view tests/test-arbitraryfilectx.t @ 35280:8e72f9152c4d

lfs: introduce a user level cache for lfs files

This is the same mechanism in place for largefiles, and solves several problems
working with multiple local repositories.  The existing largefiles method is
reused in place, because I suspect that there are other functions that can be
shared.  If we wait a bit to identify more before `hg cp lfutil.py ...`, the
history will be easier to trace.

The push between repo14 and repo15 in test-lfs.t arguably shouldn't be uploading
any files with a local push.  Maybe we can revisit that when `hg push` without
'lfs.url' can upload files to the push destination.  Then it would be consistent
for blobs in a local push to be linked to the local destination's cache.

The cache property is added to run-tests.py, the same as the largefiles
property, so that test generated files don't pollute the real location.  Having
files available locally broke a couple existing lfs-test-server tests, so the
cache is cleared in a few places to force file download.

Setup:
  $ cat > eval.py <<EOF
  > from __future__ import absolute_import
  > import filecmp
  > from mercurial import commands, context, registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'eval', [], 'hg eval CMD')
  > def eval_(ui, repo, *cmds, **opts):
  >     cmd = " ".join(cmds)
  >     res = str(eval(cmd, globals(), locals()))
  >     ui.warn("%s" % res)
  > EOF

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "eval=`pwd`/eval.py" >> $HGRCPATH

Arbitraryfilectx.cmp does not follow symlinks:
  $ mkdir case1
  $ cd case1
  $ hg init
#if symlink
  $ printf "A" > real_A
  $ printf "foo" > A
  $ printf "foo" > B
  $ ln -s A sym_A
  $ hg add .
  adding A
  adding B
  adding real_A
  adding sym_A
  $ hg commit -m "base"
#else
  $ hg import -q --bypass - <<EOF
  > # HG changeset patch
  > # User test
  > # Date 0 0
  > base
  > 
  > diff --git a/A b/A
  > new file mode 100644
  > --- /dev/null
  > +++ b/A
  > @@ -0,0 +1,1 @@
  > +foo
  > \ No newline at end of file
  > diff --git a/B b/B
  > new file mode 100644
  > --- /dev/null
  > +++ b/B
  > @@ -0,0 +1,1 @@
  > +foo
  > \ No newline at end of file
  > diff --git a/real_A b/real_A
  > new file mode 100644
  > --- /dev/null
  > +++ b/real_A
  > @@ -0,0 +1,1 @@
  > +A
  > \ No newline at end of file
  > diff --git a/sym_A b/sym_A
  > new file mode 120000
  > --- /dev/null
  > +++ b/sym_A
  > @@ -0,0 +1,1 @@
  > +A
  > \ No newline at end of file
  > EOF
  $ hg up -q
#endif

These files are different and should return True (different):
(Note that filecmp.cmp's return semantics are inverted from ours, so we invert
for simplicity):
  $ hg eval "context.arbitraryfilectx('A', repo).cmp(repo[None]['real_A'])"
  True (no-eol)
  $ hg eval "not filecmp.cmp('A', 'real_A')"
  True (no-eol)

These files are identical and should return False (same):
  $ hg eval "context.arbitraryfilectx('A', repo).cmp(repo[None]['A'])"
  False (no-eol)
  $ hg eval "context.arbitraryfilectx('A', repo).cmp(repo[None]['B'])"
  False (no-eol)
  $ hg eval "not filecmp.cmp('A', 'B')"
  False (no-eol)

This comparison should also return False, since A and sym_A are substantially
the same in the eyes of ``filectx.cmp``, which looks at data only.
  $ hg eval "context.arbitraryfilectx('real_A', repo).cmp(repo[None]['sym_A'])"
  False (no-eol)

A naive use of filecmp on those two would wrongly return True, since it follows
the symlink to "A", which has different contents.
#if symlink
  $ hg eval "not filecmp.cmp('real_A', 'sym_A')"
  True (no-eol)
#else
  $ hg eval "not filecmp.cmp('real_A', 'sym_A')"
  False (no-eol)
#endif