view tests/test-narrow.t @ 39764:e4e881572382

localrepo: iteratively derive local repository type

This commit implements the dynamic local repository type derivation
that was explained in the recent commit
bfeab472e3c0 "localrepo: create new function for instantiating a local
repo object."

Instead of a static localrepository class/type which must be customized
after construction, we now dynamically construct a type by building up
base classes/types to represent specific repository interfaces.

Conceptually, the end state is similar to what was happening when
various extensions would monkeypatch the __class__ of newly-constructed
repo instances. However, the approach is inverted. Instead of making
the instance then customizing it, we do the customization up front
by influencing the behavior of the type then we instantiate that
custom type.

This approach gives us much more flexibility. For example, we can
use completely separate classes for implementing different aspects
of the repository. For example, we could have one class representing
revlog-based file storage and another representing non-revlog based
file storage. When then choose which implementation to use based on
the presence of repo requirements.

A concern with this approach is that it creates a lot more types
and complexity and that complexity adds overhead. Yes, it is true that
this approach will result in more types being created. Yes, this is
more complicated than traditional "instantiate a static type." However,
I believe the alternatives to supporting alternate storage backends
are just as complicated. (Before I arrived at this solution, I had
patches storing factory functions on local repo instances for e.g.
constructing a file storage instance. We ended up having a handful
of these. And this was logically identical to assigning custom
methods. Since we were logically changing the type of the instance,
I figured it would be better to just use specialized types instead
of introducing levels of abstraction at run-time.)

On the performance front, I don't believe that having N base classes
has any significant performance overhead compared to just a single base
class. Intuition says that Python will need to iterate the base classes
to find an attribute. However, CPython caches method lookups: as long as
the __class__ or MRO isn't changing, method attribute lookup should be
constant time after first access. And non-method attributes are stored
in __dict__, of which there is only 1 per object, so the number of
base classes for __dict__ is irrelevant.

Anyway, this commit splits up the monolithic completelocalrepository
interface into sub-interfaces: 1 for file storage and 1 representing
everything else.

We've taught ``makelocalrepository()`` to call a series of factory
functions which will produce types implementing specific interfaces.
It then calls type() to create a new type from the built-up list of
base types.

This commit should be considered a start and not the end state. I
suspect we'll hit a number of problems as we start to implement
alternate storage backends:

* Passing custom arguments to __init__ and setting custom attributes
  on __dict__.
* Customizing the set of interfaces that are needed. e.g. the
  "readonly" intent could translate to not requesting an interface
  providing methods related to writing.
* More ergonomic way for extensions to insert themselves so their
  callbacks aren't unconditionally called.
* Wanting to modify vfs instances, other arguments passed to __init__.

That being said, this code is usable in its current state and I'm
convinced future commits will demonstrate the value in this approach.

Differential Revision: https://phab.mercurial-scm.org/D4642

#testcases flat tree

  $ . "$TESTDIR/narrow-library.sh"

#if tree
  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > treemanifest = 1
  > EOF
#endif

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [narrow]
  > serveellipses=True
  > EOF
  $ for x in `$TESTDIR/seq.py 0 10`
  > do
  >   mkdir d$x
  >   echo $x > d$x/f
  >   hg add d$x/f
  >   hg commit -m "add d$x/f"
  > done
  $ hg log -T "{rev}: {desc}\n"
  10: add d10/f
  9: add d9/f
  8: add d8/f
  7: add d7/f
  6: add d6/f
  5: add d5/f
  4: add d4/f
  3: add d3/f
  2: add d2/f
  1: add d1/f
  0: add d0/f
  $ cd ..

Error if '.' or '..' are in the directory to track.
  $ hg clone --narrow ssh://user@dummy/master foo --include ./asdf
  abort: "." and ".." are not allowed in narrowspec paths
  [255]
  $ hg clone --narrow ssh://user@dummy/master foo --include asdf/..
  abort: "." and ".." are not allowed in narrowspec paths
  [255]
  $ hg clone --narrow ssh://user@dummy/master foo --include a/./c
  abort: "." and ".." are not allowed in narrowspec paths
  [255]

Names with '.' in them are OK.
  $ hg clone --narrow ssh://user@dummy/master should-work --include a/.b/c
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files
  new changesets * (glob)
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

