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// Copyright 2018-2020 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/>. //! # Contract Module //! //! The Contract module provides functionality for the runtime to deploy and execute WebAssembly smart-contracts. //! //! - [`contract::Trait`](./trait.Trait.html) //! - [`Call`](./enum.Call.html) //! //! ## Overview //! //! This module extends accounts based on the `Currency` trait to have smart-contract functionality. It can //! be used with other modules that implement accounts based on `Currency`. These "smart-contract accounts" //! have the ability to instantiate smart-contracts and make calls to other contract and non-contract accounts. //! //! The smart-contract code is stored once in a `code_cache`, and later retrievable via its `code_hash`. //! This means that multiple smart-contracts can be instantiated from the same `code_cache`, without replicating //! the code each time. //! //! When a smart-contract is called, its associated code is retrieved via the code hash and gets executed. //! This call can alter the storage entries of the smart-contract account, instantiate new smart-contracts, //! or call other smart-contracts. //! //! Finally, when an account is reaped, its associated code and storage of the smart-contract account //! will also be deleted. //! //! ### Gas //! //! Senders must specify a gas limit with every call, as all instructions invoked by the smart-contract require gas. //! Unused gas is refunded after the call, regardless of the execution outcome. //! //! If the gas limit is reached, then all calls and state changes (including balance transfers) are only //! reverted at the current call's contract level. For example, if contract A calls B and B runs out of gas mid-call, //! then all of B's calls are reverted. Assuming correct error handling by contract A, A's other calls and state //! changes still persist. //! //! ### Notable Scenarios //! //! Contract call failures are not always cascading. When failures occur in a sub-call, they do not "bubble up", //! and the call will only revert at the specific contract level. For example, if contract A calls contract B, and B //! fails, A can decide how to handle that failure, either proceeding or reverting A's changes. //! //! ## Interface //! //! ### Dispatchable functions //! //! * `put_code` - Stores the given binary Wasm code into the chain's storage and returns its `code_hash`. //! * `instantiate` - Deploys a new contract from the given `code_hash`, optionally transferring some balance. //! This instantiates a new smart contract account and calls its contract deploy handler to //! initialize the contract. //! * `call` - Makes a call to an account, optionally transferring some balance. //! //! ## Usage //! //! The Contract module is a work in progress. The following examples show how this Contract module //! can be used to instantiate and call contracts. //! //! * [`ink`](https://github.com/paritytech/ink) is //! an [`eDSL`](https://wiki.haskell.org/Embedded_domain_specific_language) that enables writing //! WebAssembly based smart contracts in the Rust programming language. This is a work in progress. //! //! ## Related Modules //! //! * [Balances](../pallet_balances/index.html) #![cfg_attr(not(feature = "std"), no_std)] #[macro_use] mod gas; mod storage; mod exec; mod wasm; mod rent; mod benchmarking; #[cfg(test)] mod tests; use crate::exec::ExecutionContext; use crate::wasm::{WasmLoader, WasmVm}; pub use crate::gas::{Gas, GasMeter}; pub use crate::exec::{ExecResult, ExecReturnValue}; pub use crate::wasm::ReturnCode as RuntimeReturnCode; #[cfg(feature = "std")] use serde::{Serialize, Deserialize}; use sp_core::crypto::UncheckedFrom; use sp_std::{prelude::*, marker::PhantomData, fmt::Debug}; use codec::{Codec, Encode, Decode}; use sp_runtime::{ traits::{ Hash, StaticLookup, Zero, MaybeSerializeDeserialize, Member, Convert, Saturating, }, RuntimeDebug, }; use