cuprate_helper/
tx.rs

1//! Utils for working with [`Transaction`]
2
3use monero_oxide::transaction::{Input, Transaction};
4
5/// Calculates the fee of the [`Transaction`].
6///
7/// # Panics
8/// This will panic if the inputs overflow or the transaction outputs too much, so should only
9/// be used on known to be valid txs.
10pub fn tx_fee(tx: &Transaction) -> u64 {
11    let mut fee = 0_u64;
12
13    match &tx {
14        Transaction::V1 { prefix, .. } => {
15            for input in &prefix.inputs {
16                match input {
17                    Input::Gen(_) => return 0,
18                    Input::ToKey { amount, .. } => {
19                        fee = fee.checked_add(amount.unwrap_or(0)).unwrap();
20                    }
21                }
22            }
23
24            for output in &prefix.outputs {
25                fee = fee.checked_sub(output.amount.unwrap_or(0)).unwrap();
26            }
27        }
28        Transaction::V2 { proofs, .. } => {
29            fee = proofs.as_ref().unwrap().base.fee;
30        }
31    }
32
33    fee
34}
35
36#[cfg(test)]
37mod test {
38    use monero_oxide::{
39        io::CompressedPoint,
40        transaction::{NotPruned, Output, Timelock, TransactionPrefix},
41    };
42
43    use super::*;
44
45    #[test]
46    #[should_panic(expected = "called `Option::unwrap()` on a `None` value")]
47    fn tx_fee_panic() {
48        let input = Input::ToKey {
49            amount: Some(u64::MAX),
50            key_offsets: vec![],
51            key_image: CompressedPoint([0; 32]),
52        };
53
54        let output = Output {
55            amount: Some(u64::MAX),
56            key: CompressedPoint([0; 32]),
57            view_tag: None,
58        };
59
60        let tx = Transaction::<NotPruned>::V1 {
61            prefix: TransactionPrefix {
62                additional_timelock: Timelock::None,
63                inputs: vec![input; 2],
64                outputs: vec![output],
65                extra: vec![],
66            },
67            signatures: vec![],
68        };
69
70        tx_fee(&tx);
71    }
72}
cuprate_helper/tx.rs

cuprate_helper/
tx.rs
