solutions/runtime/src/lib.rs

//! The Substrate Node Template runtime. This can be compiled with `#[no_std]`, ready for Wasm.

#![cfg_attr(not(feature = "std"), no_std)]
// `construct_runtime!` does a lot of recursion and requires us to increase the limit to 256.
#![recursion_limit="256"]

// Make the WASM binary available.
#[cfg(feature = "std")]
include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));

use rstd::prelude::*;
use primitives::{OpaqueMetadata, crypto::key_types};
use sr_primitives::{
	ApplyResult, transaction_validity::TransactionValidity, generic, create_runtime_str,
	impl_opaque_keys, AnySignature
};
use sr_primitives::traits::{NumberFor, BlakeTwo256, Block as BlockT, DigestFor, StaticLookup, Verify, ConvertInto};
use sr_primitives::weights::Weight;
use babe::{AuthorityId as BabeId};
use grandpa::{AuthorityId as GrandpaId, AuthorityWeight as GrandpaWeight};
use grandpa::fg_primitives::{self, ScheduledChange};
use client::{
	block_builder::api::{CheckInherentsResult, InherentData, self as block_builder_api},
	runtime_api as client_api, impl_runtime_apis
};
use version::RuntimeVersion;
#[cfg(feature = "std")]
use version::NativeVersion;

// A few exports that help ease life for downstream crates.
#[cfg(any(feature = "std", test))]
pub use sr_primitives::BuildStorage;
pub use timestamp::Call as TimestampCall;
pub use balances::Call as BalancesCall;
pub use sr_primitives::{Permill, Perbill};
pub use support::{StorageValue, construct_runtime, parameter_types};

/// An index to a block.
pub type BlockNumber = u32;

/// Alias to 512-bit hash when used in the context of a transaction signature on the chain.
pub type Signature = AnySignature;

/// Some way of identifying an account on the chain. We intentionally make it equivalent
/// to the public key of our transaction signing scheme.
pub type AccountId = <Signature as Verify>::Signer;

/// The type for looking up accounts. We don't expect more than 4 billion of them, but you
/// never know...
pub type AccountIndex = u32;

/// Balance of an account.
pub type Balance = u128;

/// Index of a transaction in the chain.
pub type Index = u32;

/// A hash of some data used by the chain.
pub type Hash = primitives::H256;

/// Digest item type.
pub type DigestItem = generic::DigestItem<Hash>;

/// Used for the module template in `./template.rs`
mod template;

/// Opaque types. These are used by the CLI to instantiate machinery that don't need to know
/// the specifics of the runtime. They can then be made to be agnostic over specific formats
/// of data like extrinsics, allowing for them to continue syncing the network through upgrades
/// to even the core datastructures.
pub mod opaque {
	use super::*;

	pub use sr_primitives::OpaqueExtrinsic as UncheckedExtrinsic;

	/// Opaque block header type.
	pub type Header = generic::Header<BlockNumber, BlakeTwo256>;
	/// Opaque block type.
	pub type Block = generic::Block<Header, UncheckedExtrinsic>;
	/// Opaque block identifier type.
	pub type BlockId = generic::BlockId<Block>;

	pub type SessionHandlers = (Grandpa, Babe);

	impl_opaque_keys! {
		pub struct SessionKeys {
			#[id(key_types::GRANDPA)]
			pub grandpa: GrandpaId,
			#[id(key_types::BABE)]
			pub babe: BabeId,
		}
	}
}

/// This runtime version.
pub const VERSION: RuntimeVersion = RuntimeVersion {
	spec_name: create_runtime_str!("node-template"),
	impl_name: create_runtime_str!("node-template"),
	authoring_version: 3,
	spec_version: 4,
	impl_version: 4,
	apis: RUNTIME_API_VERSIONS,
};

/// Constants for Babe.

/// Since BABE is probabilistic this is the average expected block time that
/// we are targetting. Blocks will be produced at a minimum duration defined
/// by `SLOT_DURATION`, but some slots will not be allocated to any
/// authority and hence no block will be produced. We expect to have this
/// block time on average following the defined slot duration and the value
/// of `c` configured for BABE (where `1 - c` represents the probability of
/// a slot being empty).
/// This value is only used indirectly to define the unit constants below
/// that are expressed in blocks. The rest of the code should use
/// `SLOT_DURATION` instead (like the timestamp module for calculating the
/// minimum period).
/// <https://research.web3.foundation/en/latest/polkadot/BABE/Babe/#6-practical-results>
pub const MILLISECS_PER_BLOCK: u64 = 6000;

pub const SLOT_DURATION: u64 = MILLISECS_PER_BLOCK;

pub const EPOCH_DURATION_IN_BLOCKS: u32 = 10 * MINUTES;

// These time units are defined in number of blocks.
pub const MINUTES: BlockNumber = 60_000 / (MILLISECS_PER_BLOCK as BlockNumber);
pub const HOURS: BlockNumber = MINUTES * 60;
pub const DAYS: BlockNumber = HOURS * 24;

// 1 in 4 blocks (on average, not counting collisions) will be primary babe blocks.
pub const PRIMARY_PROBABILITY: (u64, u64) = (1, 4);