frame_support::{ decl_module, decl_event, decl_storage, decl_error, ensure, parameter_types, storage::child::ChildInfo, dispatch::{DispatchResult, DispatchResultWithPostInfo}, traits::{OnUnbalanced, Currency, Get, Time, Randomness}, }; use frame_system::{ensure_signed, ensure_root}; use pallet_contracts_primitives::{RentProjection, ContractAccessError}; use frame_support::weights::Weight; pub type CodeHash<T> = <T as frame_system::Trait>::Hash; pub type TrieId = Vec<u8>; /// A function that generates an `AccountId` for a contract upon instantiation. pub trait ContractAddressFor<CodeHash, AccountId> { fn contract_address_for(code_hash: &CodeHash, data: &[u8], origin: &AccountId) -> AccountId; } /// Information for managing an account and its sub trie abstraction. /// This is the required info to cache for an account #[derive(Encode, Decode, RuntimeDebug)] pub enum ContractInfo<T: Trait> { Alive(AliveContractInfo<T>), Tombstone(TombstoneContractInfo<T>), } impl<T: Trait> ContractInfo<T> { /// If contract is alive then return some alive info pub fn get_alive(self) -> Option<AliveContractInfo<T>> { if let ContractInfo::Alive(alive) = self { Some(alive) } else { None } } /// If contract is alive then return some reference to alive info pub fn as_alive(&self) -> Option<&AliveContractInfo<T>> { if let ContractInfo::Alive(ref alive) = self { Some(alive) } else { None } } /// If contract is alive then return some mutable reference to alive info pub fn as_alive_mut(&mut self) -> Option<&mut AliveContractInfo<T>> { if let ContractInfo::Alive(ref mut alive) = self { Some(alive) } else { None } } /// If contract is tombstone then return some tombstone info pub fn get_tombstone(self) -> Option<TombstoneContractInfo<T>> { if let ContractInfo::Tombstone(tombstone) = self { Some(tombstone) } else { None } } /// If contract is tombstone then return some reference to tombstone info pub fn as_tombstone(&self) -> Option<&TombstoneContractInfo<T>> { if let ContractInfo::Tombstone(ref tombstone) = self { Some(tombstone) } else { None } } /// If contract is tombstone then return some mutable reference to tombstone info pub fn as_tombstone_mut(&mut self) -> Option<&mut TombstoneContractInfo<T>> { if let ContractInfo::Tombstone(ref mut tombstone) = self { Some(tombstone) } else { None } } } pub type AliveContractInfo<T> = RawAliveContractInfo<CodeHash<T>, BalanceOf<T>, <T as frame_system::Trait>::BlockNumber>; /// Information for managing an account and its sub trie abstraction. /// This is the required info to cache for an account. #[derive(Encode, Decode, Clone, PartialEq, Eq, RuntimeDebug)] pub struct RawAliveContractInfo<CodeHash, Balance, BlockNumber> { /// Unique ID for the subtree encoded as a bytes vector. pub trie_id: TrieId, /// The total number of bytes used by this contract. /// /// It is a sum of each key-value pair stored by this contract. pub storage_size: u32, /// The number of key-value pairs that have values of zero length. /// The condition `empty_pair_count ≤ total_pair_count` always holds. pub empty_pair_count: u32, /// The total number of key-value pairs in storage of this contract. pub total_pair_count: u32, /// The code associated with a given account. pub code_hash: CodeHash, /// Pay rent at most up to this value. pub rent_allowance: Balance, /// Last block rent has been payed. pub deduct_block: BlockNumber, /// Last block child storage has been written. pub last_write: Option<BlockNumber>, } impl<CodeHash, Balance, BlockNumber> RawAliveContractInfo<CodeHash, Balance, BlockNumber> { /// Associated child trie unique id is built from the hash part of the trie id. pub fn child_trie_info(&self) -> ChildInfo { child_trie_info(&self.trie_id[..]) } } /// Associated child trie unique id is built from the hash part of the trie id. pub(crate) fn child_trie_info(trie_id: &[u8]) -> ChildInfo { ChildInfo::new_default(trie_id) } pub type