# MessagePacker - a no-std msgpack implementation
[](https://crates.io/crates/msgpacker)
[](https://docs.rs/msgpacker/)
[]()
The protocol specification can be found [here](https://github.com/msgpack/msgpack/blob/master/spec.md).
This crate targets simplicity and performance. No dependencies are used, just the standard Rust library.
It will implement `Packable` and `Unpackable` for Rust atomic types. The traits can also be implemented manually.
## Features
- alloc: Implements the functionality for `Vec`, `String`, and unlocks custom extensions.
- derive: Enables `MsgPacker` derive convenience macro.
- strict: Will panic if there is a protocol violation of the size of a buffer; the maximum allowed size is `u32::MAX`.
- std: Will implement the `Packable` and `Unpackable` for `std` collections.
## Example
```rust
use msgpacker::prelude::*;
use std::collections::HashMap;
// boilerplate derives - those aren't required
#[derive(Debug, PartialEq, Eq)]
// this convenience derive macro will implement `Packable` and `Unpackable`
#[derive(MsgPacker)]
pub struct City {
name: String,
// The traits are implemented for stdlib collections. If you have a custom map, you can use the
// directive `#[msgpacker(map)]` so the traits will be automatically implemented through the
// iterators of the map.
inhabitants_per_street: HashMap<String, u64>,
// This is also automatically implemented. The manual implementation is via `#[msgpacker(array)]`.
zones: Vec<String>,
}
// create an instance of a city.
let city = City {
name: "Kuala Lumpur".to_string(),
inhabitants_per_street: HashMap::from([
("Street 1".to_string(), 10),
("Street 2".to_string(), 20),
]),
zones: vec!["Zone 1".to_string(), "Zone 2".to_string()],
};
// serialize the city into bytes
let mut buf = Vec::new();
let n = city.pack(&mut buf);
println!("serialized {} bytes", n);
// deserialize the city and assert correctness
let (n, deserialized) = City::unpack(&buf).unwrap();
println!("deserialized {} bytes", n);
assert_eq!(city, deserialized);
```
## Benchmarks
Results obtained with `Intel(R) Core(TM) i9-9900X CPU @ 3.50GHz`.
The simplicity of the implementation unlocks a performance more than ~10x better than [rmp-serde](https://crates.io/crates/rmp-serde).
#### Pack 1.000 elements
#### Unpack 1.000 elements
