Update src/single_random_draw.rs

Co-authored-by: Thibaut Le Guilly <[email protected]>

Cargo.toml

@@ -15,12 +15,12 @@ keywords = ["crypto", "bitcoin"]
 readme = "README.md"
 
 [dependencies]
-bitcoin = { git="https://github.com/yancyribbens/rust-bitcoin", branch="master" }
+bitcoin = { git="https://github.com/rust-bitcoin/rust-bitcoin", branch="master" }
 rand = {version = "0.8.5", default-features = false, optional = true}
 
 [dev-dependencies]
 rust-bitcoin-coin-selection = {path = ".", features = ["rand"]}
 rand = "0.8.5"
 
 [patch.crates-io]
-bitcoin_hashes = { git="https://github.com/yancyribbens/rust-bitcoin.git" }
+bitcoin_hashes = { git="https://github.com/rust-bitcoin/rust-bitcoin.git" }

src/lib.rs

@@ -40,11 +40,6 @@ pub trait Utxo: Clone {
 // https://github.com/bitcoin/bitcoin/blob/f722a9bd132222d9d5cd503b5af25c905b205cdb/src/wallet/coinselection.h#L20
 const CHANGE_LOWER: Amount = Amount::from_sat(50_000);
 
-// TODO add to Rust-bitcoin
-/// The base weight is the output (32 + 4) + nSequence 4
-/// <https://github.com/bitcoin/bitcoin/blob/cd43a8444ba44f86ddbb313a03a2782482beda89/src/primitives/transaction.h#L74>
-pub const TXIN_BASE_WEIGHT: Weight = Weight::from_wu(32 + 4 + 4);
-
 // TODO: Use miniscript's max_weight_to_satisfy() method to calculate the
 // max satisfaction weight instead.  Currently, implementers of this crate
 // are required to loop through each UTXO and calculate the satisfaction_weight.

src/single_random_draw.rs

@@ -4,9 +4,9 @@
 use crate::errors::Error;
 use crate::WeightedUtxo;
 use crate::CHANGE_LOWER;
-use crate::TXIN_BASE_WEIGHT;
 use bitcoin::Amount;
 use bitcoin::FeeRate;
+use bitcoin::TxIn;
 use rand::seq::SliceRandom;
 
 /// Calculates the effective_value of an input.
@@ -23,19 +23,15 @@ fn get_effective_value(
 ) -> Result<Option<Amount>, Error> {
     let satisfaction_weight = weighted_utxo.satisfaction_weight;
 
-    let checked_weight = satisfaction_weight.checked_add(TXIN_BASE_WEIGHT);
+    let weight = satisfaction_weight
+        .checked_add(TxIn::BASE_WEIGHT)
+        .ok_or(Error::AdditionOverflow(satisfaction_weight, TxIn::BASE_WEIGHT))?;
 
-    let weight = match checked_weight {
-        Some(w) => w,
-        None => return Err(Error::AdditionOverflow(satisfaction_weight, TXIN_BASE_WEIGHT)),
-    };
+    let input_fee = fee_rate
+        .checked_mul_by_weight(weight)
+        .ok_or(Error::MultiplicationOverflow(satisfaction_weight, fee_rate))?;
 
-    let input_fee: Option<Amount> = fee_rate.checked_mul_by_weight(weight);
-
-    match input_fee {
-        Some(f) => Ok(weighted_utxo.utxo.value.checked_sub(f)),
-        None => Err(Error::MultiplicationOverflow(satisfaction_weight, fee_rate)),
-    }
+    Ok(weighted_utxo.utxo.value.checked_sub(input_fee))
 }
 
 /// Randomly select coins for the given target by shuffling the UTXO pool and