tests/test-dirstate-race2.t
author Pierre-Yves David <pierre-yves.david@octobus.net>
Thu, 07 Mar 2024 10:55:22 +0100
changeset 51531 f85f23f1479b
parent 48681 e845537f6adb
permissions -rw-r--r--
branchcache: skip entries that are topological heads in the on disk file In the majority of cases, topological heads are also branch heads. We have efficient way to get the topological heads and efficient way to retrieve their branch information. So there is little value in putting them in the branch cache file explicitly. On the contrary, writing them explicitly tend to create very large cache file that are inefficient to read and update. So the branch cache v3 format is no longer including them. This changeset focus on the format aspect and have no focus on the performance aspect. We will cover that later.

#testcases dirstate-v1 dirstate-v2

#if dirstate-v2
  $ cat >> $HGRCPATH << EOF
  > [format]
  > use-dirstate-v2=1
  > [storage]
  > dirstate-v2.slow-path=allow
  > EOF
#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 _
# this sleep is there to ensure current time has -at-least- one second away
# from the current time. It ensure the mtime is not ambiguous. If the test
# "sleep" longer this will be fine.
# It is not used to synchronise parallele operation so it is "fine" to use it.
  $ sleep 1
  $ hg status

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

  $ cat >> $TESTTMP/dirstaterace.py << EOF
  > import time
  > from mercurial import (
  >     commit,
  >     extensions,
  >     merge,
  > )
  > def extsetup(ui):
  >     extensions.wrapfunction(merge, 'applyupdates', wrap(0))
  >     extensions.wrapfunction(commit, 'commitctx', wrap(1))
  > def wrap(duration):
  >     def new(orig, *args, **kwargs):
  >         res = orig(*args, **kwargs)
  >         with open("a", "w"):
  >             pass # just truncate the file
  >         time.sleep(duration)
  >         return res
  >     return new
  > 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

Do a commit where file 'a' is changed between hg committing its new
revision into the repository, and the writing of the dirstate.

This used to results in a corrupted dirstate (size did not match committed size).

  $ echo aaa > a; hg commit -qm _
  $ hg merge -qr 1; hg resolve -m; rm a.orig
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  (no more unresolved files)
  $ cat a
  <<<<<<< working copy: be46f74ce38d - test: _
  aaa
  =======
  aa
  >>>>>>> merge rev:    eb3fc6c17aa3 - test: _
  $ hg debugdirstate --no-dates
  m   0         -2 (set  |unset)               a (re)
  $ hg commit -m _ --config extensions.race=$TESTTMP/dirstaterace.py
  $ hg debugdirstate --no-dates
  n   0         -1 unset               a
  $ cat a | wc -c
   *0 (re)
  $ hg cat -r . a | wc -c
   *105 (re)
  $ hg status; hg diff --stat
  M a
   a |  5 -----
   1 files changed, 0 insertions(+), 5 deletions(-)