Fix incorrect assertion in BM_VecSimBasics::UpdateAtBlockSize benchmark (#819)

meiravgri · meiravgri · commit e91cb524b75e · 2025-11-04T10:49:09.000+02:00
* VecSimIndexInterface: introduce indexMetaDataCapacity for testing returns metadata containers capacity * cover for tiered index (cherry picked from commit f24b65a)
diff --git a/src/VecSim/algorithms/brute_force/brute_force.h b/src/VecSim/algorithms/brute_force/brute_force.h
@@ -92,6 +92,8 @@ class BruteForceIndex : public VecSimIndexAbstract<DistType> {
 
         return actual_stored_vec;
     }
+
+    size_t indexMetaDataCapacity() const override { return idToLabelMapping.capacity(); }
 #endif
 
 protected:
diff --git a/src/VecSim/algorithms/hnsw/hnsw.h b/src/VecSim/algorithms/hnsw/hnsw.h
@@ -327,6 +327,8 @@ class HNSWIndex : public VecSimIndexAbstract<DistType>,
 
         return actual_stored_vec;
     }
+
+    size_t indexMetaDataCapacity() const override { return idToMetaData.capacity(); }
 #endif
 
 protected:
diff --git a/src/VecSim/algorithms/hnsw/hnsw_tiered.h b/src/VecSim/algorithms/hnsw/hnsw_tiered.h
@@ -226,6 +226,10 @@ class TieredHNSWIndex : public VecSimTieredIndex<DataType, DistType> {
     }
 #ifdef BUILD_TESTS
     void getDataByLabel(labelType label, std::vector<std::vector<DataType>> &vectors_output) const;
+    size_t indexMetaDataCapacity() const override {
+        return this->backendIndex->indexMetaDataCapacity() +
+               this->frontendIndex->indexMetaDataCapacity();
+    }
 #endif
 };
 
diff --git a/src/VecSim/vec_sim_interface.h b/src/VecSim/vec_sim_interface.h
@@ -262,4 +262,16 @@ struct VecSimIndexInterface : public VecsimBaseObject {
     inline static void setWriteMode(VecSimWriteMode mode) {
         VecSimIndexInterface::asyncWriteMode = mode;
     }
+#ifdef BUILD_TESTS
+    /**
+     * @brief get the capacity of the meta data containers.
+     *
+     * @return The capacity of the meta data containers in number of elements.
+     * The value returned from this function may differ from the indexCapacity() function. For
+     * example, in HNSW, the capacity of the meta data containers is the capacity of the labels
+     * lookup table, while the capacity of the data containers is the capacity of the vectors
+     * container.
+     */
+    virtual size_t indexMetaDataCapacity() const = 0;
+#endif
 };
diff --git a/tests/benchmark/bm_vecsim_basics.h b/tests/benchmark/bm_vecsim_basics.h
@@ -303,6 +303,9 @@ void BM_VecSimBasics<index_type_t>::UpdateAtBlockSize(benchmark::State &st) {
     // Calculate vectors needed to reach next block boundary
     size_t vecs_to_blocksize =
         BM_VecSimGeneral::block_size - (initial_index_size % BM_VecSimGeneral::block_size);
+    size_t initial_index_cap = index->indexMetaDataCapacity();
+    assert(initial_index_cap == N_VECTORS + vecs_to_blocksize);
+
     assert(vecs_to_blocksize < BM_VecSimGeneral::block_size);
     labelType initial_label_count = index->indexLabelCount();
     labelType curr_label = initial_label_count;
@@ -327,24 +330,29 @@ void BM_VecSimBasics<index_type_t>::UpdateAtBlockSize(benchmark::State &st) {
 
