Trait SimCodec 

pub trait SimCodec<T> {
    // Required methods
    fn encode(value: &T) -> Vec<u8> ;
    fn decode(bytes: &[u8]) -> T;
}

Available on crate feature sim only.

A serialization codec for values crossing the simulation dylib boundary.

The test and simulation dylib exchange only encoded bytes, so custom codecs do not need to use serde. See BincodeCodec for the default.

The codec is selected purely at the type level, as a type parameter of Stream::sim_output_with, Location::sim_input_with and their cluster counterparts (e.g. stream.sim_output_with::<MyCodec>()). No codec value is ever constructed, so a codec is typically a unit struct, but any type will do.

Defining a custom codec

Generated dylib code refers to the codec by its definition path. The codec must therefore:

• be public through to the crate root, and
• live outside #[cfg(test)] and integration-test targets.

Its serialization library and hydro_lang with the sim feature must be regular dependencies, not dev-dependencies.

use hydro_lang::sim::codec::SimCodec;

pub struct Message(u32);

pub struct MessageCodec;

impl SimCodec<Message> for MessageCodec {
    fn encode(value: &Message) -> Vec<u8> {
        value.0.to_le_bytes().to_vec()
    }

    fn decode(bytes: &[u8]) -> Message {
        Message(u32::from_le_bytes(bytes.try_into().unwrap()))
    }
}

Required Methods

fn encode(value: &T) -> Vec<u8>

Encodes value for transport across the simulation dylib boundary.

fn decode(bytes: &[u8]) -> T

Decodes a value received across the simulation dylib boundary.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<T: Serialize + DeserializeOwned> SimCodec<T> for BincodeCodec