1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146
// Copyright 2019-2020 Parity Technologies (UK) Ltd. // This file is part of Substrate. // Substrate 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. // Substrate 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 Substrate. If not, see <http://www.gnu.org/licenses/>. //! Primitives for BABE. #![deny(warnings)] #![forbid(unsafe_code, missing_docs, unused_variables, unused_imports)] #![cfg_attr(not(feature = "std"), no_std)] pub mod digests; pub mod inherents; use codec::{Encode, Decode}; use sp_std::vec::Vec; use sp_runtime::{ConsensusEngineId, RuntimeDebug}; use crate::digests::NextEpochDescriptor; mod app { use sp_application_crypto::{app_crypto, key_types::BABE, sr25519}; app_crypto!(sr25519, BABE); } /// The prefix used by BABE for its VRF keys. pub const BABE_VRF_PREFIX: &[u8] = b"substrate-babe-vrf"; /// A Babe authority keypair. Necessarily equivalent to the schnorrkel public key used in /// the main Babe module. If that ever changes, then this must, too. #[cfg(feature = "std")] pub type AuthorityPair = app::Pair; /// A Babe authority signature. pub type AuthoritySignature = app::Signature; /// A Babe authority identifier. Necessarily equivalent to the schnorrkel public key used in /// the main Babe module. If that ever changes, then this must, too. pub type AuthorityId = app::Public; /// The `ConsensusEngineId` of BABE. pub const BABE_ENGINE_ID: ConsensusEngineId = *b"BABE"; /// The length of the VRF output pub const VRF_OUTPUT_LENGTH: usize = 32; /// The length of the VRF proof pub const VRF_PROOF_LENGTH: usize = 64; /// The length of the public key pub const PUBLIC_KEY_LENGTH: usize = 32; /// How many blocks to wait before running the median algorithm for relative time /// This will not vary from chain to chain as it is not dependent on slot duration /// or epoch length. pub const MEDIAN_ALGORITHM_CARDINALITY: usize = 1200; // arbitrary suggestion by w3f-research. /// The index of an authority. pub type AuthorityIndex = u32; /// A slot number. pub type SlotNumber = u64; /// The weight of an authority. // NOTE: we use a unique name for the weight to avoid conflicts with other // `Weight` types, since the metadata isn't able to disambiguate. pub type BabeAuthorityWeight = u64; /// The weight of a BABE block. pub type BabeBlockWeight = u32; /// An consensus log item for BABE. #[derive(Decode, Encode, Clone, PartialEq, Eq)] pub enum ConsensusLog { /// The epoch has changed. This provides information about the _next_ /// epoch - information about the _current_ epoch (i.e. the one we've just /// entered) should already be available earlier in the chain. #[codec(index = "1")] NextEpochData(NextEpochDescriptor), /// Disable the authority with given index. #[codec(index = "2")] OnDisabled(AuthorityIndex), } /// Configuration data used by the BABE consensus engine. #[derive(Clone, PartialEq, Eq, Encode, Decode, RuntimeDebug)] pub struct BabeConfiguration { /// The slot duration in milliseconds for BABE. Currently, only /// the value provided by this type at genesis will be used. /// /// Dynamic slot duration may be supported in the future. pub slot_duration: u64, /// The duration of epochs in slots. pub epoch_length: SlotNumber, /// A constant value that is used in the threshold calculation formula. /// Expressed as a rational where the first member of the tuple is the /// numerator and the second is the denominator. The rational should /// represent a value between 0 and 1. /// In the threshold formula calculation, `1 - c` represents the probability /// of a slot being empty. pub c: (u64, u64), /// The authorities for the genesis epoch. pub genesis_authorities: Vec<(AuthorityId, BabeAuthorityWeight)>, /// The randomness for the genesis epoch. pub randomness: [u8; VRF_OUTPUT_LENGTH], /// Whether this chain should run with secondary slots, which are assigned /// in round-robin manner. pub secondary_slots: bool, } #[cfg(feature = "std")] impl sp_consensus::SlotData for BabeConfiguration { fn slot_duration(&self) -> u64 { self.slot_duration } const SLOT_KEY: &'static [u8] = b"babe_configuration"; } sp_api::decl_runtime_apis! { /// API necessary for block authorship with BABE. pub trait BabeApi { /// Return the configuration for BABE. Currently, /// only the value provided by this type at genesis will be used. /// /// Dynamic configuration may be supported in the future. fn configuration() -> BabeConfiguration; /// Returns the slot number that started the current epoch. fn current_epoch_start() -> SlotNumber; } }