Struct JournaledState

pub struct JournaledState {
    pub state: EvmState,
    pub transient_storage: TransientStorage,
    pub logs: Vec<Log>,
    pub depth: usize,
    pub journal: Vec<Vec<JournalEntry>>,
    pub spec: SpecId,
    pub warm_preloaded_addresses: HashSet<Address>,
}

A journal of state changes internal to the EVM.

On each additional call, the depth of the journaled state is increased (depth) and a new journal is added. The journal contains every state change that happens within that call, making it possible to revert changes made in a specific call.

Fields

state: EvmState

The current state.

transient_storage: TransientStorage

Transient storage that is discarded after every transaction.

See EIP-1153.

logs: Vec<Log>

Emitted logs.

depth: usize

The current call stack depth.

journal: Vec<Vec<JournalEntry>>

The journal of state changes, one for each call.

spec: SpecId

The spec ID for the EVM.

This spec is used for two things:

• EIP-161: Prior to this EIP, Ethereum had separate definitions for empty and non-existing accounts.
• EIP-6780: SELFDESTRUCT only in same transaction

warm_preloaded_addresses: HashSet<Address>

Warm loaded addresses are used to check if loaded address should be considered cold or warm loaded when the account is first accessed.

Note that this not include newly loaded accounts, account and storage is considered warm if it is found in the State.

Implementations

impl JournaledState

pub fn new( spec: SpecId, warm_preloaded_addresses: HashSet<Address>, ) -> JournaledState

Create new JournaledState.

warm_preloaded_addresses is used to determine if address is considered warm loaded. In ordinary case this is precompile or beneficiary.

Note

This function will journal state after Spurious Dragon fork. And will not take into account if account is not existing or empty.

pub fn state(&mut self) -> &mut EvmState

Return reference to state.

pub fn set_spec_id(&mut self, spec: SpecId)

Sets SpecId.

pub fn touch(&mut self, address: &Address)

Mark account as touched as only touched accounts will be added to state. This is especially important for state clear where touched empty accounts needs to be removed from state.

pub fn clear(&mut self)

Clears the JournaledState. Preserving only the spec.

pub fn finalize(&mut self) -> (EvmState, Vec<Log>)

Does cleanup and returns modified state.

This resets the JournaledState to its initial state in Self::new

pub fn account(&self, address: Address) -> &Account

Returns the loaded Account for the given address.

This assumes that the account has already been loaded.

Panics

Panics if the account has not been loaded and is missing from the state set.

pub fn depth(&self) -> u64

Returns call depth.

pub fn set_code_with_hash( &mut self, address: Address, code: Bytecode, hash: B256, )

Set code and its hash to the account.

Note: Assume account is warm and that hash is calculated from code.

pub fn set_code(&mut self, address: Address, code: Bytecode)

use it only if you know that acc is warm Assume account is warm

pub fn inc_nonce(&mut self, address: Address) -> Option<u64>

pub fn transfer<DB: Database>( &mut self, from: &Address, to: &Address, balance: U256, db: &mut DB, ) -> Result<Option<InstructionResult>, EVMError<DB::Error>>

Transfers balance from two accounts. Returns error if sender balance is not enough.

pub fn create_account_checkpoint( &mut self, caller: Address, address: Address, balance: U256, spec_id: SpecId, ) -> Result<JournalCheckpoint, InstructionResult>

Create account or return false if collision is detected.

There are few steps done:

1. Make created account warm loaded (AccessList) and this should be done before subroutine checkpoint is created.
2. Check if there is collision of newly created account with existing one.
3. Mark created account as created.
4. Add fund to created account
5. Increment nonce of created account if SpuriousDragon is active
6. Decrease balance of caller account.

Panics

Panics if the caller is not loaded inside of the EVM state. This is should have been done inside create_inner.

pub fn checkpoint(&mut self) -> JournalCheckpoint

Makes a checkpoint that in case of Revert can bring back state to this point.

pub fn checkpoint_commit(&mut self)

Commit the checkpoint.

pub fn checkpoint_revert(&mut self, checkpoint: JournalCheckpoint)

Reverts all changes to state until given checkpoint.

pub fn selfdestruct<DB: Database>( &mut self, address: Address, target: Address, db: &mut DB, ) -> Result<StateLoad<SelfDestructResult>, EVMError<DB::Error>>

Performances selfdestruct action. Transfers balance from address to target. Check if target exist/is_cold

Note: balance will be lost if address and target are the same BUT when current spec enables Cancun, this happens only when the account associated to address is created in the same tx

references:

• https://github.com/ethereum/go-ethereum/blob/141cd425310b503c5678e674a8c3872cf46b7086/core/vm/instructions.go#L832-L833
• https://github.com/ethereum/go-ethereum/blob/141cd425310b503c5678e674a8c3872cf46b7086/core/state/statedb.go#L449
• https://eips.ethereum.org/EIPS/eip-6780

pub fn initial_account_load<DB: Database>( &mut self, address: Address, storage_keys: impl IntoIterator<Item = U256>, db: &mut DB, ) -> Result<&mut Account, EVMError<DB::Error>>

Initial load of account. This load will not be tracked inside journal

pub fn load_account<DB: Database>( &mut self, address: Address, db: &mut DB, ) -> Result<StateLoad<&mut Account>, EVMError<DB::Error>>

load account into memory. return if it is cold or warm accessed

pub fn load_account_delegated<DB: Database>( &mut self, address: Address, db: &mut DB, ) -> Result<AccountLoad, EVMError<DB::Error>>

pub fn load_code<DB: Database>( &mut self, address: Address, db: &mut DB, ) -> Result<StateLoad<&mut Account>, EVMError<DB::Error>>

Loads code.

pub fn sload<DB: Database>( &mut self, address: Address, key: U256, db: &mut DB, ) -> Result<StateLoad<U256>, EVMError<DB::Error>>

Load storage slot

Panics

Panics if the account is not present in the state.

pub fn sstore<DB: Database>( &mut self, address: Address, key: U256, new: U256, db: &mut DB, ) -> Result<StateLoad<SStoreResult>, EVMError<DB::Error>>

Stores storage slot. And returns (original,present,new) slot value.

Note:

account should already be present in our state.

pub fn tload(&mut self, address: Address, key: U256) -> U256

Read transient storage tied to the account.

EIP-1153: Transient storage opcodes

pub fn tstore(&mut self, address: Address, key: U256, new: U256)

Store transient storage tied to the account.

If values is different add entry to the journal so that old state can be reverted if that action is needed.

EIP-1153: Transient storage opcodes

pub fn log(&mut self, log: Log)

push log into subroutine

Trait Implementations

impl Clone for JournaledState

fn clone(&self) -> JournaledState

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for JournaledState

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for JournaledState

fn eq(&self, other: &JournaledState) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for JournaledState

impl StructuralPartialEq for JournaledState