view tests/test-largefiles-small-disk.t @ 40924:08cfa77d7288

wireprotov2: unify file revision collection and linknode derivation

The old mechanism for choosing which file revisions to send in the
haveparents=True case was buggy in multiple ways - the most severe
of which being that file revisions were excluded when they shouldn't
have been.

This commit unifies the logic for deriving the filenodes that will
be sent by the "filesdata" command. We now consistently read files
data from manifests. The "haveparents" argument now controls whether
we iterate ctx.files() or use the full manifest to derive relevant
files.

The logic here is still woefully lacking to fully support shallow
clones. It will require an API break to fully address. This commit
should at least make the server APIs emit proper data, which is
strictly better than before.

Differential Revision: https://phab.mercurial-scm.org/D5406

Test how largefiles abort in case the disk runs full

  $ cat > criple.py <<EOF
  > from __future__ import absolute_import
  > import errno
  > import os
  > import shutil
  > from mercurial import util
  > #
  > # this makes the original largefiles code abort:
  > _origcopyfileobj = shutil.copyfileobj
  > def copyfileobj(fsrc, fdst, length=16*1024):
  >     # allow journal files (used by transaction) to be written
  >     if b'journal.' in fdst.name:
  >         return _origcopyfileobj(fsrc, fdst, length)
  >     fdst.write(fsrc.read(4))
  >     raise IOError(errno.ENOSPC, os.strerror(errno.ENOSPC))
  > shutil.copyfileobj = copyfileobj
  > #
  > # this makes the rewritten code abort:
  > def filechunkiter(f, size=131072, limit=None):
  >     yield f.read(4)
  >     raise IOError(errno.ENOSPC, os.strerror(errno.ENOSPC))
  > util.filechunkiter = filechunkiter
  > #
  > def oslink(src, dest):
  >     raise OSError("no hardlinks, try copying instead")
  > util.oslink = oslink
  > EOF

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "largefiles =" >> $HGRCPATH

  $ hg init alice
  $ cd alice
  $ echo "this is a very big file" > big
  $ hg add --large big
  $ hg commit --config extensions.criple=$TESTTMP/criple.py -m big
  abort: No space left on device
  [255]

The largefile is not created in .hg/largefiles:

  $ ls .hg/largefiles
  dirstate

The user cache is not even created:

  >>> import os; os.path.exists("$HOME/.cache/largefiles/")
  False

Make the commit with space on the device:

  $ hg commit -m big

Now make a clone with a full disk, and make sure lfutil.link function
makes copies instead of hardlinks:

  $ cd ..
  $ hg --config extensions.criple=$TESTTMP/criple.py clone --pull alice bob
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 390cf214e9ac
  updating to branch default
  getting changed largefiles
  abort: No space left on device
  [255]

The largefile is not created in .hg/largefiles:

  $ ls bob/.hg/largefiles
  dirstate