weighted-mpsc 0.1.2

A bounded tokio mpsc channel that bounds by the total weight (e.g. bytes) of in-flight messages, not their count.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67

# Contributing

Thanks for contributing to weighted-mpsc. These guidelines keep history clean and review
fast.

## Ground rules

1. Commits follow [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/).
2. Keep commits small and self-contained so each can be reviewed on its own. Split large
   changes into incremental commits/PRs; never mix unrelated changes in one commit.
3. Every change ships with tests (unit, plus integration where it fits). Coverage should not drop.
4. CI must be green before review: formatting, clippy, and tests.
5. Address review feedback by amending the relevant commit and rebasing, not with follow-up
   `fix: typo` commits. Keep history linear.

## Commit messages

A Conventional Commits subject in the present tense, imperative voice (`feat: add try_send`,
not `feat: added try_send` or `feat: adds try_send`), then an imperative body that explains
*why* when it is not obvious, wrapped at ~72 columns, ASCII only (no em-dash, no `--`).

AI-assisted commits disclose the assistant with an `Assisted-by:` trailer, following the kernel
[coding-assistants guidance](https://docs.kernel.org/process/coding-assistants.html). Do not use
`Co-Authored-By`.

```
feat: bound the channel by weight, not message count

A count buffer does not bound memory when message sizes vary. Charge each
message its Weigh weight against a semaphore budget so a burst of large
messages applies backpressure before it can exhaust memory.

Assisted-by: Claude:claude-opus-4-8
```

Agents have extra rules in [AGENTS.md](./AGENTS.md).

## Development

```shell
cargo build
cargo test --all-features
cargo fmt --all
cargo clippy --all-targets --all-features --locked -- -D warnings
cargo llvm-cov --all-features --locked --summary-only   # coverage, matches CI
```

Install [prek](https://github.com/j178/prek) and enable the git hooks once. They run typos
and rustfmt on commit, a Conventional Commits check on the message, and clippy on push:

```shell
brew install prek   # or: cargo install --locked prek
prek install
```

## Rust style

Follow the [Rust Style Guide](https://doc.rust-lang.org/nightly/style-guide/); `rustfmt` and
`clippy` are enforced in CI. Prefer idiomatic Rust. Keep comments concise and reserved for the
non-obvious; do not narrate the code. Optional: [typos](https://github.com/crate-ci/typos) for
spell checking.

## Design

The design and rationale live in the [README](./README.md), and the API is documented with
rustdoc. Keep the crate a thin, safe layer over tokio's `mpsc` and `Semaphore`: no `unsafe`, a
minimal dependency tree (`tokio` only), and no unbounded paths - backpressure is the point.