Struct ExpirationTransactionScript 

pub struct ExpirationTransactionScript { /* private fields */ }

The canonical transaction script that sets the transaction’s expiration delta to the value supplied in the first element of TX_SCRIPT_ARGS.

This is the standard tx script a network account allowlists so that the network transaction builder can bound how long a submitted transaction stays valid. Because the delta is an input rather than hardcoded, the single ExpirationTransactionScript::script_root covers every delta. It is safe to allowlist on an open network account even though an arbitrary submitter controls the argument: the delta only bounds the inclusion window of the submitter’s own transaction - it cannot touch the account’s nonce, state, or assets - and the kernel hard-caps it at 0xFFFF blocks. So the only thing the submitter decides is how soon their own transaction must be included before it expires, within that fixed bound.

The type pairs the script (via From<ExpirationTransactionScript>) with the matching TX_SCRIPT_ARGS (ExpirationTransactionScript::tx_script_args), so callers do not assemble the argument word by hand:

let script = ExpirationTransactionScript::new(delta);
let context = build_tx_context(/* .. */)
    .tx_script(script.into())
    .tx_script_args(script.tx_script_args());

Implementations

impl ExpirationTransactionScript

pub fn new(delta: NonZero<u16>) -> ExpirationTransactionScript

Creates an expiration script that sets the transaction’s expiration block delta to delta.

delta is a NonZeroU16 because the kernel’s update_expiration_block_delta only accepts a delta in 1..=0xFFFF and otherwise fails the transaction with ERR_TX_INVALID_EXPIRATION_DELTA. Encoding that bound in the type keeps this constructor infallible and guarantees the delta produced by Self::tx_script_args is always in range.

pub fn tx_script_args(&self) -> Word

The TX_SCRIPT_ARGS word the script reads its delta from: [delta, 0, 0, 0].

Since delta is a NonZeroU16, this word always carries an in-range delta, so the script never triggers the kernel’s range check. A caller that bypasses this type and hand-crafts an out-of-range first element makes the kernel reject the transaction with ERR_TX_INVALID_EXPIRATION_DELTA; it does not panic the host.

pub fn script_root() -> TransactionScriptRoot

The TransactionScriptRoot of the canonical script, to be allowlisted on a network account via AuthNetworkAccount::with_allowed_tx_scripts.

Trait Implementations

impl Clone for ExpirationTransactionScript

fn clone(&self) -> ExpirationTransactionScript

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ExpirationTransactionScript

impl Debug for ExpirationTransactionScript

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

Formats the value using the given formatter.

impl Eq for ExpirationTransactionScript

impl From<ExpirationTransactionScript> for TransactionScript

fn from(_script: ExpirationTransactionScript) -> TransactionScript

Converts to this type from the input type.

impl PartialEq for ExpirationTransactionScript

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ExpirationTransactionScript