Test repo with local changes
  $ hg clone --narrow ssh://user@dummy/master narrow-local-changes --include d0 --include d3 --include d6
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 3 changes to 3 files
  new changesets *:* (glob)
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow-local-changes
  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > evolution=createmarkers
  > EOF
  $ echo local change >> d0/f
  $ hg ci -m 'local change to d0'
  $ hg co '.^'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo local change >> d3/f
  $ hg ci -m 'local hidden change to d3'
  created new head
  $ hg ci --amend -m 'local change to d3'
  $ hg tracked --removeinclude d0
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  The following changeset(s) or their ancestors have local changes not on the remote:
  * (glob)
  abort: local changes found
  (use --force-delete-local-changes to ignore)
  [255]
Check that nothing was removed by the failed attempts
  $ hg tracked
  I path:d0
  I path:d3
  I path:d6
  $ hg files
  d0/f
  d3/f
  d6/f
  $ find *
  d0
  d0/f
  d3
  d3/f
  d6
  d6/f
  $ hg verify -q
Force deletion of local changes
  $ hg log -T "{rev}: {desc} {outsidenarrow}\n"
  8: local change to d3 
  6: local change to d0 
  5: add d10/f outsidenarrow
  4: add d6/f 
  3: add d5/f outsidenarrow
  2: add d3/f 
  1: add d2/f outsidenarrow
  0: add d0/f 
  $ hg tracked --removeinclude d0 --force-delete-local-changes
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  The following changeset(s) or their ancestors have local changes not on the remote:
  * (glob)
  saved backup bundle to $TESTTMP/narrow-local-changes/.hg/strip-backup/*-narrow.hg (glob)
  deleting data/d0/f.i (reporevlogstore !)
  deleting meta/d0/00manifest.i (tree !)
  deleting data/d0/f/362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (reposimplestore !)
  deleting data/d0/f/4374b5650fc5ae54ac857c0f0381971fdde376f7 (reposimplestore !)
  deleting data/d0/f/index (reposimplestore !)

  $ hg log -T "{rev}: {desc} {outsidenarrow}\n"
  7: local change to d3 
  5: add d10/f outsidenarrow
  4: add d6/f 
  3: add d5/f outsidenarrow
  2: add d3/f 
  1: add d2/f outsidenarrow
  0: add d0/f outsidenarrow
Can restore stripped local changes after widening
  $ hg tracked --addinclude d0 -q
  $ hg unbundle .hg/strip-backup/*-narrow.hg -q
  $ hg --hidden co -r 'desc("local change to d0")' -q
  $ cat d0/f
  0
  local change
Pruned commits affecting removed paths should not prevent narrowing
  $ hg co '.^'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugobsolete `hg log -T '{node}' -r 'desc("local change to d0")'`
  obsoleted 1 changesets
  $ hg tracked --removeinclude d0
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  saved backup bundle to $TESTTMP/narrow-local-changes/.hg/strip-backup/*-narrow.hg (glob)
  deleting data/d0/f.i (reporevlogstore !)
  deleting meta/d0/00manifest.i (tree !)
  deleting data/d0/f/362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (reposimplestore !)
  deleting data/d0/f/4374b5650fc5ae54ac857c0f0381971fdde376f7 (reposimplestore !)
  deleting data/d0/f/index (reposimplestore !)

Updates off of stripped commit if necessary
  $ hg co -r 'desc("local change to d3")' -q
  $ echo local change >> d6/f
  $ hg ci -m 'local change to d6'
  $ hg tracked --removeinclude d3 --force-delete-local-changes
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  The following changeset(s) or their ancestors have local changes not on the remote:
  * (glob)
  * (glob)
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/narrow-local-changes/.hg/strip-backup/*-narrow.hg (glob)
  deleting data/d3/f.i (reporevlogstore !)
  deleting meta/d3/00manifest.i (tree !)
  deleting data/d3/f/2661d26c649684b482d10f91960cc3db683c38b4 (reposimplestore !)
  deleting data/d3/f/99fa7136105a15e2045ce3d9152e4837c5349e4d (reposimplestore !)
  deleting data/d3/f/index (reposimplestore !)
  $ hg log -T '{desc}\n' -r .
  add d10/f
Updates to nullid if necessary
  $ hg tracked --addinclude d3 -q
  $ hg co null -q
  $ mkdir d3
  $ echo local change > d3/f
  $ hg add d3/f
  $ hg ci -m 'local change to d3'
  created new head
  $ hg tracked --removeinclude d3 --force-delete-local-changes
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  The following changeset(s) or their ancestors have local changes not on the remote:
  * (glob)
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/narrow-local-changes/.hg/strip-backup/*-narrow.hg (glob)
  deleting data/d3/f.i (reporevlogstore !)
  deleting meta/d3/00manifest.i (tree !)
  deleting data/d3/f/2661d26c649684b482d10f91960cc3db683c38b4 (reposimplestore !)
  deleting data/d3/f/5ce0767945cbdbca3b924bb9fbf5143f72ab40ac (reposimplestore !)
  deleting data/d3/f/index (reposimplestore !)
  $ hg id
  000000000000
  $ cd ..

