lib.rs

// Copyright 2017-2020 Parity Technologies (UK) Ltd.
// This file is part of Polkadot.

// Polkadot is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Polkadot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.

//! Shareable Polkadot types.

#![warn(missing_docs)]

#![cfg_attr(not(feature = "std"), no_std)]

use runtime_primitives::{generic, MultiSignature};
pub use runtime_primitives::traits::{BlakeTwo256, Hash as HashT, Verify, IdentifyAccount};

pub mod parachain;

pub use parity_scale_codec::Compact;

/// An index to a block.
pub type BlockNumber = polkadot_parachain::primitives::RelayChainBlockNumber;

/// An instant or duration in time.
pub type Moment = u64;

/// Alias to type for a signature for a transaction on the relay chain. This allows one of several
/// kinds of underlying crypto to be used, so isn't a fixed size when encoded.
pub type Signature = MultiSignature;

/// Alias to the public key used for this chain, actually a `MultiSigner`. Like the signature, this
/// also isn't a fixed size when encoded, as different cryptos have different size public keys.
pub type AccountPublic = <Signature as Verify>::Signer;

/// Alias to the opaque account ID type for this chain, actually a `AccountId32`. This is always
/// 32 bytes.
pub type AccountId = <AccountPublic as IdentifyAccount>::AccountId;

/// The type for looking up accounts. We don't expect more than 4 billion of them.
pub type AccountIndex = u32;

/// Identifier for a chain. 32-bit should be plenty.
pub type ChainId = u32;

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

/// Index of a transaction in the relay chain. 32-bit should be plenty.
pub type Nonce = u32;

/// The balance of an account.
/// 128-bits (or 38 significant decimal figures) will allow for 10m currency (10^7) at a resolution
/// to all for one second's worth of an annualised 50% reward be paid to a unit holder (10^11 unit
/// denomination), or 10^18 total atomic units, to grow at 50%/year for 51 years (10^9 multiplier)
/// for an eventual total of 10^27 units (27 significant decimal figures).
/// We round denomination to 10^12 (12 sdf), and leave the other redundancy at the upper end so
/// that 32 bits may be multiplied with a balance in 128 bits without worrying about overflow.
pub type Balance = u128;

/// Header type.
pub type Header = generic::Header<BlockNumber, BlakeTwo256>;
/// Block type.
pub type Block = generic::Block<Header, UncheckedExtrinsic>;
/// Block ID.
pub type BlockId = generic::BlockId<Block>;

/// Opaque, encoded, unchecked extrinsic.
pub use runtime_primitives::OpaqueExtrinsic as UncheckedExtrinsic;

/// Custom validity errors used in Polkadot while validating transactions.
#[repr(u8)]
pub enum ValidityError {
	/// The ethereum signature is invalid.
	InvalidEthereumSignature = 0,
	/// The signer has no claim.
	SignerHasNoClaim = 1,
	/// No permission to execute the call.
	NoPermission = 2,
}

impl From<ValidityError> for u8 {
	fn from(err: ValidityError) -> Self {
		err as u8
	}
}

/// App-specific crypto used for reporting equivocation/misbehavior in BABE,
/// GRANDPA and Parachains, described in the white paper as the fisherman role.
/// Any rewards for misbehavior reporting will be paid out to this account.
pub mod fisherman {
	use super::{Signature, Verify};
	use primitives::crypto::KeyTypeId;

	/// Key type for the reporting module. Used for reporting BABE, GRANDPA
	/// and Parachain equivocations.
	pub const KEY_TYPE: KeyTypeId = KeyTypeId(*b"fish");

	mod app {
		use application_crypto::{app_crypto, sr25519};
		app_crypto!(sr25519, super::KEY_TYPE);
	}

	/// Identity of the equivocation/misbehavior reporter.
	pub type FishermanId = app::Public;

	/// An `AppCrypto` type to allow submitting signed transactions using the fisherman
	/// application key as signer.
	pub struct FishermanAppCrypto;
	impl system::offchain::AppCrypto<<Signature as Verify>::Signer, Signature> for FishermanAppCrypto {
		type RuntimeAppPublic = FishermanId;
		type GenericSignature = primitives::sr25519::Signature;
		type GenericPublic = primitives::sr25519::Public;
	}
}