refactor!: eliminate redundant satisfaction weight in SelectorParams

examples/anti_fee_sniping.rs

@@ -1,8 +1,8 @@
 #![allow(dead_code)]
 use bdk_testenv::{bitcoincore_rpc::RpcApi, TestEnv};
 use bdk_tx::{
-    filter_unspendable, group_by_spk, selection_algorithm_lowest_fee_bnb, FeeStrategy, Output,
-    PsbtParams, ScriptSource, SelectorParams,
+    filter_unspendable, group_by_spk, selection_algorithm_lowest_fee_bnb, Output, PsbtParams,
+    SelectorParams,
 };
 use bitcoin::{absolute::LockTime, key::Secp256k1, Amount, FeeRate, Sequence};
 use miniscript::Descriptor;
@@ -75,13 +75,13 @@ fn main() -> anyhow::Result<()> {
             .into_selection(
                 selection_algorithm_lowest_fee_bnb(longterm_feerate, 100_000),
                 SelectorParams::new(
-                    FeeStrategy::FeeRate(FeeRate::from_sat_per_vb_unchecked(10)),
+                    FeeRate::from_sat_per_vb_unchecked(10),
                     vec![Output::with_script(
                         recipient_addr.script_pubkey(),
                         Amount::from_sat(50_000_000),
                     )],
-                    ScriptSource::Descriptor(Box::new(internal.at_derivation_index(0)?)),
-                    wallet.change_policy(),
+                    bdk_tx::ChangeScript::from_descriptor(internal.at_derivation_index(0)?),
+                    bdk_tx::ChangePolicy::no_dust_least_waste(longterm_feerate),
                 ),
             )?;
 

examples/common.rs

@@ -4,12 +4,11 @@ use bdk_bitcoind_rpc::{Emitter, NO_EXPECTED_MEMPOOL_TXIDS};
 use bdk_chain::{
     bdk_core, Anchor, Balance, CanonicalizationParams, ChainPosition, ConfirmationBlockTime,
 };
-use bdk_coin_select::{ChangePolicy, DrainWeights};
 use bdk_testenv::{bitcoincore_rpc::RpcApi, TestEnv};
 use bdk_tx::{
     CanonicalUnspents, ConfirmationStatus, Input, InputCandidates, RbfParams, TxWithStatus,
 };
-use bitcoin::{absolute, Address, Amount, BlockHash, OutPoint, Transaction, TxOut, Txid};
+use bitcoin::{absolute, Address, BlockHash, OutPoint, Transaction, Txid};
 use miniscript::{
     plan::{Assets, Plan},
     Descriptor, DescriptorPublicKey, ForEachKey,
@@ -143,51 +142,6 @@ impl Wallet {
             .map(|c_tx| (c_tx.tx_node.tx, status_from_position(c_tx.chain_position)))
     }
 
-    /// Computes the weight of a change output plus the future weight to spend it.
-    pub fn drain_weights(&self) -> DrainWeights {
-        // Get descriptor of change keychain at a derivation index.
-        let desc = self
-            .graph
-            .index
-            .get_descriptor(INTERNAL)
-            .unwrap()
-            .at_derivation_index(0)
-            .unwrap();
-
-        // Compute the weight of a change output for this wallet.
-        let output_weight = TxOut {
-            script_pubkey: desc.script_pubkey(),
-            value: Amount::ZERO,
-        }
-        .weight()
-        .to_wu();
-
-        // The spend weight is the default input weight plus the plan satisfaction weight
-        // (this code assumes that we're only dealing with segwit transactions).
-        let plan = desc.plan(&self.assets()).expect("failed to create Plan");
-        let spend_weight =
-            bitcoin::TxIn::default().segwit_weight().to_wu() + plan.satisfaction_weight() as u64;
-
-        DrainWeights {
-            output_weight,
-            spend_weight,
-            n_outputs: 1,
-        }
-    }
-
-    /// Get the default change policy for this wallet.
-    pub fn change_policy(&self) -> ChangePolicy {
-        let spk_0 = self
-            .graph
-            .index
-            .spk_at_index(INTERNAL, 0)
-            .expect("spk should exist in wallet");
-        ChangePolicy {
-            min_value: spk_0.minimal_non_dust().to_sat(),
-            drain_weights: self.drain_weights(),
-        }
-    }
-
     pub fn all_candidates(&self) -> bdk_tx::InputCandidates {
         let index = &self.graph.index;
         let assets = self.assets();

