225 lines
7.6 KiB
Rust
225 lines
7.6 KiB
Rust
use crate::error::ErrorCode;
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use crate::{
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Accounts, AccountsClose, AccountsExit, Key, ToAccountInfo, ToAccountInfos, ToAccountMetas,
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ZeroCopy,
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};
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use solana_program::account_info::AccountInfo;
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use solana_program::entrypoint::ProgramResult;
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use solana_program::instruction::AccountMeta;
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use solana_program::program_error::ProgramError;
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use solana_program::pubkey::Pubkey;
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use std::cell::{Ref, RefMut};
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use std::fmt;
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use std::io::Write;
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use std::marker::PhantomData;
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use std::ops::DerefMut;
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/// Account loader facilitating on demand zero copy deserialization.
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/// Note that using accounts in this way is distinctly different from using,
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/// for example, the [`ProgramAccount`](./struct.ProgramAccount.html). Namely,
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/// one must call `load`, `load_mut`, or `load_init`, before reading or writing
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/// to the account. For more details on zero-copy-deserialization, see the
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/// [`account`](./attr.account.html) attribute.
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///
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/// When using it's important to be mindful of any calls to `load` so as not to
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/// induce a `RefCell` panic, especially when sharing accounts across CPI
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/// boundaries. When in doubt, one should make sure all refs resulting from a
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/// call to `load` are dropped before CPI.
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#[deprecated(since = "0.18.0", note = "Please use AccountLoader instead")]
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pub struct Loader<'info, T: ZeroCopy> {
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acc_info: AccountInfo<'info>,
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phantom: PhantomData<&'info T>,
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy + fmt::Debug> fmt::Debug for Loader<'info, T> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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f.debug_struct("Loader")
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.field("acc_info", &self.acc_info)
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.field("phantom", &self.phantom)
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.finish()
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> Loader<'info, T> {
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fn new(acc_info: AccountInfo<'info>) -> Loader<'info, T> {
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Self {
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acc_info,
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phantom: PhantomData,
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}
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}
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/// Constructs a new `Loader` from a previously initialized account.
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#[inline(never)]
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#[allow(deprecated)]
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pub fn try_from(
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program_id: &Pubkey,
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acc_info: &AccountInfo<'info>,
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) -> Result<Loader<'info, T>, ProgramError> {
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if acc_info.owner != program_id {
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return Err(ErrorCode::AccountNotProgramOwned.into());
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}
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let data: &[u8] = &acc_info.try_borrow_data()?;
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// Discriminator must match.
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let mut disc_bytes = [0u8; 8];
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disc_bytes.copy_from_slice(&data[..8]);
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if disc_bytes != T::discriminator() {
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return Err(ErrorCode::AccountDiscriminatorMismatch.into());
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}
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Ok(Loader::new(acc_info.clone()))
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}
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/// Constructs a new `Loader` from an uninitialized account.
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#[allow(deprecated)]
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#[inline(never)]
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pub fn try_from_unchecked(
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program_id: &Pubkey,
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acc_info: &AccountInfo<'info>,
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) -> Result<Loader<'info, T>, ProgramError> {
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if acc_info.owner != program_id {
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return Err(ErrorCode::AccountNotProgramOwned.into());
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}
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Ok(Loader::new(acc_info.clone()))
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}
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/// Returns a Ref to the account data structure for reading.
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#[allow(deprecated)]
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pub fn load(&self) -> Result<Ref<T>, ProgramError> {
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let data = self.acc_info.try_borrow_data()?;
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let mut disc_bytes = [0u8; 8];
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disc_bytes.copy_from_slice(&data[..8]);
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if disc_bytes != T::discriminator() {
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return Err(ErrorCode::AccountDiscriminatorMismatch.into());
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}
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Ok(Ref::map(data, |data| bytemuck::from_bytes(&data[8..])))
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}
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/// Returns a `RefMut` to the account data structure for reading or writing.
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#[allow(deprecated)]
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pub fn load_mut(&self) -> Result<RefMut<T>, ProgramError> {
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// AccountInfo api allows you to borrow mut even if the account isn't
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// writable, so add this check for a better dev experience.
