From caa0f13d40d000229dd867e6c52039a0c897fed2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=BF=97=E5=AE=87?= <hello@evanlinjin.me>
Date: Tue, 10 Dec 2024 21:56:37 +1100
Subject: [PATCH] docs(wallet): Explain `.take` usage

---
 crates/wallet/src/wallet/mod.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crates/wallet/src/wallet/mod.rs b/crates/wallet/src/wallet/mod.rs
index 542db3b06..98559d4d9 100644
--- a/crates/wallet/src/wallet/mod.rs
+++ b/crates/wallet/src/wallet/mod.rs
@@ -1844,6 +1844,9 @@ impl Wallet {
             .graph()
             .list_canonical_txs(&self.chain, chain_tip)
             .filter(|canon_tx| prev_txids.contains(&canon_tx.tx_node.txid))
+            // This is for a small performance gain. Although `.filter` filters out excess txs, it
+            // will still consume the internal `CanonicalIter` entirely. Having a `.take` here
+            // allows us to stop further unnecessary canonicalization.
             .take(prev_txids.len())
             .map(|canon_tx| {
                 let txid = canon_tx.tx_node.txid;