Add float16 support for CAGRA extend

c/src/neighbors/cagra.cpp

@@ -618,6 +618,8 @@ extern "C" cuvsError_t cuvsCagraExtend(cuvsResources_t res,
 
     if ((dataset.dtype.code == kDLFloat) && (dataset.dtype.bits == 32)) {
       _extend<float>(res, *params, index, additional_dataset_tensor);
+    } else if (dataset.dtype.code == kDLFloat && dataset.dtype.bits == 16) {
+      _extend<half>(res, *params, index, additional_dataset_tensor);
     } else if (dataset.dtype.code == kDLInt && dataset.dtype.bits == 8) {
       _extend<int8_t>(res, *params, index, additional_dataset_tensor);
     } else if (dataset.dtype.code == kDLUInt && dataset.dtype.bits == 8) {

cpp/CMakeLists.txt

@@ -437,6 +437,7 @@ if(NOT BUILD_CPU_ONLY)
     src/neighbors/cagra_build_int8.cu
     src/neighbors/cagra_build_uint8.cu
     src/neighbors/cagra_extend_float.cu
+    src/neighbors/cagra_extend_half.cu
     src/neighbors/cagra_extend_int8.cu
     src/neighbors/cagra_extend_uint8.cu
     src/neighbors/cagra_optimize.cu

cpp/include/cuvs/neighbors/cagra.hpp

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2023-2025, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION.
  * SPDX-License-Identifier: Apache-2.0
  */
 
@@ -1242,7 +1242,83 @@ void extend(
  *
  * Usage example:
  * @code{.cpp}
- *   using namespace cuvs::neighbors;
+ *   using namespace raft::neighbors;
+ *   auto additional_dataset = raft::make_device_matrix<half, int64_t>(handle,add_size,dim);
+ *   // set_additional_dataset(additional_dataset.view());
+ *
+ *   cagra::extend_params params;
+ *   cagra::extend(res, params, raft::make_const_mdspan(additional_dataset.view()), index);
+ * @endcode
+ *
+ * @param[in] handle raft resources
+ * @param[in] params extend params
+ * @param[in] additional_dataset additional dataset on device memory
+ * @param[in,out] idx CAGRA index
+ * @param[out] new_dataset_buffer_view memory buffer view for the dataset including the additional
+ * part. The data will be copied from the current index in this function. The num rows must be the
+ * sum of the original and additional datasets, cols must be the dimension of the dataset, and the
+ * stride must be the same as the original index dataset. This view will be stored in the output
+ * index. It is the caller's responsibility to ensure that dataset stays alive as long as the index.
+ * This option is useful when users want to manage the memory space for the dataset themselves.
+ * @param[out] new_graph_buffer_view memory buffer view for the graph including the additional part.
+ * The data will be copied from the current index in this function. The num rows must be the sum of
+ * the original and additional datasets and cols must be the graph degree. This view will be stored
+ * in the output index. It is the caller's responsibility to ensure that dataset stays alive as long
+ * as the index. This option is useful when users want to manage the memory space for the graph
+ * themselves.
+ */
+void extend(
+  raft::resources const& handle,
+  const cagra::extend_params& params,
+  raft::device_matrix_view<const half, int64_t, raft::row_major> additional_dataset,
+  cuvs::neighbors::cagra::index<half, uint32_t>& idx,
+  std::optional<raft::device_matrix_view<half, int64_t, raft::layout_stride>>
+    new_dataset_buffer_view                                                        = std::nullopt,
+  std::optional<raft::device_matrix_view<uint32_t, int64_t>> new_graph_buffer_view = std::nullopt);
+
+/** @brief Add new vectors to a CAGRA index
+ *
+ * Usage example:
+ * @code{.cpp}
+ *   using namespace raft::neighbors;
+ *   auto additional_dataset = raft::make_host_matrix<half, int64_t>(handle,add_size,dim);
+ *   // set_additional_dataset(additional_dataset.view());
+ *
+ *   cagra::extend_params params;
+ *   cagra::extend(res, params, raft::make_const_mdspan(additional_dataset.view()), index);
+ * @endcode
+ *
+ * @param[in] handle raft resources
+ * @param[in] params extend params
+ * @param[in] additional_dataset additional dataset on host memory
+ * @param[in,out] idx CAGRA index
+ * @param[out] new_dataset_buffer_view memory buffer view for the dataset including the additional
+ * part. The data will be copied from the current index in this function. The num rows must be the
+ * sum of the original and additional datasets, cols must be the dimension of the dataset, and the
+ * stride must be the same as the original index dataset. This view will be stored in the output
+ * index. It is the caller's responsibility to ensure that dataset stays alive as long as the index.
+ * This option is useful when users want to manage the memory space for the dataset themselves.
+ * @param[out] new_graph_buffer_view memory buffer view for the graph including the additional part.
+ * The data will be copied from the current index in this function. The num rows must be the sum of
+ * the original and additional datasets and cols must be the graph degree. This view will be stored
+ * in the output index. It is the caller's responsibility to ensure that dataset stays alive as long
+ * as the index. This option is useful when users want to manage the memory space for the graph
+ * themselves.
+ */
+void extend(
+  raft::resources const& handle,
+  const cagra::extend_params& params,
+  raft::host_matrix_view<const half, int64_t, raft::row_major> additional_dataset,
+  cuvs::neighbors::cagra::index<half, uint32_t>& idx,
+  std::optional<raft::device_matrix_view<half, int64_t, raft::layout_stride>>
+    new_dataset_buffer_view                                                        = std::nullopt,
+  std::optional<raft::device_matrix_view<uint32_t, int64_t>> new_graph_buffer_view = std::nullopt);
+
+/** @brief Add new vectors to a CAGRA index
+ *
+ * Usage example:
+ * @code{.cpp}
+ *   using namespace raft::neighbors;
  *   auto additional_dataset = raft::make_device_matrix<int8_t, int64_t>(handle,add_size,dim);
  *   // set_additional_dataset(additional_dataset.view());
  *

