diff --git a/Cargo.lock b/Cargo.lock index 64aa540ce4e01..5a5a061bded99 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -4010,6 +4010,7 @@ dependencies = [ "pallet-transaction-payment", "parity-scale-codec", "parity-wasm 0.41.0", + "pretty_assertions", "pwasm-utils", "serde", "sp-core", diff --git a/frame/contracts/Cargo.toml b/frame/contracts/Cargo.toml index b2ba8d014ae78..57c278a3fb2a9 100644 --- a/frame/contracts/Cargo.toml +++ b/frame/contracts/Cargo.toml @@ -31,6 +31,7 @@ pallet-transaction-payment = { version = "2.0.0-rc3", default-features = false, wabt = "0.9.2" assert_matches = "1.3.0" hex-literal = "0.2.1" +pretty_assertions = "0.6.1" pallet-balances = { version = "2.0.0-rc3", path = "../balances" } pallet-timestamp = { version = "2.0.0-rc3", path = "../timestamp" } pallet-randomness-collective-flip = { version = "2.0.0-rc3", path = "../randomness-collective-flip" } diff --git a/frame/contracts/fixtures/restoration.wat b/frame/contracts/fixtures/restoration.wat index 4e11f97d5a2cc..225fdde817800 100644 --- a/frame/contracts/fixtures/restoration.wat +++ b/frame/contracts/fixtures/restoration.wat @@ -1,6 +1,10 @@ (module (import "env" "ext_set_storage" (func $ext_set_storage (param i32 i32 i32))) - (import "env" "ext_restore_to" (func $ext_restore_to (param i32 i32 i32 i32 i32 i32 i32 i32))) + (import "env" "ext_restore_to" + (func $ext_restore_to + (param i32 i32 i32 i32 i32 i32 i32 i32) + ) + ) (import "env" "memory" (memory 1 1)) (func (export "call") diff --git a/frame/contracts/src/account_db.rs b/frame/contracts/src/account_db.rs deleted file mode 100644 index 5e1b0c34b5734..0000000000000 --- a/frame/contracts/src/account_db.rs +++ /dev/null @@ -1,450 +0,0 @@ -// 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 . - -//! Auxiliaries to help with managing partial changes to accounts state. - -use super::{ - AliveContractInfo, BalanceOf, CodeHash, ContractInfo, ContractInfoOf, Trait, TrieId, - TrieIdGenerator, -}; -use crate::exec::StorageKey; -use sp_std::cell::RefCell; -use sp_std::collections::btree_map::{BTreeMap, Entry}; -use sp_std::prelude::*; -use sp_io::hashing::blake2_256; -use sp_runtime::traits::{Bounded, Zero}; -use frame_support::traits::{Currency, Imbalance, SignedImbalance}; -use frame_support::{storage::child, StorageMap}; -use frame_system; - -// Note: we don't provide Option because we can't create -// the trie_id in the overlay, thus we provide an overlay on the fields -// specifically. -pub struct ChangeEntry { - /// If Some(_), then the account balance is modified to the value. If None and `reset` is false, - /// the balance unmodified. If None and `reset` is true, the balance is reset to 0. - balance: Option>, - /// If Some(_), then a contract is instantiated with the code hash. If None and `reset` is false, - /// then the contract code is unmodified. If None and `reset` is true, the contract is deleted. - code_hash: Option>, - /// If Some(_), then the rent allowance is set to the value. If None and `reset` is false, then - /// the rent allowance is unmodified. If None and `reset` is true, the contract is deleted. - rent_allowance: Option>, - storage: BTreeMap>>, - /// If true, indicates that the existing contract and all its storage entries should be removed - /// and replaced with the fields on this change entry. Otherwise, the fields on this change - /// entry are updates merged into the existing contract info and storage. - reset: bool, -} - -impl ChangeEntry { - fn balance(&self) -> Option> { - self.balance.or_else(|| { - if self.reset { - Some(>::zero()) - } else { - None - } - }) - } - - fn code_hash(&self) -> Option>> { - if self.reset { - Some(self.code_hash) - } else { - self.code_hash.map(Some) - } - } - - fn rent_allowance(&self) -> Option>> { - if self.reset { - Some(self.rent_allowance) - } else { - self.rent_allowance.map(Some) - } - } - - fn storage(&self, location: &StorageKey) -> Option>> { - let value = self.storage.get(location).cloned(); - if self.reset { - Some(value.unwrap_or(None)) - } else { - value - } - } -} - -// Cannot derive(Default) since it erroneously bounds T by Default. -impl Default for ChangeEntry { - fn default() -> Self { - ChangeEntry { - rent_allowance: Default::default(), - balance: Default::default(), - code_hash: Default::default(), - storage: Default::default(), - reset: false, - } - } -} - -pub type ChangeSet = BTreeMap<::AccountId, ChangeEntry>; - -pub trait AccountDb { - /// Account is used when overlayed otherwise trie_id must be provided. - /// This is for performance reason. - /// - /// Trie id is None iff account doesn't have an associated trie id in >. - /// Because DirectAccountDb bypass the lookup for this association. - fn get_storage( - &self, - account: &T::AccountId, - trie_id: Option<&TrieId>, - location: &StorageKey, - ) -> Option>; - /// If account has an alive contract then return the code hash associated. - fn get_code_hash(&self, account: &T::AccountId) -> Option>; - /// If account has an alive contract then return the rent allowance associated. - fn get_rent_allowance(&self, account: &T::AccountId) -> Option>; - /// Returns false iff account has no alive contract nor tombstone. - fn contract_exists(&self, account: &T::AccountId) -> bool; - fn get_balance(&self, account: &T::AccountId) -> BalanceOf; - - fn commit(&mut self, change_set: ChangeSet); -} - -pub struct DirectAccountDb; -impl AccountDb for DirectAccountDb { - fn get_storage( - &self, - _account: &T::AccountId, - trie_id: Option<&TrieId>, - location: &StorageKey, - ) -> Option> { - trie_id - .and_then(|id| child::get_raw(&crate::child_trie_info(&id[..]), &blake2_256(location))) - } - fn get_code_hash(&self, account: &T::AccountId) -> Option> { - >::get(account).and_then(|i| i.as_alive().map(|i| i.code_hash)) - } - fn get_rent_allowance(&self, account: &T::AccountId) -> Option> { - >::get(account).and_then(|i| i.as_alive().map(|i| i.rent_allowance)) - } - fn contract_exists(&self, account: &T::AccountId) -> bool { - >::contains_key(account) - } - fn get_balance(&self, account: &T::AccountId) -> BalanceOf { - T::Currency::free_balance(account) - } - fn commit(&mut self, s: ChangeSet) { - let mut total_imbalance = SignedImbalance::zero(); - for (address, changed) in s.into_iter() { - if let Some(balance) = changed.balance() { - let imbalance = T::Currency::make_free_balance_be(&address, balance); - total_imbalance = total_imbalance.merge(imbalance); - } - - if changed.code_hash().is_some() - || changed.rent_allowance().is_some() - || !changed.storage.is_empty() - || changed.reset - { - let old_info = match >::get(&address) { - Some(ContractInfo::Alive(alive)) => Some(alive), - None => None, - // Cannot commit changes to tombstone contract - Some(ContractInfo::Tombstone(_)) => continue, - }; - - let mut new_info = match (changed.reset, old_info.clone(), changed.code_hash) { - // Existing contract is being modified. - (false, Some(info), _) => info, - // Existing contract is being removed. - (true, Some(info), None) => { - child::kill_storage(&info.child_trie_info()); - >::remove(&address); - continue; - } - // Existing contract is being replaced by a new one. - (true, Some(info), Some(code_hash)) => { - child::kill_storage(&info.child_trie_info()); - AliveContractInfo:: { - code_hash, - storage_size: 0, - empty_pair_count: 0, - total_pair_count: 0, - trie_id: ::TrieIdGenerator::trie_id(&address), - deduct_block: >::block_number(), - rent_allowance: >::max_value(), - last_write: None, - } - } - // New contract is being instantiated. - (_, None, Some(code_hash)) => AliveContractInfo:: { - code_hash, - storage_size: 0, - empty_pair_count: 0, - total_pair_count: 0, - trie_id: ::TrieIdGenerator::trie_id(&address), - deduct_block: >::block_number(), - rent_allowance: >::max_value(), - last_write: None, - }, - // There is no existing at the address nor a new one to be instantiated. - (_, None, None) => continue, - }; - - if let Some(rent_allowance) = changed.rent_allowance { - new_info.rent_allowance = rent_allowance; - } - - if let Some(code_hash) = changed.code_hash { - new_info.code_hash = code_hash; - } - - if !changed.storage.is_empty() { - new_info.last_write = Some(>::block_number()); - } - - // NB: this call allocates internally. To keep allocations to the minimum we cache - // the child trie info here. - let child_trie_info = new_info.child_trie_info(); - - // Here we iterate over all storage key-value pairs that were changed throughout the - // execution of a contract and apply them to the substrate storage. - for (key, opt_new_value) in changed.storage.into_iter() { - let hashed_key = blake2_256(&key); - - // In order to correctly update the book keeping we need to fetch the previous - // value of the key-value pair. - // - // It might be a bit more clean if we had an API that supported getting the size - // of the value without going through the loading of it. But at the moment of - // writing, there is no such API. - // - // That's not a show stopper in any case, since the performance