TombstoneContractInfo<T> = RawTombstoneContractInfo<<T as frame_system::Trait>::Hash, <T as frame_system::Trait>::Hashing>; #[derive(Encode, Decode, PartialEq, Eq, RuntimeDebug)] pub struct RawTombstoneContractInfo<H, Hasher>(H, PhantomData<Hasher>); impl<H, Hasher> RawTombstoneContractInfo<H, Hasher> where H: Member + MaybeSerializeDeserialize+ Debug + AsRef<[u8]> + AsMut<[u8]> + Copy + Default + sp_std::hash::Hash + Codec, Hasher: Hash<Output=H>, { fn new(storage_root: &[u8], code_hash: H) -> Self { let mut buf = Vec::new(); storage_root.using_encoded(|encoded| buf.extend_from_slice(encoded)); buf.extend_from_slice(code_hash.as_ref()); RawTombstoneContractInfo(<Hasher as Hash>::hash(&buf[..]), PhantomData) } } impl<T: Trait> From<AliveContractInfo<T>> for ContractInfo<T> { fn from(alive_info: AliveContractInfo<T>) -> Self { Self::Alive(alive_info) } } /// Get a trie id (trie id must be unique and collision resistant depending upon its context). /// Note that it is different than encode because trie id should be collision resistant /// (being a proper unique identifier). pub trait TrieIdGenerator<AccountId> { /// Get a trie id for an account, using reference to parent account trie id to ensure /// uniqueness of trie id. /// /// The implementation must ensure every new trie id is unique: two consecutive calls with the /// same parameter needs to return different trie id values. fn trie_id(account_id: &AccountId) -> TrieId; } /// Get trie id from `account_id`. pub struct TrieIdFromParentCounter<T: Trait>(PhantomData<T>); /// This generator uses inner counter for account id and applies the hash over `AccountId + /// accountid_counter`. impl<T: Trait> TrieIdGenerator<T::AccountId> for TrieIdFromParentCounter<T> where T::AccountId: AsRef<[u8]> { fn trie_id(account_id: &T::AccountId) -> TrieId { // Note that skipping a value due to error is not an issue here. // We only need uniqueness, not sequence. let new_seed = AccountCounter::mutate(|v| { *v = v.wrapping_add(1); *v }); let mut buf = Vec::new(); buf.extend_from_slice(account_id.as_ref()); buf.extend_from_slice(&new_seed.to_le_bytes()[..]); T::Hashing::hash(&buf[..]).as_ref().into() } } pub type BalanceOf<T> = <<T as Trait>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::Balance; pub type NegativeImbalanceOf<T> = <<T as Trait>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::NegativeImbalance; parameter_types! { /// A reasonable default value for [`Trait::SignedClaimedHandicap`]. pub const DefaultSignedClaimHandicap: u32 = 2; /// A reasonable default value for [`Trait::TombstoneDeposit`]. pub const DefaultTombstoneDeposit: u32 = 16; /// A reasonable default value for [`Trait::StorageSizeOffset`]. pub const DefaultStorageSizeOffset: u32 = 8; /// A reasonable default value for [`Trait::RentByteFee`]. pub const DefaultRentByteFee: u32 = 4; /// A reasonable default value for [`Trait::RentDepositOffset`]. pub const DefaultRentDepositOffset: u32 = 1000; /// A reasonable default value for [`Trait::SurchargeReward`]. pub const DefaultSurchargeReward: u32 = 150; /// A reasonable default value for [`Trait::MaxDepth`]. pub const DefaultMaxDepth: u32 = 32; /// A reasonable default value for [`Trait::MaxValueSize`]. pub const DefaultMaxValueSize: u32 = 16_384; } pub trait Trait: frame_system::Trait { type Time: Time; type Randomness: Randomness<Self::Hash>; /// The currency in which fees are paid and contract balances are held. type Currency: Currency<Self::AccountId>; /// The overarching event type. type Event: From<Event<Self>> + Into<<Self as frame_system::Trait>::Event>; /// A function type to get the contract address given the instantiator. type DetermineContractAddress: ContractAddressFor<CodeHash<Self>, Self::AccountId>; /// trie id generator type TrieIdGenerator: TrieIdGenerator<Self::AccountId>; /// Handler for rent payments. type RentPayment: OnUnbalanced<NegativeImbalanceOf<Self>>; /// Number of block delay an extrinsic claim