Struct anchor_lang::accounts::account_loader::AccountLoader
source · pub struct AccountLoader<'info, T: ZeroCopy + Owner> { /* private fields */ }
Expand description
Type facilitating on demand zero copy deserialization.
Note that using accounts in this way is distinctly different from using,
for example, the Account
. Namely,
one must call
load_init
after initializing an account (this will ignore the missing account discriminator that gets added only after the user’s instruction code)load
when the account is not mutableload_mut
when the account is mutable
For more details on zero-copy-deserialization, see the
account
attribute.
⚠️ When using this type it's important to be mindful
of any calls to the load
functions 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 a load
function are dropped before CPI.
This can be done explicitly by calling drop(my_var)
or implicitly
by wrapping the code using the Ref
in braces {..}
or
moving it into its own function.
§Example
use anchor_lang::prelude::*;
declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
#[program]
pub mod bar {
use super::*;
pub fn create_bar(ctx: Context<CreateBar>, data: u64) -> Result<()> {
let bar = &mut ctx.accounts.bar.load_init()?;
bar.authority = ctx.accounts.authority.key();
bar.data = data;
Ok(())
}
pub fn update_bar(ctx: Context<UpdateBar>, data: u64) -> Result<()> {
(*ctx.accounts.bar.load_mut()?).data = data;
Ok(())
}
}
#[account(zero_copy)]
#[derive(Default)]
pub struct Bar {
authority: Pubkey,
data: u64
}
#[derive(Accounts)]
pub struct CreateBar<'info> {
#[account(
init,
payer = authority
)]
bar: AccountLoader<'info, Bar>,
#[account(mut)]
authority: Signer<'info>,
system_program: AccountInfo<'info>,
}
#[derive(Accounts)]
pub struct UpdateBar<'info> {
#[account(
mut,
has_one = authority,
)]
pub bar: AccountLoader<'info, Bar>,
pub authority: Signer<'info>,
}
Implementations§
source§impl<'info, T: ZeroCopy + Owner> AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AccountLoader<'info, T>
sourcepub fn try_from(
acc_info: &'info AccountInfo<'info>,
) -> Result<AccountLoader<'info, T>>
pub fn try_from( acc_info: &'info AccountInfo<'info>, ) -> Result<AccountLoader<'info, T>>
Constructs a new Loader
from a previously initialized account.
sourcepub fn try_from_unchecked(
_program_id: &Pubkey,
acc_info: &'info AccountInfo<'info>,
) -> Result<AccountLoader<'info, T>>
pub fn try_from_unchecked( _program_id: &Pubkey, acc_info: &'info AccountInfo<'info>, ) -> Result<AccountLoader<'info, T>>
Constructs a new Loader
from an uninitialized account.
sourcepub fn load(&self) -> Result<Ref<'_, T>>
pub fn load(&self) -> Result<Ref<'_, T>>
Returns a Ref to the account data structure for reading.
Trait Implementations§
source§impl<'info, B, T: ZeroCopy + Owner> Accounts<'info, B> for AccountLoader<'info, T>
impl<'info, B, T: ZeroCopy + Owner> Accounts<'info, B> for AccountLoader<'info, T>
source§fn try_accounts(
_program_id: &Pubkey,
accounts: &mut &'info [AccountInfo<'info>],
_ix_data: &[u8],
_bumps: &mut B,
_reallocs: &mut BTreeSet<Pubkey>,
) -> Result<Self>
fn try_accounts( _program_id: &Pubkey, accounts: &mut &'info [AccountInfo<'info>], _ix_data: &[u8], _bumps: &mut B, _reallocs: &mut BTreeSet<Pubkey>, ) -> Result<Self>
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. Read moresource§impl<'info, T: ZeroCopy + Owner> AccountsClose<'info> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AccountsClose<'info> for AccountLoader<'info, T>
source§impl<'info, T: ZeroCopy + Owner> AccountsExit<'info> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AccountsExit<'info> for AccountLoader<'info, T>
source§impl<'info, T: ZeroCopy + Owner> AsRef<AccountInfo<'info>> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AsRef<AccountInfo<'info>> for AccountLoader<'info, T>
source§fn as_ref(&self) -> &AccountInfo<'info>
fn as_ref(&self) -> &AccountInfo<'info>
source§impl<'info, T: Clone + ZeroCopy + Owner> Clone for AccountLoader<'info, T>
impl<'info, T: Clone + ZeroCopy + Owner> Clone for AccountLoader<'info, T>
source§fn clone(&self) -> AccountLoader<'info, T>
fn clone(&self) -> AccountLoader<'info, T>
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl<'info, T: ZeroCopy + Owner> ToAccountInfos<'info> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> ToAccountInfos<'info> for AccountLoader<'info, T>
fn to_account_infos(&self) -> Vec<AccountInfo<'info>>
source§impl<'info, T: ZeroCopy + Owner> ToAccountMetas for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> ToAccountMetas for AccountLoader<'info, T>
source§fn to_account_metas(&self, is_signer: Option<bool>) -> Vec<AccountMeta>
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.Auto Trait Implementations§
impl<'info, T> Freeze for AccountLoader<'info, T>
impl<'info, T> !RefUnwindSafe for AccountLoader<'info, T>
impl<'info, T> !Send for AccountLoader<'info, T>
impl<'info, T> !Sync for AccountLoader<'info, T>
impl<'info, T> Unpin for AccountLoader<'info, T>
impl<'info, T> !UnwindSafe for AccountLoader<'info, T>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more