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pezkuwi-subxt/substrate/primitives/consensus/babe/src/inherents.rs
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2020-05-15 13:21:56 +02:00

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Rust

// This file is part of Substrate.
// Copyright (C) 2019-2020 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//! Inherents for BABE
use sp_inherents::{Error, InherentData, InherentIdentifier};
#[cfg(feature = "std")]
use sp_inherents::{InherentDataProviders, ProvideInherentData};
#[cfg(feature = "std")]
use sp_timestamp::TimestampInherentData;
#[cfg(feature = "std")]
use codec::Decode;
use sp_std::result::Result;
/// The BABE inherent identifier.
pub const INHERENT_IDENTIFIER: InherentIdentifier = *b"babeslot";
/// The type of the BABE inherent.
pub type InherentType = u64;
/// Auxiliary trait to extract BABE inherent data.
pub trait BabeInherentData {
/// Get BABE inherent data.
fn babe_inherent_data(&self) -> Result<InherentType, Error>;
/// Replace BABE inherent data.
fn babe_replace_inherent_data(&mut self, new: InherentType);
}
impl BabeInherentData for InherentData {
fn babe_inherent_data(&self) -> Result<InherentType, Error> {
self.get_data(&INHERENT_IDENTIFIER)
.and_then(|r| r.ok_or_else(|| "BABE inherent data not found".into()))
}
fn babe_replace_inherent_data(&mut self, new: InherentType) {
self.replace_data(INHERENT_IDENTIFIER, &new);
}
}
/// Provides the slot duration inherent data for BABE.
#[cfg(feature = "std")]
pub struct InherentDataProvider {
slot_duration: u64,
}
#[cfg(feature = "std")]
impl InherentDataProvider {
/// Constructs `Self`
pub fn new(slot_duration: u64) -> Self {
Self { slot_duration }
}
}
#[cfg(feature = "std")]
impl ProvideInherentData for InherentDataProvider {
fn on_register(&self, providers: &InherentDataProviders) -> Result<(), Error> {
if !providers.has_provider(&sp_timestamp::INHERENT_IDENTIFIER) {
// Add the timestamp inherent data provider, as we require it.
providers.register_provider(sp_timestamp::InherentDataProvider)
} else {
Ok(())
}
}
fn inherent_identifier(&self) -> &'static InherentIdentifier {
&INHERENT_IDENTIFIER
}
fn provide_inherent_data(&self, inherent_data: &mut InherentData) -> Result<(), Error> {
let timestamp = inherent_data.timestamp_inherent_data()?;
let slot_number = timestamp / self.slot_duration;
inherent_data.put_data(INHERENT_IDENTIFIER, &slot_number)
}
fn error_to_string(&self, error: &[u8]) -> Option<String> {
Error::decode(&mut &error[..]).map(|e| e.into_string()).ok()
}
}