Struct anchor_lang::accounts::account_loader::AccountLoader
source · [−]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) -> ProgramResult {
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) -> ProgramResult {
(*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
sourceimpl<'info, T: ZeroCopy + Owner> AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AccountLoader<'info, T>
sourcepub fn try_from(
acc_info: &AccountInfo<'info>
) -> Result<AccountLoader<'info, T>, ProgramError>
pub fn try_from(
acc_info: &AccountInfo<'info>
) -> Result<AccountLoader<'info, T>, ProgramError>
Constructs a new Loader
from a previously initialized account.
sourcepub fn try_from_unchecked(
_program_id: &Pubkey,
acc_info: &AccountInfo<'info>
) -> Result<AccountLoader<'info, T>, ProgramError>
pub fn try_from_unchecked(
_program_id: &Pubkey,
acc_info: &AccountInfo<'info>
) -> Result<AccountLoader<'info, T>, ProgramError>
Constructs a new Loader
from an uninitialized account.
sourcepub fn load(&self) -> Result<Ref<'_, T>, ProgramError>
pub fn load(&self) -> Result<Ref<'_, T>, ProgramError>
Returns a Ref to the account data structure for reading.
sourcepub fn load_mut(&self) -> Result<RefMut<'_, T>, ProgramError>
pub fn load_mut(&self) -> Result<RefMut<'_, T>, ProgramError>
Returns a RefMut
to the account data structure for reading or writing.
sourcepub fn load_init(&self) -> Result<RefMut<'_, T>, ProgramError>
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
sourceimpl<'info, T: ZeroCopy + Owner> Accounts<'info> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> Accounts<'info> for AccountLoader<'info, T>
sourcefn try_accounts(
_program_id: &Pubkey,
accounts: &mut &[AccountInfo<'info>],
_ix_data: &[u8],
_bumps: &mut BTreeMap<String, u8>
) -> Result<Self, ProgramError>
fn try_accounts(
_program_id: &Pubkey,
accounts: &mut &[AccountInfo<'info>],
_ix_data: &[u8],
_bumps: &mut BTreeMap<String, 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. Read more
sourceimpl<'info, T: ZeroCopy + Owner> AccountsClose<'info> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AccountsClose<'info> for AccountLoader<'info, T>
fn close(&self, sol_destination: AccountInfo<'info>) -> ProgramResult
sourceimpl<'info, T: ZeroCopy + Owner> AccountsExit<'info> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AccountsExit<'info> for AccountLoader<'info, T>
sourcefn exit(&self, _program_id: &Pubkey) -> ProgramResult
fn exit(&self, _program_id: &Pubkey) -> ProgramResult
program_id
is the currently executing program.
sourceimpl<'info, T: ZeroCopy + Owner> AsRef<AccountInfo<'info>> for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> AsRef<AccountInfo<'info>> for AccountLoader<'info, T>
sourcefn as_ref(&self) -> &AccountInfo<'info>
fn as_ref(&self) -> &AccountInfo<'info>
Converts this type into a shared reference of the (usually inferred) input type.
sourceimpl<'info, T: Clone + ZeroCopy + Owner> Clone for AccountLoader<'info, T>
impl<'info, T: Clone + ZeroCopy + Owner> Clone for AccountLoader<'info, T>
sourcefn clone(&self) -> AccountLoader<'info, T>
fn clone(&self) -> AccountLoader<'info, T>
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
sourceimpl<'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>>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
A: Allocator,
sourceimpl<'info, T: ZeroCopy + Owner> ToAccountMetas for AccountLoader<'info, T>
impl<'info, T: ZeroCopy + Owner> ToAccountMetas for AccountLoader<'info, T>
sourcefn to_account_metas(&self, is_signer: Option<bool>) -> Vec<AccountMeta>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
fn to_account_metas(&self, is_signer: Option<bool>) -> Vec<AccountMeta>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
A: Allocator,
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. Read more
Auto Trait Implementations
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
impl<T> AbiExample for T
impl<T> AbiExample for T
default fn example() -> T
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<T> Pointable for T
impl<T> Pointable for T
sourceimpl<'info, T> ToAccountInfo<'info> for T where
T: AsRef<AccountInfo<'info>>,
impl<'info, T> ToAccountInfo<'info> for T where
T: AsRef<AccountInfo<'info>>,
fn to_account_info(&self) -> AccountInfo<'info>
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcefn clone_into(&self, target: &mut T)
fn clone_into(&self, target: &mut T)
toowned_clone_into
)Uses borrowed data to replace owned data, usually by cloning. Read more