surcharge has. /// /// When claim surcharge is called by an extrinsic the rent is checked /// for current_block - delay type SignedClaimHandicap: Get<Self::BlockNumber>; /// The minimum amount required to generate a tombstone. type TombstoneDeposit: Get<BalanceOf<Self>>; /// A size offset for an contract. A just created account with untouched storage will have that /// much of storage from the perspective of the state rent. /// /// This is a simple way to ensure that contracts with empty storage eventually get deleted by /// making them pay rent. This creates an incentive to remove them early in order to save rent. type StorageSizeOffset: Get<u32>; /// Price of a byte of storage per one block interval. Should be greater than 0. type RentByteFee: Get<BalanceOf<Self>>; /// The amount of funds a contract should deposit in order to offset /// the cost of one byte. /// /// Let's suppose the deposit is 1,000 BU (balance units)/byte and the rent is 1 BU/byte/day, /// then a contract with 1,000,000 BU that uses 1,000 bytes of storage would pay no rent. /// But if the balance reduced to 500,000 BU and the storage stayed the same at 1,000, /// then it would pay 500 BU/day. type RentDepositOffset: Get<BalanceOf<Self>>; /// Reward that is received by the party whose touch has led /// to removal of a contract. type SurchargeReward: Get<BalanceOf<Self>>; /// The maximum nesting level of a call/instantiate stack. type MaxDepth: Get<u32>; /// The maximum size of a storage value in bytes. type MaxValueSize: Get<u32>; /// Used to answer contracts's queries regarding the current weight price. This is **not** /// used to calculate the actual fee and is only for informational purposes. type WeightPrice: Convert<Weight, BalanceOf<Self>>; } /// Simple contract address determiner. /// /// Address calculated from the code (of the constructor), input data to the constructor, /// and the account id that requested the account creation. /// /// Formula: `blake2_256(blake2_256(code) + blake2_256(data) + origin)` pub struct SimpleAddressDeterminer<T: Trait>(PhantomData<T>); impl<T: Trait> ContractAddressFor<CodeHash<T>, T::AccountId> for SimpleAddressDeterminer<T> where T::AccountId: UncheckedFrom<T::Hash> + AsRef<[u8]> { fn contract_address_for(code_hash: &CodeHash<T>, data: &[u8], origin: &T::AccountId) -> T::AccountId { let data_hash = T::Hashing::hash(data); let mut buf = Vec::new(); buf.extend_from_slice(code_hash.as_ref()); buf.extend_from_slice(data_hash.as_ref()); buf.extend_from_slice(origin.as_ref()); UncheckedFrom::unchecked_from(T::Hashing::hash(&buf[..])) } } decl_error! { /// Error for the contracts module. pub enum Error for Module<T: Trait> { /// A new schedule must have a greater version than the current one. InvalidScheduleVersion, /// An origin must be signed or inherent and auxiliary sender only provided on inherent. InvalidSurchargeClaim, /// Cannot restore from nonexisting or tombstone contract. InvalidSourceContract, /// Cannot restore to nonexisting or alive contract. InvalidDestinationContract, /// Tombstones don't match. InvalidTombstone, /// An origin TrieId written in the current block. InvalidContractOrigin, /// The executed contract exhausted its gas limit. OutOfGas, /// The output buffer supplied to a contract API call was too small. OutputBufferTooSmall, /// Performing the requested transfer would have brought the contract below /// the subsistence threshold. No transfer is allowed to do this in order to allow /// for a tombstone to be created. Use `seal_terminate` to remove a contract without /// leaving a tombstone behind. BelowSubsistenceThreshold, /// The newly created contract is below the subsistence threshold after executing /// its contructor. No contracts are allowed to exist below that threshold. NewContractNotFunded, /// Performing the requested transfer failed for a reason originating in the /// chosen currency implementation of the runtime. Most probably