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if !self.acc_info.is_writable {
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return Err(ErrorCode::AccountNotMutable.into());
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}
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let data = self.acc_info.try_borrow_mut_data()?;
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let mut disc_bytes = [0u8; 8];
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disc_bytes.copy_from_slice(&data[..8]);
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if disc_bytes != T::discriminator() {
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return Err(ErrorCode::AccountDiscriminatorMismatch.into());
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}
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Ok(RefMut::map(data, |data| {
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bytemuck::from_bytes_mut(&mut data.deref_mut()[8..])
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}))
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}
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/// Returns a `RefMut` to the account data structure for reading or writing.
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/// Should only be called once, when the account is being initialized.
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#[allow(deprecated)]
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pub fn load_init(&self) -> Result<RefMut<T>, ProgramError> {
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// AccountInfo api allows you to borrow mut even if the account isn't
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// writable, so add this check for a better dev experience.
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if !self.acc_info.is_writable {
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return Err(ErrorCode::AccountNotMutable.into());
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}
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let data = self.acc_info.try_borrow_mut_data()?;
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// The discriminator should be zero, since we're initializing.
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let mut disc_bytes = [0u8; 8];
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disc_bytes.copy_from_slice(&data[..8]);
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let discriminator = u64::from_le_bytes(disc_bytes);
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if discriminator != 0 {
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return Err(ErrorCode::AccountDiscriminatorAlreadySet.into());
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}
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Ok(RefMut::map(data, |data| {
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bytemuck::from_bytes_mut(&mut data.deref_mut()[8..])
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}))
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> Accounts<'info> for Loader<'info, T> {
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#[inline(never)]
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fn try_accounts(
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program_id: &Pubkey,
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accounts: &mut &[AccountInfo<'info>],
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_ix_data: &[u8],
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) -> Result<Self, ProgramError> {
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if accounts.is_empty() {
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return Err(ErrorCode::AccountNotEnoughKeys.into());
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}
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let account = &accounts[0];
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*accounts = &accounts[1..];
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let l = Loader::try_from(program_id, account)?;
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Ok(l)
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> AccountsExit<'info> for Loader<'info, T> {
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// The account *cannot* be loaded when this is called.
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fn exit(&self, _program_id: &Pubkey) -> ProgramResult {
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let mut data = self.acc_info.try_borrow_mut_data()?;
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let dst: &mut [u8] = &mut data;
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let mut cursor = std::io::Cursor::new(dst);
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cursor.write_all(&T::discriminator()).unwrap();
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Ok(())
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> AccountsClose<'info> for Loader<'info, T> {
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fn close(&self, sol_destination: AccountInfo<'info>) -> ProgramResult {
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crate::common::close(self.to_account_info(), sol_destination)
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> ToAccountMetas for Loader<'info, T> {
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fn to_account_metas(&self, is_signer: Option<bool>) -> Vec<AccountMeta> {
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let is_signer = is_signer.unwrap_or(self.acc_info.is_signer);
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let meta = match self.acc_info.is_writable {
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false => AccountMeta::new_readonly(*self.acc_info.key, is_signer),
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true => AccountMeta::new(*self.acc_info.key, is_signer),
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};
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vec![meta]
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> AsRef<AccountInfo<'info>> for Loader<'info, T> {
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fn as_ref(&self) -> &AccountInfo<'info> {
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&self.acc_info
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> ToAccountInfos<'info> for Loader<'info, T> {
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fn to_account_infos(&self) -> Vec<AccountInfo<'info>> {
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vec![self.acc_info.clone()]
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> ToAccountInfo<'info> for Loader<'info, T> {
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fn to_account_info(&self) -> AccountInfo<'info> {
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self.acc_info.clone()
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}
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}
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#[allow(deprecated)]
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impl<'info, T: ZeroCopy> Key for Loader<'info, T> {
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fn key(&self) -> Pubkey {
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*self.acc_info.key
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}
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}
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