cost is - // dominated by the trie traversal anyway. - let opt_prev_value = child::get_raw(&child_trie_info, &hashed_key); - - // Update the total number of KV pairs and the number of empty pairs. - match (&opt_prev_value, &opt_new_value) { - (Some(prev_value), None) => { - new_info.total_pair_count -= 1; - if prev_value.is_empty() { - new_info.empty_pair_count -= 1; - } - }, - (None, Some(new_value)) => { - new_info.total_pair_count += 1; - if new_value.is_empty() { - new_info.empty_pair_count += 1; - } - }, - (Some(prev_value), Some(new_value)) => { - if prev_value.is_empty() { - new_info.empty_pair_count -= 1; - } - if new_value.is_empty() { - new_info.empty_pair_count += 1; - } - } - (None, None) => {} - } - - // Update the total storage size. - let prev_value_len = opt_prev_value - .as_ref() - .map(|old_value| old_value.len() as u32) - .unwrap_or(0); - let new_value_len = opt_new_value - .as_ref() - .map(|new_value| new_value.len() as u32) - .unwrap_or(0); - new_info.storage_size = new_info - .storage_size - .saturating_add(new_value_len) - .saturating_sub(prev_value_len); - - // Finally, perform the change on the storage. - match opt_new_value { - Some(new_value) => child::put_raw(&child_trie_info, &hashed_key, &new_value[..]), - None => child::kill(&child_trie_info, &hashed_key), - } - } - - if old_info - .map(|old_info| old_info != new_info) - .unwrap_or(true) - { - >::insert(&address, ContractInfo::Alive(new_info)); - } - } - } - - match total_imbalance { - // If we've detected a positive imbalance as a result of our contract-level machinations - // then it's indicative of a buggy contracts system. - // Panicking is far from ideal as it opens up a DoS attack on block validators, however - // it's a less bad option than allowing arbitrary value to be created. - SignedImbalance::Positive(ref p) if !p.peek().is_zero() => { - panic!("contract subsystem resulting in positive imbalance!") - } - _ => {} - } - } -} - -pub struct OverlayAccountDb<'a, T: Trait + 'a> { - local: RefCell>, - underlying: &'a dyn AccountDb, -} -impl<'a, T: Trait> OverlayAccountDb<'a, T> { - pub fn new(underlying: &'a dyn AccountDb) -> OverlayAccountDb<'a, T> { - OverlayAccountDb { - local: RefCell::new(ChangeSet::new()), - underlying, - } - } - - pub fn into_change_set(self) -> ChangeSet { - self.local.into_inner() - } - - pub fn set_storage( - &mut self, - account: &T::AccountId, - location: StorageKey, - value: Option>, - ) { - self.local - .borrow_mut() - .entry(account.clone()) - .or_insert(Default::default()) - .storage - .insert(location, value); - } - - /// Return an error if contract already exists (either if it is alive or tombstone) - pub fn instantiate_contract( - &mut self, - account: &T::AccountId, - code_hash: CodeHash, - ) -> Result<(), &'static str> { - if self.contract_exists(account) { - return Err("Alive contract or tombstone already exists"); - } - - let mut local = self.local.borrow_mut(); - let contract = local.entry(account.clone()).or_default(); - - contract.code_hash = Some(code_hash); - contract.rent_allowance = Some(>::max_value()); - - Ok(()) - } - - /// Mark a contract as deleted. - pub fn destroy_contract(&mut self, account: &T::AccountId) { - let mut local = self.local.borrow_mut(); - local.insert( - account.clone(), - ChangeEntry { - reset: true, - ..Default::default() - }, - ); - } - - /// Assume contract exists - pub fn set_rent_allowance(&mut self, account: &T::AccountId, rent_allowance: BalanceOf) { - self.local - .borrow_mut() - .entry(account.clone()) - .or_insert(Default::default()) - .rent_allowance = Some(rent_allowance); - } - pub fn set_balance(&mut self, account: &T::AccountId, balance: BalanceOf) { - self.local - .borrow_mut() - .entry(account.clone()) - .or_insert(Default::default()) - .balance = Some(balance); - } -} - -impl<'a, T: Trait> AccountDb for OverlayAccountDb<'a, T> { - fn get_storage( - &self, - account: &T::AccountId, - trie_id: Option<&TrieId>, - location: &StorageKey, - ) -> Option> { - self.local - .borrow() - .get(account) - .and_then(|changes| changes.storage(location)) - .unwrap_or_else(|| self.underlying.get_storage(account, trie_id, location)) - } - fn get_code_hash(&self, account: &T::AccountId) -> Option> { - self.local - .borrow() - .get(account) - .and_then(|changes| changes.code_hash()) - .unwrap_or_else(|| self.underlying.get_code_hash(account)) - } - fn get_rent_allowance(&self, account: &T::AccountId) -> Option> { - self.local - .borrow() - .get(account) - .and_then(|changes| changes.rent_allowance()) - .unwrap_or_else(|| self.underlying.get_rent_allowance(account)) - } - fn contract_exists(&self, account: &T::AccountId) -> bool { - self.local - .borrow() - .get(account) - .and_then(|changes| changes.code_hash().map(|code_hash| code_hash.is_some())) - .unwrap_or_else(|| self.underlying.contract_exists(account)) - } - fn get_balance(&self, account: &T::AccountId) -> BalanceOf { - self.local - .borrow() - .get(account) - .and_then(|changes| changes.balance()) - .unwrap_or_else(|| self.underlying.get_balance(account)) - } - fn commit(&mut self, s: ChangeSet) { - let mut local = self.local.borrow_mut(); - - for (address, changed) in s.into_iter() { - match local.entry(address) { - Entry::Occupied(e) => { - let mut value = e.into_mut(); - if changed.reset { - *value = changed; - } else { - value.balance = changed.balance.or(value.balance); - value.code_hash = changed.code_hash.or(value.code_hash); - value.rent_allowance = changed.rent_allowance.or(value.rent_allowance); - value.storage.extend(changed.storage.into_iter()); - } - } - Entry::Vacant(e) => { - e.insert(changed); - } - } - } - } -} diff --git a/frame/contracts/src/exec.rs b/frame/contracts/src/exec.rs index 9cc1c50260db9..ff0d4d9dc0de1 100644 --- a/frame/contracts/src/exec.rs +++ b/frame/contracts/src/exec.rs @@ -15,16 +15,16 @@ // along with Substrate. If not, see . use super::{CodeHash, Config, ContractAddressFor, Event, RawEvent, Trait, - TrieId, BalanceOf, ContractInfo}; -use crate::account_db::{AccountDb, DirectAccountDb, OverlayAccountDb}; + TrieId, BalanceOf, ContractInfo, TrieIdGenerator}; use crate::gas::{Gas, GasMeter, Token}; use crate::rent; +use crate::storage; use sp_std::prelude::*; -use sp_runtime::traits::{Bounded, CheckedAdd, CheckedSub, Zero}; +use sp_runtime::traits::{Bounded, Zero}; use frame_support::{ storage::unhashed, dispatch::DispatchError, - traits::{WithdrawReason, Currency, Time, Randomness}, + traits::{ExistenceRequirement, Currency, Time, Randomness}, }; pub type AccountIdOf = ::AccountId; @@ -105,8 +105,8 @@ pub trait Ext { fn get_storage(&self, key: &StorageKey) -> Option>; /// Sets the storage entry by the given key to the specified value. If `value` is `None` then - /// the storage entry is deleted. Returns an Err if the value size is too large. - fn set_storage(&mut self, key: StorageKey, value: Option>) -> Result<(), &'static str>; + /// the storage entry is deleted. + fn set_storage(&mut self, key: StorageKey, value: Option>); /// Instantiate a contract from the given code. /// @@ -129,6 +129,12 @@ pub trait Ext { ) -> Result<(), DispatchError>; /// Transfer all funds to `beneficiary` and delete the contract. + /// + /// Since this function removes the self contract eagerly, if succeeded, no further actions should + /// be performed on this `Ext` instance. + /// + /// This function will fail if the same contract is present on the contract + /// call stack. fn terminate( &mut self, beneficiary: &AccountIdOf, @@ -147,14 +153,20 @@ pub trait Ext { /// Notes a call dispatch. fn note_dispatch_call(&mut self, call: CallOf); - /// Notes a restoration request. - fn note_restore_to( + /// Restores the given destination contract sacrificing the current one. + /// + /// Since this function removes the self contract eagerly, if succeeded, no further actions should + /// be performed on this `Ext` instance. + /// + /// This function will fail if the same contract is present + /// on the contract call stack. + fn restore_to( &mut self, dest: AccountIdOf, code_hash: CodeHash, rent_allowance: BalanceOf, delta: Vec, - ); + ) -> Result<(), &'static str>; /// Returns a reference to the account id of the caller. fn caller(&self) -> &AccountIdOf; @@ -264,38 +276,18 @@ impl Token for ExecFeeToken { #[cfg_attr(any(feature = "std", test), derive(PartialEq, Eq, Clone))] #[derive(sp_runtime::RuntimeDebug)] pub enum DeferredAction { - DepositEvent { - /// A list of topics this event will be deposited with. - topics: Vec, - /// The event to deposit. - event: Event, - }, DispatchRuntimeCall { /// The account id of the contract who dispatched this call. origin: T::AccountId, /// The call to dispatch. call: ::Call, }, - RestoreTo { - /// The account id of the contract which is removed during the restoration and transfers - /// its storage to the restored contract. - donor: T::AccountId, - /// The account id of the restored contract. - dest: T::AccountId, - /// The code hash of the restored contract. - code_hash: CodeHash, - /// The