fncache: move fncache writing to be in a transaction
Previously the fncache was written at lock.release time. This meant it was not
tracked by a transaction, and if an error occurred during the fncache write it
would fail to update the fncache, but would not rollback the transaction,
resulting in an fncache that was not in sync with the files on disk (which
causes verify to fail, and causes streaming clones to not copy all the revlogs).
This uses the new transaction backup mechanism to make the fncache transacted.
It also moves the fncache from being written at lock.release time, to being
written at transaction.close time.
$ cat >> $HGRCPATH <<EOF
> [alias]
> tlog = log --template "{rev}:{node|short}: '{desc}' {branches}\n"
> tglog = tlog -G
> tout = out --template "{rev}:{node|short}: '{desc}' {branches}\n"
> EOF
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Aqm0
$ echo foo >> a
$ hg ci -Aqm1
$ hg up -q 0
$ hg branch stable
marked working directory as branch stable
(branches are permanent and global, did you want a bookmark?)
$ echo bar >> a
$ hg ci -qm2
$ hg tglog
@ 2:7bee6c3bea3a: '2' stable
|
| o 1:3560197d8331: '1'
|/
o 0:f7b1eb17ad24: '0'
$ cd ..
$ hg clone -q a#stable b
$ cd b
$ cat .hg/hgrc
[paths]
default = $TESTTMP/a#stable (glob)
$ echo red >> a
$ hg ci -qm3
$ hg up -q default
$ echo blue >> a
$ hg ci -qm4
$ hg tglog
@ 3:f0461977a3db: '4'
|
| o 2:1d4099801a4e: '3' stable
| |
| o 1:7bee6c3bea3a: '2' stable
|/
o 0:f7b1eb17ad24: '0'
$ hg tout
comparing with $TESTTMP/a (glob)
searching for changes
2:1d4099801a4e: '3' stable
$ hg tlog -r 'outgoing()'
2:1d4099801a4e: '3' stable
$ hg tout ../a#default
comparing with ../a
searching for changes
3:f0461977a3db: '4'
$ hg tlog -r 'outgoing("../a#default")'
3:f0461977a3db: '4'
$ echo "green = ../a#default" >> .hg/hgrc
$ cat .hg/hgrc
[paths]
default = $TESTTMP/a#stable (glob)
green = ../a#default
$ hg tout green
comparing with $TESTTMP/a (glob)
searching for changes
3:f0461977a3db: '4'
$ hg tlog -r 'outgoing("green")'
3:f0461977a3db: '4'
$ cd ..