the balance is /// too low or locks are placed on it. TransferFailed, /// Performing a call was denied because the calling depth reached the limit /// of what is specified in the schedule. MaxCallDepthReached, /// The contract that was called is either no contract at all (a plain account) /// or is a tombstone. NotCallable, /// The code supplied to `put_code` exceeds the limit specified in the current schedule. CodeTooLarge, /// No code could be found at the supplied code hash. CodeNotFound, /// A buffer outside of sandbox memory was passed to a contract API function. OutOfBounds, /// Input passed to a contract API function failed to decode as expected type. DecodingFailed, /// Contract trapped during execution. ContractTrapped, } } decl_module! { /// Contracts module. pub struct Module<T: Trait> for enum Call where origin: <T as frame_system::Trait>::Origin { type Error = Error<T>; /// Number of block delay an extrinsic claim surcharge has. /// /// When claim surcharge is called by an extrinsic the rent is checked /// for current_block - delay const SignedClaimHandicap: T::BlockNumber = T::SignedClaimHandicap::get(); /// The minimum amount required to generate a tombstone. const TombstoneDeposit: BalanceOf<T> = T::TombstoneDeposit::get(); /// A size offset for an contract. A just created account with untouched storage will have that /// much of storage from the perspective of the state rent. /// /// This is a simple way to ensure that contracts with empty storage eventually get deleted /// by making them pay rent. This creates an incentive to remove them early in order to save /// rent. const StorageSizeOffset: u32 = T::StorageSizeOffset::get(); /// Price of a byte of storage per one block interval. Should be greater than 0. const RentByteFee: BalanceOf<T> = T::RentByteFee::get(); /// The amount of funds a contract should deposit in order to offset /// the cost of one byte. /// /// Let's suppose the deposit is 1,000 BU (balance units)/byte and the rent is 1 BU/byte/day, /// then a contract with 1,000,000 BU that uses 1,000 bytes of storage would pay no rent. /// But if the balance reduced to 500,000 BU and the storage stayed the same at 1,000, /// then it would pay 500 BU/day. const RentDepositOffset: BalanceOf<T> = T::RentDepositOffset::get(); /// Reward that is received by the party whose touch has led /// to removal of a contract. const SurchargeReward: BalanceOf<T> = T::SurchargeReward::get(); /// The maximum nesting level of a call/instantiate stack. A reasonable default /// value is 100. const MaxDepth: u32 = T::MaxDepth::get(); /// The maximum size of a storage value in bytes. A reasonable default is 16 KiB. const MaxValueSize: u32 = T::MaxValueSize::get(); fn deposit_event() = default; /// Updates the schedule for metering contracts. /// /// The schedule must have a greater version than the stored schedule. #[weight = 0] pub fn update_schedule(origin, schedule: Schedule) -> DispatchResult { ensure_root(origin)?; if <Module<T>>::current_schedule().version >= schedule.version { Err(Error::<T>::InvalidScheduleVersion)? } Self::deposit_event(RawEvent::ScheduleUpdated(schedule.version)); CurrentSchedule::put(schedule); Ok(()) } /// Stores the given binary Wasm code into the chain's storage and returns its `codehash`. /// You can instantiate contracts only with stored code. #[weight = Module::<T>::calc_code_put_costs(&code)] pub fn put_code( origin, code: Vec<u8> ) -> DispatchResult { ensure_signed(origin)?; let schedule = <Module<T>>::current_schedule(); ensure!