Struct anchor_lang::Loader

pub struct Loader<'info, T: ZeroCopy> { /* private fields */ }

Account loader facilitating on demand zero copy deserialization. Note that using accounts in this way is distinctly different from using, for example, the ProgramAccount. Namely, one must call load, load_mut, or load_init, before reading or writing to the account. For more details on zero-copy-deserialization, see the account attribute.

When using it’s important to be mindful of any calls to load so as not to induce a RefCell panic, especially when sharing accounts across CPI boundaries. When in doubt, one should make sure all refs resulting from a call to load are dropped before CPI.

Implementations

impl<'info, T: ZeroCopy> Loader<'info, T>

pub fn try_from(
    program_id: &Pubkey,
    acc_info: &AccountInfo<'info>
) -> Result<Loader<'info, T>, ProgramError>

Constructs a new Loader from a previously initialized account.

pub fn try_from_unchecked(
    program_id: &Pubkey,
    acc_info: &AccountInfo<'info>
) -> Result<Loader<'info, T>, ProgramError>

Constructs a new Loader from an uninitialized account.

pub fn load(&self) -> Result<Ref<'_, T>, ProgramError>

Returns a Ref to the account data structure for reading.

pub fn load_mut(&self) -> Result<RefMut<'_, T>, ProgramError>

Returns a RefMut to the account data structure for reading or writing.

pub fn load_init(&self) -> Result<RefMut<'_, T>, ProgramError>

Returns a RefMut to the account data structure for reading or writing. Should only be called once, when the account is being initialized.

Trait Implementations

impl<'info, T: ZeroCopy> Accounts<'info> for Loader<'info, T>

fn try_accounts(
    program_id: &Pubkey,
    accounts: &mut &[AccountInfo<'info>],
    _ix_data: &[u8]
) -> Result<Self, ProgramError>

Returns the validated accounts struct. What constitutes “valid” is program dependent. However, users of these types should never have to worry about account substitution attacks. For example, if a program expects a Mint account from the SPL token program in a particular field, then it should be impossible for this method to return Ok if any other account type is given–from the SPL token program or elsewhere.

impl<'info, T: ZeroCopy> AccountsClose<'info> for Loader<'info, T>

fn close(&self, sol_destination: AccountInfo<'info>) -> ProgramResult

impl<'info, T: ZeroCopy> AccountsExit<'info> for Loader<'info, T>

fn exit(&self, _program_id: &Pubkey) -> ProgramResult

program_id is the currently executing program.

impl<'info, T: ZeroCopy> AsRef<AccountInfo<'info>> for Loader<'info, T>

fn as_ref(&self) -> &AccountInfo<'info>

Converts this type into a shared reference of the (usually inferred) input type.

impl<'info, T: ZeroCopy> Key for Loader<'info, T>

fn key(&self) -> Pubkey

impl<'info, T: ZeroCopy> ToAccountInfo<'info> for Loader<'info, T>

fn to_account_info(&self) -> AccountInfo<'info>

impl<'info, T: ZeroCopy> ToAccountInfos<'info> for Loader<'info, T>

fn to_account_infos(&self) -> Vec<AccountInfo<'info>>

impl<'info, T: ZeroCopy> ToAccountMetas for Loader<'info, T>

fn to_account_metas(&self, is_signer: Option<bool>) -> Vec<AccountMeta>

is_signer is given as an optional override for the signer meta field. This covers the edge case when a program-derived-address needs to relay a transaction from a client to another program but sign the transaction before the relay. The client cannot mark the field as a signer, and so we have to override the is_signer meta field given by the client.