//! # Cumulus
//!
//! Substrate provides a framework ([FRAME]) through which a blockchain node and runtime can easily
//! be created. Cumulus aims to extend the same approach to creation of Polkadot parachains.
//!
//! > Cumulus clouds are shaped sort of like dots; together they form a system that is intricate,
//! > beautiful and functional.
//!
//! ## Example: Runtime
//!
//! A Cumulus-based runtime is fairly similar to other [FRAME]-based runtimes. Most notably, the
//! following changes are applied to a normal FRAME-based runtime to make it a Cumulus-based
//! runtime:
//!
//! #### Cumulus Pallets
//!
//! A parachain runtime should use a number of pallets that are provided by Cumulus and Substrate.
//! Notably:
//!
//! - [`frame-system`](frame::prelude::frame_system), like all FRAME-based runtimes.
//! - [`cumulus_pallet_parachain_system`]
//! - [`parachain_info`]
#![doc = docify::embed!("./src/polkadot_sdk/cumulus.rs", system_pallets)]
//!
//! Given that all Cumulus-based runtimes use a simple Aura-based consensus mechanism, the following
//! pallets also need to be added:
//!
//! - [`pallet_timestamp`]
//! - [`pallet_aura`]
//! - [`cumulus_pallet_aura_ext`]
#![doc = docify::embed!("./src/polkadot_sdk/cumulus.rs", consensus_pallets)]
//!
//!
//! Finally, a separate macro, similar to
//! [`impl_runtime_api`](frame::runtime::prelude::impl_runtime_apis), which creates the default set
//! of runtime APIs, will generate the parachain runtime's validation runtime API, also known as
//! parachain validation function (PVF). Without this API, the relay chain is unable to validate
//! blocks produced by our parachain.
#![doc = docify::embed!("./src/polkadot_sdk/cumulus.rs", validate_block)]
//!
//! ---
//!
//! [FRAME]: crate::polkadot_sdk::frame_runtime
#![deny(rustdoc::broken_intra_doc_links)]
#![deny(rustdoc::private_intra_doc_links)]
#[cfg(test)]
mod tests {
mod runtime {
pub use frame::{
deps::sp_consensus_aura::sr25519::AuthorityId as AuraId, prelude::*,
runtime::prelude::*, testing_prelude::*,
};
#[docify::export(CR)]
construct_runtime!(
pub enum Runtime {
// system-level pallets.
System: frame_system,
Timestamp: pallet_timestamp,
ParachainSystem: cumulus_pallet_parachain_system,
ParachainInfo: parachain_info,
// parachain consensus support -- mandatory.
Aura: pallet_aura,
AuraExt: cumulus_pallet_aura_ext,
}
);
#[docify::export]
mod system_pallets {
use super::*;
#[derive_impl(frame_system::config_preludes::TestDefaultConfig)]
impl frame_system::Config for Runtime {
type Block = MockBlock<Self>;
type OnSetCode = cumulus_pallet_parachain_system::ParachainSetCode<Self>;
}
impl cumulus_pallet_parachain_system::Config for Runtime {
type RuntimeEvent = RuntimeEvent;
type OnSystemEvent = ();
type SelfParaId = parachain_info::Pallet<Runtime>;
type OutboundXcmpMessageSource = ();
type XcmpMessageHandler = ();
type ReservedDmpWeight = ();
type ReservedXcmpWeight = ();
type CheckAssociatedRelayNumber =
cumulus_pallet_parachain_system::RelayNumberMonotonicallyIncreases;
type ConsensusHook = cumulus_pallet_aura_ext::FixedVelocityConsensusHook<
Runtime,
6000, // relay chain block time
1,
1,
>;
type WeightInfo = ();
type DmpQueue = frame::traits::EnqueueWithOrigin<(), sp_core::ConstU8<0>>;
type SelectCore = cumulus_pallet_parachain_system::DefaultCoreSelector<Runtime>;
}
impl parachain_info::Config for Runtime {}
}
#[docify::export]
mod consensus_pallets {
use super::*;
impl pallet_aura::Config for Runtime {
type AuthorityId = AuraId;
type DisabledValidators = ();
type MaxAuthorities = ConstU32<100_000>;
type AllowMultipleBlocksPerSlot = ConstBool<false>;
type SlotDuration = pallet_aura::MinimumPeriodTimesTwo<Self>;
}
#[docify::export(timestamp)]
#[derive_impl(pallet_timestamp::config_preludes::TestDefaultConfig)]
impl pallet_timestamp::Config for Runtime {}
impl cumulus_pallet_aura_ext::Config for Runtime {}
}
#[docify::export(validate_block)]
cumulus_pallet_parachain_system::register_validate_block! {
Runtime = Runtime,
BlockExecutor = cumulus_pallet_aura_ext::BlockExecutor::<Runtime, Executive>,
}
}
}