initial rent allowance to set. - rent_allowance: BalanceOf, - /// The keys to delete upon restoration. - delta: Vec, - }, } pub struct ExecutionContext<'a, T: Trait + 'a, V, L> { pub caller: Option<&'a ExecutionContext<'a, T, V, L>>, pub self_account: T::AccountId, pub self_trie_id: Option, - pub overlay: OverlayAccountDb<'a, T>, pub depth: usize, pub deferred: Vec>, pub config: &'a Config, @@ -320,7 +312,6 @@ where caller: None, self_trie_id: None, self_account: origin, - overlay: OverlayAccountDb::::new(&DirectAccountDb), depth: 0, deferred: Vec::new(), config: &cfg, @@ -338,7 +329,6 @@ where caller: Some(self), self_trie_id: trie_id, self_account: dest, - overlay: OverlayAccountDb::new(&self.overlay), depth: self.depth + 1, deferred: Vec::new(), config: self.config, @@ -349,23 +339,6 @@ where } } - /// Transfer balance to `dest` without calling any contract code. - pub fn transfer( - &mut self, - dest: T::AccountId, - value: BalanceOf, - gas_meter: &mut GasMeter - ) -> Result<(), DispatchError> { - transfer( - gas_meter, - TransferCause::Call, - &self.self_account.clone(), - &dest, - value, - self, - ) - } - /// Make a call to the specified address, optionally transferring some funds. pub fn call( &mut self, @@ -424,8 +397,8 @@ where // If code_hash is not none, then the destination account is a live contract, otherwise // it is a regular account since tombstone accounts have already been rejected. - match nested.overlay.get_code_hash(&dest) { - Some(dest_code_hash) => { + match storage::code_hash::(&dest) { + Ok(dest_code_hash) => { let executable = try_or_exec_error!( nested.loader.load_main(&dest_code_hash), input_data @@ -437,10 +410,9 @@ where input_data, gas_meter, )?; - Ok(output) } - None => Ok(ExecReturnValue { status: STATUS_SUCCESS, data: Vec::new() }), + Err(storage::ContractAbsentError) => Ok(ExecReturnValue { status: STATUS_SUCCESS, data: Vec::new() }), } }) } @@ -477,11 +449,20 @@ where ); // TrieId has not been generated yet and storage is empty since contract is new. - let dest_trie_id = None; + // + // Generate it now. + let dest_trie_id = ::TrieIdGenerator::trie_id(&dest); - let output = self.with_nested_context(dest.clone(), dest_trie_id, |nested| { + let output = self.with_nested_context(dest.clone(), Some(dest_trie_id), |nested| { try_or_exec_error!( - nested.overlay.instantiate_contract(&dest, code_hash.clone()), + storage::place_contract::( + &dest, + nested + .self_trie_id + .clone() + .expect("the nested context always has to have self_trie_id"), + code_hash.clone() + ), input_data ); @@ -512,7 +493,7 @@ where )?; // Error out if insufficient remaining balance. - if nested.overlay.get_balance(&dest) < nested.config.existential_deposit { + if T::Currency::free_balance(&dest) < nested.config.existential_deposit { return Err(ExecError { reason: "insufficient remaining balance".into(), buffer: output.data, @@ -520,10 +501,7 @@ where } // Deposit an instantiation event. - nested.deferred.push(DeferredAction::DepositEvent { - event: RawEvent::Instantiated(caller.clone(), dest.clone()), - topics: Vec::new(), - }); + deposit_event::(vec![], RawEvent::Instantiated(caller.clone(), dest.clone())); Ok(output) })?; @@ -531,32 +509,6 @@ where Ok((dest, output)) } - pub fn terminate( - &mut self, - beneficiary: &T::AccountId, - gas_meter: &mut GasMeter, - ) -> Result<(), DispatchError> { - let self_id = self.self_account.clone(); - let value = self.overlay.get_balance(&self_id); - if let Some(caller) = self.caller { - if caller.is_live(&self_id) { - return Err(DispatchError::Other( - "Cannot terminate a contract that is present on the call stack", - )); - } - } - transfer( - gas_meter, - TransferCause::Terminate, - &self_id, - beneficiary, - value, - self, - )?; - self.overlay.destroy_contract(&self_id); - Ok(()) - } - fn new_call_context<'b>( &'b mut self, caller: T::AccountId, @@ -573,21 +525,26 @@ where } } + /// Execute the given closure within a nested execution context. fn with_nested_context(&mut self, dest: T::AccountId, trie_id: Option, func: F) -> ExecResult where F: FnOnce(&mut ExecutionContext) -> ExecResult { - let (output, change_set, deferred) = { + use frame_support::storage::TransactionOutcome::*; + let (output, deferred) = { let mut nested = self.nested(dest, trie_id); - let output = func(&mut nested)?; - (output, nested.overlay.into_change_set(), nested.deferred) + let output = frame_support::storage::with_transaction(|| { + let output = func(&mut nested); + match output { + Ok(ref rv) if rv.is_success() => Commit(output), + _ => Rollback(output), + } + })?; + (output, nested.deferred) }; - if output.is_success() { - self.overlay.commit(change_set); self.deferred.extend(deferred); } - Ok(output) } @@ -676,48 +633,27 @@ fn transfer<'a, T: Trait, V: Vm, L: Loader>( Err("not enough gas to pay transfer fee")? } - // We allow balance to go below the existential deposit here: - let from_balance = ctx.overlay.get_balance(transactor); - let new_from_balance = match from_balance.checked_sub(&value) { - Some(b) => b, - None => Err("balance too low to send value")?, - }; - let to_balance = ctx.overlay.get_balance(dest); - if to_balance.is_zero() && value < ctx.config.existential_deposit { - Err("value too low to create account")? - } - // Only ext_terminate is allowed to bring the sender below the existential deposit - let required_balance = match cause { - Terminate => 0.into(), - _ => ctx.config.existential_deposit - }; - - T::Currency::ensure_can_withdraw( - transactor, - value, - WithdrawReason::Transfer.into(), - new_from_balance.checked_sub(&required_balance) - .ok_or("brings sender below existential deposit")?, - )?; - - let new_to_balance = match to_balance.checked_add(&value) { - Some(b) => b, - None => Err("destination balance too high to receive value")?, + let existence_requirement = match cause { + Terminate => ExistenceRequirement::AllowDeath, + _ => ExistenceRequirement::KeepAlive, }; - - if transactor != dest { - ctx.overlay.set_balance(transactor, new_from_balance); - ctx.overlay.set_balance(dest, new_to_balance); - ctx.deferred.push(DeferredAction::DepositEvent { - event: RawEvent::Transfer(transactor.clone(), dest.clone(), value), - topics: Vec::new(), - }); - } + T::Currency::transfer(transactor, dest, value, existence_requirement)?; Ok(()) } +/// A context that is active within a call. +/// +/// This context has some invariants that must be held at all times. Specifically: +///`ctx` always points to a context of an alive contract. That implies that it has an existent +/// `self_trie_id`. +/// +/// Be advised that there are brief time spans where these invariants could be invalidated. +/// For example, when a contract requests self-termination the contract is removed eagerly. That +/// implies that the control won't be returned to the contract anymore, but there is still some code +/// on the path of the return from that call context. Therefore, care must be taken in these +/// situations. struct CallContext<'a, 'b: 'a, T: Trait + 'b, V: Vm + 'b, L: Loader> { ctx: &'a mut ExecutionContext<'b, T, V, L>, caller: T::AccountId, @@ -735,20 +671,32 @@ where type T = T; fn get_storage(&self, key: &StorageKey) -> Option> { - self.ctx.overlay.get_storage(&self.ctx.self_account, self.ctx.self_trie_id.as_ref(), key) + let trie_id = self.ctx.self_trie_id.as_ref().expect( + "`ctx.self_trie_id` points to an alive contract within the `CallContext`;\ + it cannot be `None`;\ + expect can't fail;\ + qed", + ); + storage::read_contract_storage(trie_id, key) } - fn set_storage(&mut self, key: StorageKey, value: Option>) -> Result<(), &'static str> { - if let Some(ref value) = value { - if self.max_value_size() < value.len() as u32 { - return Err("value size exceeds maximum"); - } + fn set_storage(&mut self, key: StorageKey, value: Option>) { + let trie_id = self.ctx.self_trie_id.as_ref().expect( + "`ctx.self_trie_id` points to an alive contract within the `CallContext`;\ + it cannot be `None`;\ + expect can't fail;\ + qed", + ); + if let Err(storage::ContractAbsentError) = + storage::write_contract_storage::(&self.ctx.self_account, trie_id, &key, value) + { + panic!