rkyv (archive) is a zero-copy deserialization framework for Rust

Resources

Learning Materials

• The rkyv book covers the motivation, architecture, and major features of rkyv
• The rkyv discord is a great place to get help with specific issues and meet other people using rkyv

Documentation

• rkyv, the core library
• rkyv_dyn, which adds trait object support to rkyv

Benchmarks

• The rust serialization benchmark is a shootout style benchmark comparing many rust serialization solutions. It includes special benchmarks for zero-copy serialization solutions like rkyv.

Sister Crates

• rend, which rkyv uses for endian-agnostic features
• bytecheck, which rkyv uses for validation
• rancor, which rkyv uses for error handling
• ptr_meta, which rkyv uses for pointer manipulation

Example

use rkyv::{deserialize, rancor::Error, Archive, Deserialize, Serialize};

#[derive(Archive, Deserialize, Serialize, Debug, PartialEq)]
#[rkyv(
    // This will generate a PartialEq impl between our unarchived
    // and archived types
    compare(PartialEq),
    // Derives can be passed through to the generated type:
    derive(Debug),
)]
struct Test {
    int: u8,
    string: String,
    option: Option<Vec<i32>>,
}

fn main() {
    let value = Test {
        int: 42,
        string: "hello world".to_string(),
        option: Some(vec![1, 2, 3, 4]),
    };

    // Serializing is as easy as a single function call
    let _bytes = rkyv::to_bytes::<Error>(&value).unwrap();

    // Or you can customize your serialization for better performance or control
    // over resource usage
    use rkyv::{api::high::to_bytes_with_alloc, ser::allocator::Arena};

    let mut arena = Arena::new();
    let bytes =
        to_bytes_with_alloc::<_, Error>(&value, arena.acquire()).unwrap();

    // You can use the safe API for fast zero-copy deserialization
    let archived = rkyv::access::<ArchivedTest, Error>(&bytes[..]).unwrap();
    assert_eq!(archived, &value);

    // Or you can use the unsafe API for maximum performance
    let archived =
        unsafe { rkyv::access_unchecked::<ArchivedTest>(&bytes[..]) };
    assert_eq!(archived, &value);

    // And you can always deserialize back to the original type
    let deserialized = deserialize::<Test, Error>(archived).unwrap();
    assert_eq!(deserialized, value);
}

Note: the safe API requires the bytecheck feature (enabled by default) Read more about available features.

Thanks

Thanks to all the sponsors that keep development sustainable. Special thanks to the following sponsors for going above and beyond supporting rkyv:

Bronze Sponsors

Climatiq provides an embedded carbon intelligence solution that enables developers to automate GHG emission calculations based on verified scientific models. Its suite of products includes the largest dataset of emission factors, and intelligent APIs that integrate with any software platform for real time monitoring of greenhouse gas emissions.