revset: stop serializing node when using "%ln"
Turning hundred of thousand of node from node to hex and back can be slow… what
about we stop doing it?
In many case were we are using node id we should be using revision id. However
this is not a good reason to have a stupidly slow implementation of "%ln".
This caught my attention again because the phase discovery during push make an
extensive use of "%ln" or huge set. In absolute, that phase discovery probably
should use "%ld" and need to improves its algorithmic complexity, but improving
"%ln" seems simple and long overdue. This greatly speeds up `hg push` on
repository with many drafts.
Here are some relevant poulpe benchmarks:
### data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
# benchmark.name = hg.command.push
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.explicit-rev = all-out-heads
# benchmark.variants.issue6528 = disabled
# benchmark.variants.protocol = ssh
# benchmark.variants.reuse-external-delta-parent = default
## benchmark.variants.revs = any-1-extra-rev
before: 44.235070
after: 20.416329 (-53.85%, -23.82)
## benchmark.variants.revs = any-100-extra-rev
before: 49.234697
after: 26.519829 (-46.14%, -22.71)
### benchmark.name = hg.command.bundle
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.revs = all
# benchmark.variants.type = none-streamv2
## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog
before: 10.138396
after: 7.750458 (-23.55%, -2.39)
## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog
before: 1.263859
after: 0.700229 (-44.60%, -0.56)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 399.484481
after: 346.5089 (-13.26%, -52.98)
## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog
before: 4.540080
after: 3.401700 (-25.07%, -1.14)
## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog
before: 2.975765
after: 1.870798 (-37.13%, -1.10)
$ cat >> $HGRCPATH << EOF
> [storage]
> dirstate-v2.slow-path=allow
> [format]
> use-dirstate-v2=no
> EOF
Set up a v1 repo
$ hg init repo
$ cd repo
$ echo a > a
$ touch file-with-somewhat-long-name-to-make-dirstate-v1-bigger-than-v2
$ hg commit -Aqm a
$ hg debugrequires | grep dirstate
[1]
$ ls -1 .hg/dirstate*
.hg/dirstate
Copy v1 dirstate
$ cp .hg/dirstate $TESTTMP/dirstate-v1-backup
Upgrade it to v2
$ hg debugupgraderepo -q --config format.use-dirstate-v2=1 --run | grep -E 'added:|removed:'
added: dirstate-v2
$ hg debugrequires | grep dirstate
dirstate-v2
$ ls -1 .hg/dirstate*
.hg/dirstate
.hg/dirstate.* (glob)
Manually reset to dirstate v1 to simulate an incomplete dirstate-v2 upgrade
$ rm .hg/dirstate*
$ cp $TESTTMP/dirstate-v1-backup .hg/dirstate
There should be no errors, but a v2 dirstate should be written back to disk
$ hg st
$ ls -1 .hg/dirstate*
.hg/dirstate
.hg/dirstate.* (glob)
Corrupt the dirstate to see how the errors show up to the user
$ echo "I ate your data" > .hg/dirstate
$ hg st
abort: working directory state appears damaged! (no-rhg !)
(falling back to dirstate-v1 from v2 also failed) (no-rhg !)
abort: Too little data for dirstate: 16 bytes. (rhg !)
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