     // Benchmark loop: repeatedly delete/add same vector to trigger grow-shrink cycles
     labelType label_to_update = curr_label - 1;
-    size_t index_cap = index->indexCapacity();
+    size_t index_cap = index->indexMetaDataCapacity();
+    std::cout << "index_cap after adding vectors " << index_cap << std::endl;
+    assert(index_cap == initial_index_cap + BM_VecSimGeneral::block_size);
+
     for (auto _ : st) {
         // Remove the vector directly from hnsw
         size_t ret = VecSimIndex_DeleteVector(
             INDICES[st.range(0) == VecSimAlgo_TIERED ? VecSimAlgo_HNSWLIB : st.range(0)],
             label_to_update);
         assert(ret == 1);
-        assert(index->indexCapacity() == index_cap - BM_VecSimGeneral::block_size);
-        // Capacity should shrink by one block after deletion
+
+        // Capacity should not change
+        size_t curr_cap = index->indexMetaDataCapacity();
+        assert(curr_cap == index_cap);
         ret = VecSimIndex_AddVector(index, QUERIES[(added_vec_count - 1) % N_QUERIES].data(),
                                     label_to_update);
         assert(ret == 1);
         BM_VecSimGeneral::mock_thread_pool.thread_pool_wait();
         assert(VecSimIndex_IndexSize(
                    INDICES[st.range(0) == VecSimAlgo_TIERED ? VecSimAlgo_HNSWLIB : st.range(0)]) ==
                N_VECTORS + added_vec_count);
-        // Capacity should grow back to original size after addition
-        assert(index->indexCapacity() == index_cap);
+        // Capacity should not change
+        assert(index->indexMetaDataCapacity() == index_cap);
     }
     assert(VecSimIndex_IndexSize(index) == N_VECTORS + added_vec_count);
 
diff --git a/tests/unit/test_allocator.cpp b/tests/unit/test_allocator.cpp
@@ -120,6 +120,7 @@ TYPED_TEST(IndexAllocatorTest, test_bf_index_block_size_1) {
 
         ASSERT_EQ(bfIndex->indexCapacity(), expected_map_containers_size);
         ASSERT_EQ(bfIndex->idToLabelMapping.capacity(), expected_map_containers_size);
+        ASSERT_EQ(bfIndex->indexMetaDataCapacity(), expected_map_containers_size);
         ASSERT_EQ(bfIndex->idToLabelMapping.size(), expected_map_containers_size);
         ASSERT_GE(bfIndex->labelToIdLookup.bucket_count(), expected_map_containers_size);
     };
@@ -530,6 +531,7 @@ TYPED_TEST(IndexAllocatorTest, test_hnsw_reclaim_memory) {
         ASSERT_EQ(hnswIndex->getStoredVectorsCount(), expected_size);
 
         ASSERT_EQ(hnswIndex->idToMetaData.capacity(), expected_map_containers_size);
+        ASSERT_EQ(hnswIndex->indexMetaDataCapacity(), expected_map_containers_size);
         ASSERT_EQ(hnswIndex->idToMetaData.size(), expected_map_containers_size);
         ASSERT_GE(hnswIndex->labelLookup.bucket_count(), expected_map_containers_size);
         // Also validate that there are no unidirectional connections (these add memory to the
diff --git a/tests/unit/test_hnsw_tiered.cpp b/tests/unit/test_hnsw_tiered.cpp
@@ -3795,6 +3795,11 @@ TYPED_TEST(HNSWTieredIndexTestBasic, HNSWResize) {
     ASSERT_EQ(tiered_index->getMainIndexGuardWriteLockCount(), resize_operations);
     ASSERT_EQ(hnsw_index->indexSize(), 1);
     ASSERT_EQ(hnsw_index->indexCapacity(), blockSize);
+    ASSERT_EQ(hnsw_index->indexMetaDataCapacity(), blockSize);
+    ASSERT_EQ(tiered_index->frontendIndex->indexMetaDataCapacity(), 0);
+    ASSERT_EQ(tiered_index->indexMetaDataCapacity(),
+              hnsw_index->indexMetaDataCapacity() +
+                  tiered_index->frontendIndex->indexMetaDataCapacity());
 
     // add up to block size
     for (size_t i = 1; i < blockSize; i++) {
@@ -3805,6 +3810,11 @@ TYPED_TEST(HNSWTieredIndexTestBasic, HNSWResize) {
     ASSERT_EQ(tiered_index->getMainIndexGuardWriteLockCount(), resize_operations);
     ASSERT_EQ(hnsw_index->indexSize(), blockSize);
     ASSERT_EQ(hnsw_index->indexCapacity(), blockSize);
+    ASSERT_EQ(hnsw_index->indexMetaDataCapacity(), blockSize);
+    ASSERT_EQ(tiered_index->frontendIndex->indexMetaDataCapacity(), 0);
+    ASSERT_EQ(tiered_index->indexMetaDataCapacity(),
+              hnsw_index->indexMetaDataCapacity() +
+                  tiered_index->frontendIndex->indexMetaDataCapacity());
 