/// The version infromation used to identify this runtime when compiled natively.
#[cfg(feature = "std")]
pub fn native_version() -> NativeVersion {
	NativeVersion {
		runtime_version: VERSION,
		can_author_with: Default::default(),
	}
}

parameter_types! {
	pub const BlockHashCount: BlockNumber = 250;
	pub const MaximumBlockWeight: Weight = 1_000_000;
	pub const AvailableBlockRatio: Perbill = Perbill::from_percent(75);
	pub const MaximumBlockLength: u32 = 5 * 1024 * 1024;
	pub const Version: RuntimeVersion = VERSION;
}

impl system::Trait for Runtime {
	/// The identifier used to distinguish between accounts.
	type AccountId = AccountId;
	/// The aggregated dispatch type that is available for extrinsics.
	type Call = Call;
	/// The lookup mechanism to get account ID from whatever is passed in dispatchers.
	type Lookup = Indices;
	/// The index type for storing how many extrinsics an account has signed.
	type Index = Index;
	/// The index type for blocks.
	type BlockNumber = BlockNumber;
	/// The type for hashing blocks and tries.
	type Hash = Hash;
	/// The hashing algorithm used.
	type Hashing = BlakeTwo256;
	/// The header type.
	type Header = generic::Header<BlockNumber, BlakeTwo256>;
	/// The ubiquitous event type.
	type Event = Event;
	/// Update weight (to fee) multiplier per-block.
	type WeightMultiplierUpdate = ();
	/// The ubiquitous origin type.
	type Origin = Origin;
	/// Maximum number of block number to block hash mappings to keep (oldest pruned first).
	type BlockHashCount = BlockHashCount;
	/// Maximum weight of each block. With a default weight system of 1byte == 1weight, 4mb is ok.
	type MaximumBlockWeight = MaximumBlockWeight;
	/// Maximum size of all encoded transactions (in bytes) that are allowed in one block.
	type MaximumBlockLength = MaximumBlockLength;
	/// Portion of the block weight that is available to all normal transactions.
	type AvailableBlockRatio = AvailableBlockRatio;
	type Version = Version;
}

parameter_types! {
	pub const EpochDuration: u64 = EPOCH_DURATION_IN_BLOCKS as u64;
	pub const ExpectedBlockTime: u64 = MILLISECS_PER_BLOCK;
}

impl babe::Trait for Runtime {
	type EpochDuration = EpochDuration;
	type ExpectedBlockTime = ExpectedBlockTime;
}

impl grandpa::Trait for Runtime {
	type Event = Event;
}

impl indices::Trait for Runtime {
	/// The type for recording indexing into the account enumeration. If this ever overflows, there
	/// will be problems!
	type AccountIndex = u32;
	/// Use the standard means of resolving an index hint from an id.
	type ResolveHint = indices::SimpleResolveHint<Self::AccountId, Self::AccountIndex>;
	/// Determine whether an account is dead.
	type IsDeadAccount = Balances;
	/// The ubiquitous event type.
	type Event = Event;
}

parameter_types! {
	pub const MinimumPeriod: u64 = 5000;
}

impl timestamp::Trait for Runtime {
	/// A timestamp: milliseconds since the unix epoch.
	type Moment = u64;
	type OnTimestampSet = Babe;
	type MinimumPeriod = MinimumPeriod;
}

parameter_types! {
	pub const ExistentialDeposit: u128 = 500;
	pub const TransferFee: u128 = 0;
	pub const CreationFee: u128 = 0;
	pub const TransactionBaseFee: u128 = 0;
	pub const TransactionByteFee: u128 = 1;
}

impl balances::Trait for Runtime {
	/// The type for recording an account's balance.
	type Balance = Balance;
	/// What to do if an account's free balance gets zeroed.
	type OnFreeBalanceZero = ();
	/// What to do if a new account is created.
	type OnNewAccount = Indices;
	/// The ubiquitous event type.
	type Event = Event;

	type TransactionPayment = ();
	type DustRemoval = ();
	type TransferPayment = ();
	type ExistentialDeposit = ExistentialDeposit;
	type TransferFee = TransferFee;
	type CreationFee = CreationFee;
	type TransactionBaseFee = TransactionBaseFee;
	type TransactionByteFee = TransactionByteFee;
	type WeightToFee = ConvertInto;
}

impl sudo::Trait for Runtime {
	type Event = Event;
	type Proposal = Call;
}

/// Used for the module template in `./template.rs`
impl template::Trait for Runtime {
	type Event = Event;
}

construct_runtime!(
	pub enum Runtime where
		Block = Block,
		NodeBlock = opaque::Block,
		UncheckedExtrinsic = UncheckedExtrinsic
	{
		System: system::{Module, Call, Storage, Config, Event},
		Timestamp: timestamp::{Module, Call, Storage, Inherent},
		Babe: babe::{Module, Call, Storage, Config, Inherent(Timestamp)},
		Grandpa: grandpa::{Module, Call, Storage, Config, Event},
		Indices: indices::{default, Config<T>},
		Balances: balances,
		Sudo: sudo,
		// Used for the module template in `./template.rs`
		TemplateModule: template::{Module, Call, Storage, Event<T>},
	}
);

