Struct Substate 

pub struct Substate {
    pub refunded_gas: u64,
    /* private fields */
}

Execution substate that tracks changes during transaction execution.

The substate maintains all information that may need to be reverted if a call fails, including:

• Self-destructed accounts
• Accessed addresses and storage slots (for EIP-2929 gas accounting)
• Created accounts
• Gas refunds
• Transient storage (EIP-1153)
• Event logs

Backup Mechanism

The substate supports checkpointing via [push_backup] and restoration via [revert_backup] or commitment via [commit_backup]. This is used to handle nested calls where inner calls may fail and need to be reverted.

Most fields are private by design. The backup mechanism only works correctly if data modifications are append-only.

Fields

refunded_gas: u64

Accumulated gas refund (e.g., from storage clears).

Implementations

impl Substate

pub fn from_accesses( fork: Fork, accessed_addresses: FxHashSet<Address>, accessed_storage_slots: FxHashMap<Address, FxHashSet<H256>>, ) -> Self

pub fn push_backup(&mut self)

Push a checkpoint that can be either reverted or committed. All data up to this point is still accessible.

pub fn commit_backup(&mut self)

Pop and merge with the last backup.

Does nothing if the substate has no backup.

pub fn revert_backup(&mut self)

Discard current changes and revert to last backup.

Does nothing if the substate has no backup.

pub fn iter_selfdestruct(&self) -> impl Iterator<Item = &Address>

Return an iterator over all selfdestruct addresses.

pub fn add_selfdestruct(&mut self, address: Address) -> bool

Mark an address as selfdestructed and return whether is was already marked.

pub fn is_selfdestruct(&self, address: &Address) -> bool

Return whether an address is already marked as selfdestructed.

pub fn make_access_list(&self) -> Vec<AccessListEntry>

Build an access list from all accessed storage slots.

pub fn add_accessed_slot(&mut self, address: Address, key: H256) -> bool

Mark an address as accessed and return whether the slot was cold.

pub fn is_slot_accessed(&self, address: &Address, key: &H256) -> bool

Return whether an address has already been accessed.

pub fn get_accessed_storage_slots(&self, address: &Address) -> BTreeSet<H256>

Returns all accessed storage slots for a given address. Used by SELFDESTRUCT to record storage reads in BAL per EIP-7928: “SELFDESTRUCT: Include modified/read storage keys as storage_read”

pub fn add_accessed_address(&mut self, address: Address) -> bool

Mark an address as accessed and return whether the address was cold.

pub fn is_address_accessed(&self, address: &Address) -> bool

Return whether an address has already been accessed.

pub fn add_created_account(&mut self, address: Address) -> bool

Mark an address as a new account and return whether is was already marked.

pub fn is_account_created(&self, address: &Address) -> bool

Return whether an address has already been marked as a new account.

pub fn get_transient(&self, to: &Address, key: &U256) -> U256

Return the data associated with a transient storage entry, or zero if not present.

pub fn set_transient(&mut self, to: &Address, key: &U256, value: U256)

Return the data associated with a transient storage entry, or zero if not present.

pub fn extract_logs(&self) -> Vec<Log>

Extract all logs in order.

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

Push a log record.

impl Substate

pub fn initialize( env: &Environment, tx: &Transaction, ) -> Result<Substate, VMError>

Initializes the VM substate, mainly adding addresses to the “accessed_addresses” field and the same with storage slots

Trait Implementations

impl Debug for Substate

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

Formats the value using the given formatter.

impl Default for Substate

fn default() -> Substate

Returns the “default value” for a type.