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).
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepo ()
> {
> hg init $1
> cd $1
> for x in a b c d e f ; do
> echo $x$x$x$x$x > $x
> hg add $x
> done
> hg ci -m 'Initial commit'
> for x in a b c d e f ; do
> echo $x > $x
> hg ci -m $x
> done
> echo 'I can haz no commute' > e
> hg ci -m 'does not commute with e'
> cd ..
> }
$ initrepo r
$ cd r
Initial generation of the command files
$ EDITED="$TESTTMP/editedhistory"
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
$ hg log --template 'fold {node|short} {rev} {desc}\n' -r 7 >> $EDITED
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
$ cat $EDITED
pick 65a9a84f33fd 3 c
pick 00f1c5383965 4 d
fold 39522b764e3d 7 does not commute with e
pick 7b4e2f4b7bcd 5 e
pick 500cac37a696 6 f
log before edit
$ hg log --graph
@ changeset: 7:39522b764e3d
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: does not commute with e
|
o changeset: 6:500cac37a696
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 5:7b4e2f4b7bcd
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 4:00f1c5383965
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 3:65a9a84f33fd
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 2:da6535b52e45
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 1:c1f09da44841
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: a
|
o changeset: 0:1715188a53c7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Initial commit
edit the history
$ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
merging e
warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
Fix up the change (fold 39522b764e3d)
(hg histedit --continue to resume)
fix up
$ echo 'I can haz no commute' > e
$ hg resolve --mark e
(no more unresolved files)
continue: hg histedit --continue
$ HGEDITOR=cat hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
d
***
does not commute with e
HG: Enter commit message. Lines beginning with 'HG:' are removed.
HG: Leave message empty to abort commit.
HG: --
HG: user: test
HG: branch 'default'
HG: changed d
HG: changed e
merging e
warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
Fix up the change (pick 7b4e2f4b7bcd)
(hg histedit --continue to resume)
just continue this time
keep the non-commuting change, and thus the pending change will be dropped
$ hg revert -r 'p1()' e
$ hg resolve --mark e
(no more unresolved files)
continue: hg histedit --continue
$ hg diff
$ hg histedit --continue 2>&1 | fixbundle
7b4e2f4b7bcd: skipping changeset (no changes)
log after edit
$ hg log --graph
@ changeset: 5:d9cf42e54966
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:10486af2e984
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 3:65a9a84f33fd
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 2:da6535b52e45
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 1:c1f09da44841
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: a
|
o changeset: 0:1715188a53c7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Initial commit
contents of e
$ hg cat e
I can haz no commute
manifest
$ hg manifest
a
b
c
d
e
f
$ cd ..
Repeat test using "roll", not "fold". "roll" folds in changes but drops message
$ initrepo r2
$ cd r2
Initial generation of the command files
$ EDITED="$TESTTMP/editedhistory.2"
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
$ hg log --template 'roll {node|short} {rev} {desc}\n' -r 7 >> $EDITED
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
$ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
$ cat $EDITED
pick 65a9a84f33fd 3 c
pick 00f1c5383965 4 d
roll 39522b764e3d 7 does not commute with e
pick 7b4e2f4b7bcd 5 e
pick 500cac37a696 6 f
log before edit
$ hg log --graph
@ changeset: 7:39522b764e3d
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: does not commute with e
|
o changeset: 6:500cac37a696
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 5:7b4e2f4b7bcd
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 4:00f1c5383965
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 3:65a9a84f33fd
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 2:da6535b52e45
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 1:c1f09da44841
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: a
|
o changeset: 0:1715188a53c7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Initial commit
edit the history
$ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
merging e
warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
Fix up the change (roll 39522b764e3d)
(hg histedit --continue to resume)
fix up
$ echo 'I can haz no commute' > e
$ hg resolve --mark e
(no more unresolved files)
continue: hg histedit --continue
$ hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
merging e
warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
Fix up the change (pick 7b4e2f4b7bcd)
(hg histedit --continue to resume)
just continue this time
$ hg revert -r 'p1()' e
$ hg resolve --mark e
(no more unresolved files)
continue: hg histedit --continue
$ hg histedit --continue 2>&1 | fixbundle
7b4e2f4b7bcd: skipping changeset (no changes)
log after edit
$ hg log --graph
@ changeset: 5:e7c4f5d4eb75
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:803d1bb561fc
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 3:65a9a84f33fd
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 2:da6535b52e45
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 1:c1f09da44841
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: a
|
o changeset: 0:1715188a53c7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Initial commit
contents of e
$ hg cat e
I can haz no commute
manifest
$ hg manifest
a
b
c
d
e
f
description is taken from rollup target commit
$ hg log --debug --rev 4
changeset: 4:803d1bb561fceac3129ec778db9da249a3106fc3
phase: draft
parent: 3:65a9a84f33fdeb1ad5679b3941ec885d2b24027b
parent: -1:0000000000000000000000000000000000000000
manifest: 4:b068a323d969f22af1296ec6a5ea9384cef437ac
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: d e
extra: branch=default
extra: histedit_source=00f1c53839651fa5c76d423606811ea5455a79d0,39522b764e3d26103f08bd1fa2ccd3e3d7dbcf4e
description:
d
done with repo r2
$ cd ..