( + "the contract must be in the alive state within the `CallContext`;\ + the contract cannot be absent in storage; + write_contract_storage cannot return `None`; + qed" + ); } - - self.ctx - .overlay - .set_storage(&self.ctx.self_account, key, value); - Ok(()) } fn instantiate( @@ -767,7 +715,14 @@ where value: BalanceOf, gas_meter: &mut GasMeter, ) -> Result<(), DispatchError> { - self.ctx.transfer(to.clone(), value, gas_meter) + transfer( + gas_meter, + TransferCause::Call, + &self.ctx.self_account.clone(), + &to, + value, + self.ctx, + ) } fn terminate( @@ -775,7 +730,30 @@ where beneficiary: &AccountIdOf, gas_meter: &mut GasMeter, ) -> Result<(), DispatchError> { - self.ctx.terminate(beneficiary, gas_meter) + let self_id = self.ctx.self_account.clone(); + let value = T::Currency::free_balance(&self_id); + if let Some(caller_ctx) = self.ctx.caller { + if caller_ctx.is_live(&self_id) { + return Err(DispatchError::Other( + "Cannot terminate a contract that is present on the call stack", + )); + } + } + transfer( + gas_meter, + TransferCause::Terminate, + &self_id, + beneficiary, + value, + self.ctx, + )?; + let self_trie_id = self.ctx.self_trie_id.as_ref().expect( + "this function is only invoked by in the context of a contract;\ + a contract has a trie id;\ + this can't be None; qed", + ); + storage::destroy_contract::(&self_id, self_trie_id); + Ok(()) } fn call( @@ -795,20 +773,40 @@ where }); } - fn note_restore_to( + fn restore_to( &mut self, dest: AccountIdOf, code_hash: CodeHash, rent_allowance: BalanceOf, delta: Vec, - ) { - self.ctx.deferred.push(DeferredAction::RestoreTo { - donor: self.ctx.self_account.clone(), - dest, - code_hash, + ) -> Result<(), &'static str> { + if let Some(caller_ctx) = self.ctx.caller { + if caller_ctx.is_live(&self.ctx.self_account) { + return Err( + "Cannot perform restoration of a contract that is present on the call stack", + ); + } + } + + let result = crate::rent::restore_to::( + self.ctx.self_account.clone(), + dest.clone(), + code_hash.clone(), rent_allowance, delta, - }); + ); + if let Ok(_) = result { + deposit_event::( + vec![], + RawEvent::Restored( + self.ctx.self_account.clone(), + dest, + code_hash, + rent_allowance, + ), + ); + } + result } fn address(&self) -> &T::AccountId { @@ -820,7 +818,7 @@ where } fn balance(&self) -> BalanceOf { - self.ctx.overlay.get_balance(&self.ctx.self_account) + T::Currency::free_balance(&self.ctx.self_account) } fn value_transferred(&self) -> BalanceOf { @@ -844,18 +842,25 @@ where } fn deposit_event(&mut self, topics: Vec, data: Vec) { - self.ctx.deferred.push(DeferredAction::DepositEvent { + deposit_event::( topics, - event: RawEvent::ContractExecution(self.ctx.self_account.clone(), data), - }); + RawEvent::ContractExecution(self.ctx.self_account.clone(), data) + ); } fn set_rent_allowance(&mut self, rent_allowance: BalanceOf) { - self.ctx.overlay.set_rent_allowance(&self.ctx.self_account, rent_allowance) + if let Err(storage::ContractAbsentError) = + storage::set_rent_allowance::(&self.ctx.self_account, rent_allowance) + { + panic!( + "`self_account` points to an alive contract within the `CallContext`; + set_rent_allowance cannot return `Err`; qed" + ); + } } fn rent_allowance(&self) -> BalanceOf { - self.ctx.overlay.get_rent_allowance(&self.ctx.self_account) + storage::rent_allowance::(&self.ctx.self_account) .unwrap_or(>::max_value()) // Must never be triggered actually } @@ -877,30 +882,37 @@ where } } +fn deposit_event( + topics: Vec, + event: Event, +) { + >::deposit_event_indexed( + &*topics, + ::Event::from(event).into(), + ) +} + /// These tests exercise the executive layer. /// /// In these tests the VM/loader are mocked. Instead of dealing with wasm bytecode they use simple closures. /// This allows you to tackle executive logic more thoroughly without writing a /// wasm VM code. -/// -/// Because it's the executive layer: -/// -/// - no gas meter setup and teardown logic. All balances are *AFTER* gas purchase. -/// - executive layer doesn't alter any storage! #[cfg(test)] mod tests { use super::{ - BalanceOf, ExecFeeToken, ExecutionContext, Ext, Loader, TransferFeeKind, TransferFeeToken, - Vm, ExecResult, RawEvent, DeferredAction, + BalanceOf, Event, ExecFeeToken, ExecResult, ExecutionContext, Ext, Loader, + RawEvent, TransferFeeKind, TransferFeeToken, Vm, }; use crate::{ - account_db::AccountDb, gas::GasMeter, tests::{ExtBuilder, Test}, + gas::GasMeter, tests::{ExtBuilder, Test, MetaEvent}, exec::{ExecReturnValue, ExecError, STATUS_SUCCESS}, CodeHash, Config, gas::Gas, + storage, }; - use std::{cell::RefCell, rc::Rc, collections::HashMap, marker::PhantomData}; - use assert_matches::assert_matches; + use crate::tests::test_utils::{place_contract, set_balance, get_balance}; use sp_runtime::DispatchError; + use assert_matches::assert_matches; + use std::{cell::RefCell, collections::HashMap, marker::PhantomData, rc::Rc}; const ALICE: u64 = 1; const BOB: u64 = 2; @@ -908,19 +920,14 @@ mod tests { const GAS_LIMIT: Gas = 10_000_000_000; - impl<'a, T, V, L> ExecutionContext<'a, T, V, L> - where T: crate::Trait - { - fn events(&self) -> Vec> { - self.deferred - .iter() - .filter(|action| match *action { - DeferredAction::DepositEvent { .. } => true, - _ => false, - }) - .cloned() - .collect() - } + fn events() -> Vec> { + >::events() + .into_iter() + .filter_map(|meta| match meta.event { + MetaEvent::contracts(contract_event) => Some(contract_event), + _ => None, + }) + .collect() } struct MockCtx<'a> { @@ -1029,7 +1036,7 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.instantiate_contract(&BOB, exec_ch).unwrap(); + place_contract(&BOB, exec_ch); assert_matches!( ctx.call(BOB, value, &mut gas_meter, data), @@ -1051,8 +1058,8 @@ mod tests { let loader = MockLoader::empty(); let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.set_balance(&origin, 100); - ctx.overlay.set_balance(&dest, 0); + set_balance(&origin, 100); + set_balance(&dest, 0); let mut gas_meter = GasMeter::::new(GAS_LIMIT); @@ -1072,7 +1079,7 @@ mod tests { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.set_balance(&origin, 100); + set_balance(&origin, 100); let mut gas_meter = GasMeter::::new(GAS_LIMIT); @@ -1097,8 +1104,8 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.set_balance(&origin, 100); - ctx.overlay.set_balance(&dest, 0); + set_balance(&origin, 100); + set_balance(&dest, 0); let output = ctx.call( dest, @@ -1108,15 +1115,15 @@ mod tests { ).unwrap(); assert!(output.is_success()); - assert_eq!(ctx.overlay.get_balance(&origin), 45); - assert_eq!(ctx.overlay.get_balance(&dest), 55); + assert_eq!(get_balance(&origin), 45); + assert_eq!(get_balance(&dest), 55); }); } #[test] fn changes_are_reverted_on_failing_call() { - // This test verifies that a contract is able to transfer - // some funds to another account. + // This test verifies that changes are reverted on a call which fails (or equally, returns + // a non-zero status code). let origin = ALICE; let dest = BOB; @@ -1129,9 +1136,9 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.instantiate_contract(&BOB, return_ch).unwrap(); - ctx.overlay.set_balance(&origin, 100); - ctx.overlay.set_balance(&dest, 0); + place_contract(&BOB, return_ch); + set_balance(&origin, 100); + set_balance(&dest, 0); let output = ctx.call( dest, @@ -1141,8 +1148,8 @@ mod tests { ).unwrap(); assert!(!output.is_success()); - assert_eq!(ctx.overlay.get_balance(&origin), 100); - assert_eq!(ctx.overlay.get_balance(&dest), 0); + assert_eq!(get_balance(&origin), 100); + assert_eq!(get_balance(&dest), 0); }); } @@ -1159,8 +1166,8 @@ mod tests { let loader = MockLoader::empty(); let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.set_balance(&origin, 100); - ctx.overlay.set_balance(&dest, 0); + set_balance(&origin, 100); + set_balance(&dest, 0); let mut gas_meter = GasMeter::::new(GAS_LIMIT); @@ -1184,8 +1191,8 @@ mod tests { let loader = MockLoader::empty(); let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.set_balance(&origin, 100); - ctx.overlay.set_balance(&dest, 15); + set_balance(&origin, 100); + set_balance(&dest, 15); let mut gas_meter = GasMeter::::new(GAS_LIMIT); @@ -1212,8 +1219,8 @@ mod tests { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.set_balance(&origin, 100); - ctx.overlay.set_balance(&dest, 15); + set_balance(&origin, 100); + set_balance(&dest, 15); let mut gas_meter = GasMeter::::new(GAS_LIMIT); @@ -1244,7 +1251,7 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.set_balance(&origin, 0); + set_balance(&origin, 0); let result = ctx.call( dest, @@ -1256,12 +1263,12 @@ mod tests { assert_matches!( result, Err(ExecError { - reason: DispatchError::Other("balance too low to send value"), + reason: DispatchError::Module { message: Some("InsufficientBalance"), .. }, buffer: _, }) ); - assert_eq!(ctx.overlay.get_balance(&origin), 0); - assert_eq!(ctx.overlay.get_balance(&dest), 0); + assert_eq!(get_balance(&origin), 0); + assert_eq!(get_balance(&dest), 0); }); } @@ -1281,7 +1288,7 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.instantiate_contract(&BOB, return_ch).unwrap(); + place_contract(&BOB, return_ch); let result = ctx.call( dest, @@ -1312,7 +1319,7 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.instantiate_contract(&BOB, return_ch).unwrap(); + place_contract(&BOB, return_ch); let result = ctx.call( dest, @@ -1340,7 +1347,7 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.instantiate_contract(&BOB, input_data_ch).unwrap(); + place_contract(&BOB, input_data_ch); let result = ctx.call( BOB, @@ -1366,7 +1373,7 @@ mod tests { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.set_balance(&ALICE, 100); + set_balance(&ALICE, 100); let result = ctx.instantiate( 1, @@ -1414,8 +1421,8 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.set_balance(&BOB, 1); - ctx.overlay.instantiate_contract(&BOB, recurse_ch).unwrap(); + set_balance(&BOB, 1); + place_contract(&BOB, recurse_ch); let result = ctx.call( BOB, @@ -1460,8 +1467,8 @@ mod tests { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(origin, &cfg, &vm, &loader); - ctx.overlay.instantiate_contract(&dest, bob_ch).unwrap(); - ctx.overlay.instantiate_contract(&CHARLIE, charlie_ch).unwrap(); + place_contract(&dest, bob_ch); + place_contract(&CHARLIE, charlie_ch); let result = ctx.call( dest, @@ -1501,8 +1508,8 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.instantiate_contract(&BOB, bob_ch).unwrap(); - ctx.overlay.instantiate_contract(&CHARLIE, charlie_ch).unwrap(); + place_contract(&BOB, bob_ch); + place_contract(&CHARLIE, charlie_ch); let result = ctx.call( BOB, @@ -1550,7 +1557,7 @@ mod tests { ExtBuilder::default().existential_deposit(15).build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.set_balance(&ALICE, 1000); + set_balance(&ALICE, 1000); let instantiated_contract_address = assert_matches!