frost/bdk
3
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat(tx_graph)!: change TxGraph::calculate_fee to return Result<u64,CalculateFeeError>

Browse Source 
added
- tx_graph::CalculateFeeError enum

BREAKING CHANGES:

changed
- TxGraph::calculate_fee function to return Result<u64,CalculateFeeError> instead of Option<i64>
This commit is contained in:
Steve Myers
2023-08-01 12:42:37 -05:00
parent b4c31cd5ba
commit d443fe7f66
6 changed files with 72 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
crates/chain/src/tx_graph.rs
View File

@@ -135,6 +135,15 @@ pub struct CanonicalTx<'a, T, A> {
pub tx_node: TxNode<'a, T, A>,
}
/// Errors returned by `TxGraph::calculate_fee`.
#[derive(Debug, PartialEq, Eq)]
pub enum CalculateFeeError {
/// Missing `TxOut` for one or more of the inputs of the tx
MissingTxOut(Vec<OutPoint>),
/// When the transaction is invalid according to the graph it has a negative fee
NegativeFee(i64),
}
impl<A> TxGraph<A> {
/// Iterate over all tx outputs known by [`TxGraph`].
///
@@ -236,25 +245,33 @@ impl<A> TxGraph<A> {
}
/// Calculates the fee of a given transaction. Returns 0 if `tx` is a coinbase transaction.
/// Returns `Some(_)` if we have all the `TxOut`s being spent by `tx` in the graph (either as
/// the full transactions or individual txouts). If the returned value is negative, then the
/// transaction is invalid according to the graph.
///
/// Returns `None` if we're missing an input for the tx in the graph.
/// Returns `OK(_)` if we have all the `TxOut`s being spent by `tx` in the graph (either as
/// the full transactions or individual txouts).
///
/// Note `tx` does not have to be in the graph for this to work.
pub fn calculate_fee(&self, tx: &Transaction) -> Option<i64> {
pub fn calculate_fee(&self, tx: &Transaction) -> Result<u64, CalculateFeeError> {
if tx.is_coin_base() {
return Some(0);
return Ok(0);
}
let inputs_sum = tx
.input
.iter()
.map(|txin| {
self.get_txout(txin.previous_output)
.map(|txout| txout.value as i64)
})
.sum::<Option<i64>>()?;
let inputs_sum = tx.input.iter().fold(
(0_u64, Vec::new()),
|(mut sum, mut missing_outpoints), txin| match self.get_txout(txin.previous_output) {
None => {
missing_outpoints.push(txin.previous_output);
(sum, missing_outpoints)
}
Some(txout) => {
sum += txout.value;
(sum, missing_outpoints)
}
},
);
let inputs_sum = if inputs_sum.1.is_empty() {
Ok(inputs_sum.0 as i64)
} else {
Err(CalculateFeeError::MissingTxOut(inputs_sum.1))
}?;
let outputs_sum = tx
.output
@@ -262,7 +279,12 @@ impl<A> TxGraph<A> {
.map(|txout| txout.value as i64)
.sum::<i64>();
Some(inputs_sum - outputs_sum)
let fee = inputs_sum - outputs_sum;
if fee < 0 {
Err(CalculateFeeError::NegativeFee(fee))
} else {
Ok(fee as u64)
}
}
/// The transactions spending from this output.