Receipt Tokens

1// Pyth gives us a price and an exponent
2//   price * 10^exponent = current USD per unit token
3//
4// Combined exponent normalizes for token decimals and USDC's 6 decimals:
5let combined_exponent = exponent + USDC_DECIMALS - token_decimals as i32;
6let base_value        = receipt_tokens_amount * price;
7
8let oracle_value = if combined_exponent >= 0 {
9    base_value * 10u128.pow(combined_exponent as u32)
10} else {
11    base_value / 10u128.pow((-combined_exponent) as u32)
12};
13
14// Example: 1 jitoSOL at $200, exponent = -8
15//   tokens = 1_000_000_000 (9 decimals)
16//   price  = 20_000_000_000
17//   value  = 200_000_000  // 200 USDC (6 decimals)

1// Expected value if exchange rate were exactly the one stored at lock
2let expected_value = receipt_tokens_amount * exchange_rate_at_lock / EXCHANGE_RATE_SCALE;
3
4// ±10% tolerance (ORACLE_TOLERANCE_BPS = 1000)
5let tolerance      = expected_value * ORACLE_TOLERANCE_BPS / 10_000;
6let min_acceptable = expected_value - tolerance;
7let max_acceptable = expected_value + tolerance;
8
9require!(
10    current_token_value >= min_acceptable && current_token_value <= max_acceptable,
11    PayflowError::InvalidTokenValue
12);