(code.len() as u32 <= schedule.max_code_size, Error::<T>::CodeTooLarge); let result = wasm::save_code::<T>(code, &schedule); if let Ok(code_hash) = result { Self::deposit_event(RawEvent::CodeStored(code_hash)); } result.map(|_| ()).map_err(Into::into) } /// Makes a call to an account, optionally transferring some balance. /// /// * If the account is a smart-contract account, the associated code will be /// executed and any value will be transferred. /// * If the account is a regular account, any value will be transferred. /// * If no account exists and the call value is not less than `existential_deposit`, /// a regular account will be created and any value will be transferred. #[weight = *gas_limit] pub fn call( origin, dest: <T::Lookup as StaticLookup>::Source, #[compact] value: BalanceOf<T>, #[compact] gas_limit: Gas, data: Vec<u8> ) -> DispatchResultWithPostInfo { let origin = ensure_signed(origin)?; let dest = T::Lookup::lookup(dest)?; let mut gas_meter = GasMeter::new(gas_limit); let result = Self::execute_wasm(origin, &mut gas_meter, |ctx, gas_meter| { ctx.call(dest, value, gas_meter, data) }); gas_meter.into_dispatch_result(result) } /// Instantiates a new contract from the `codehash` generated by `put_code`, optionally transferring some balance. /// /// Instantiation is executed as follows: /// /// - The destination address is computed based on the sender and hash of the code. /// - The smart-contract account is created at the computed address. /// - The `ctor_code` is executed in the context of the newly-created account. Buffer returned /// after the execution is saved as the `code` of the account. That code will be invoked /// upon any call received by this account. /// - The contract is initialized. #[weight = *gas_limit] pub fn instantiate( origin, #[compact] endowment: BalanceOf<T>, #[compact] gas_limit: Gas, code_hash: CodeHash<T>, data: Vec<u8> ) -> DispatchResultWithPostInfo { let origin = ensure_signed(origin)?; let mut gas_meter = GasMeter::new(gas_limit); let result = Self::execute_wasm(origin, &mut gas_meter, |ctx, gas_meter| { ctx.instantiate(endowment, gas_meter, &code_hash, data) .map(|(_address, output)| output) }); gas_meter.into_dispatch_result(result) } /// Allows block producers to claim a small reward for evicting a contract. If a block producer /// fails to do so, a regular users will be allowed to claim the reward. /// /// If contract is not evicted as a result of this call, no actions are taken and /// the sender is not eligible for the reward. #[weight = 0] fn claim_surcharge(origin, dest: T::AccountId, aux_sender: Option<T::AccountId>) { let origin = origin.into(); let (signed, rewarded) = match (origin, aux_sender) { (Ok(frame_system::RawOrigin::Signed(account)), None) => { (true, account) }, (Ok(frame_system::RawOrigin::None), Some(aux_sender)) => { (false, aux_sender) }, _ => Err(Error::<T>::InvalidSurchargeClaim)?, }; // Add some advantage for block producers (who send unsigned extrinsics) by // adding a handicap: for signed extrinsics we use a slightly older block number // for the eviction check. This can be viewed as if we pushed regular users back in past. let handicap = if signed { T::SignedClaimHandicap::get() } else { Zero::zero() }; // If poking the contract has lead to eviction of the contract, give out the rewards. if rent::snitch_contract_should_be_evicted::<T>(&dest, handicap) { T::Currency::deposit_into_existing(&rewarded, T::SurchargeReward::get())?; } } } } /// Public APIs provided by the contracts module. impl<T: Trait> Module<T> { /// Perform a call to a specified contract. /// /// This function is similar to `Self::call`, but doesn't perform any address lookups and better /// suitable for calling directly from Rust. /// /// It returns the exection result and the amount of used weight. pub fn bare_call( origin: T::AccountId, dest: T::AccountId, value: BalanceOf<T>, gas_limit: Gas, input_data: Vec<u8>, ) -> (ExecResult, Gas) { let mut gas_meter = GasMeter::new(gas_limit); ( Self::execute_wasm(origin, &mut gas_meter, |ctx, gas_meter| { ctx.call(dest, value, gas_meter, input_data) }), gas_meter.gas_spent(), ) } /// Query storage of a specified contract under a specified key. pub fn get_storage( address: T::AccountId, key: [u8; 32], ) -> sp_std::result::Result<Option<Vec<u8>>, ContractAccessError> { let