Struct codee::binary::ProstCodec

pub struct ProstCodec;

A codec for storing ProtoBuf messages that relies on prost to parse.

Protocol buffers is a serialisation format useful for long-term storage. It provides semantics for versioning that are not present in JSON or other formats. prost is a Rust implementation of Protocol Buffers.

This codec uses prost to encode the message into a byte stream. To use it with local storage in the example below we wrap it with [Base64] to represent the bytes as a string.

Example

// Primitive types:
let (get, set, remove) = use_local_storage::<i32, Base64<ProstCodec>>("my-key");

// Structs:
#[derive(Clone, PartialEq, prost::Message)]
pub struct MyState {
    #[prost(string, tag = "1")]
    pub hello: String,
}
let (get, set, remove) = use_local_storage::<MyState, Base64<ProstCodec>>("my-struct-key");

Note: we’ve defined and used the prost attribute here for brevity. Alternate usage would be to describe the message in a .proto file and use prost_build to auto-generate the Rust code.

Trait Implementations

impl<T: Message + Default> Decoder<T> for ProstCodec

type Error = DecodeError

type Encoded = [u8]

fn decode(val: &Self::Encoded) -> Result<T, Self::Error>

impl<T: Message> Encoder<T> for ProstCodec

type Error = ()

type Encoded = Vec<u8>

fn encode(val: &T) -> Result<Self::Encoded, Self::Error>