view tests/test-narrow-expanddirstate.t @ 38486:4c0683655599

namespaces: let namespaces override singlenode() definition

Some namespaces have multiple nodes per name (meaning that their
namemap() returns multiple nodes). One such namespace is the "topics"
namespace (from the evolve repo). We also have our own internal
namespace at Google (for review units) that has multiple nodes per
name. These namespaces may not want to use the default "pick highest
revnum" resolution that we currently use when resolving a name to a
single node. As an example, they may decide that `hg co <name>` should
check out a commit that's last in some sense even if an earlier commit
had just been amended and thus had a higher revnum [1]. This patch
gives the namespace the option to continue to return multiple nodes
and to override how the best node is picked. Allowing namespaces to
override that may also be useful as an optimization (it may be cheaper
for the namespace to find just that node).

I have been arguing (in D3715) for using all the nodes returned from
namemap() when resolving the symbol to a revset, so e.g. `hg log -r
stable` would resolve to *all* nodes on stable, not just the one with
the highest revnum (except that I don't actually think we should
change it for the branch namespace because of BC). Most people seem
opposed to that. If we decide not to do it, I think we can deprecate
the namemap() function in favor of the new singlenode() (I find it
weird to have namespaces, like the branch namespace, where namemap()
isn't nodemap()'s inverse). I therefore think this patch makes sense
regardless of what we decide on that issue.


 [1] Actually, even the branch namespace would have wanted to override
     singlenode() if it had supported multiple nodes. That's because
     closes branch heads are mostly ignored, so "hg co default" will
     not check out the highest-revnum node if that's a closed head.

Differential Revision: https://phab.mercurial-scm.org/D3852

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

  $ hg init master
  $ cd master

  $ mkdir inside
  $ echo inside > inside/f1
  $ mkdir outside
  $ echo outside > outside/f2
  $ mkdir patchdir
  $ echo patch_this > patchdir/f3
  $ hg ci -Aqm 'initial'

  $ cd ..

  $ hg clone --narrow ssh://user@dummy/master narrow --include inside
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets dff6a2a6d433
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cd narrow

  $ mkdir outside
  $ echo other_contents > outside/f2
  $ grep outside .hg/narrowspec
  [1]
  $ grep outside .hg/dirstate
  [1]
  $ hg status

`hg status` did not add outside.
  $ grep outside .hg/narrowspec
  [1]
  $ grep outside .hg/dirstate
  [1]

Unfortunately this is not really a candidate for adding to narrowhg proper,
since it depends on some other source for providing the manifests (when using
treemanifests) and file contents. Something like a virtual filesystem and/or
remotefilelog. We want to be useful when not using those systems, so we do not
have this method available in narrowhg proper at the moment.
  $ cat > "$TESTTMP/expand_extension.py" <<EOF
  > import os
  > import sys
  > 
  > from mercurial import encoding
  > from mercurial import extensions
  > from mercurial import localrepo
  > from mercurial import match as matchmod
  > from mercurial import narrowspec
  > from mercurial import patch
  > from mercurial import util as hgutil
  > 
  > def expandnarrowspec(ui, repo, newincludes=None):
  >   if not newincludes:
  >     return
  >   import sys
  >   newincludes = set([newincludes])
  >   includes, excludes = repo.narrowpats
  >   currentmatcher = narrowspec.match(repo.root, includes, excludes)
  >   includes = includes | newincludes
  >   if not repo.currenttransaction():
  >     ui.develwarn(b'expandnarrowspec called outside of transaction!')
  >   repo.setnarrowpats(includes, excludes)
  >   newmatcher = narrowspec.match(repo.root, includes, excludes)
  >   added = matchmod.differencematcher(newmatcher, currentmatcher)
  >   for f in repo[b'.'].manifest().walk(added):
  >     repo.dirstate.normallookup(f)
  > 
  > def wrapds(ui, repo, ds):
  >   class expandingdirstate(ds.__class__):
  >     @hgutil.propertycache
  >     def _map(self):
  >       ret = super(expandingdirstate, self)._map
  >       with repo.wlock(), repo.lock(), repo.transaction(
  >           b'expandnarrowspec'):
  >         expandnarrowspec(ui, repo,
  >                          encoding.environ.get(b'DIRSTATEINCLUDES'))
  >       return ret
  >   ds.__class__ = expandingdirstate
  >   return ds
  > 
  > def reposetup(ui, repo):
  >   class expandingrepo(repo.__class__):
  >     def _makedirstate(self):
  >       dirstate = super(expandingrepo, self)._makedirstate()
  >       return wrapds(ui, repo, dirstate)
  >   repo.__class__ = expandingrepo
  > 
  > def extsetup(unused_ui):
  >   def overridepatch(orig, ui, repo, *args, **kwargs):
  >     with repo.wlock():
  >       expandnarrowspec(ui, repo, encoding.environ.get(b'PATCHINCLUDES'))
  >       return orig(ui, repo, *args, **kwargs)
  > 
  >   extensions.wrapfunction(patch, b'patch', overridepatch)
  > EOF
  $ cat >> ".hg/hgrc" <<EOF
  > [extensions]
  > expand_extension = $TESTTMP/expand_extension.py
  > EOF

Since we do not have the ability to rely on a virtual filesystem or
remotefilelog in the test, we just fake it by copying the data from the 'master'
repo.
  $ cp -a ../master/.hg/store/data/* .hg/store/data
Do that for patchdir as well.
  $ cp -a ../master/patchdir .

`hg status` will now add outside, but not patchdir.
  $ DIRSTATEINCLUDES=path:outside hg status
  M outside/f2
  $ grep outside .hg/narrowspec
  path:outside
  $ grep outside .hg/dirstate > /dev/null
  $ grep patchdir .hg/narrowspec
  [1]
  $ grep patchdir .hg/dirstate
  [1]

Get rid of the modification to outside/f2.
  $ hg update -C .
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

This patch will not apply cleanly at the moment, so `hg import` will break
  $ cat > "$TESTTMP/foo.patch" <<EOF
  > --- patchdir/f3
  > +++ patchdir/f3
  > @@ -1,1 +1,1 @@
  > -this should be "patch_this", but its not, so patch fails
  > +this text is irrelevant
  > EOF
  $ PATCHINCLUDES=path:patchdir hg import -p0 -e "$TESTTMP/foo.patch" -m ignored
  applying $TESTTMP/foo.patch
  patching file patchdir/f3
  Hunk #1 FAILED at 0
  1 out of 1 hunks FAILED -- saving rejects to file patchdir/f3.rej
  abort: patch failed to apply
  [255]
  $ grep patchdir .hg/narrowspec
  [1]
  $ grep patchdir .hg/dirstate > /dev/null
  [1]

Let's make it apply cleanly and see that it *did* expand properly
  $ cat > "$TESTTMP/foo.patch" <<EOF
  > --- patchdir/f3
  > +++ patchdir/f3
  > @@ -1,1 +1,1 @@
  > -patch_this
  > +patched_this
  > EOF
  $ PATCHINCLUDES=path:patchdir hg import -p0 -e "$TESTTMP/foo.patch" -m message
  applying $TESTTMP/foo.patch
  $ cat patchdir/f3
  patched_this
  $ grep patchdir .hg/narrowspec
  path:patchdir
  $ grep patchdir .hg/dirstate > /dev/null