view tests/test-largefiles-small-disk.t @ 22288:4e2559841d6c

largefiles: update largefiles even if rebase is aborted by conflict

Before this patch, largefiles in the working directory aren't updated
correctly, if rebase is aborted by conflict. This prevents users from
viewing appropriate largefiles while resolving conflicts.

While rebase, largefiles in the working directory are updated only at
successful committing in the special code path of
"lfilesrepo.commit()".

To update largefiles even if rebase is aborted by conflict, this patch
centralizes the logic of updating largefiles in the working directory
into the "mergeupdate" wrapping "merge.update".


This is a temporary way to fix with less changes. For fundamental
resolution of this kind of problems in the future, largefiles in the
working directory should be updated with other (normal) files
simultaneously while "merge.update" execution: maybe by hooking
"applyupdates".

"Action list based updating" introduced by hooking "applyupdates" will
also improve performance of updating, because it automatically
decreases target files to be checked.


Just after this patch, there are some improper things in "Case 0" code
path of "lfilesrepo.commit()":

  - "updatelfiles" invocation is redundant for rebase
  - detailed comment doesn't meet to rebase behavior

These will be resolved after the subsequent patch for transplant,
because this code path is shared with transplant.


Even though replacing "merge.update" in rebase extension by "hg.merge"
can also avoid this problem, this patch chooses centralizing the logic
into "mergeupdate", because:

  - "merge.update" invocation in rebase extension can't be directly
    replaced by "hg.merge", because:

    - rebase requires some extra arguments, which "hg.merge" doesn't
      take (e.g. "ancestor")

    - rebase doesn't require statistics information forcibly displayed
      in "hg.merge"

  - introducing "mergeupdate" can resolve also problem of some other
    code paths directly using "merge.update"

    largefiles in the working directory aren't updated regardless of
    the result of commands below, before this patch:

    - backout (for revisions other than the parent revision of the
      working directory without "--merge")

    - graft

    - histedit (for revisions other than the parent of the working
      directory


When "partial" is specified, "merge.update" doesn't update dirstate
entries for standins, even though standins themselves are updated.

In this case, "normallookup" should be used to mark largefiles as
"possibly dirty" forcibly, because applying "normal" on lfdirstate
treats them as "clean" unexpectedly.

This is reason why "normallookup=partial" is specified for
"lfcommands.updatelfiles".


This patch doesn't test "hg rebase --continue", because it doesn't
work correctly if largefiles in the working directory are modified
manually while resolving conflicts. This will be fixed in the next
step of refactoring for largefiles.

All changes of tests/*.t files other than test-largefiles-update.t in
this patch come from invoking "updatelfiles" not after but before
statistics output of "hg.update", "hg.clean" and "hg.merge".

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