contract_info = ContractInfoOf::<T>::get(&address) .ok_or(ContractAccessError::DoesntExist)? .get_alive() .ok_or(ContractAccessError::IsTombstone)?; let maybe_value = storage::read_contract_storage(&contract_info.trie_id, &key); Ok(maybe_value) } pub fn rent_projection( address: T::AccountId, ) -> sp_std::result::Result<RentProjection<T::BlockNumber>, ContractAccessError> { rent::compute_rent_projection::<T>(&address) } } impl<T: Trait> Module<T> { fn calc_code_put_costs(code: &Vec<u8>) -> Gas { <Module<T>>::current_schedule().put_code_per_byte_cost.saturating_mul(code.len() as Gas) } fn execute_wasm( origin: T::AccountId, gas_meter: &mut GasMeter<T>, func: impl FnOnce(&mut ExecutionContext<T, WasmVm, WasmLoader>, &mut GasMeter<T>) -> ExecResult, ) -> ExecResult { let cfg = Config::preload(); let vm = WasmVm::new(&cfg.schedule); let loader = WasmLoader::new(&cfg.schedule); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); func(&mut ctx, gas_meter) } } decl_event! { pub enum Event<T> where Balance = BalanceOf<T>, <T as frame_system::Trait>::AccountId, <T as frame_system::Trait>::Hash { /// Contract deployed by address at the specified address. [owner, contract] Instantiated(AccountId, AccountId), /// Contract has been evicted and is now in tombstone state. /// [contract, tombstone] /// /// # Params /// /// - `contract`: `AccountId`: The account ID of the evicted contract. /// - `tombstone`: `bool`: True if the evicted contract left behind a tombstone. Evicted(AccountId, bool), /// Restoration for a contract has been successful. /// [donor, dest, code_hash, rent_allowance] /// /// # Params /// /// - `donor`: `AccountId`: Account ID of the restoring contract /// - `dest`: `AccountId`: Account ID of the restored contract /// - `code_hash`: `Hash`: Code hash of the restored contract /// - `rent_allowance: `Balance`: Rent allowance of the restored contract Restored(AccountId, AccountId, Hash, Balance), /// Code with the specified hash has been stored. /// [code_hash] CodeStored(Hash), /// Triggered when the current [schedule] is updated. ScheduleUpdated(u32), /// An event deposited upon execution of a contract from the account. /// [account, data] ContractExecution(AccountId, Vec<u8>), } } decl_storage! { trait Store for Module<T: Trait> as Contracts { /// Current cost schedule for contracts. CurrentSchedule get(fn current_schedule) config(): Schedule = Schedule::default(); /// A mapping from an original code hash to the original code, untouched by instrumentation. pub PristineCode: map hasher(identity) CodeHash<T> => Option<Vec<u8>>; /// A mapping between an original code hash and instrumented wasm code, ready for execution. pub CodeStorage: map hasher(identity) CodeHash<T> => Option<wasm::PrefabWasmModule>; /// The subtrie counter. pub AccountCounter: u64 = 0; /// The code associated with a given account. /// /// TWOX-NOTE: SAFE since `AccountId` is a secure hash. pub ContractInfoOf: map hasher(twox_64_concat) T::AccountId => Option<ContractInfo<T>>; } } /// In-memory cache of configuration values. /// /// We assume that these values can't be changed in the /// course of transaction execution. pub struct Config<T: Trait> { pub schedule: Schedule, pub existential_deposit: BalanceOf<T>, pub tombstone_deposit: BalanceOf<T>, pub max_depth: u32, pub max_value_size: u32, } impl<T: Trait> Config<T> { fn preload() -> Config<T> { Config { schedule: <Module<T>>::current_schedule(), existential_deposit: T::Currency::minimum_balance(), tombstone_deposit: T::TombstoneDeposit::get(), max_depth: T::MaxDepth::get(), max_value_size: T::MaxValueSize::get(), } } /// Subsistence threshold is the extension of the minimum balance (aka existential deposit) by the /// tombstone deposit, required for leaving a tombstone. /// /// Rent or any contract initiated balance transfer mechanism cannot make the balance lower /// than the subsistence threshold in order to guarantee that a tombstone is