lib.rs

// This file is part of Substrate.

// Copyright (C) 2017-2021 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.

//! # System Pallet
//!
//! The System pallet provides low-level access to core types and cross-cutting utilities.
//! It acts as the base layer for other pallets to interact with the Substrate framework components.
//!
//! - [`Config`]
//!
//! ## Overview
//!
//! The System pallet defines the core data types used in a Substrate runtime.
//! It also provides several utility functions (see [`Pallet`]) for other FRAME pallets.
//!
//! In addition, it manages the storage items for extrinsics data, indexes, event records, and digest items,
//! among other things that support the execution of the current block.
//!
//! It also handles low-level tasks like depositing logs, basic set up and take down of
//! temporary storage entries, and access to previous block hashes.
//!
//! ## Interface
//!
//! ### Dispatchable Functions
//!
//! The System pallet does not implement any dispatchable functions.
//!
//! ### Public Functions
//!
//! See the [`Pallet`] struct for details of publicly available functions.
//!
//! ### Signed Extensions
//!
//! The System pallet defines the following extensions:
//!
//!   - [`CheckWeight`]: Checks the weight and length of the block and ensure that it does not
//!     exceed the limits.
//!   - [`CheckNonce`]: Checks the nonce of the transaction. Contains a single payload of type
//!     `T::Index`.
//!   - [`CheckEra`]: Checks the era of the transaction. Contains a single payload of type `Era`.
//!   - [`CheckGenesis`]: Checks the provided genesis hash of the transaction. Must be a part of the
//!     signed payload of the transaction.
//!   - [`CheckSpecVersion`]: Checks that the runtime version is the same as the one used to sign the
//!     transaction.
//!   - [`CheckTxVersion`]: Checks that the transaction version is the same as the one used to sign the
//!     transaction.
//!
//! Lookup the runtime aggregator file (e.g. `node/runtime`) to see the full list of signed
//! extensions included in a chain.

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

#[cfg(feature = "std")]
use serde::Serialize;
use sp_std::prelude::*;
#[cfg(any(feature = "std", test))]
use sp_std::map;
use sp_std::marker::PhantomData;
use sp_std::fmt::Debug;
use sp_version::RuntimeVersion;
use sp_runtime::{
	RuntimeDebug, Perbill, DispatchError, Either, generic,
	traits::{
		self, CheckEqual, AtLeast32Bit, Zero, Lookup, LookupError,
		SimpleBitOps, Hash, Member, MaybeDisplay, BadOrigin,
		MaybeSerializeDeserialize, MaybeMallocSizeOf, StaticLookup, One, Bounded,
		Dispatchable, AtLeast32BitUnsigned, Saturating, StoredMapError,
	},
	offchain::storage_lock::BlockNumberProvider,
};

use sp_core::{ChangesTrieConfiguration, storage::well_known_keys};
use frame_support::{
	Parameter, debug, storage,
	traits::{
		Contains, Get, PalletInfo, OnNewAccount, OnKilledAccount, HandleLifetime,
		StoredMap, EnsureOrigin, OriginTrait, Filter,
	},
	weights::{
		Weight, RuntimeDbWeight, DispatchInfo, DispatchClass,
		extract_actual_weight, PerDispatchClass,
	},
	dispatch::DispatchResultWithPostInfo,
};
use codec::{Encode, Decode, FullCodec, EncodeLike};

#[cfg(feature = "std")]
use frame_support::traits::GenesisBuild;
#[cfg(any(feature = "std", test))]
use sp_io::TestExternalities;

pub mod offchain;
pub mod limits;
#[cfg(test)]
pub(crate) mod mock;

mod extensions;
pub mod weights;
#[cfg(test)]
mod tests;
#[cfg(feature = "std")]
pub mod mocking;


pub use extensions::{
	check_mortality::CheckMortality, check_genesis::CheckGenesis, check_nonce::CheckNonce,
	check_spec_version::CheckSpecVersion, check_tx_version::CheckTxVersion,
	check_weight::CheckWeight,
};
// Backward compatible re-export.
pub use extensions::check_mortality::CheckMortality as CheckEra;
pub use weights::WeightInfo;

/// Compute the trie root of a list of extrinsics.
pub fn extrinsics_root<H: Hash, E: codec::Encode>(extrinsics: &[E]) -> H::Output {
	extrinsics_data_root::<H>(extrinsics.iter().map(codec::Encode::encode).collect())
}

/// Compute the trie root of a list of extrinsics.
pub fn extrinsics_data_root<H: Hash>(xts: Vec<Vec<u8>>) -> H::Output {
	H::ordered_trie_root(xts)
}

/// An object to track the currently used extrinsic weight in a block.
pub type ConsumedWeight = PerDispatchClass<Weight>;

pub use pallet::*;

#[frame_support::pallet]
pub mod pallet {
	use crate::{*, pallet_prelude::*, self as frame_system};
	use frame_support::pallet_prelude::*;

	/// System configuration trait. Implemented by runtime.
	#[pallet::config]
	#[pallet::disable_frame_system_supertrait_check]
	pub trait Config: 'static + Eq + Clone {
		/// The basic call filter to use in Origin. All origins are built with this filter as base,
		/// except Root.
		type BaseCallFilter: Filter<Self::Call>;

		/// Block & extrinsics weights: base values and limits.
		#[pallet::constant]
		type BlockWeights: Get<limits::BlockWeights>;

		/// The maximum length of a block (in bytes).
		#[pallet::constant]
		type BlockLength: Get<limits::BlockLength>;

		/// The `Origin` type used by dispatchable calls.
		type Origin:
			Into<Result<RawOrigin<Self::AccountId>, Self::Origin>>
			+ From<RawOrigin<Self::AccountId>>
			+ Clone
			+ OriginTrait<Call=Self::Call>;

		/// The aggregated `Call` type.
		type Call: Dispatchable + Debug;

		/// Account index (aka nonce) type. This stores the number of previous transactions associated
		/// with a sender account.
		type Index:
			Parameter + Member + MaybeSerializeDeserialize + Debug + Default + MaybeDisplay + AtLeast32Bit
			+ Copy;

		/// The block number type used by the runtime.
		type BlockNumber:
			Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay +
			AtLeast32BitUnsigned + Default + Bounded + Copy + sp_std::hash::Hash +
			sp_std::str::FromStr + MaybeMallocSizeOf;

		/// The output of the `Hashing` function.
		type Hash:
			Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay + SimpleBitOps + Ord
			+ Default + Copy + CheckEqual + sp_std::hash::Hash + AsRef<[u8]> + AsMut<[u8]> + MaybeMallocSizeOf;

		/// The hashing system (algorithm) being used in the runtime (e.g. Blake2).
		type Hashing: Hash<Output=Self::Hash>;

		/// The user account identifier type for the runtime.
		type AccountId: Parameter + Member + MaybeSerializeDeserialize + Debug + MaybeDisplay + Ord
			+ Default;

		/// Converting trait to take a source type and convert to `AccountId`.
		///
		/// Used to define the type and conversion mechanism for referencing accounts in transactions.