( ctx.instantiate( @@ -1564,16 +1571,9 @@ mod tests { // Check that the newly created account has the expected code hash and // there are instantiation event. - assert_eq!(ctx.overlay.get_code_hash(&instantiated_contract_address).unwrap(), dummy_ch); - assert_eq!(&ctx.events(), &[ - DeferredAction::DepositEvent { - event: RawEvent::Transfer(ALICE, instantiated_contract_address, 100), - topics: Vec::new(), - }, - DeferredAction::DepositEvent { - event: RawEvent::Instantiated(ALICE, instantiated_contract_address), - topics: Vec::new(), - } + assert_eq!(storage::code_hash::(&instantiated_contract_address).unwrap(), dummy_ch); + assert_eq!(&events(), &[ + RawEvent::Instantiated(ALICE, instantiated_contract_address) ]); }); } @@ -1590,7 +1590,7 @@ mod tests { ExtBuilder::default().existential_deposit(15).build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.set_balance(&ALICE, 1000); + set_balance(&ALICE, 1000); let instantiated_contract_address = assert_matches!( ctx.instantiate( @@ -1603,8 +1603,8 @@ mod tests { ); // Check that the account has not been created. - assert!(ctx.overlay.get_code_hash(&instantiated_contract_address).is_none()); - assert!(ctx.events().is_empty()); + assert!(storage::code_hash::(&instantiated_contract_address).is_err()); + assert!(events().is_empty()); }); } @@ -1635,9 +1635,9 @@ mod tests { ExtBuilder::default().existential_deposit(15).build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.set_balance(&ALICE, 1000); - ctx.overlay.set_balance(&BOB, 100); - ctx.overlay.instantiate_contract(&BOB, instantiator_ch).unwrap(); + set_balance(&ALICE, 1000); + set_balance(&BOB, 100); + place_contract(&BOB, instantiator_ch); assert_matches!( ctx.call(BOB, 20, &mut GasMeter::::new(GAS_LIMIT), vec![]), @@ -1648,20 +1648,9 @@ mod tests { // Check that the newly created account has the expected code hash and // there are instantiation event. - assert_eq!(ctx.overlay.get_code_hash(&instantiated_contract_address).unwrap(), dummy_ch); - assert_eq!(&ctx.events(), &[ - DeferredAction::DepositEvent { - event: RawEvent::Transfer(ALICE, BOB, 20), - topics: Vec::new(), - }, - DeferredAction::DepositEvent { - event: RawEvent::Transfer(BOB, instantiated_contract_address, 15), - topics: Vec::new(), - }, - DeferredAction::DepositEvent { - event: RawEvent::Instantiated(BOB, instantiated_contract_address), - topics: Vec::new(), - }, + assert_eq!(storage::code_hash::(&instantiated_contract_address).unwrap(), dummy_ch); + assert_eq!(&events(), &[ + RawEvent::Instantiated(BOB, instantiated_contract_address) ]); }); } @@ -1695,9 +1684,9 @@ mod tests { ExtBuilder::default().existential_deposit(15).build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.set_balance(&ALICE, 1000); - ctx.overlay.set_balance(&BOB, 100); - ctx.overlay.instantiate_contract(&BOB, instantiator_ch).unwrap(); + set_balance(&ALICE, 1000); + set_balance(&BOB, 100); + place_contract(&BOB, instantiator_ch); assert_matches!( ctx.call(BOB, 20, &mut GasMeter::::new(GAS_LIMIT), vec![]), @@ -1706,12 +1695,7 @@ mod tests { // The contract wasn't instantiated so we don't expect to see an instantiation // event here. - assert_eq!(&ctx.events(), &[ - DeferredAction::DepositEvent { - event: RawEvent::Transfer(ALICE, BOB, 20), - topics: Vec::new(), - }, - ]); + assert_eq!(&events(), &[]); }); } @@ -1732,7 +1716,7 @@ mod tests { .execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - ctx.overlay.set_balance(&ALICE, 1000); + set_balance(&ALICE, 1000); assert_matches!( ctx.instantiate( @@ -1748,7 +1732,7 @@ mod tests { ); assert_eq!( - &ctx.events(), + &events(), &[] ); }); @@ -1768,8 +1752,7 @@ mod tests { ExtBuilder::default().build().execute_with(|| { let cfg = Config::preload(); let mut ctx = ExecutionContext::top_level(ALICE, &cfg, &vm, &loader); - - ctx.overlay.set_balance(&ALICE, 100); + set_balance(&ALICE, 100); let result = ctx.instantiate( 1, diff --git a/frame/contracts/src/lib.rs b/frame/contracts/src/lib.rs index 245c95a4fa4e9..c12029a856c9d 100644 --- a/frame/contracts/src/lib.rs +++ b/frame/contracts/src/lib.rs @@ -81,8 +81,7 @@ #[macro_use] mod gas; - -mod account_db; +mod storage; mod exec; mod wasm; mod rent; @@ -91,7 +90,6 @@ mod rent; mod tests; use crate::exec::ExecutionContext; -use crate::account_db::{AccountDb, DirectAccountDb}; use crate::wasm::{WasmLoader, WasmVm}; pub use crate::gas::{Gas, GasMeter}; @@ -102,7 +100,6 @@ use serde::{Serialize, Deserialize}; use sp_core::crypto::UncheckedFrom; use sp_std::{prelude::*, marker::PhantomData, fmt::Debug}; use codec::{Codec, Encode, Decode}; -use sp_io::hashing::blake2_256; use sp_runtime::{ traits::{ Hash, StaticLookup, Zero, MaybeSerializeDeserialize, Member, @@ -114,7 +111,7 @@ use frame_support::dispatch::{ }; use frame_support::{ Parameter, decl_module, decl_event, decl_storage, decl_error, - parameter_types, IsSubType, storage::child::{self, ChildInfo}, + parameter_types, IsSubType, storage::child::ChildInfo, }; use frame_support::traits::{OnUnbalanced, Currency, Get, Time, Randomness}; use frame_support::weights::GetDispatchInfo; @@ -129,11 +126,6 @@ pub trait ContractAddressFor { fn contract_address_for(code_hash: &CodeHash, data: &[u8], origin: &AccountId) -> AccountId; } -/// A function that returns the fee for dispatching a `Call`. -pub trait ComputeDispatchFee { - fn compute_dispatch_fee(call: &Call) -> Balance; -} - /// Information for managing an account and its sub trie abstraction. /// This is the required info to cache for an account #[derive(Encode, Decode, RuntimeDebug)] @@ -255,6 +247,12 @@ where } } +impl From> for ContractInfo { + fn from(alive_info: AliveContractInfo) -> 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). @@ -612,12 +610,7 @@ impl Module { .get_alive() .ok_or(ContractAccessError::IsTombstone)?; - let maybe_value = AccountDb::::get_storage( - &DirectAccountDb, - &address, - Some(&contract_info.trie_id), - &key, - ); + let maybe_value = storage::read_contract_storage(&contract_info.trie_id, &key); Ok(maybe_value) } @@ -636,7 +629,7 @@ impl Module { fn execute_wasm( origin: T::AccountId, gas_meter: &mut GasMeter, - func: impl FnOnce(&mut ExecutionContext, &mut GasMeter) -> ExecResult + func: impl FnOnce(&mut ExecutionContext, &mut GasMeter) -> ExecResult, ) -> ExecResult { let cfg = Config::preload(); let vm = WasmVm::new(&cfg.schedule); @@ -645,22 +638,10 @@ impl Module { let result = func(&mut ctx, gas_meter); - if result.as_ref().map(|output| output.is_success()).unwrap_or(false) { - // Commit all changes that made it thus far into the persistent storage. - DirectAccountDb.commit(ctx.overlay.into_change_set()); - } - // Execute deferred actions. ctx.deferred.into_iter().for_each(|deferred| { use self::exec::DeferredAction::*; match deferred { - DepositEvent { - topics, - event, - } => >::deposit_event_indexed( - &*topics, - ::Event::from(event).into(), - ), DispatchRuntimeCall { origin: who, call, @@ -674,112 +655,11 @@ impl Module { gas_meter.refund(post_info.calc_unspent(&info)); Self::deposit_event(RawEvent::Dispatched(who, result.is_ok())); } - RestoreTo { - donor, - dest, - code_hash, - rent_allowance, - delta, - } => { - let result = Self::restore_to( - donor.clone(), dest.clone(), code_hash.clone(), rent_allowance.clone(), delta - ); - Self::deposit_event( - RawEvent::Restored(donor, dest, code_hash, rent_allowance, result.is_ok()) - ); - } } }); result } - - fn restore_to( - origin: T::AccountId, - dest: T::AccountId, - code_hash: CodeHash, - rent_allowance: BalanceOf, - delta: Vec, - ) -> DispatchResult { - let mut origin_contract = >::get(&origin) - .and_then(|c| c.get_alive()) - .ok_or(Error::::InvalidSourceContract)?; - - let current_block = >::block_number(); - - if origin_contract.last_write == Some(current_block) { - Err(Error::::InvalidContractOrigin)? - } - - let dest_tombstone = >::get(&dest) - .and_then(|c| c.get_tombstone()) - .ok_or(Error::::InvalidDestinationContract)?; - - let last_write = if !delta.is_empty() { - Some(current_block) - } else { - origin_contract.last_write - }; - - let key_values_taken = delta.iter() - .filter_map(|key| { - child::get_raw( - &origin_contract.child_trie_info(), - &blake2_256(key), - ).map(|value| { - child::kill( - &origin_contract.child_trie_info(), - &blake2_256(key), - ); - - (key, value) - }) - }) - .collect::>(); - - let tombstone = >::new( - // This operation is cheap enough because last_write (delta not included) - // is not this block as it has been checked earlier. - &child::root( - &origin_contract.child_trie_info(), - )[..], - code_hash, - ); - - if tombstone != dest_tombstone { - for (key, value) in key_values_taken { - child::put_raw( - &origin_contract.child_trie_info(), - &blake2_256(key), - &value, - ); - } - - return Err(Error::::InvalidTombstone.into()); - } - - origin_contract.storage_size -= key_values_taken.iter() - .map(|(_, value)| value.len() as u32) - .sum::(); - - >::remove(&origin); - >::insert(&dest, ContractInfo::Alive(RawAliveContractInfo { - trie_id: origin_contract.trie_id, - storage_size: origin_contract.storage_size, - empty_pair_count: origin_contract.empty_pair_count, - total_pair_count: origin_contract.total_pair_count, - code_hash, - rent_allowance, - deduct_block: current_block, - last_write, - })); - - let origin_free_balance = T::Currency::free_balance(&origin); - T::Currency::make_free_balance_be(&origin, >::zero()); - T::Currency::deposit_creating(&dest, origin_free_balance); - - Ok(()) - } } decl_event! { @@ -789,9 +669,6 @@ decl_event! { ::AccountId, ::Hash { - /// Transfer happened `from` to `to` with given `value` as part of a `call` or `instantiate`. - Transfer(AccountId, AccountId, Balance), - /// Contract deployed by address at the specified address. Instantiated(AccountId, AccountId), @@ -803,7 +680,7 @@ decl_event! { /// - `tombstone`: `bool`: True if the evicted contract left behind a tombstone. Evicted(AccountId, bool), - /// Restoration for a contract has been initiated. + /// Restoration for a contract has been successful. /// /// # Params /// @@ -811,8 +688,7 @@ decl_event! { /// - `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 - /// - `success`: `bool`: True if the restoration was successful - Restored(AccountId, AccountId, Hash, Balance, bool), + Restored(AccountId, AccountId, Hash, Balance), /// Code with the specified hash has been stored. CodeStored(Hash), diff --git a/frame/contracts/src/rent.rs b/frame/contracts/src/rent.rs index 1d8f47462731b..6afd85aa8eb42 100644 --- a/frame/contracts/src/rent.rs +++ b/frame/contracts/src/rent.rs @@ -18,8 +18,10 @@ use crate::{ AliveContractInfo, BalanceOf, ContractInfo, ContractInfoOf, Module, RawEvent, - TombstoneContractInfo, Trait, + TombstoneContractInfo, Trait, CodeHash, }; +use sp_std::prelude::*; +use sp_io::hashing::blake2_256; use frame_support::storage::child; use frame_support::traits::{Currency, ExistenceRequirement, Get, OnUnbalanced, WithdrawReason}; use frame_support::StorageMap; @@ -396,3 +398,90 @@ pub fn compute_rent_projection( current_block_number + blocks_left, )) } + +/// Restores the destination account using the origin as prototype. +/// +/// The restoration will be performed iff: +/// - origin exists and is alive, +/// - the origin's storage is not written in the current block +/// - the restored account has tombstone +/// - the tombstone matches the hash of the origin storage root, and code hash. +/// +/// Upon succesful restoration, `origin` will be destroyed, all its funds are transferred to +/// the restored account. The restored account will inherit the last write block and its last +/// deduct block will be set to the current block. +pub fn restore_to( + origin: T::AccountId, + dest: T::AccountId, + code_hash: CodeHash, + rent_allowance: BalanceOf, + delta: Vec, +) -> Result<(), &'static str> { + let mut origin_contract = >::get(&origin) + .and_then(|c| c.get_alive()) + .ok_or("Cannot restore from inexisting or tombstone contract")?; + + let child_trie_info = origin_contract.child_trie_info(); + + let current_block = >::block_number(); + + if origin_contract.last_write == Some(current_block) { + return Err("Origin TrieId written in the current block"); + } + + let dest_tombstone = >::get(&dest) + .and_then(|c| c.get_tombstone()) + .ok_or("Cannot restore to inexisting or alive contract")?; + + let last_write = if !delta.is_empty() { + Some(current_block) + } else { + origin_contract.last_write + }; + + let key_values_taken = delta.iter() + .filter_map(|key| { + child::get_raw(&child_trie_info, &blake2_256(key)).map(|value| { + child::kill(&child_trie_info, &blake2_256(key)); + (key, value) + }) + }) + .collect::>(); + + let tombstone = >::new( + // This operation is cheap enough because last_write (delta not included) + // is not this block as it has been checked earlier. + &child::root(&child_trie_info)[..], + code_hash, + ); + + if tombstone != dest_tombstone { + for (key, value) in key_values_taken { + child::put_raw(&child_trie_info, &blake2_256(key), &value); + } + + return Err("Tombstones don't match"); + } + + origin_contract.storage_size -= key_values_taken.iter() + .map(|(_, value)| value.len() as u32) + .sum::(); + + >::remove(&origin); + >::insert(&dest, ContractInfo::Alive(AliveContractInfo:: { + trie_id: origin_contract.trie_id, + storage_size: origin_contract.storage_size, + empty_pair_count: origin_contract.empty_pair_count, + total_pair_count: origin_contract.total_pair_count, + code_hash, + rent_allowance, + deduct_block: current_block, + last_write, + })); + + let origin_free_balance = T::Currency::free_balance(&origin); + T::Currency::make_free_balance_be(&origin, >::zero()); + T::Currency::deposit_creating(&dest, origin_free_balance); + + Ok(()) +} diff --git a/frame/contracts/src/storage.rs b/frame/contracts/src/storage.rs new file mode 100644 index 0000000000000..4c5ad892a967b --- /dev/null +++ b/frame/contracts/src/storage.rs @@ -0,0 +1,195 @@ +// Copyright 2019 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 . + +//! This module contains routines for accessing and altering a contract related state. + +use crate::{ + exec::{AccountIdOf, StorageKey}, + AliveContractInfo, BalanceOf, CodeHash, ContractInfo, ContractInfoOf, Trait, TrieId, +}; +use sp_std::prelude::*; +use sp_io::hashing::blake2_256; +use sp_runtime::traits::Bounded; +use frame_support::{storage::child, StorageMap}; + +/// An error that means that the account requested either doesn't exist or represents a tombstone +/// account. +#[cfg_attr(test, derive(PartialEq, Eq, Debug))] +pub struct ContractAbsentError; + +/// Reads a storage kv pair of a contract. +/// +/// The read is performed from the `trie_id` only. The `address` is not necessary. If the contract +/// doesn't store under the given `key` `None` is returned. +pub fn read_contract_storage(trie_id: &TrieId, key: &StorageKey) -> Option> { + child::get_raw(&crate::child_trie_info(&trie_id), &blake2_256(key)) +} + +/// Update a storage entry into a contract's kv storage. +/// +/// If the `opt_new_value` is `None` then the kv pair is removed. +/// +/// This function also updates the bookkeeping info such as: number of total non-empty pairs a +/// contract owns, the last block the storage was written to, etc. That's why, in contrast to +/// `read_contract_storage`, this function also requires the `account` ID. +/// +/// If the contract specified by the id `account` doesn't exist `Err` is returned.` +pub fn write_contract_storage( + account: &AccountIdOf, + trie_id: &TrieId, + key: &StorageKey, + opt_new_value: Option>, +) -> Result<(), ContractAbsentError> { + let mut new_info = match >::get(account) { + Some(ContractInfo::Alive(alive)) => alive, + None | Some(ContractInfo::Tombstone(_)) => return Err(ContractAbsentError), + }; + + let hashed_key = blake2_256(key); + let child_trie_info = &crate::child_trie_info(&trie_id); + + // In order to correctly update the book keeping we need to fetch the previous + // value of the key-value pair. + // + // It might be a bit more clean if we had an API that supported getting the size + // of the value without going through the loading of it. But at the moment of + // writing, there is no such API. + // + // That's not a show stopper in any case, since the performance cost is + // dominated by the trie traversal anyway. + let opt_prev_value = child::get_raw(&child_trie_info, &hashed_key); + + // Update the total number of KV pairs and the number of empty pairs. + match (&opt_prev_value, &opt_new_value) { + (Some(prev_value), None) => { + new_info.total_pair_count -= 1; + if prev_value.is_empty() { + new_info.empty_pair_count -= 1; + } + }, + (None, Some(new_value)) => { + new_info.total_pair_count += 1; + if new_value.is_empty() { + new_info.empty_pair_count += 1; + } + }, + (Some(prev_value), Some(new_value)) => { + if prev_value.is_empty() { + new_info.empty_pair_count -= 1; + } + if new_value.is_empty() { + new_info.empty_pair_count += 1; + } + } + (None, None) => {} + } + + // Update the total storage size. + let prev_value_len = opt_prev_value + .as_ref() + .map(|old_value| old_value.len() as u32) + .unwrap_or(0); + let new_value_len = opt_new_value + .as_ref() + .map(|new_value| new_value.len() as u32) + .unwrap_or(0); + new_info.storage_size = new_info + .storage_size + .saturating_add(new_value_len) + .saturating_sub(prev_value_len); + + new_info.last_write = Some(>::block_number()); + >::insert(&account, ContractInfo::Alive(new_info)); + + // Finally, perform the change on the storage. + match opt_new_value { + Some(new_value) => child::put_raw(&child_trie_info, &hashed_key, &new_value[..]), + None => child::kill(&child_trie_info, &hashed_key), + } + + Ok(()) +} + +/// Returns the rent allowance set for the contract give by the account id. +pub fn rent_allowance( + account: &AccountIdOf, +) -> Result, ContractAbsentError> { + >::get(account) + .and_then(|i| i.as_alive().map(|i| i.rent_allowance)) + .ok_or(ContractAbsentError) +} + +/// Set the rent allowance for the contract given by the account id. +/// +/// Returns `Err` if the contract doesn't exist or is a tombstone. +pub fn set_rent_allowance( + account: &AccountIdOf, + rent_allowance: BalanceOf, +) -> Result<(), ContractAbsentError> { + >::mutate(account, |maybe_contract_info| match maybe_contract_info { + Some(ContractInfo::Alive(ref mut alive_info)) => { + alive_info.rent_allowance = rent_allowance; + Ok(()) + } + _ => Err(ContractAbsentError), + }) +} + +/// Returns the code hash of the contract specified by `account` ID. +pub fn code_hash(account: &AccountIdOf) -> Result, ContractAbsentError> { + >::get(account) + .and_then(|i| i.as_alive().map(|i| i.code_hash)) + .ok_or(ContractAbsentError) +} + +/// Creates a new contract descriptor in the storage with the given code hash at the given address. +/// +/// Returns `Err` if there is already a contract (or a tombstone) exists at the given address. +pub fn place_contract( + account: &AccountIdOf, + trie_id: TrieId, + ch: CodeHash, +) -> Result<(), &'static str> { + >::mutate(account, |maybe_contract_info| { + if maybe_contract_info.is_some() { + return Err("Alive contract or tombstone already exists"); + } + + *maybe_contract_info = Some( + AliveContractInfo:: { + code_hash: ch, + storage_size: 0, + trie_id, + deduct_block: >::block_number(), + rent_allowance: >::max_value(), + empty_pair_count: 0, + total_pair_count: 0, + last_write: None, + } + .into(), + ); + + Ok(()) + }) +} + +/// Removes the contract and all the storage associated with it. +/// +/// This function doesn't affect the account. +pub fn destroy_contract(address: &AccountIdOf, trie_id: &TrieId) { + >::remove(address); + child::kill_storage(&crate::child_trie_info(&trie_id)); +} diff --git a/frame/contracts/src/tests.rs b/frame/contracts/src/tests.rs index a98fdf2d25804..df6afa8ac51e0 100644 --- a/frame/contracts/src/tests.rs +++ b/frame/contracts/src/tests.rs @@ -16,9 +16,7 @@ use crate::{ BalanceOf, ContractAddressFor, ContractInfo, ContractInfoOf, GenesisConfig, Module, - RawAliveContractInfo, RawEvent, Trait, TrieId, Schedule, TrieIdGenerator, - account_db::{AccountDb, DirectAccountDb, OverlayAccountDb}, - gas::Gas, + RawAliveContractInfo, RawEvent, Trait, TrieId, Schedule, TrieIdGenerator, gas::Gas, }; use assert_matches::assert_matches; use hex_literal::*; @@ -64,6 +62,34 @@ impl_outer_dispatch! { } } +pub mod test_utils { + use super::{Test, Balances}; + use crate::{ContractInfoOf, TrieIdGenerator, CodeHash}; + use crate::storage::{write_contract_storage, read_contract_storage}; + use crate::exec::StorageKey; + use frame_support::{StorageMap, traits::Currency}; + + pub fn set_storage(addr: &u64, key: &StorageKey, value: Option>) { + let contract_info = >::get(&addr).unwrap().get_alive().unwrap(); + write_contract_storage::(&1, &contract_info.trie_id, key, value).unwrap(); + } + pub fn get_storage(addr: &u64, key: &StorageKey) -> Option> { + let contract_info = >::get(&addr).unwrap().get_alive().unwrap(); + read_contract_storage(&contract_info.trie_id, key) + } + pub fn place_contract(address: &u64, code_hash: CodeHash) { + let trie_id = ::TrieIdGenerator::trie_id(address); + crate::storage::place_contract::(&address, trie_id, code_hash).unwrap() + } + pub fn set_balance(who: &u64, amount: u64) { + let imbalance = Balances::deposit_creating(who, amount); + drop(imbalance); + } + pub fn get_balance(who: &u64) -> u64 { + Balances::free_balance(who) + } +} + thread_local! { static EXISTENTIAL_DEPOSIT: RefCell = RefCell::new(0); } @@ -280,6 +306,8 @@ fn returns_base_call_cost() { #[test] fn account_removal_does_not_remove_storage() { + use self::test_utils::{set_storage, get_storage}; + ExtBuilder::default().existential_deposit(100).build().execute_with(|| { let trie_id1 = ::TrieIdGenerator::trie_id(&1); let trie_id2 = ::TrieIdGenerator::trie_id(&2); @@ -288,8 +316,7 @@ fn account_removal_does_not_remove_storage() { // Set up two accounts with free balance above the existential threshold. { - let _ = Balances::deposit_creating(&1, 110); - ContractInfoOf::::insert(1, &ContractInfo::Alive(RawAliveContractInfo { + let alice_contract_info = ContractInfo::Alive(RawAliveContractInfo { trie_id: trie_id1.clone(), storage_size: 0, empty_pair_count: 0, @@ -298,15 +325,13 @@ fn account_removal_does_not_remove_storage() { code_hash: H256::repeat_byte(1), rent_allowance: 40, last_write: None, - })); + }); + let _ = Balances::deposit_creating(&ALICE, 110); + ContractInfoOf::::insert(ALICE, &alice_contract_info); + set_storage(&ALICE, &key1, Some(b"1".to_vec())); + set_storage(&ALICE, &key2, Some(b"2".to_vec())); - let mut overlay = OverlayAccountDb::::new(&DirectAccountDb); - overlay.set_storage(&1, key1.clone(), Some(b"1".to_vec())); - overlay.set_storage(&1, key2.clone(), Some(b"2".to_vec())); - DirectAccountDb.commit(overlay.into_change_set()); - - let _ = Balances::deposit_creating(&2, 110); - ContractInfoOf::::insert(2, &ContractInfo::Alive(RawAliveContractInfo { + let bob_contract_info = ContractInfo::Alive(RawAliveContractInfo { trie_id: trie_id2.clone(), storage_size: 0, empty_pair_count: 0, @@ -315,40 +340,39 @@ fn account_removal_does_not_remove_storage() { code_hash: H256::repeat_byte(2), rent_allowance: 40, last_write: None, - })); - - let mut overlay = OverlayAccountDb::::new(&DirectAccountDb); - overlay.set_storage(&2, key1.clone(), Some(b"3".to_vec())); - overlay.set_storage(&2, key2.clone(), Some(b"4".to_vec())); - DirectAccountDb.commit(overlay.into_change_set()); + }); + let _ = Balances::deposit_creating(&BOB, 110); + ContractInfoOf::::insert(BOB, &bob_contract_info); + set_storage(&BOB, &key1, Some(b"3".to_vec())); + set_storage(&BOB, &key2, Some(b"4".to_vec())); } - // Transfer funds from account 1 of such amount that after this transfer - // the balance of account 1 will be below the existential threshold. + // Transfer funds from ALICE account of such amount that after this transfer + // the balance of the ALICE account will be below the existential threshold. // // This does not remove the contract storage as we are not notified about a // account removal. This cannot happen in reality because a contract can only // remove itself by `ext_terminate`. There is no external event that can remove // the account appart from that. - assert_ok!(Balances::transfer(Origin::signed(1), 2, 20)); + assert_ok!(Balances::transfer(Origin::signed(ALICE), BOB, 20)); // Verify that no entries are removed. { assert_eq!( - >::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key1), + get_storage(&ALICE, key1), Some(b"1".to_vec()) ); assert_eq!( - >::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key2), + get_storage(&ALICE, key2), Some(b"2".to_vec()) ); assert_eq!( - >::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key1), + get_storage(&BOB, key1), Some(b"3".to_vec()) ); assert_eq!( - >::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key2), + get_storage(&BOB, key2), Some(b"4".to_vec()) ); } @@ -376,7 +400,7 @@ fn instantiate_and_call_and_deposit_event() { vec![], ); - assert_eq!(System::events(), vec![ + pretty_assertions::assert_eq!(System::events(), vec![ EventRecord { phase: Phase::Initialization, event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)), @@ -406,7 +430,9 @@ fn instantiate_and_call_and_deposit_event() { }, EventRecord { phase: Phase::Initialization, - event: MetaEvent::contracts(RawEvent::Transfer(ALICE, BOB, 100)), + event: MetaEvent::balances( + pallet_balances::RawEvent::Transfer(ALICE, BOB, 100) + ), topics: vec![], }, EventRecord { @@ -479,7 +505,7 @@ fn dispatch_call() { vec![], )); - assert_eq!(System::events(), vec![ + pretty_assertions::assert_eq!(System::events(), vec![ EventRecord { phase: Phase::Initialization, event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)), @@ -509,7 +535,9 @@ fn dispatch_call() { }, EventRecord { phase: Phase::Initialization, - event: MetaEvent::contracts(RawEvent::Transfer(ALICE, BOB, 100)), + event: MetaEvent::balances( + pallet_balances::RawEvent::Transfer(ALICE, BOB, 100) + ), topics: vec![], }, EventRecord { @@ -606,7 +634,7 @@ fn dispatch_call_not_dispatched_after_top_level_transaction_failure() { ), "contract trapped during execution" ); - assert_eq!