created. /// /// The only way to completely kill a contract without a tombstone is calling `seal_terminate`. pub fn subsistence_threshold(&self) -> BalanceOf<T> { self.existential_deposit.saturating_add(self.tombstone_deposit) } /// The same as `subsistence_threshold` but without the need for a preloaded instance. /// /// This is for cases where this value is needed in rent calculation rather than /// during contract execution. pub fn subsistence_threshold_uncached() -> BalanceOf<T> { T::Currency::minimum_balance().saturating_add(T::TombstoneDeposit::get()) } } /// Definition of the cost schedule and other parameterizations for wasm vm. #[cfg_attr(feature = "std", derive(Serialize, Deserialize))] #[derive(Clone, Encode, Decode, PartialEq, Eq, RuntimeDebug)] pub struct Schedule { /// Version of the schedule. pub version: u32, /// Cost of putting a byte of code into storage. pub put_code_per_byte_cost: Gas, /// Gas cost of a growing memory by single page. pub grow_mem_cost: Gas, /// Gas cost of a regular operation. pub regular_op_cost: Gas, /// Gas cost per one byte returned. pub return_data_per_byte_cost: Gas, /// Gas cost to deposit an event; the per-byte portion. pub event_data_per_byte_cost: Gas, /// Gas cost to deposit an event; the cost per topic. pub event_per_topic_cost: Gas, /// Gas cost to deposit an event; the base. pub event_base_cost: Gas, /// Base gas cost to call into a contract. pub call_base_cost: Gas, /// Base gas cost to instantiate a contract. pub instantiate_base_cost: Gas, /// Base gas cost to dispatch a runtime call. pub dispatch_base_cost: Gas, /// Gas cost per one byte read from the sandbox memory. pub sandbox_data_read_cost: Gas, /// Gas cost per one byte written to the sandbox memory. pub sandbox_data_write_cost: Gas, /// Cost for a simple balance transfer. pub transfer_cost: Gas, /// Cost for instantiating a new contract. pub instantiate_cost: Gas, /// The maximum number of topics supported by an event. pub max_event_topics: u32, /// Maximum allowed stack height. /// /// See https://wiki.parity.io/WebAssembly-StackHeight to find out /// how the stack frame cost is calculated. pub max_stack_height: u32, /// Maximum number of memory pages allowed for a contract. pub max_memory_pages: u32, /// Maximum allowed size of a declared table. pub max_table_size: u32, /// Whether the `seal_println` function is allowed to be used contracts. /// MUST only be enabled for `dev` chains, NOT for production chains pub enable_println: bool, /// The maximum length of a subject used for PRNG generation. pub max_subject_len: u32, /// The maximum length of a contract code in bytes. This limit applies to the uninstrumented // and pristine form of the code as supplied to `put_code`. pub max_code_size: u32, } // 500 (2 instructions per nano second on 2GHZ) * 1000x slowdown through wasmi // This is a wild guess and should be viewed as a rough estimation. // Proper benchmarks are needed before this value and its derivatives can be used in production. const WASM_INSTRUCTION_COST: Gas = 500_000; impl Default for Schedule { fn default() -> Schedule { Schedule { version: 0, put_code_per_byte_cost: WASM_INSTRUCTION_COST, grow_mem_cost: WASM_INSTRUCTION_COST, regular_op_cost: WASM_INSTRUCTION_COST, return_data_per_byte_cost: WASM_INSTRUCTION_COST, event_data_per_byte_cost: WASM_INSTRUCTION_COST, event_per_topic_cost: WASM_INSTRUCTION_COST, event_base_cost: WASM_INSTRUCTION_COST, call_base_cost: 135 * WASM_INSTRUCTION_COST, dispatch_base_cost: 135 * WASM_INSTRUCTION_COST, instantiate_base_cost: 175 * WASM_INSTRUCTION_COST, sandbox_data_read_cost: WASM_INSTRUCTION_COST, sandbox_data_write_cost: WASM_INSTRUCTION_COST, transfer_cost: 100 * WASM_INSTRUCTION_COST, instantiate_cost: 200 * WASM_INSTRUCTION_COST, max_event_topics: 4, max_stack_height: 64 * 1024, max_memory_pages: 16, max_table_size: 16 * 1024, enable_println: false, max_subject_len: 32, max_code_size: 512 * 1024, } } }