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-reposimplestore
Test unionrepo functionality
Create one repository
$ hg init repo1
$ cd repo1
$ touch repo1-0
$ echo repo1-0 > f
$ hg ci -Aqmrepo1-0
$ touch repo1-1
$ echo repo1-1 >> f
$ hg ci -Aqmrepo1-1
$ touch repo1-2
$ echo repo1-2 >> f
$ hg ci -Aqmrepo1-2
$ hg log --template '{rev}:{node|short} {desc|firstline}\n'
2:68c0685446a3 repo1-2
1:8a58db72e69d repo1-1
0:f093fec0529b repo1-0
$ tip1=`hg id -q`
$ cd ..
- and a clone with a not-completely-trivial history
$ hg clone -q repo1 --rev 0 repo2
$ cd repo2
$ touch repo2-1
$ sed '1i\
> repo2-1 at top
> ' f > f.tmp
$ mv f.tmp f
$ hg ci -Aqmrepo2-1
$ touch repo2-2
$ hg pull -q ../repo1 -r 1
$ hg merge -q
$ hg ci -Aqmrepo2-2-merge
$ touch repo2-3
$ echo repo2-3 >> f
$ hg ci -mrepo2-3
$ hg log --template '{rev}:{node|short} {desc|firstline}\n'
4:2f0d178c469c repo2-3
3:9e6fb3e0b9da repo2-2-merge
2:8a58db72e69d repo1-1
1:c337dba826e7 repo2-1
0:f093fec0529b repo1-0
$ cd ..
revisions from repo2 appear as appended / pulled to repo1
$ hg -R union:repo1+repo2 log --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
4:9e6fb3e0b9da repo2-2-merge
3:c337dba826e7 repo2-1
2:68c0685446a3 repo1-2
1:8a58db72e69d repo1-1
0:f093fec0529b repo1-0
manifest can be retrieved for revisions in both repos
$ hg -R union:repo1+repo2 mani -r $tip1
f
repo1-0
repo1-1
repo1-2
$ hg -R union:repo1+repo2 mani -r 4
f
repo1-0
repo1-1
repo2-1
repo2-2
files can be retrieved form both repos
$ hg -R repo1 cat repo1/f -r2
repo1-0
repo1-1
repo1-2
$ hg -R union:repo1+repo2 cat -r$tip1 repo1/f
repo1-0
repo1-1
repo1-2
$ hg -R union:repo1+repo2 cat -r4 $TESTTMP/repo1/f
repo2-1 at top
repo1-0
repo1-1
files can be compared across repos
$ hg -R union:repo1+repo2 diff -r$tip1 -rtip
diff -r 68c0685446a3 -r 2f0d178c469c f
--- a/f Thu Jan 01 00:00:00 1970 +0000
+++ b/f Thu Jan 01 00:00:00 1970 +0000
@@ -1,3 +1,4 @@
+repo2-1 at top
repo1-0
repo1-1
-repo1-2
+repo2-3
heads from both repos are found correctly
$ hg -R union:repo1+repo2 heads --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
2:68c0685446a3 repo1-2
revsets works across repos
$ hg -R union:repo1+repo2 id -r "ancestor($tip1, 5)"
8a58db72e69d
annotate works - an indication that linkrevs works
$ hg --cwd repo1 -Runion:../repo2 annotate $TESTTMP/repo1/f -r tip
3: repo2-1 at top
0: repo1-0
1: repo1-1
5: repo2-3
union repos can be cloned ... and clones works correctly
$ hg clone -U union:repo1+repo2 repo3
requesting all changes
adding changesets
adding manifests
adding file changes
added 6 changesets with 11 changes to 6 files (+1 heads)
new changesets f093fec0529b:2f0d178c469c (6 drafts)
$ hg -R repo3 paths
default = union:repo1+repo2
$ hg -R repo3 verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 6 changesets with 11 changes to 6 files
$ hg -R repo3 heads --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
2:68c0685446a3 repo1-2
$ hg -R repo3 log --template '{rev}:{node|short} {desc|firstline}\n'
5:2f0d178c469c repo2-3
4:9e6fb3e0b9da repo2-2-merge
3:c337dba826e7 repo2-1
2:68c0685446a3 repo1-2
1:8a58db72e69d repo1-1
0:f093fec0529b repo1-0
union repos should use the correct rev number (issue5024)
$ hg init a
$ cd a
$ echo a0 >> f
$ hg ci -Aqm a0
$ cd ..
$ hg init b
$ cd b
$ echo b0 >> f
$ hg ci -Aqm b0
$ echo b1 >> f
$ hg ci -qm b1
$ cd ..
"hg files -v" to call fctx.size() -> fctx.iscensored()
$ hg files -R union:b+a -r2 -v
3 b/f