Struct StateAccount 

pub struct StateAccount<T>(/* private fields */);

A zero-copy accessor over a settlement state account’s canonical byte representation: the discriminator byte followed by the current holder of each Role.

T is the borrow backing it, anything that dereferences to the account’s bytes: &[u8] grant read access; &mut [u8] grants write access.

Implementations

impl<T: Deref<Target = [u8]>> StateAccount<T>

pub fn attach(bytes: T) -> Result<Self, ProgramError>

Wrap an account’s bytes, checking they begin with the settlement-state discriminator and are at least a full header long. Every accessor relies on that guarantee not to panic.

pub fn authority(&self, role: Role) -> Pubkey

Current holder of role.

pub fn solver_search(&self, solver: &Pubkey) -> Result<usize, usize>

Locate solver in the sorted solver list, mirroring slice::binary_search: Ok(index) if present, Err(index) with the slot it would occupy otherwise. The list is sorted by address bytes.

pub fn is_solver(&self, solver: &Pubkey) -> bool

Whether solver is in the solver list.

pub fn solvers(&self) -> impl Iterator<Item = Pubkey> + '_

The stored solvers, in order (sorted ascending by address).

pub fn grown_len(&self) -> Result<usize, ProgramError>

The account’s data length after growing it by one solver slot: the size it must be resized to before insert_solver can fill that new slot.

Returns ProgramError::ArithmeticOverflow if that length overflows usize, which a caller handling data from a real account can treat as unreachable: the runtime caps account data at MAX_PERMITTED_DATA_LENGTH.

impl<'a> StateAccount<Ref<'a, [u8]>>

pub fn from_account(account: &'a AccountView) -> Result<Self, ProgramError>

impl<T: DerefMut<Target = [u8]>> StateAccount<T>

pub fn initialize(bytes: T, args: &StateInitArgs) -> Result<Self, ProgramError>

Stamp a fresh header (discriminator + role holders) into a zeroed account and return the accessor over it.

The generated data is a full header long, which is needed for the read accessors not to panic.

pub fn set_authority(&mut self, role: Role, new: &Pubkey)

Set role’s holder to new in place.

pub fn insert_solver(&mut self, solver: &Pubkey) -> Result<(), ProgramError>

Insert solver into the sorted solver list, or fail with SettlementError::SolverAlreadyExists if it is already stored.

The account must already be grown by one solver slot (grown_len): the trailing slot is spare capacity for the new entry, so the live list is every entry but that last one. The solver is placed in sorted order by shifting all entries and inserting the new solver in the initial slot. An error is returned if the solver is already included.

pub fn remove_solver(&mut self, solver: &Pubkey) -> Result<usize, ProgramError>

Remove solver from the sorted solver list, or fail with SettlementError::SolverNotFound if it isn’t stored. Returns the length the account must be resized down to.

The entries after the removed one are shifted one slot left to close the gap; the now-stale trailing slot is left in place for the caller to drop by resizing the account down to the returned length.