From 763987523a542bc2440f359dfa3cd38b46327c88 Mon Sep 17 00:00:00 2001
From: Andrija Antonijevic <anantoni@microsoft.com>
Date: Fri, 31 Jan 2025 16:02:37 -0800
Subject: [PATCH 1/2] Comment out non-threadsafe error message output that can
 cause crashes

The method would be called many times per second, so printing an error message
is not appropriate, there's already a return code.
---
 src/index.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/index.cpp b/src/index.cpp
index 17a285992..bc346c3de 100644
--- a/src/index.cpp
+++ b/src/index.cpp
@@ -796,7 +796,7 @@ template <typename T, typename TagT, typename LabelT> int Index<T, TagT, LabelT>
     std::shared_lock<std::shared_timed_mutex> lock(_tag_lock);
     if (_tag_to_location.find(tag) == _tag_to_location.end())
     {
-        diskann::cout << "Tag " << tag << " does not exist" << std::endl;
+        // diskann::cout << "Tag " << tag << " does not exist" << std::endl;
         return -1;
     }
 

From b9923f2b6b005386e73dbb1d8600a5ef8870b772 Mon Sep 17 00:00:00 2001
From: Denis Deyneko <denisdey@microsoft.com>
Date: Wed, 2 Jul 2025 14:07:12 -0700
Subject: [PATCH 2/2] Comment out the non-thread-safe code when vector is not
 found. Use iterator instead of operator[] to access the found tag.

---
 src/index.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/index.cpp b/src/index.cpp
index bc346c3de..29153d7a2 100644
--- a/src/index.cpp
+++ b/src/index.cpp
@@ -794,13 +794,14 @@ size_t Index<T, TagT, LabelT>::load_graph(std::string filename, size_t expected_
 template <typename T, typename TagT, typename LabelT> int Index<T, TagT, LabelT>::get_vector_by_tag(TagT &tag, T *vec)
 {
     std::shared_lock<std::shared_timed_mutex> lock(_tag_lock);
-    if (_tag_to_location.find(tag) == _tag_to_location.end())
+    const auto tagIt = _tag_to_location.find(tag);
+    if (tagIt == _tag_to_location.end())
     {
         // diskann::cout << "Tag " << tag << " does not exist" << std::endl;
         return -1;
     }
 
-    size_t location = _tag_to_location[tag];
+    const unsigned location = tagIt->second;
     memcpy((void *)vec, (void *)(_data + location * _aligned_dim), (size_t)_dim * sizeof(T));
     return 0;
 }