filelog: wrap revlog instead of inheriting it (API)
The revlog base class exposes a ton of methods. Inheriting the
revlog class for filelog will make it difficult to expose a
clean interface. There will be abstraction violations.
This commit breaks the inheritance of revlog by the filelog
class. Filelog instances now contain a reference to a revlog
instance. Various properties and methods are now proxied to
that instance.
There is precedence for doing this: manifestlog does something
similar. Although, manifestlog has a cleaner interface than
filelog. We'll get there with filelog...
The new filelog class exposes a handful of extra properties and
methods that aren't part of the declared filelog interface.
Every extra item was added in order to get a test to pass. The
set of tests that failed without these extra proxies has
significant overlap with the set of tests that don't work with
the simple store repo. There should be no surprise there.
Hopefully the hardest part about this commit to review are the
changes to bundlerepo and unionrepo. Both repository types
define a custom revlog or revlog-like class and then have a
custom filelog that inherits from both filelog and their custom
revlog. This code has been changed so the filelog types don't
inherit from revlog. Instead, they replace the revlog instance
on the created filelog. This is super hacky. I plan to fix this
in a future commit by parameterizing filelog.__init__.
Because Python function call overhead is a thing, this change
could impact performance by introducing a nearly empty proxy
function for various methods and properties. I would gladly
measure the performance impact of it, but I'm not sure what
operations have tight loops over filelog attribute lookups
or function calls. I know some of the DAG traversal code can
be sensitive about the performance of e.g. parentrevs(). However,
many of these functions are implemented on the revlog class and
therefore have direct access to self.parentrevs() and aren't
going through a proxy.
.. api::
filelog.filelog is now a standalone class and doesn't inherit
from revlog. Instead, it wraps a revlog instance at self._revlog.
This change was made in an attempt to formalize storage APIs and
prevent revlog implementation details leaking through to callers.
Differential Revision: https://phab.mercurial-scm.org/D3154
#testcases flat tree
$ . "$TESTDIR/narrow-library.sh"
#if tree
$ cat << EOF >> $HGRCPATH
> [experimental]
> treemanifest = 1
> EOF
#endif
create full repo
$ hg init master
$ cd master
$ mkdir inside
$ echo inside > inside/f1
$ mkdir outside
$ echo outside > outside/f1
$ hg ci -Aqm 'initial'
$ echo modified > inside/f1
$ hg ci -qm 'modify inside'
$ echo modified > outside/f1
$ hg ci -qm 'modify outside'
$ cd ..
$ hg clone --narrow ssh://user@dummy/master narrow --include inside
requesting all changes
adding changesets
adding manifests
adding file changes
added 3 changesets with 2 changes to 1 files
new changesets *:* (glob)
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
Can show patch touching paths outside
$ hg log -p
changeset: 2:* (glob)
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: modify outside
changeset: 1:* (glob)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: modify inside
diff -r * -r * inside/f1 (glob)
--- a/inside/f1 Thu Jan 01 00:00:00 1970 +0000
+++ b/inside/f1 Thu Jan 01 00:00:00 1970 +0000
@@ -1,1 +1,1 @@
-inside
+modified
changeset: 0:* (glob)
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: initial
diff -r 000000000000 -r * inside/f1 (glob)
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/inside/f1 Thu Jan 01 00:00:00 1970 +0000
@@ -0,0 +1,1 @@
+inside
$ hg status --rev 1 --rev 2
Can show copies inside the narrow clone
$ hg cp inside/f1 inside/f2
$ hg diff --git
diff --git a/inside/f1 b/inside/f2
copy from inside/f1
copy to inside/f2