view tests/test-largefiles-small-disk.t @ 20858:bc56ec9e64df stable

hg: introduce "wirepeersetupfuncs" to setup wire peer by extensions (issue4109)

Since changeset 6f72e7d28b35, "reposetup()" of each extensions is
invoked only on repositories enabling corresponded extensions.

This causes that largefiles specific interactions between the
repository enabling largefiles locally and remote (wire) peer fail,
because there is no way to know whether largefiles is enabled on the
remote repository behind the wire peer, and largefiles specific
"wireproto functions" are not given to any wire peers.

To avoid this problem, largefiles should be enabled in wider scope
than each repositories (e.g. user-wide "${HOME}/.hgrc").

This patch introduces "wirepeersetupfuncs" to setup wire peer by
extensions already enabled. Functions registered into
"wirepeersetupfuncs" are invoked for all wire peers.

This patch uses plain list instead of "util.hooks" for
"wirepeersetupfuncs", because the former allows to control order of
function invocation by order of extension enabling: it may be useful
for workaround of problems with combination of enabled extensions

Test how largefiles abort in case the disk runs full

  $ cat > criple.py <<EOF
  > import os, errno, shutil
  > from mercurial import util
  > #
  > # this makes the original largefiles code abort:
  > def copyfileobj(fsrc, fdst, length=16*1024):
  >     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=65536, 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
  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