Crate polkadot_parachain

source ·
Expand description

Defines primitive types for creating or validating a parachain.

When compiled with standard library support, this crate exports a wasm module that can be used to validate parachain WASM.

Parachain WASM

Polkadot parachain WASM is in the form of a module which imports a memory instance and exports a function validate_block.

validate accepts as input two i32 values, representing a pointer/length pair respectively, that encodes [ValidationParams].

validate returns an u64 which is a pointer to an u8 array and its length. The data in the array is expected to be a SCALE encoded [ValidationResult].

ASCII-diagram demonstrating the return data format:

ⓘ
[pointer][length]
  32bit   32bit
        ^~~ returned pointer & length

The wasm-api (enabled only when std feature is not enabled and wasm-api feature is enabled) provides utilities for setting up a parachain WASM module in Rust.

Modules

  • primitives
    Primitive types which are strictly necessary from a parachain-execution point of view.