f Account for ConfirmationTarget::MempoolMinimum

src/bitcoind_client.rs

@@ -1,4 +1,4 @@
-use crate::convert::{BlockchainInfo, FeeResponse, FundedTx, NewAddress, RawTx, SignedTx};
+use crate::convert::{BlockchainInfo, FeeResponse, FundedTx, NewAddress, RawTx, SignedTx, MempoolMinFeeResponse};
 use crate::disk::FilesystemLogger;
 use base64;
 use bitcoin::blockdata::transaction::Transaction;
@@ -32,6 +32,7 @@ pub struct BitcoindClient {
 
 #[derive(Clone, Eq, Hash, PartialEq)]
 pub enum Target {
+	MempoolMinimum,
 	Background,
 	Normal,
 	HighPriority,
@@ -75,6 +76,7 @@ impl BitcoindClient {
 				"Failed to make initial call to bitcoind - please check your RPC user/password and access settings")
 			})?;
 		let mut fees: HashMap<Target, AtomicU32> = HashMap::new();
+		fees.insert(Target::MempoolMinimum, AtomicU32::new(MIN_FEERATE));
 		fees.insert(Target::Background, AtomicU32::new(MIN_FEERATE));
 		fees.insert(Target::Normal, AtomicU32::new(2000));
 		fees.insert(Target::HighPriority, AtomicU32::new(5000));
@@ -102,6 +104,19 @@ impl BitcoindClient {
 	) {
 		handle.spawn(async move {
 			loop {
+				let mempoolmin_estimate = {
+					let resp = rpc_client
+						.call_method::<MempoolMinFeeResponse>(
+							"getmempoolinfo",
+							&vec![],
+						)
+						.await
+						.unwrap();
+					match resp.feerate_sat_per_kw {
+						Some(feerate) => std::cmp::max(feerate, MIN_FEERATE),
+						None => MIN_FEERATE,
+					}
+				};
 				let background_estimate = {
 					let background_conf_target = serde_json::json!(144);
 					let background_estimate_mode = serde_json::json!("ECONOMICAL");
@@ -151,6 +166,9 @@ impl BitcoindClient {
 					}
 				};
 
+				fees.get(&Target::MempoolMinimum)
+					.unwrap()
+					.store(mempoolmin_estimate, Ordering::Release);
 				fees.get(&Target::Background)
 					.unwrap()
 					.store(background_estimate, Ordering::Release);
@@ -238,6 +256,9 @@ impl BitcoindClient {
 impl FeeEstimator for BitcoindClient {
 	fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32 {
 		match confirmation_target {
+			ConfirmationTarget::MempoolMinimum => {
+				self.fees.get(&Target::MempoolMinimum).unwrap().load(Ordering::Acquire)
+			}
 			ConfirmationTarget::Background => {
 				self.fees.get(&Target::Background).unwrap().load(Ordering::Acquire)
 			}

src/convert.rs

@@ -49,7 +49,6 @@ impl TryInto<NewAddress> for JsonResponse {
 		Ok(NewAddress(self.0.as_str().unwrap().to_string()))
 	}
 }
-
 pub struct FeeResponse {
 	pub feerate_sat_per_kw: Option<u32>,
 	pub errored: bool,
@@ -74,6 +73,32 @@ impl TryInto<FeeResponse> for JsonResponse {
 	}
 }
 
+#[derive(Debug)]
+pub struct MempoolMinFeeResponse {
+	pub feerate_sat_per_kw: Option<u32>,
+	pub errored: bool,
+}
+
+impl TryInto<MempoolMinFeeResponse> for JsonResponse {
+	type Error = std::io::Error;
+	fn try_into(self) -> std::io::Result<MempoolMinFeeResponse> {
+		let errored = !self.0["errors"].is_null();
+		Ok(MempoolMinFeeResponse {
+			errored,
+			feerate_sat_per_kw: match self.0["mempoolminfee"].as_f64() {
+				// Bitcoin Core gives us a feerate in BTC/KvB, which we need to convert to
+				// satoshis/KW. Thus, we first multiply by 10^8 to get satoshis, then divide by 4
+				// to convert virtual-bytes into weight units.
+				Some(feerate_btc_per_kvbyte) => {
+					Some((feerate_btc_per_kvbyte * 100_000_000.0 / 4.0).round() as u32)
+				}
+				None => None,
+			},
+		})
+	}
+}
+
+
 pub struct BlockchainInfo {
 	pub latest_height: usize,
 	pub latest_blockhash: BlockHash,