examples/synopsis.rs

@@ -1,7 +1,7 @@
 use bdk_testenv::{bitcoincore_rpc::RpcApi, TestEnv};
 use bdk_tx::{
-    filter_unspendable, group_by_spk, selection_algorithm_lowest_fee_bnb, FeeStrategy, Output,
-    PsbtParams, ScriptSource, SelectorParams, Signer,
+    filter_unspendable, group_by_spk, selection_algorithm_lowest_fee_bnb, Output, PsbtParams,
+    SelectorParams, Signer,
 };
 use bitcoin::{key::Secp256k1, Amount, FeeRate, Sequence};
 use miniscript::Descriptor;
@@ -55,13 +55,13 @@ fn main() -> anyhow::Result<()> {
         .into_selection(
             selection_algorithm_lowest_fee_bnb(longterm_feerate, 100_000),
             SelectorParams::new(
-                FeeStrategy::FeeRate(FeeRate::from_sat_per_vb_unchecked(10)),
+                FeeRate::from_sat_per_vb_unchecked(10),
                 vec![Output::with_script(
                     recipient_addr.script_pubkey(),
                     Amount::from_sat(21_000_000),
                 )],
-                ScriptSource::Descriptor(Box::new(internal.at_derivation_index(0)?)),
-                wallet.change_policy(),
+                bdk_tx::ChangeScript::from_descriptor(internal.at_derivation_index(0)?),
+                bdk_tx::ChangePolicy::no_dust_least_waste(longterm_feerate),
             ),
         )?;
 
@@ -128,18 +128,19 @@ fn main() -> anyhow::Result<()> {
                 SelectorParams {
                     // This is just a lower-bound feerate. The actual result will be much higher to
                     // satisfy mempool-replacement policy.
-                    fee_strategy: FeeStrategy::FeeRate(FeeRate::from_sat_per_vb_unchecked(1)),
+                    target_feerate: FeeRate::from_sat_per_vb_unchecked(1),
                     // We cancel the tx by specifying no target outputs. This way, all excess returns
                     // to our change output (unless if the prevouts picked are so small that it will
                     // be less wasteful to have no output, however that will not be a valid tx).
                     // If you only want to fee bump, put the original txs' recipients here.
                     target_outputs: vec![],
-                    change_script: ScriptSource::Descriptor(Box::new(
+                    change_script: bdk_tx::ChangeScript::from_descriptor(
                         internal.at_derivation_index(1)?,
-                    )),
-                    change_policy: wallet.change_policy(),
+                    ),
+                    change_policy: bdk_tx::ChangePolicy::no_dust_least_waste(longterm_feerate),
                     // This ensures that we satisfy mempool-replacement policy rules 4 and 6.
                     replace: Some(rbf_params),
+                    dust_relay_feerate: None,
                 },
             )?;
 

src/input_candidates.rs

@@ -8,7 +8,7 @@ use miniscript::bitcoin;
 
 use crate::collections::{BTreeMap, HashSet};
 use crate::{
-    cs_feerate, CannotMeetTarget, Input, InputGroup, Selection, Selector, SelectorError,
+    CannotMeetTarget, FeeRateExt, Input, InputGroup, Selection, Selector, SelectorError,
     SelectorParams,
 };
 
@@ -291,10 +291,10 @@ pub fn selection_algorithm_lowest_fee_bnb(
     longterm_feerate: FeeRate,
     max_rounds: usize,
 ) -> impl FnMut(&mut Selector) -> Result<(), NoBnbSolution> {
-    let long_term_feerate = cs_feerate(longterm_feerate);
+    let long_term_feerate = longterm_feerate.into_cs_feerate();
     move |selector| {
         let target = selector.target();
-        let change_policy = selector.change_policy();
+        let change_policy = selector.cs_change_policy();
         selector
             .inner_mut()
             .run_bnb(

src/lib.rs

@@ -49,3 +49,15 @@ pub(crate) mod collections {
 
 /// Definite descriptor.
 pub type DefiniteDescriptor = Descriptor<DefiniteDescriptorKey>;
+
+/// Extension trait for converting [`bitcoin::FeeRate`] to [`bdk_coin_select::FeeRate`].
+pub trait FeeRateExt {
+    /// Convert to a [`bdk_coin_select::FeeRate`].
+    fn into_cs_feerate(self) -> bdk_coin_select::FeeRate;
+}
+
+impl FeeRateExt for bitcoin::FeeRate {
+    fn into_cs_feerate(self) -> bdk_coin_select::FeeRate {
+        bdk_coin_select::FeeRate::from_sat_per_wu(self.to_sat_per_kwu() as f32 / 1000.0)
+    }
+}

src/selection.rs

@@ -2,7 +2,6 @@ use alloc::boxed::Box;
 use alloc::vec::Vec;
 use core::fmt::{Debug, Display};
 
-use bdk_coin_select::FeeRate;
 use miniscript::bitcoin;
 use miniscript::bitcoin::{
     absolute::{self, LockTime},
@@ -15,10 +14,6 @@ use crate::{apply_anti_fee_sniping, Finalizer, Input, Output};
 
 const FALLBACK_SEQUENCE: bitcoin::Sequence = bitcoin::Sequence::ENABLE_LOCKTIME_NO_RBF;
 
-pub(crate) fn cs_feerate(feerate: bitcoin::FeeRate) -> bdk_coin_select::FeeRate {
-    FeeRate::from_sat_per_wu(feerate.to_sat_per_kwu() as f32 / 1000.0)
-}
-
 /// Final selection of inputs and outputs.
 #[derive(Debug, Clone)]
 pub struct Selection {