From 94d3eb3f3862e49101bdecef13de02f71f989fce Mon Sep 17 00:00:00 2001
From: ardocrat <ardocrat@gri.mw>
Date: Sat, 11 Apr 2026 02:08:51 +0300
Subject: [PATCH] scan: save last scanned block info for initial wallet
 scanning

---
 libwallet/src/api_impl/owner.rs | 31 +++++++++++++++++++++++--------
 libwallet/src/internal/scan.rs  | 33 +++++++++++++++++++++++++++++++--
 2 files changed, 54 insertions(+), 10 deletions(-)

diff --git a/libwallet/src/api_impl/owner.rs b/libwallet/src/api_impl/owner.rs
index 017bf4e..9fc556a 100644
--- a/libwallet/src/api_impl/owner.rs
+++ b/libwallet/src/api_impl/owner.rs
@@ -983,6 +983,7 @@ where
 		wallet_inst.clone(),
 		keychain_mask,
 		delete_unconfirmed,
+		None,
 		start_height,
 		tip.0,
 		status_send_channel,
@@ -1110,12 +1111,14 @@ where
 	let last_scanned_block = {
 		wallet_lock!(wallet_inst, w);
 		match w.init_status()? {
-			WalletInitStatus::InitNeedsScanning => ScannedBlockInfo {
-				height: 0,
-				hash: "".to_owned(),
-				start_pmmr_index: 0,
-				last_pmmr_index: 0,
-			},
+			WalletInitStatus::InitNeedsScanning => {
+				w.last_scanned_block().unwrap_or(ScannedBlockInfo {
+					height: 0,
+					hash: "".to_owned(),
+					start_pmmr_index: 0,
+					last_pmmr_index: 0,
+				})
+			}
 			WalletInitStatus::InitNoScanning => ScannedBlockInfo {
 				height: tip.clone().0,
 				hash: tip.clone().1,
@@ -1126,7 +1129,12 @@ where
 		}
 	};
 
-	let start_index = last_scanned_block.height.saturating_sub(100);
+	let start_height = last_scanned_block.height.saturating_sub(100);
+
+	debug!(
+		"update_wallet_state: last_scanned_block: {:?}",
+		last_scanned_block
+	);
 
 	if last_scanned_block.height == 0 {
 		let msg = "This wallet has not been scanned against the current chain. Beginning full scan... (this first scan may take a while, but subsequent scans will be much quicker)".to_string();
@@ -1135,11 +1143,18 @@ where
 		}
 	}
 
+	let start_pmmr_index = if last_scanned_block.start_pmmr_index == 0 {
+		None
+	} else {
+		Some(last_scanned_block.start_pmmr_index)
+	};
+
 	let mut info = scan::scan(
 		wallet_inst.clone(),
 		keychain_mask,
 		false,
-		start_index,
+		start_pmmr_index,
+		start_height,
 		tip.0,
 		status_send_channel,
 	)?;
diff --git a/libwallet/src/internal/scan.rs b/libwallet/src/internal/scan.rs
index 129e99c..92efceb 100644
--- a/libwallet/src/internal/scan.rs
+++ b/libwallet/src/internal/scan.rs
@@ -226,7 +226,9 @@ where
 	Ok(vw)
 }
 
-fn collect_chain_outputs<'a, C, K>(
+fn collect_chain_outputs<'a, L, C, K>(
+	wallet_inst: &Arc<Mutex<Box<dyn WalletInst<'a, L, C, K>>>>,
+	keychain_mask: &Option<&SecretKey>,
 	keychain: &K,
 	client: C,
 	start_index: u64,
@@ -234,6 +236,7 @@ fn collect_chain_outputs<'a, C, K>(
 	status_send_channel: &Option<Sender<StatusMessage>>,
 ) -> Result<(Vec<OutputResult>, u64), Error>
 where
+	L: WalletLCProvider<'a, C, K>,
 	C: NodeClient + 'a,
 	K: Keychain + 'a,
 {
@@ -242,6 +245,13 @@ where
 	let mut start_index = start_index;
 	let mut result_vec: Vec<OutputResult> = vec![];
 	let last_retrieved_return_index;
+
+	debug!(
+		"collect_chain_outputs: start_index {}, end_index {}",
+		start_index,
+		end_index.unwrap_or(0)
+	);
+
 	loop {
 		let (highest_index, last_retrieved_index, outputs) =
 			client.get_outputs_by_pmmr_index(start_index, end_index, batch_size)?;
@@ -267,6 +277,21 @@ where
 			perc_complete as u8,
 		)?);
 
+		// Save last scanned block info.
+		{
+			wallet_lock!(wallet_inst, w);
+			let mut batch = w.batch(*keychain_mask)?;
+			batch.save_last_scanned_block(ScannedBlockInfo {
+				height: 0,
+				hash: "".to_string(),
+				start_pmmr_index: start_index,
+				last_pmmr_index: last_retrieved_index,
+			})?;
+			batch.commit()?;
+
+			debug!("collect_chain_outputs: save_last_scanned_block: start_index {}, last_pmmr_index {}", start_index, last_retrieved_index);
+		}
+
 		if highest_index <= last_retrieved_index {
 			last_retrieved_return_index = last_retrieved_index;
 			break;
@@ -458,6 +483,7 @@ pub fn scan<'a, L, C, K>(
 	wallet_inst: Arc<Mutex<Box<dyn WalletInst<'a, L, C, K>>>>,
 	keychain_mask: Option<&SecretKey>,
 	delete_unconfirmed: bool,
+	start_pmmr_index: Option<u64>,
 	start_height: u64,
 	end_height: u64,
 	status_send_channel: &Option<Sender<StatusMessage>>,
@@ -479,10 +505,13 @@ where
 	// Retrieve the actual PMMR index range we're looking for
 	let pmmr_range = client.height_range_to_pmmr_indices(start_height, Some(end_height))?;
 
+	let start_pmmr_index = start_pmmr_index.unwrap_or(pmmr_range.0);
 	let (chain_outs, last_index) = collect_chain_outputs(
+		&wallet_inst,
+		&keychain_mask,
 		&keychain,
 		client,
-		pmmr_range.0,
+		start_pmmr_index,
 		Some(pmmr_range.1),
 		status_send_channel,
 	)?;