Can remove last include, making repo empty
  $ hg clone --narrow ssh://user@dummy/master narrow-empty --include d0 -r 5
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 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-empty
  $ hg tracked --removeinclude d0
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  deleting data/d0/f.i (reporevlogstore !)
  deleting meta/d0/00manifest.i (tree !)
  deleting data/d0/f/362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (reposimplestore !)
  deleting data/d0/f/index (reposimplestore !)
  $ hg tracked
  $ hg files
  [1]
  $ test -d d0
  [1]
Do some work in the empty clone
  $ hg diff --change .
  $ hg branch foo
  marked working directory as branch foo
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -m empty
  $ hg pull -q
Can widen the empty clone
  $ hg tracked --addinclude d0
  comparing with ssh://user@dummy/master
  searching for changes
  no changes found
  saved backup bundle to $TESTTMP/narrow-empty/.hg/strip-backup/*-widen.hg (glob)
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 1 changes to 1 files
  new changesets *:* (glob)
  $ hg tracked
  I path:d0
  $ hg files
  d0/f
  $ find *
  d0
  d0/f
  $ cd ..

TODO(martinvonz): test including e.g. d3/g and then removing it once
https://bitbucket.org/Google/narrowhg/issues/6 is fixed

  $ hg clone --narrow ssh://user@dummy/master narrow --include d0 --include d3 --include d6 --include d9
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 4 changes to 4 files
  new changesets *:* (glob)
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow
  $ hg tracked
  I path:d0
  I path:d3
  I path:d6
  I path:d9
  $ hg tracked --removeinclude d6
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  deleting data/d6/f.i (reporevlogstore !)
  deleting meta/d6/00manifest.i (tree !)
  deleting data/d6/f/7339d30678f451ac8c3f38753beeb4cf2e1655c7 (reposimplestore !)
  deleting data/d6/f/index (reposimplestore !)
  $ hg tracked
  I path:d0
  I path:d3
  I path:d9
#if repofncache
  $ hg debugrebuildfncache
  fncache already up to date
#endif
  $ find *
  d0
  d0/f
  d3
  d3/f
  d9
  d9/f
  $ hg verify -q
  $ hg tracked --addexclude d3/f
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  deleting data/d3/f.i (reporevlogstore !)
  deleting data/d3/f/2661d26c649684b482d10f91960cc3db683c38b4 (reposimplestore !)
  deleting data/d3/f/index (reposimplestore !)
  $ hg tracked
  I path:d0
  I path:d3
  I path:d9
  X path:d3/f
#if repofncache
  $ hg debugrebuildfncache
  fncache already up to date
#endif
  $ find *
  d0
  d0/f
  d9
  d9/f
  $ hg verify -q
  $ hg tracked --addexclude d0
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  deleting data/d0/f.i (reporevlogstore !)
  deleting meta/d0/00manifest.i (tree !)
  deleting data/d0/f/362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (reposimplestore !)
  deleting data/d0/f/index (reposimplestore !)
  $ hg tracked
  I path:d3
  I path:d9
  X path:d0
  X path:d3/f
#if repofncache
  $ hg debugrebuildfncache
  fncache already up to date
#endif
  $ find *
  d9
  d9/f

Make a 15 of changes to d9 to test the path without --verbose
(Note: using regexes instead of "* (glob)" because if the test fails, it
produces more sensible diffs)
  $ hg tracked
  I path:d3
  I path:d9
  X path:d0
  X path:d3/f
  $ for x in `$TESTDIR/seq.py 1 15`
  > do
  >   echo local change >> d9/f
  >   hg commit -m "change $x to d9/f"
  > done
  $ hg tracked --removeinclude d9
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  The following changeset(s) or their ancestors have local changes not on the remote:
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ...and 5 more, use --verbose to list all
  abort: local changes found
  (use --force-delete-local-changes to ignore)
  [255]
Now test it *with* verbose.
  $ hg tracked --removeinclude d9 --verbose
  comparing with ssh://user@dummy/master
  searching for changes
  looking for local changes to affected paths
  The following changeset(s) or their ancestors have local changes not on the remote:
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  ^[0-9a-f]{12}$ (re)
  abort: local changes found
  (use --force-delete-local-changes to ignore)
  [255]