localrepo: stop doing special dirstate backup at transaction open
Since the dirstate writes are already managed by the transaction, we already do
a backup of the dirstate when necessary (and even trigger one to keep `hg
rollback` happy).
We needs some special code to deal with the initial empty checkout, but it is
not too complicated.
Managing variable filename (as dirstate-v2 uses) at the "journalfile" level, is
complex and fragile (which is consistent with the fact these files are not
journal…). If we no longer do it, our life is significantly simpler.
In some sense, we apply the xkcd-1134¹ solution to our savebackup/restorebackup
problem.
[1] https://xkcd.com/1134/
(the change to test-hardlink are expect as decreasing the number of duplicated
backup drive the hardlink count down)
A new repository uses zlib storage, which doesn't need a requirement
$ cat << EOF >> $HGRCPATH
> [format]
> # stabilize test accross variant
> revlog-compression=zlib
> EOF
$ hg init default
$ cd default
$ hg debugrequires | grep compression
[1]
$ touch foo
$ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text to trigger compression'
$ hg debugrevlog -c | grep 0x78
0x78 (x) : 1 (100.00%)
0x78 (x) : 110 (100.00%)
$ cd ..
Unknown compression engine to format.compression aborts
$ hg --config format.revlog-compression=unknown init unknown
abort: compression engines "unknown" defined by format.revlog-compression not available
(run "hg debuginstall" to list available compression engines)
[255]
unknown compression engine in a list with known one works fine
$ hg --config format.revlog-compression=zlib,unknown init zlib-before-unknow
$ hg --config format.revlog-compression=unknown,zlib init unknown-before-zlib
A requirement specifying an unknown compression engine results in bail
$ hg init unknownrequirement
$ cd unknownrequirement
$ echo exp-compression-unknown >> .hg/requires
$ hg log
abort: repository requires features unknown to this Mercurial: exp-compression-unknown
(see https://mercurial-scm.org/wiki/MissingRequirement for more information)
[255]
$ cd ..
Specifying a new format.compression on an existing repo won't introduce data
with that engine or a requirement
$ cd default
$ touch bar
$ hg --config format.revlog-compression=none -q commit -A -m 'add bar with a lot of repeated repeated repeated text'
$ hg debugrequires | grep compression
[1]
$ hg debugrevlog -c | grep 0x78
0x78 (x) : 2 (100.00%)
0x78 (x) : 199 (100.00%)
$ cd ..
#if zstd
$ hg --config format.revlog-compression=zstd init zstd
$ cd zstd
$ hg debugrequires | grep compression
revlog-compression-zstd
$ touch foo
$ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text'
$ hg debugrevlog -c | grep 0x28
0x28 : 1 (100.00%)
0x28 : 98 (100.00%)
$ cd ..
#endif
checking zlib options
=====================
$ hg init zlib-level-default
$ hg init zlib-level-1
$ cat << EOF >> zlib-level-1/.hg/hgrc
> [storage]
> revlog.zlib.level=1
> EOF
$ hg init zlib-level-9
$ cat << EOF >> zlib-level-9/.hg/hgrc
> [storage]
> revlog.zlib.level=9
> EOF
$ commitone() {
> repo=$1
> cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
> hg -R $repo add $repo/a
> hg -R $repo commit -m some-commit
> }
$ for repo in zlib-level-default zlib-level-1 zlib-level-9; do
> commitone $repo
> done
$ $RUNTESTDIR/f -s */.hg/store/data/*
default/.hg/store/data/bar.i: size=64
default/.hg/store/data/foo.i: size=64
zlib-level-1/.hg/store/data/a.i: size=4146
zlib-level-9/.hg/store/data/a.i: size=4138
zlib-level-default/.hg/store/data/a.i: size=4138
zstd/.hg/store/data/foo.i: size=64 (zstd !)
Test error cases
$ hg init zlib-level-invalid
$ cat << EOF >> zlib-level-invalid/.hg/hgrc
> [storage]
> revlog.zlib.level=foobar
> EOF
$ commitone zlib-level-invalid
config error: storage.revlog.zlib.level is not a valid integer ('foobar')
config error: storage.revlog.zlib.level is not a valid integer ('foobar')
[30]
$ hg init zlib-level-out-of-range
$ cat << EOF >> zlib-level-out-of-range/.hg/hgrc
> [storage]
> revlog.zlib.level=42
> EOF
$ commitone zlib-level-out-of-range
abort: invalid value for `storage.revlog.zlib.level` config: 42
abort: invalid value for `storage.revlog.zlib.level` config: 42
[255]
checking details of none compression
====================================
$ hg init none-compression --config format.revlog-compression=none
$ commitone() {
> repo=$1
> cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
> hg -R $repo add $repo/a
> hg -R $repo commit -m some-commit
> }
$ commitone none-compression
$ hg log -R none-compression
changeset: 0:68b53da39cd8
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: some-commit
$ hg debugrequires -R none-compression/ | grep compression
exp-compression-none
$ $RUNTESTDIR/f -s none-compression/.hg/store/data/*
none-compression/.hg/store/data/a.i: size=4216
#if zstd
checking zstd options
=====================
$ hg init zstd-level-default --config format.revlog-compression=zstd
$ hg init zstd-level-1 --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-1/.hg/hgrc
> [storage]
> revlog.zstd.level=1
> EOF
$ hg init zstd-level-22 --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-22/.hg/hgrc
> [storage]
> revlog.zstd.level=22
> EOF
$ commitone() {
> repo=$1
> cp $RUNTESTDIR/bundles/issue4438-r1.hg $repo/a
> hg -R $repo add $repo/a
> hg -R $repo commit -m some-commit
> }
$ for repo in zstd-level-default zstd-level-1 zstd-level-22; do
> commitone $repo
> done
$ $RUNTESTDIR/f -s zstd-*/.hg/store/data/*
zstd-level-1/.hg/store/data/a.i: size=4114
zstd-level-22/.hg/store/data/a.i: size=4091
zstd-level-default/\.hg/store/data/a\.i: size=(4094|4102) (re)
Test error cases
$ hg init zstd-level-invalid --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-invalid/.hg/hgrc
> [storage]
> revlog.zstd.level=foobar
> EOF
$ commitone zstd-level-invalid
config error: storage.revlog.zstd.level is not a valid integer ('foobar')
config error: storage.revlog.zstd.level is not a valid integer ('foobar')
[30]
$ hg init zstd-level-out-of-range --config format.revlog-compression=zstd
$ cat << EOF >> zstd-level-out-of-range/.hg/hgrc
> [storage]
> revlog.zstd.level=42
> EOF
$ commitone zstd-level-out-of-range
abort: invalid value for `storage.revlog.zstd.level` config: 42
abort: invalid value for `storage.revlog.zstd.level` config: 42
[255]
#endif