scmutil: add file object wrapper class to check ambiguity at closing
In Mercurial source tree, opening a file in "a"/"a+" mode like below
doesn't specify atomictemp=True for vfs, and this avoids file stat
ambiguity check by atomictempfile.
- writing changes out in revlog layer uses "a+" mode
- truncation in repair.strip() uses "a" mode
- truncation in transaction._playback() uses "a" mode
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
This patch adds file object wrapper class checkambigatclosing to check
(and get rid of) ambiguity at closing. It is used by vfs in subsequent
patch.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
BTW, checkambigatclosing is tested in test-filecache.py, even though
it doesn't use filecache itself, because filecache assumes that file
stat ambiguity never occurs (and there is no another test-*.py related
to filecache).
$ hg init t
$ cd t
$ echo 1 > foo
$ hg ci -Am m
adding foo
$ cd ..
$ hg clone t tt
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd tt
$ echo 1.1 > foo
$ hg ci -Am m
$ cd ../t
$ echo 1.2 > foo
$ hg ci -Am m
Should not update to the other topological branch:
$ hg pull -u ../tt
pulling from ../tt
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 other heads for branch "default"
$ cd ../tt
Should not update to the other branch:
$ hg pull -u ../t
pulling from ../t
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 other heads for branch "default"
$ HGMERGE=true hg merge
merging foo
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -mm
$ cd ../t
Should work:
$ hg pull -u ../tt
pulling from ../tt
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (-1 heads)
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Similarity between "hg update" and "hg pull -u" in handling bookmark
====================================================================
Test that updating activates the bookmark, which matches with the
explicit destination of the update.
$ echo 4 >> foo
$ hg commit -m "#4"
$ hg bookmark active-after-pull
$ cd ../tt
(1) activating by --rev BOOKMARK
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u -r active-after-pull
pulling from $TESTTMP/t (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
adding remote bookmark active-after-pull
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark active-after-pull)
$ hg parents -q
4:f815b3da6163
$ hg bookmarks
* active-after-pull 4:f815b3da6163
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
(2) activating by URL#BOOKMARK
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u $TESTTMP/t#active-after-pull
pulling from $TESTTMP/t (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
adding remote bookmark active-after-pull
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark active-after-pull)
$ hg parents -q
4:f815b3da6163
$ hg bookmarks
* active-after-pull 4:f815b3da6163
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
Test that updating deactivates current active bookmark, if the
destination of the update is explicitly specified, and it doesn't
match with the name of any exsiting bookmarks.
$ cd ../t
$ hg bookmark -d active-after-pull
$ hg branch bar -q
$ hg commit -m "#5 (bar #1)"
$ cd ../tt
(1) deactivating by --rev REV
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u -r b5e4babfaaa7
pulling from $TESTTMP/t (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(leaving bookmark active-before-pull)
$ hg parents -q
5:b5e4babfaaa7
$ hg bookmarks
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
(2) deactivating by --branch BRANCH
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u -b bar
pulling from $TESTTMP/t (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(leaving bookmark active-before-pull)
$ hg parents -q
5:b5e4babfaaa7
$ hg bookmarks
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
(3) deactivating by URL#ANOTHER-BRANCH
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u $TESTTMP/t#bar
pulling from $TESTTMP/t (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(leaving bookmark active-before-pull)
$ hg parents -q
5:b5e4babfaaa7
$ hg bookmarks
active-before-pull 3:483b76ad4309
$ cd ..