perf: clear vfs audit_cache before each run
When generating a stream clone, we spend a large amount of time auditing path.
Before this changes, the first run was warming the vfs cache for the other
runs, leading to a large runtime difference and a "faulty" reported timing for
the operation.
We now clear this important cache between run to get a more realistic timing.
Below are some example of median time change when clearing these cases. The
maximum time for a run did not changed significantly.
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# benchmark.name = hg.perf.exchange.stream.generate
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.version = latest
no-clearing: 17.289905
cache-clearing: 21.587965 (+24.86%, +4.30)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
no-clearing: 32.670748
cache-clearing: 40.467095 (+23.86%, +7.80)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
no-clearing: 37.838858
cache-clearing: 46.072749 (+21.76%, +8.23)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
no-clearing: 32.969395
cache-clearing: 39.646209 (+20.25%, +6.68)
In addition, this significantly reduce the timing difference between the
performance command, from the perf extensions and a `real `hg bundle` call
producing a stream bundle. Some significant differences remain especially on
the "mozilla-try" repositories, but they are now smaller.
Note that some of that difference will actually not be
attributable to the stream generation (like maybe phases or branch map
computation).
Below are some benchmarks done on a currently draft changeset fixing some
unrelated slowness in `hg bundle` (34a78972af409d1ff37c29e60f6ca811ad1a457d)
### data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
hg.perf.exchange.stream.generate: 21.587965
hg.command.bundle: 24.301799 (+12.57%, +2.71)
## data-env-vars.name = mozilla-central-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 40.467095
hg.command.bundle: 44.831317 (+10.78%, +4.36)
## data-env-vars.name = mozilla-unified-2024-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 39.646209
hg.command.bundle: 45.395258 (+14.50%, +5.75)
## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 46.072749
hg.command.bundle: 55.882608 (+21.29%, +9.81)
## data-env-vars.name = mozilla-try-2023-03-22-zlib-general-delta
hg.perf.exchange.stream.generate: 334.716708
hg.command.bundle: 377.856767 (+12.89%, +43.14)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
hg.perf.exchange.stream.generate: 302.972301
hg.command.bundle: 326.098755 (+7.63%, +23.13)
== New Features ==
* There is a new config section for templates used by hg commands. It
is called `[command-templates]`. Some existing config options have
been deprecated in favor of config options in the new
section. These are: `ui.logtemplate` to `command-templates.log`,
`ui.graphnodetemplate` to `command-templates.graphnode`,
`ui.mergemarkertemplate` to `command-templates.mergemarker`,
`ui.pre-merge-tool-output-template` to
`command-templates.pre-merge-tool-output`.
* There is a new set of config options for the template used for the
one-line commit summary displayed by various commands, such as `hg
rebase`. The main one is `command-templates.oneline-summary`. That
can be overridden per command with
`command-templates.oneline-summary.<command>`, where `<command>`
can be e.g. `rebase`. As part of this effort, the default format
from `hg rebase` was reorganized a bit.
* `hg purge` is now a core command using `--confirm` by default.
* `hg diff` and `hg extdiff` now support `--from <rev>` and `--to <rev>`
arguments as clearer alternatives to `-r <revs>`. `-r <revs>` has been
deprecated.
* The memory footprint per changeset during pull/unbundle
operations has been further reduced.
* There is a new internal merge tool called `internal:mergediff` (can
be set as the value for the `merge` config in the `[ui]`
section). It resolves merges the same was as `internal:merge` and
`internal:merge3`, but it shows conflicts differently. Instead of
showing 2 or 3 snapshots of the conflicting pieces of code, it
shows one snapshot and a diff. This may be useful when at least one
side of the conflict is similar to the base. The new marker style
is also supported by "premerge" as
`merge-tools.<tool>.premerge=keep-mergediff`.
* External hooks are now called with `HGPLAIN=1` preset. This has the side
effect of ignoring aliases, templates, revsetaliases, and a few other config
options in any `hg` command spawned by the hook. The previous behavior
can be restored by setting HGPLAINEXCEPT appropriately in the parent process.
See `hg help environment` for the list of items, and how to set it.
* The `branchmap` cache is updated more intelligently and can be
significantly faster for repositories with many branches and changesets.
* The `rev-branch-cache` is now updated incrementally whenever changesets
are added.
== New Experimental Features ==
* `experimental.single-head-per-branch:public-changes-only` can be used
restrict the single head check to public revision. This is useful for
overlay repository that have both a publishing and non-publishing view
of the same storage.
== Bug Fixes ==
== Backwards Compatibility Changes ==
* `--force-lock` and `--force-wlock` options on `hg debuglock` command are
renamed to `--force-free-lock` and `--force-free-wlock` respectively.
== Internal API Changes ==
* `changelog.branchinfo` is deprecated and will be removed after 5.8.
It is superseded by `changelogrevision.branchinfo`.