- Remove some unused code
- Use `is_multiple_of()` instead of '%'
- Collapse consecuative "if let" statements
- Elided lifetime fixes
It is enough just to review the code of your team
Second PR for the hashmap behind the updated LFC implementation ([see
first here](https://github.com/neondatabase/neon/pull/12595)). This only
adds the raw code for the hashmap/lock implementations and doesn't plug
it into the crate (that's dependent on the previous PR and should
probably be done when the full integration into the new communicator is
merged alongside `communicator-rewrite` changes?).
Some high level details: the communicator codebase expects to be able to
store references to entries within this hashmap for arbitrary periods of
time and so the hashmap cannot be allowed to move them during a rehash.
As a result, this implementation has a slightly unusual structure where
key-value pairs (and hash chains) are allocated in a separate region
with a freelist. The core hashmap structure is then an array of
"dictionary entries" that are just indexes into this region of key-value
pairs.
Concurrency support is very naive at the moment with the entire map
guarded by one big `RwLock` (which is implemented on top of a
`pthread_rwlock_t` since Rust doesn't guarantee that a
`std::sync::RwLock` is safe to use in shared memory). This (along with a
lot of other things) is being changed on the
`quantumish/lfc-resizable-map` branch.
Initial PR for the hashmap behind the updated LFC implementation. This
refactors `neon-shmem` so that the actual shared memory utilities are in
a separate module within the crate. Beyond that, it slightly changes
some of the docstrings so that they play nicer with `cargo doc`.
attach_writer()/reader() are called from each forked process. It's too
late to do initialization there, in fact we used to overwrite the
contents of the hash table (or at least the freelist?) every time a
new process attached to it. The initialization must be done earlier,
in the HashMapInit() constructors.
The 1.88.0 stable release is near (this Thursday). We'd like to fix most
warnings beforehand so that the compiler upgrade doesn't require
approval from too many teams.
This is therefore a preparation PR (like similar PRs before it).
There is a lot of changes for this release, mostly because the
`uninlined_format_args` lint has been added to the `style` lint group.
One can read more about the lint
[here](https://rust-lang.github.io/rust-clippy/master/#/uninlined_format_args).
The PR is the result of `cargo +beta clippy --fix` and `cargo fmt`. One
remaining warning is left for the proxy team.
---------
Co-authored-by: Conrad Ludgate <conrad@neon.tech>
The new implementation lives in a separately allocated shared memory
area, which could be resized. Resizing it isn't actually implemented
yet, though. It would require some co-operation from the LFC code.
Use that instead of the half-baked Adaptive Radix Tree
implementation. ART would probably be better in the long run, but more
complicated to implement.
You still need to provide a max size up-front, but memory is only
allocated for the portion that is in use.
The module is currently unused, but will be used by the new compute
communicator project, in the neon Postgres extension. See
https://github.com/neondatabase/neon/issues/11729
---------
Co-authored-by: Erik Grinaker <erik@neon.tech>
