exchange: improve computation of relevant markers for large repos
Compute the candidate nodes with relevant markers directly
from keys of the predecessors/successors/children dictionaries of
obsstore. This is faster than iterating over all nodes directly.
This test could be further improved for repositories with relative
few markers compared to the repository size, but this is no longer
hot already. With the current loop structure, the obshashrange use
works as well as before as it passes lists with a single node.
Adjust the interface by allowing revision lists as well as node lists.
This helps cases that computes ancestors as it reduces the
materialisation cost. Use this in _pushdiscoveryobsmarker and
_getbundleobsmarkerpart. Improve the latter further by directly using
ancestors().
Performance benchmarks show notable and welcome improvement to no-op push and
pull (that would also apply to other push/pull). This apply to push and pull
done without evolve.
### push/pull Benchmark parameter
# bin-env-vars.hg.flavor = default
# benchmark.variants.explicit-rev = none
# benchmark.variants.protocol = ssh
# benchmark.variants.revs = none
## benchmark.name = hg.command.pull
# data-env-vars.name = mercurial-devel-2024-03-22-zstd-sparse-revlog
before: 5.968537 seconds
after: 5.668507 seconds (-5.03%, -0.30)
# data-env-vars.name = tryton-devel-2024-03-22-zstd-sparse-revlog
before: 1.446232 seconds
after: 0.835553 seconds (-42.23%, -0.61)
# data-env-vars.name = netbsd-src-draft-2024-09-19-zstd-sparse-revlog
before: 5.777412 seconds
after: 2.523454 seconds (-56.32%, -3.25)
## benchmark.name = hg.command.push
# data-env-vars.name = mercurial-devel-2024-03-22-zstd-sparse-revlog
before: 6.155501 seconds
after: 5.885072 seconds (-4.39%, -0.27)
# data-env-vars.name = tryton-devel-2024-03-22-zstd-sparse-revlog
before: 1.491054 seconds
after: 0.934882 seconds (-37.30%, -0.56)
# data-env-vars.name = netbsd-src-draft-2024-09-19-zstd-sparse-revlog
before: 5.902494 seconds
after: 2.957644 seconds (-49.89%, -2.94)
There is not notable different in these result using the "rust" flavor instead
of the "default". The performance impact on the same operation when using
evolve were also tested and no impact was noted.
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.
Notes for packagers
===================
Mercurial ships a copy of the python-zstandard sources. This is used to
provide support for zstd compression and decompression functionality. The
module is not intended to be replaced by the plain python-zstandard nor
is it intended to use a system zstd library. Patches can result in hard
to diagnose errors and are explicitly discouraged as unsupported
configuration.