ff242c32ff745d4799aaa26ccda44
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files+: d
extra: branch=default
extra: histedit_source=055a42cdd88768532f9cf79daa407fc8d138de9b
description:
d
manifest after edit
$ hg manifest
a
b
d
e
f
Drop the last changeset
$ hg histedit ee283cb5f2d5 --commands - 2>&1 << EOF | fixbundle
> pick ee283cb5f2d5 e
> pick a4f7421b80f7 f
> drop f518305ce889 d
> EOF
$ hg log --graph
@ changeset: 3:a4f7421b80f7
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:ee283cb5f2d5
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ hg histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> pick cb9a9f314b8b a
> pick ee283cb5f2d5 e
> EOF
hg: parse error: missing rules for changeset a4f7421b80f7
(use "drop a4f7421b80f7" to discard, see also: 'hg help -e histedit.config')
$ hg --config histedit.dropmissing=True histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> EOF
hg: parse error: no rules provided
(use strip extension to remove commits)
$ hg --config histedit.dropmissing=True histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> pick cb9a9f314b8b a
> pick ee283cb5f2d5 e
> EOF
$ hg log --graph
@ changeset: 1:e99c679bf03e
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a