Struct EvmState

pub struct EvmState {
    pub accounts: HashMap<[u8; 20], AccountState>,
    pub codes: HashMap<[u8; 32], Vec<u8>>,
    pub logs: Vec<Log>,
    pub static_mode: bool,
    pub provider: Option<Provider<Http>>,
}

Represents the state of the Ethereum Virtual Machine (EVM).

Fields

accounts: HashMap<[u8; 20], AccountState>

A mapping of account addresses to their respective account states.

codes: HashMap<[u8; 32], Vec<u8>>

A mapping of code hashes to their respective code.

logs: Vec<Log>

A vector of logs generated during the execution of the EVM.

static_mode: bool

A flag indicating whether the EVM is in static mode or not.

provider: Option<Provider<Http>>

An optional provider for interacting with the Ethereum network.

Implementations

impl EvmState

Implementation of the EVM state.

pub fn new(fork_url: Option<String>) -> Self

Creates a new instance of the State struct.

Arguments

• fork_url - An optional String representing the URL of the fork to use.

Returns

A new instance of the State struct.

pub fn transfer( &mut self, from: [u8; 20], to: [u8; 20], value: [u8; 32], ) -> Result<(), ExecutionError>

Transfers a given value from one account to another.

Arguments

• from - An array of 20 bytes representing the address of the account to transfer from.
• to - An array of 20 bytes representing the address of the account to transfer to.
• value - An array of 32 bytes representing the value to transfer.

Errors

Returns an ExecutionError if:

• The static mode is enabled (static call).
• The account to transfer from does not exist.
• The account to transfer to does not exist.
• The balance of the account to transfer from is insufficient.

Returns

Returns Ok(()) if the transfer was successful.

pub fn sload( &mut self, account: [u8; 20], slot: [u8; 32], ) -> Result<[u8; 32], ExecutionError>

Loads a 256-bit value from the storage of the given account at the given slot. If the account is not found in the emulator’s local state, the storage value is fetched from the provider. If the provider is not set, or if the storage fetch fails, the function returns a zero-filled 256-bit value.

Arguments

• account - An array of 20 bytes representing the address of the account to load from.
• slot - An array of 32 bytes representing the slot to load from.

Errors

Never return an error, but returns a 32-byte array of zero instead.

Returns

Returns a 32-byte array representing the value at the given slot.

pub fn sstore( &mut self, account: [u8; 20], slot: [u8; 32], value: [u8; 32], ) -> Result<(), ExecutionError>

Stores a value in the storage of an account.

Arguments

• account - The address of the account to store the value in.
• slot - The slot in the storage to store the value in.
• value - The value to store in the specified slot.

Errors

Returns an ExecutionError if the static mode is enabled or if the account is not found.

pub fn get_code_at( &mut self, address: [u8; 20], ) -> Result<&Vec<u8>, ExecutionError>

Returns the code at the given address. If the code is not already in the state, it will be fetched from the blockchain using the provider.

Arguments

• address - The address of the contract to get the code for.

Errors

Returns an ExecutionError if the code is not found.

Returns

Returns a reference to the Vec of the code.

pub fn put_code_at( &mut self, address: [u8; 20], code: Vec<u8>, ) -> Result<(), ExecutionError>

Stores the code of an account at the given address.

Arguments

• address - A 20-byte array representing the address of the account.
• code - A vector of bytes representing the code to be stored.

Errors

Returns an ExecutionError if the account is not found.

Returns

Returns Ok(()) if the code is successfully stored.

pub fn debug_state(&mut self)

Print the state of the EVM This function is used for debugging purposes.

Trait Implementations

impl Debug for EvmState

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

Formats the value using the given formatter.