(System::events(), vec![ + pretty_assertions::assert_eq!(System::events(), vec![ EventRecord { phase: Phase::Initialization, event: MetaEvent::system(frame_system::RawEvent::NewAccount(1)), @@ -636,7 +664,9 @@ fn dispatch_call_not_dispatched_after_top_level_transaction_failure() { }, EventRecord { phase: Phase::Initialization, - event: MetaEvent::contracts(RawEvent::Transfer(ALICE, BOB, 100)), + event: MetaEvent::balances( + pallet_balances::RawEvent::Transfer(ALICE, BOB, 100) + ), topics: vec![], }, EventRecord { @@ -1323,9 +1353,6 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage: // Advance 4 blocks, to the 5th. initialize_block(5); - // Preserve `BOB`'s code hash for later introspection. - let bob_code_hash = ContractInfoOf::::get(BOB).unwrap() - .get_alive().unwrap().code_hash; // Call `BOB`, which makes it pay rent. Since the rent allowance is set to 0 // we expect that it will get removed leaving tombstone. assert_err_ignore_postinfo!( @@ -1367,17 +1394,25 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage: // Perform a call to `DJANGO`. This should either perform restoration successfully or // fail depending on the test parameters. - assert_ok!(Contracts::call( - Origin::signed(ALICE), - DJANGO, - 0, - GAS_LIMIT, - vec![], - )); + let perform_the_restoration = || { + Contracts::call( + Origin::signed(ALICE), + DJANGO, + 0, + GAS_LIMIT, + vec![], + ) + }; if test_different_storage || test_restore_to_with_dirty_storage { // Parametrization of the test imply restoration failure. Check that `DJANGO` aka // restoration contract is still in place and also that `BOB` doesn't exist. + + assert_err_ignore_postinfo!( + perform_the_restoration(), + "contract trapped during execution" + ); + assert!(ContractInfoOf::::get(BOB).unwrap().get_tombstone().is_some()); let django_contract = ContractInfoOf::::get(DJANGO).unwrap() .get_alive().unwrap(); @@ -1386,18 +1421,10 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage: assert_eq!(django_contract.deduct_block, System::block_number()); match (test_different_storage, test_restore_to_with_dirty_storage) { (true, false) => { - assert_eq!(System::events(), vec![ - EventRecord { - phase: Phase::Initialization, - event: MetaEvent::contracts( - RawEvent::Restored(DJANGO, BOB, bob_code_hash, 50, false) - ), - topics: vec![], - }, - ]); + assert_eq!(System::events(), vec![]); } (_, true) => { - assert_eq!(System::events(), vec![ + pretty_assertions::assert_eq!(System::events(), vec![ EventRecord { phase: Phase::Initialization, event: MetaEvent::contracts(RawEvent::Evicted(BOB, true)), @@ -1425,7 +1452,9 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage: }, EventRecord { phase: Phase::Initialization, - event: MetaEvent::contracts(RawEvent::Transfer(CHARLIE, DJANGO, 30_000)), + event: MetaEvent::balances( + pallet_balances::RawEvent::Transfer(CHARLIE, DJANGO, 30_000) + ), topics: vec![], }, EventRecord { @@ -1433,22 +1462,13 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage: event: MetaEvent::contracts(RawEvent::Instantiated(CHARLIE, DJANGO)), topics: vec![], }, - EventRecord { - phase: Phase::Initialization, - event: MetaEvent::contracts(RawEvent::Restored( - DJANGO, - BOB, - bob_code_hash, - 50, - false, - )), - topics: vec![], - }, ]); } _ => unreachable!(), } } else { + assert_ok!(perform_the_restoration()); + // Here we expect that the restoration is succeeded. Check that the restoration // contract `DJANGO` ceased to exist and that `BOB` returned back. println!("{:?}", ContractInfoOf::::get(BOB)); @@ -1468,7 +1488,7 @@ fn restoration(test_different_storage: bool, test_restore_to_with_dirty_storage: EventRecord { phase: Phase::Initialization, event: MetaEvent::contracts( - RawEvent::Restored(DJANGO, BOB, bob_contract.code_hash, 50, true) + RawEvent::Restored(DJANGO, BOB, bob_contract.code_hash, 50) ), topics: vec![], }, diff --git a/frame/contracts/src/wasm/mod.rs b/frame/contracts/src/wasm/mod.rs index cb69cd689b265..890915a793d46 100644 --- a/frame/contracts/src/wasm/mod.rs +++ b/frame/contracts/src/wasm/mod.rs @@ -229,11 +229,8 @@ mod tests { fn get_storage(&self, key: &StorageKey) -> Option> { self.storage.get(key).cloned() } - fn set_storage(&mut self, key: StorageKey, value: Option>) - -> Result<(), &'static str> - { + fn set_storage(&mut self, key: StorageKey, value: Option>) { *self.storage.entry(key).or_insert(Vec::new()) = value.unwrap_or(Vec::new()); - Ok(()) } fn instantiate( &mut self, @@ -304,19 +301,20 @@ mod tests { fn note_dispatch_call(&mut self, call: Call) { self.dispatches.push(DispatchEntry(call)); } - fn note_restore_to( + fn restore_to( &mut self, dest: u64, code_hash: H256, rent_allowance: u64, delta: Vec, - ) { + ) -> Result<(), &'static str> { self.restores.push(RestoreEntry { dest, code_hash, rent_allowance, delta, }); + Ok(()) } fn caller(&self) -> &u64 { &42 @@ -386,9 +384,7 @@ mod tests { fn get_storage(&self, key: &[u8; 32]) -> Option> { (**self).get_storage(key) } - fn set_storage(&mut self, key: [u8; 32], value: Option>) - -> Result<(), &'static str> - { + fn set_storage(&mut self, key: [u8; 32], value: Option>) { (**self).set_storage(key, value) } fn instantiate( @@ -427,14 +423,14 @@ mod tests { fn note_dispatch_call(&mut self, call: Call) { (**self).note_dispatch_call(call) } - fn note_restore_to( + fn restore_to( &mut self, dest: u64, code_hash: H256, rent_allowance: u64, delta: Vec, - ) { - (**self).note_restore_to( + ) -> Result<(), &'static str> { + (**self).restore_to( dest, code_hash, rent_allowance, diff --git a/frame/contracts/src/wasm/runtime.rs b/frame/contracts/src/wasm/runtime.rs index f87f5d1ef53cc..b393898835ba3 100644 --- a/frame/contracts/src/wasm/runtime.rs +++ b/frame/contracts/src/wasm/runtime.rs @@ -51,6 +51,8 @@ enum SpecialTrap { /// Signals that a trap was generated in response to a succesful call to the /// `ext_terminate` host function. Termination, + /// Signals that a trap was generated because of a successful restoration. + Restoration, } /// Can only be used for one call. @@ -100,6 +102,12 @@ pub(crate) fn to_execution_result( data: Vec::new(), }) }, + Some(SpecialTrap::Restoration) => { + return Ok(ExecReturnValue { + status: STATUS_SUCCESS, + data: Vec::new(), + }) + } Some(SpecialTrap::OutOfGas) => { return Err(ExecError { reason: "ran out of gas during contract execution".into(), @@ -387,7 +395,7 @@ define_env!(Env, , let mut key: StorageKey = [0; 32]; read_sandbox_memory_into_buf(ctx, key_ptr, &mut key)?; let value = Some(read_sandbox_memory(ctx, value_ptr, value_len)?); - ctx.ext.set_storage(key, value).map_err(|_| sp_sandbox::HostError)?; + ctx.ext.set_storage(key, value); Ok(()) }, @@ -399,7 +407,7 @@ define_env!(Env, , ext_clear_storage(ctx, key_ptr: u32) => { let mut key: StorageKey = [0; 32]; read_sandbox_memory_into_buf(ctx, key_ptr, &mut key)?; - ctx.ext.set_storage(key, None).map_err(|_| sp_sandbox::HostError)?; + ctx.ext.set_storage(key, None); Ok(()) }, @@ -799,17 +807,18 @@ define_env!(Env, , Ok(()) }, - // Record a request to restore the caller contract to the specified contract. + // Try to restore the given destination contract sacrificing the caller. // - // At the finalization stage, i.e. when all changes from the extrinsic that invoked this - // contract are committed, this function will compute a tombstone hash from the caller's - // storage and the given code hash and if the hash matches the hash found in the tombstone at - // the specified address - kill the caller contract and restore the destination contract and set - // the specified `rent_allowance`. All caller's funds are transferred to the destination. + // This function will compute a tombstone hash from the caller's storage and the given code hash + // and if the hash matches the hash found in the tombstone at the specified address - kill + // the caller contract and restore the destination contract and set the specified `rent_allowance`. + // All caller's funds are transfered to the destination. // - // This function doesn't perform restoration right away but defers it to the end of the - // transaction. If there is no tombstone in the destination address or if the hashes don't match - // then restoration is cancelled and no changes are made. + // If there is no tombstone at the destination address, the hashes don't match or this contract + // instance is already present on the contract call stack, a trap is generated. + // + // Otherwise, the destination contract is restored. This function is diverging and stops execution + // even on success. // // `dest_ptr`, `dest_len` - the pointer and the length of a buffer that encodes `T::AccountId` // with the address of the to be restored contract. @@ -857,14 +866,15 @@ define_env!(Env, , delta }; - ctx.ext.note_restore_to( + if let Ok(()) = ctx.ext.restore_to( dest, code_hash, rent_allowance, delta, - ); - - Ok(()) + ) { + ctx.special_trap = Some(SpecialTrap::Restoration); + } + Err(sp_sandbox::HostError) }, // Returns the size of the scratch buffer.