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
$ cat <<'EOF' >> "$HGRCPATH"
> [extensions]
> convert =
> [templates]
> l = '{rev}:{node|short} p={p1rev},{p2rev} m={manifest} f={files|json}'
> EOF
$ check_convert_identity () {
> hg convert -q "$1" "$1.converted"
> hg outgoing -q -R "$1.converted" "$1"
> if [ "$?" != 1 ]; then
> echo '*** BUG: hash changes on convert ***'
> hg log -R "$1.converted" -GTl
> fi
> }
Files added at both parents:
$ hg init added-both
$ cd added-both
$ touch a b c
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ hg ci -qAm2 c
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
committing files:
b
not reusing manifest (no file change in changelog, but manifest differs)
committing manifest
committing changelog
updating the branch cache
committed changeset 3:7aa8a293f5d97377037afc21e871e036e718d659
$ hg log -GTl
@ 3:7aa8a293f5d9 p=2,1 m=3:8667461869a1 f=[]
|\
| o 2:e0ea47086fce p=0,-1 m=2:b2e5b07f9374 f=["c"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-both
Files added at both parents, but the other removed at the merge:
(In this case, ctx.files() after the commit contains the removed file "b", but
its manifest does not differ from p1.)
$ hg init added-both-removed-at-merge
$ cd added-both-removed-at-merge
$ touch a b c
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ hg ci -qAm2 c
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg rm -f b
$ hg ci --debug -m merge
committing files:
committing manifest
committing changelog
updating the branch cache
committed changeset 3:915745f3ca3d9d699925269474c2d0a9526e8dfa
$ hg log -GTl
@ 3:915745f3ca3d p=2,1 m=3:8e9cf3456921 f=["b"]
|\
| o 2:e0ea47086fce p=0,-1 m=2:b2e5b07f9374 f=["c"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-both
An identical file added at both parents:
$ hg init added-identical
$ cd added-identical
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b
$ hg ci -qAm2 b
$ hg merge
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 3:de26182cd210f0c3fb175ca7616704ab963d3024
$ hg log -GTl
@ 3:de26182cd210 p=2,1 m=1:686dbf0aeca4 f=[]
|\
| o 2:f00991f11eca p=0,-1 m=1:686dbf0aeca4 f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-identical
#if execbit
An identical file added at both parents, but the flag differs. Take local:
$ hg init flag-change-take-p1
$ cd flag-change-take-p1
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b
$ chmod +x b
$ hg ci -qAm2 b
$ hg merge
warning: cannot merge flags for b without common ancestor - keeping local flags
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ chmod +x b
$ hg ci --debug -m merge
committing files:
b
reusing manifest form p1 (listed files actually unchanged)
committing changelog
updating the branch cache
committed changeset 3:c8d50407916ef8a5a97cb6e36ca9bc844a6ee13e
$ hg log -GTl
@ 3:c8d50407916e p=2,1 m=2:36b69ba4b24b f=[]
|\
| o 2:99451f16b3f5 p=0,-1 m=2:36b69ba4b24b f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ hg files -vr3
0 a
0 x b
$ cd ..
$ check_convert_identity flag-change-take-p1
An identical file added at both parents, but the flag differs. Take other:
$ hg init flag-change-take-p2
$ cd flag-change-take-p2
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b
$ chmod +x b
$ hg ci -qAm2 b
$ hg merge
warning: cannot merge flags for b without common ancestor - keeping local flags
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ chmod -x b
$ hg ci --debug -m merge
committing files:
b
committing manifest
committing changelog
updating the branch cache
committed changeset 3:06a62a687d87c7d8944743dee1ee9d8c66b3f6e3
$ hg log -GTl
@ 3:06a62a687d87 p=2,1 m=3:2a315ba1aa45 f=["b"]
|\
| o 2:99451f16b3f5 p=0,-1 m=2:36b69ba4b24b f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ hg files -vr3
0 a
0 b
$ cd ..
