usage: add configuration option to adjust resources usage They currently do nothing, but this open the way to actually use them.

usage: add a `usage.repository-role` config This config will be used for behavior and performance adjustment depending of the repository role.

common-pattern: cover "elapsed time" line These are perfect targets for the common-pattern matching.

branching: merge with stable I need the fix to `generate-churning-bundle.py`.

narrow: strip trailing `/` from manifest dir before matching it Commit 17a822d7943e broke some of our internal tests at Google because the `dir` variable contains a trailing slash since that commit. Let's restore the old behavior by stripping that trailing slash.

tests: demonstrate error when narrowing with `rootfilesin:` pattern This demonstrates a bug introduced in 17a822d7943e.

matchers: use correct method for finding index in vector The path matcher has an optimization for when all paths are `rootfilesin:`. This optimization exists in both Python and Rust. However, the Rust implementation currently has a bug that makes it fail in most cases. The bug is that it `rfind()` where it was clearly intended to use `rposition()`. This patch fixes that and adds a test.

dirstate: make the `transaction` argument of `setbranch` mandatory This is deprecated since 6.4. We should drop it now.

rust-clippy: apply some more trivial fixes All of these were hinted at by clippy and make the code simpler.

rust-clippy: simplify `match` to `if let` This was hinted at by clippy, and makes it more obvious that nothing is happening in the `None` case.

censor: accept multiple revision in a single call This is useful when dealing with corruption, as all the corrupted revision can be dealt with in one go.

censor: be more verbose about the other steps too If we informs the user about head checking, we should tell him when the other operation happens too. Otherwise the user can imagine to still be in the head checking part.

censor: add a command flag to skip the head checks In some case we spend hours of time checking the heads to censors a simple file is not a good behavior. Especially when censors is used to removed corrupted content.

censor: inform the user that we are spending time checking heads The time this can consume can be a surprise to the user, lets be explicit about it.

censor: mention that we check the heads in the help And add a message to will explain the possibly long time spent doing this.

rust-index: only access offsets if revlog is inline Accessing the `RwLock` ended up showing up in profiles even with no contention. Offsets only exist for inline revlogs, so gate everything behind an inline check.

rust-index: cache the head nodeids python list Same optimization as before, but for the nodeids this time.

rust-index: add fast-path for getting a list of all heads as nodes This avoids a lot of back-and-forth between Python and Rust. We forgo adding a fast-path in the `filteredchangelog` case yet. If it shows up in profiling, we might add the variant with a filter.

rust-index-cpython: cache the heads' PyList representation This is the same optimization that the C index does, we just have more separation of the Python and native sides.

rust-index: use a `BitVec` instead of plain `Vec` for heads computation The `Vec` method uses one byte per revision, this uses 1 per 8 revisions, which improves our memory footprint. For large graphs (10+ millions), this can make a measurable difference server-side. I have seen no measurable impact on execution speed.

rust-index: implement faster retain heads using a vec instead of a hashset This is the same optimization that the C index does, we're only catching up now because this showed up as slow in benchmarking.

rust-index: allow inlining VCSGraph parents across crates

rust-index: allow inlining `parents` across crates

rust-index: allow inlining `check_revision` across crates

rust-index: document safety invariants being upheld for every `unsafe` block We've added a lot of `unsafe` code that shares Rust structs with Python. While this is unfortunate, it is also unavoidable, so let's at least systematically explain why each call to `unsafe` is sound. If any of the unsafe code ends up being wrong (because everyone screws up at some point), this change at least continues the unspoken rule of always explaining the need for `unsafe`, so we at least get a chance to think.

rust-index: renamed `MixedIndex` as `Index` It is simply not mixed any more, hence the name had become a future source of confusion.

rust-index: stop instantiating a C Index The only missing piece was the `cache` to be returned from `revlog.parse_index_v1_mixed`, and it really seems that it is essentially repetition of the input, if `inline` is `True`. Not worth a Rust implementation (C implementation is probably there for historical reasons).

rust-revlog: using the ad-hoc `NodeTree` in scmutil Now that we have an independent `NodeTree` class able to work natively on the pure Rust index, we use it in `mercurial.scmutil`, with automatic invalidation after mutation of the index. This code path is tested by `test-revisions.t` and `test-template-functions.t`