refactor loaders into utils

utils/src/lib.rs

@@ -1,3 +1,4 @@
+pub mod loaders;
 #[cfg(feature = "spl")]
 pub mod spl;
 

utils/src/loaders.rs

@@ -0,0 +1,200 @@
+use solana_program::{
+    account_info::AccountInfo, program_error::ProgramError, program_pack::Pack, pubkey::Pubkey,
+    system_program, sysvar,
+};
+#[cfg(feature = "spl")]
+use spl_token::state::Mint;
+
+/// Errors if:
+/// - Account is not a signer.
+pub fn load_signer<'a, 'info>(info: &'a AccountInfo<'info>) -> Result<(), ProgramError> {
+    if !info.is_signer {
+        return Err(ProgramError::MissingRequiredSignature);
+    }
+
+    Ok(())
+}
+
+/// Errors if:
+/// - Owner is not SPL token program.
+/// - Address does not match the expected mint address.
+/// - Data is empty.
+/// - Data cannot deserialize into a mint account.
+/// - Expected to be writable, but is not.
+#[cfg(feature = "spl")]
+pub fn load_mint<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    address: Pubkey,
+    is_writable: bool,
+) -> Result<(), ProgramError> {
+    if info.owner.ne(&spl_token::id()) {
+        return Err(ProgramError::InvalidAccountOwner);
+    }
+
+    if info.key.ne(&address) {
+        return Err(ProgramError::InvalidSeeds);
+    }
+
+    if info.data_is_empty() {
+        return Err(ProgramError::UninitializedAccount);
+    }
+
+    Mint::unpack(&info.data.borrow())?;
+
+    if is_writable && !info.is_writable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}
+
+/// Errors if:
+/// - Owner is not SPL token program.
+/// - Data is empty.
+/// - Data cannot deserialize into a token account.
+/// - Token account owner does not match the expected owner address.
+/// - Token account mint does not match the expected mint address.
+/// - Expected to be writable, but is not.
+#[cfg(feature = "spl")]
+pub fn load_token_account<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    owner: Option<&Pubkey>,
+    mint: &Pubkey,
+    is_writable: bool,
+) -> Result<(), ProgramError> {
+    if info.owner.ne(&spl_token::id()) {
+        return Err(ProgramError::InvalidAccountOwner);
+    }
+
+    if info.data_is_empty() {
+        return Err(ProgramError::UninitializedAccount);
+    }
+
+    let account_data = info.data.borrow();
+    let account = spl_token::state::Account::unpack(&account_data)?;
+
+    if account.mint.ne(&mint) {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    if let Some(owner) = owner {
+        if account.owner.ne(owner) {
+            return Err(ProgramError::InvalidAccountData);
+        }
+    }
+
+    if is_writable && !info.is_writable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}
+
+/// Errors if:
+/// - Address does not match PDA derived from provided seeds.
+/// - Cannot load as an uninitialized account.
+pub fn load_uninitialized_pda<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    seeds: &[&[u8]],
+    bump: u8,
+    program_id: &Pubkey,
+) -> Result<(), ProgramError> {
+    let pda = Pubkey::find_program_address(seeds, program_id);
+
+    if info.key.ne(&pda.0) {
+        return Err(ProgramError::InvalidSeeds);
+    }
+
+    if bump.ne(&pda.1) {
+        return Err(ProgramError::InvalidSeeds);
+    }
+
+    load_system_account(info, true)
+}
+
+/// Errors if:
+/// - Owner is not the system program.
+/// - Data is not empty.
+/// - Account is not writable.
+pub fn load_system_account<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    is_writable: bool,
+) -> Result<(), ProgramError> {
+    if info.owner.ne(&system_program::id()) {
+        return Err(ProgramError::InvalidAccountOwner);
+    }
+
+    if !info.data_is_empty() {
+        return Err(ProgramError::AccountAlreadyInitialized);
+    }
+
+    if is_writable && !info.is_writable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}
+
+/// Errors if:
+/// - Owner is not the sysvar address.
+/// - Account cannot load with the expected address.
+pub fn load_sysvar<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    key: Pubkey,
+) -> Result<(), ProgramError> {
+    if info.owner.ne(&sysvar::id()) {
+        return Err(ProgramError::InvalidAccountOwner);
+    }
+
+    load_account(info, key, false)
+}
+
+/// Errors if:
+/// - Address does not match the expected value.
+/// - Expected to be writable, but is not.
+pub fn load_account<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    key: Pubkey,
+    is_writable: bool,
+) -> Result<(), ProgramError> {
+    if info.key.ne(&key) {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    if is_writable && !info.is_writable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}
+
+/// Errors if:
+/// - Address does not match the expected value.
+/// - Account is not executable.
+pub fn load_program<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    key: Pubkey,
+) -> Result<(), ProgramError> {
+    if info.key.ne(&key) {
+        return Err(ProgramError::IncorrectProgramId);
+    }
+
+    if !info.executable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}
+
+/// Errors if:
+/// - Account is not writable.
+pub fn load_any<'a, 'info>(
+    info: &'a AccountInfo<'info>,
+    is_writable: bool,
+) -> Result<(), ProgramError> {
+    if is_writable && !info.is_writable {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
+    Ok(())
+}