lib.rs

// This file is part of Substrate.

// Copyright (C) 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.

//! # Substrate Primitives: IO
//!
//! This crate contains interfaces for the runtime to communicate with the outside world, ergo `io`.
//! In other context, such interfaces are referred to as "**host functions**".
//!
//! Each set of host functions are defined with an instance of the
//! [`sp_runtime_interface::runtime_interface`] macro.
//!
//! Most notably, this crate contains host functions for:
//!
//! - [`hashing`]
//! - [`crypto`]
//! - [`trie`]
//! - [`offchain`]
//! - [`storage`]
//! - [`allocator`]
//! - [`logging`]
//!
//! All of the default host functions provided by this crate, and by default contained in all
//! substrate-based clients are amalgamated in [`SubstrateHostFunctions`].
//!
//! ## Externalities
//!
//! Host functions go hand in hand with the concept of externalities. Externalities are an
//! environment in which host functions are provided, and thus can be accessed. Some host functions
//! are only accessible in an externality environment that provides it.
//!
//! A typical error for substrate developers is the following:
//!
//! ```should_panic
//! use sp_io::storage::get;
//! # fn main() {
//! let data = get(b"hello world");
//! # }
//! ```
//!
//! This code will panic with the following error:
//!
//! ```no_compile
//! thread 'main' panicked at '`get_version_1` called outside of an Externalities-provided environment.'
//! ```
//!
//! Such error messages should always be interpreted as "code accessing host functions accessed
//! outside of externalities".
//!
//! An externality is any type that implements [`sp_externalities::Externalities`]. A simple example
//! of which is [`TestExternalities`], which is commonly used in tests and is exported from this
//! crate.
//!
//! ```
//! use sp_io::{storage::get, TestExternalities};
//! # fn main() {
//! TestExternalities::default().execute_with(|| {
//! 	let data = get(b"hello world");
//! });
//! # }
//! ```

#![warn(missing_docs)]
#![cfg_attr(not(feature = "std"), no_std)]
#![cfg_attr(enable_alloc_error_handler, feature(alloc_error_handler))]

use sp_std::vec::Vec;

#[cfg(feature = "std")]
use tracing;

#[cfg(feature = "std")]
use sp_core::{
	crypto::Pair,
	hexdisplay::HexDisplay,
	offchain::{OffchainDbExt, OffchainWorkerExt, TransactionPoolExt},
	storage::ChildInfo,
};
#[cfg(feature = "std")]
use sp_keystore::KeystoreExt;

use sp_core::{
	crypto::KeyTypeId,
	ecdsa, ed25519,
	offchain::{
		HttpError, HttpRequestId, HttpRequestStatus, OpaqueNetworkState, StorageKind, Timestamp,
	},
	sr25519,
	storage::StateVersion,
	LogLevel, LogLevelFilter, OpaquePeerId, H256,
};

#[cfg(feature = "std")]
use sp_trie::{LayoutV0, LayoutV1, TrieConfiguration};

use sp_runtime_interface::{
	pass_by::{PassBy, PassByCodec},
	runtime_interface, Pointer,
};

use codec::{Decode, Encode};

#[cfg(feature = "std")]
use secp256k1::{
	ecdsa::{RecoverableSignature, RecoveryId},
	Message, SECP256K1,
};

#[cfg(feature = "std")]
use sp_externalities::{Externalities, ExternalitiesExt};

pub use sp_externalities::MultiRemovalResults;

#[cfg(feature = "std")]
const LOG_TARGET: &str = "runtime::io";

/// Error verifying ECDSA signature
#[derive(Encode, Decode)]
pub enum EcdsaVerifyError {
	/// Incorrect value of R or S
	BadRS,
	/// Incorrect value of V
	BadV,
	/// Invalid signature
	BadSignature,
}

/// The outcome of calling `storage_kill`. Returned value is the number of storage items
/// removed from the backend from making the `storage_kill` call.
#[derive(PassByCodec, Encode, Decode)]
pub enum KillStorageResult {
	/// All keys to remove were removed, return number of iterations performed during the
	/// operation.
	AllRemoved(u32),
	/// Not all key to remove were removed, return number of iterations performed during the
	/// operation.
	SomeRemaining(u32),
}

impl From<MultiRemovalResults> for KillStorageResult {
	fn from(r: MultiRemovalResults) -> Self {
		// We use `loops` here rather than `backend` because that's the same as the original
		// functionality pre-#11490. This won't matter once we switch to the new host function
		// since we won't be using the `KillStorageResult` type in the runtime any more.
		match r.maybe_cursor {
			None => Self::AllRemoved(r.loops),
			Some(..) => Self::SomeRemaining(r.loops),
		}
	}
}

/// Interface for accessing the storage from within the runtime.
#[runtime_interface]
pub trait Storage {
	/// Returns the data for `key` in the storage or `None` if the key can not be found.
	fn get(&self, key: &[u8]) -> Option<bytes::Bytes> {
		self.storage(key).map(|s| bytes::Bytes::from(s.to_vec()))
	}

	/// Get `key` from storage, placing the value into `value_out` and return the number of
	/// bytes that the entry in storage has beyond the offset or `None` if the storage entry
	/// doesn't exist at all.
	/// If `value_out` length is smaller than the returned length, only `value_out` length bytes
	/// are copied into `value_out`.
	fn read(&self, key: &[u8], value_out: &mut [u8], value_offset: u32) -> Option<u32> {
		self.storage(key).map(|value| {
			let value_offset = value_offset as usize;
			let data = &value[value_offset.min(value.len())..];
			let written = std::cmp::min(data.len(), value_out.len());
			value_out[..written].copy_from_slice(&data[..written]);
			data.len() as u32
		})
	}

	/// Set `key` to `value` in the storage.
	fn set(&mut self, key: &[u8], value: &[u8]) {
		self.set_storage(key.to_vec(), value.to_vec());
	}

	/// Clear the storage of the given `key` and its value.
	fn clear(&mut self, key: &[u8]) {
		self.clear_storage(key)
	}

	/// Check whether the given `key` exists in storage.
	fn exists(&self, key: &[u8]) -> bool {
		self.exists_storage(key)