/// The address format for describing accounts.
pub type Address = <Indices as StaticLookup>::Source;
/// Block header type as expected by this runtime.
pub type Header = generic::Header<BlockNumber, BlakeTwo256>;
/// Block type as expected by this runtime.
pub type Block = generic::Block<Header, UncheckedExtrinsic>;
/// A Block signed with a Justification
pub type SignedBlock = generic::SignedBlock<Block>;
/// BlockId type as expected by this runtime.
pub type BlockId = generic::BlockId<Block>;
/// The SignedExtension to the basic transaction logic.
pub type SignedExtra = (
	system::CheckVersion<Runtime>,
	system::CheckGenesis<Runtime>,
	system::CheckEra<Runtime>,
	system::CheckNonce<Runtime>,
	system::CheckWeight<Runtime>,
	balances::TakeFees<Runtime>
);
/// Unchecked extrinsic type as expected by this runtime.
pub type UncheckedExtrinsic = generic::UncheckedExtrinsic<Address, Call, Signature, SignedExtra>;
/// Extrinsic type that has already been checked.
pub type CheckedExtrinsic = generic::CheckedExtrinsic<AccountId, Call, SignedExtra>;
/// Executive: handles dispatch to the various modules.
pub type Executive = executive::Executive<Runtime, Block, system::ChainContext<Runtime>, Runtime, AllModules>;

impl_runtime_apis! {
	impl client_api::Core<Block> for Runtime {
		fn version() -> RuntimeVersion {
			VERSION
		}

		fn execute_block(block: Block) {
			Executive::execute_block(block)
		}

		fn initialize_block(header: &<Block as BlockT>::Header) {
			Executive::initialize_block(header)
		}
	}

	impl client_api::Metadata<Block> for Runtime {
		fn metadata() -> OpaqueMetadata {
			Runtime::metadata().into()
		}
	}

	impl block_builder_api::BlockBuilder<Block> for Runtime {
		fn apply_extrinsic(extrinsic: <Block as BlockT>::Extrinsic) -> ApplyResult {
			Executive::apply_extrinsic(extrinsic)
		}

		fn finalize_block() -> <Block as BlockT>::Header {
			Executive::finalize_block()
		}

		fn inherent_extrinsics(data: InherentData) -> Vec<<Block as BlockT>::Extrinsic> {
			data.create_extrinsics()
		}

		fn check_inherents(block: Block, data: InherentData) -> CheckInherentsResult {
			data.check_extrinsics(&block)
		}

		fn random_seed() -> <Block as BlockT>::Hash {
			System::random_seed()
		}
	}

	impl client_api::TaggedTransactionQueue<Block> for Runtime {
		fn validate_transaction(tx: <Block as BlockT>::Extrinsic) -> TransactionValidity {
			Executive::validate_transaction(tx)
		}
	}

	impl offchain_primitives::OffchainWorkerApi<Block> for Runtime {
		fn offchain_worker(number: NumberFor<Block>) {
			Executive::offchain_worker(number)
		}
	}

	impl fg_primitives::GrandpaApi<Block> for Runtime {
		fn grandpa_pending_change(digest: &DigestFor<Block>)
			-> Option<ScheduledChange<NumberFor<Block>>>
		{
			Grandpa::pending_change(digest)
		}

		fn grandpa_forced_change(digest: &DigestFor<Block>)
			-> Option<(NumberFor<Block>, ScheduledChange<NumberFor<Block>>)>
		{
			Grandpa::forced_change(digest)
		}

		fn grandpa_authorities() -> Vec<(GrandpaId, GrandpaWeight)> {
			Grandpa::grandpa_authorities()
		}
	}

	impl babe_primitives::BabeApi<Block> for Runtime {
		fn startup_data() -> babe_primitives::BabeConfiguration {
			// The choice of `c` parameter (where `1 - c` represents the
			// probability of a slot being empty), is done in accordance to the
			// slot duration and expected target block time, for safely
			// resisting network delays of maximum two seconds.
			// <https://research.web3.foundation/en/latest/polkadot/BABE/Babe/#6-practical-results>
			babe_primitives::BabeConfiguration {
				median_required_blocks: 1000,
				slot_duration: Babe::slot_duration(),
				c: PRIMARY_PROBABILITY,
			}
		}

		fn epoch() -> babe_primitives::Epoch {
			babe_primitives::Epoch {
				start_slot: Babe::epoch_start_slot(),
				authorities: Babe::authorities(),
				epoch_index: Babe::epoch_index(),
				randomness: Babe::randomness(),
				duration: EpochDuration::get(),
				secondary_slots: Babe::secondary_slots().0,
			}
		}
	}

	impl substrate_session::SessionKeys<Block> for Runtime {
		fn generate_session_keys(seed: Option<Vec<u8>>) -> Vec<u8> {
			let seed = seed.as_ref().map(|s| rstd::str::from_utf8(&s).expect("Seed is an utf8 string"));
			opaque::SessionKeys::generate(seed)
		}
	}
}