     // add one more vector to trigger another resize
     GenerateAndAddVector<TEST_DATA_T>(tiered_index, dim, blockSize);
@@ -3814,6 +3824,11 @@ TYPED_TEST(HNSWTieredIndexTestBasic, HNSWResize) {
     ASSERT_EQ(tiered_index->getMainIndexGuardWriteLockCount(), resize_operations);
     ASSERT_EQ(hnsw_index->indexSize(), blockSize + 1);
     ASSERT_EQ(hnsw_index->indexCapacity(), 2 * blockSize);
+    ASSERT_EQ(hnsw_index->indexMetaDataCapacity(), 2 * blockSize);
+    ASSERT_EQ(tiered_index->frontendIndex->indexMetaDataCapacity(), 0);
+    ASSERT_EQ(tiered_index->indexMetaDataCapacity(),
+              hnsw_index->indexMetaDataCapacity() +
+                  tiered_index->frontendIndex->indexMetaDataCapacity());
 
     // delete a vector to shrink data blocks
     ASSERT_EQ(VecSimIndex_DeleteVector(tiered_index, 0), 1) << "Failed to delete vector 0";
@@ -3825,6 +3840,8 @@ TYPED_TEST(HNSWTieredIndexTestBasic, HNSWResize) {
     ASSERT_EQ(tiered_index->getMainIndexGuardWriteLockCount(), resize_operations);
     ASSERT_EQ(hnsw_index->indexSize(), blockSize);
     ASSERT_EQ(hnsw_index->indexCapacity(), blockSize);
+    // meta data capacity should not shrink
+    ASSERT_EQ(hnsw_index->indexMetaDataCapacity(), 2 * blockSize);
 
     // add this vector again and verify lock was acquired to resize
     GenerateAndAddVector<TEST_DATA_T>(tiered_index, dim, 0);
@@ -3833,6 +3850,11 @@ TYPED_TEST(HNSWTieredIndexTestBasic, HNSWResize) {
     ASSERT_EQ(tiered_index->getMainIndexGuardWriteLockCount(), resize_operations);
     ASSERT_EQ(hnsw_index->indexSize(), blockSize + 1);
     ASSERT_EQ(hnsw_index->indexCapacity(), 2 * blockSize);
+    ASSERT_EQ(hnsw_index->indexMetaDataCapacity(), 2 * blockSize);
+    ASSERT_EQ(tiered_index->frontendIndex->indexMetaDataCapacity(), 0);
+    ASSERT_EQ(tiered_index->indexMetaDataCapacity(),
+              hnsw_index->indexMetaDataCapacity() +
+                  tiered_index->frontendIndex->indexMetaDataCapacity());
 
     // add up to block size (count = 2 blockSize), the lock shouldn't be acquired because no resize
     // is required
@@ -3843,4 +3865,9 @@ TYPED_TEST(HNSWTieredIndexTestBasic, HNSWResize) {
     ASSERT_EQ(tiered_index->getMainIndexGuardWriteLockCount(), resize_operations);
     ASSERT_EQ(hnsw_index->indexSize(), 2 * blockSize);
     ASSERT_EQ(hnsw_index->indexCapacity(), 2 * blockSize);
+    ASSERT_EQ(hnsw_index->indexMetaDataCapacity(), 2 * blockSize);
+    ASSERT_EQ(tiered_index->frontendIndex->indexMetaDataCapacity(), 0);
+    ASSERT_EQ(tiered_index->indexMetaDataCapacity(),
+              hnsw_index->indexMetaDataCapacity() +
+                  tiered_index->frontendIndex->indexMetaDataCapacity());
 }

Original file line number	Diff line number	Diff line change
`@@ -92,6 +92,8 @@ class BruteForceIndex : public VecSimIndexAbstract<DistType> {`
`92`	`92`
`93`	`93`	`return actual_stored_vec;`
`94`	`94`	`}`
	`95`	`+`
	`96`	`+ size_t indexMetaDataCapacity() const override { return idToLabelMapping.capacity(); }`
`95`	`97`	`#endif`
`96`	`98`
`97`	`99`	`protected:`
Original file line number	Diff line number	Diff line change
`@@ -327,6 +327,8 @@ class HNSWIndex : public VecSimIndexAbstract<DistType>,`
`327`	`327`
`328`	`328`	`return actual_stored_vec;`
`329`	`329`	`}`
	`330`	`+`
	`331`	`+ size_t indexMetaDataCapacity() const override { return idToMetaData.capacity(); }`
`330`	`332`	`#endif`
`331`	`333`
`332`	`334`	`protected:`