spl_token_2022/extension/
reallocate.rs

1use {
2    crate::{
3        error::TokenError,
4        extension::{
5            set_account_type, AccountType, BaseStateWithExtensions, ExtensionType,
6            StateWithExtensions, StateWithExtensionsMut,
7        },
8        processor::Processor,
9        state::Account,
10    },
11    solana_program::{
12        account_info::{next_account_info, AccountInfo},
13        entrypoint::ProgramResult,
14        msg,
15        program::invoke,
16        program_option::COption,
17        pubkey::Pubkey,
18        system_instruction,
19        sysvar::{rent::Rent, Sysvar},
20    },
21};
22
23/// Processes a [Reallocate](enum.TokenInstruction.html) instruction
24pub fn process_reallocate(
25    program_id: &Pubkey,
26    accounts: &[AccountInfo],
27    new_extension_types: Vec<ExtensionType>,
28) -> ProgramResult {
29    let account_info_iter = &mut accounts.iter();
30    let token_account_info = next_account_info(account_info_iter)?;
31    let payer_info = next_account_info(account_info_iter)?;
32    let system_program_info = next_account_info(account_info_iter)?;
33    let authority_info = next_account_info(account_info_iter)?;
34    let authority_info_data_len = authority_info.data_len();
35
36    // check that account is the right type and validate owner
37    let (mut current_extension_types, native_token_amount) = {
38        let token_account = token_account_info.data.borrow();
39        let account = StateWithExtensions::<Account>::unpack(&token_account)?;
40        Processor::validate_owner(
41            program_id,
42            &account.base.owner,
43            authority_info,
44            authority_info_data_len,
45            account_info_iter.as_slice(),
46        )?;
47        let native_token_amount = account.base.is_native().then_some(account.base.amount);
48        (account.get_extension_types()?, native_token_amount)
49    };
50
51    // check that all desired extensions are for the right account type
52    if new_extension_types
53        .iter()
54        .any(|extension_type| extension_type.get_account_type() != AccountType::Account)
55    {
56        return Err(TokenError::InvalidState.into());
57    }
58    // ExtensionType::try_calculate_account_len() dedupes types, so just a dumb
59    // concatenation is fine here
60    current_extension_types.extend_from_slice(&new_extension_types);
61    let needed_account_len =
62        ExtensionType::try_calculate_account_len::<Account>(&current_extension_types)?;
63
64    // if account is already large enough, return early
65    if token_account_info.data_len() >= needed_account_len {
66        return Ok(());
67    }
68
69    // reallocate
70    msg!(
71        "account needs realloc, +{:?} bytes",
72        needed_account_len - token_account_info.data_len()
73    );
74    token_account_info.realloc(needed_account_len, false)?;
75
76    // if additional lamports needed to remain rent-exempt, transfer them
77    let rent = Rent::get()?;
78    let new_rent_exempt_reserve = rent.minimum_balance(needed_account_len);
79
80    let current_lamport_reserve = token_account_info
81        .lamports()
82        .checked_sub(native_token_amount.unwrap_or(0))
83        .ok_or(TokenError::Overflow)?;
84    let lamports_diff = new_rent_exempt_reserve.saturating_sub(current_lamport_reserve);
85    if lamports_diff > 0 {
86        invoke(
87            &system_instruction::transfer(payer_info.key, token_account_info.key, lamports_diff),
88            &[
89                payer_info.clone(),
90                token_account_info.clone(),
91                system_program_info.clone(),
92            ],
93        )?;
94    }
95
96    // set account_type, if needed
97    let mut token_account_data = token_account_info.data.borrow_mut();
98    set_account_type::<Account>(&mut token_account_data)?;
99
100    // sync the rent exempt reserve for native accounts
101    if let Some(native_token_amount) = native_token_amount {
102        let mut token_account = StateWithExtensionsMut::<Account>::unpack(&mut token_account_data)?;
103        // sanity check that there are enough lamports to cover the token amount
104        // and the rent exempt reserve
105        let minimum_lamports = new_rent_exempt_reserve
106            .checked_add(native_token_amount)
107            .ok_or(TokenError::Overflow)?;
108        if token_account_info.lamports() < minimum_lamports {
109            return Err(TokenError::InvalidState.into());
110        }
111        token_account.base.is_native = COption::Some(new_rent_exempt_reserve);
112        token_account.pack_base();
113    }
114
115    Ok(())
116}
spl_token_2022/extension/reallocate.rs

spl_token_2022/extension/
reallocate.rs
