view tests/test-dirstate-race2.t @ 47476:f23eafb036af

dirstate-v2: Use 32-bit integers instead of 64-bit for offsets

This saves 12 bytes per node. (Nodes representing files or directories.)

These are offsets to other parts of the file. This would only be a limitation
for a `.hg/dirstate` file larger than 4 GiB, which would only happen for a
repository with dozens of millions of files and directories.

Differential Revision: https://phab.mercurial-scm.org/D10920

#testcases dirstate-v1 dirstate-v1-tree dirstate-v2

#if dirstate-v1-tree
#require rust
  $ echo '[experimental]' >> $HGRCPATH
  $ echo 'dirstate-tree.in-memory=1' >> $HGRCPATH
#endif

#if dirstate-v2
#require rust
  $ echo '[format]' >> $HGRCPATH
  $ echo 'exp-dirstate-v2=1' >> $HGRCPATH
#endif

Checking the size/permissions/file-type of files stored in the
dirstate after an update where the files are changed concurrently
outside of hg's control.

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg commit -qAm _
  $ echo aa > a
  $ hg commit -m _

  $ hg debugdirstate --no-dates
  n 644          3 (set  |unset)               a (re)

  $ cat >> $TESTTMP/dirstaterace.py << EOF
  > from mercurial import (
  >     extensions,
  >     merge,
  > )
  > def extsetup(ui):
  >     extensions.wrapfunction(merge, 'applyupdates', wrap)
  > def wrap(orig, *args, **kwargs):
  >     res = orig(*args, **kwargs)
  >     with open("a", "w"):
  >         pass # just truncate the file
  >     return res
  > EOF

Do an update where file 'a' is changed between hg writing it to disk
and hg writing the dirstate. The dirstate is correct nonetheless, and
so hg status correctly shows a as clean.

  $ hg up -r 0 --config extensions.race=$TESTTMP/dirstaterace.py
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugdirstate --no-dates
  n 644          2 (set  |unset)               a (re)
  $ echo a > a; hg status; hg diff