$ check_convert_identity flag-change-take-p2
#endif
An identical file added at both parents, one more file added at p2:
$ hg init added-some-p2
$ cd added-some-p2
$ touch a b c
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg ci -qAm2 c
$ hg up -q 0
$ touch b
$ hg ci -qAm3 b
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
committing files:
c
not reusing manifest (no file change in changelog, but manifest differs)
committing manifest
committing changelog
updating the branch cache
committed changeset 4:f7fbc4e4d9a8fde03ba475adad675578c8bf472d
$ hg log -GTl
@ 4:f7fbc4e4d9a8 p=3,2 m=3:92acd5bfd716 f=[]
|\
| o 3:e9d9f3cc981f p=0,-1 m=1:686dbf0aeca4 f=["b"]
| |
o | 2:93c5529a4ec7 p=1,-1 m=2:ae25a31b30b3 f=["c"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-some-p2
An identical file added at both parents, one more file added at p1:
(In this case, p1 manifest is reused at the merge commit, which means the
manifest DAG does not have the same shape as the changelog.)
$ hg init added-some-p1
$ cd added-some-p1
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b c
$ hg ci -qAm2 b
$ hg ci -qAm3 c
$ hg merge
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 4:a9f0f589a913f5a149dc10dfbd5af726977c36c4
$ hg log -GTl
@ 4:a9f0f589a913 p=3,1 m=2:ae25a31b30b3 f=[]
|\
| o 3:b8dc385241b5 p=2,-1 m=2:ae25a31b30b3 f=["c"]
| |
| o 2:f00991f11eca p=0,-1 m=1:686dbf0aeca4 f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-some-p1
A file added at p2, a named branch created at p1:
$ hg init named-branch-p1
$ cd named-branch-p1
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ hg branch -q foo
$ hg ci -m2
$ hg merge default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
committing files:
b
not reusing manifest (no file change in changelog, but manifest differs)
committing manifest
committing changelog
updating the branch cache
committed changeset 3:fb97d83b02fd072295cfc2171f21b7d38509bfd7
$ hg log -GT'{l} branch={branch}'
@ 3:fb97d83b02fd p=2,1 m=2:9091c64f4ea1 f=[] branch=foo
|\
| o 2:a3a9fa6587e5 p=0,-1 m=0:8515d4bfda76 f=[] branch=foo
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"] branch=default
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
$ cd ..
$ check_convert_identity named-branch-p1
A file added at p1, a named branch created at p2:
(In this case, p1 manifest is reused at the merge commit, which means the
manifest DAG does not have the same shape as the changelog.)
$ hg init named-branch-p2
$ cd named-branch-p2
$ touch a b
$ hg ci -qAm0 a
$ hg branch -q foo
$ hg ci -m1
$ hg up -q 0
$ hg ci -qAm1 b
$ hg merge foo
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 3:036823e24692218324d4af43b07ff89f8a000096
$ hg log -GT'{l} branch={branch}'
@ 3:036823e24692 p=2,1 m=1:686dbf0aeca4 f=[] branch=default
|\
| o 2:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"] branch=default
| |
o | 1:da38c8e00727 p=0,-1 m=0:8515d4bfda76 f=[] branch=foo
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
$ cd ..
$ check_convert_identity named-branch-p2
A file changed once at both parents, but amended to have identical content:
$ hg init amend-p1
$ cd amend-p1
$ touch a
$ hg ci -qAm0 a
$ echo foo > a
$ hg ci -m1
$ hg up -q 0
$ echo bar > a
$ hg ci -qm2
$ echo foo > a
$ hg ci -qm3 --amend
$ hg merge
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 3:314e5bc5adf5c58ea571efabe33eedba20a201aa
$ hg log -GT'{l} branch={branch}'
@ 3:314e5bc5adf5 p=2,1 m=1:d33ea248bd73 f=[] branch=default
|\
| o 2:de9c64f226a3 p=0,-1 m=1:d33ea248bd73 f=["a"] branch=default
| |
o | 1:6a74aec01b3c p=0,-1 m=1:d33ea248bd73 f=["a"] branch=default
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
$ cd ..
$ check_convert_identity amend-p1