From 2e1e509c8c291c532993352041367e25676f4d5f Mon Sep 17 00:00:00 2001
From: pranav2007 <raipranav71@gmail.com>
Date: Wed, 28 Oct 2026 06:35:50 +0530
Subject: [PATCH] use merge_and_prune() only when needed

---
 crates/index/src/hnsw/search.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/crates/index/src/hnsw/search.rs b/crates/index/src/hnsw/search.rs
index 8be71db..a93b069 100644
--- a/crates/index/src/hnsw/search.rs
+++ b/crates/index/src/hnsw/search.rs
@@ -197,6 +197,20 @@ impl HnswIndex {
             if n == p {
                 continue;
             }
+
+            self.ensure_level(n, level);
+            let node = self.index.nodes.get_mut(&n).unwrap();
+            let list = &mut node.neighbors[level];
+
+            // The list has room: just add p, no need to compute distances or sort
+            if list.len() < m {
+                if !list.contains(&p) {
+                    list.push(p);
+                }
+                continue;
+            }
+
+            // The list is full: keep only the closest m
             self.merge_and_prune(n, level, &[p], m)?;
         }
         Ok(())