cpp/src/neighbors/cagra_extend_half.cu

@@ -0,0 +1,36 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "cagra.cuh"
+#include <cuvs/neighbors/cagra.hpp>
+
+namespace cuvs::neighbors::cagra {
+
+#define RAFT_INST_CAGRA_EXTEND(T, IdxT)                                                         \
+  void extend(raft::resources const& handle,                                                    \
+              const cagra::extend_params& params,                                               \
+              raft::device_matrix_view<const T, int64_t, raft::row_major> additional_dataset,   \
+              cuvs::neighbors::cagra::index<T, IdxT>& idx,                                      \
+              std::optional<raft::device_matrix_view<T, int64_t, raft::layout_stride>> ndv,     \
+              std::optional<raft::device_matrix_view<IdxT, int64_t>> ngv)                       \
+  {                                                                                             \
+    cuvs::neighbors::cagra::extend<T, IdxT>(handle, additional_dataset, idx, params, ndv, ngv); \
+  }                                                                                             \
+                                                                                                \
+  void extend(raft::resources const& handle,                                                    \
+              const cagra::extend_params& params,                                               \
+              raft::host_matrix_view<const T, int64_t, raft::row_major> additional_dataset,     \
+              cuvs::neighbors::cagra::index<T, IdxT>& idx,                                      \
+              std::optional<raft::device_matrix_view<T, int64_t, raft::layout_stride>> ndv,     \
+              std::optional<raft::device_matrix_view<IdxT, int64_t>> ngv)                       \
+  {                                                                                             \
+    cuvs::neighbors::cagra::extend<T, IdxT>(handle, additional_dataset, idx, params, ndv, ngv); \
+  }
+
+RAFT_INST_CAGRA_EXTEND(half, uint32_t);
+
+#undef RAFT_INST_CAGRA_EXTEND
+
+}  // namespace cuvs::neighbors::cagra

cpp/tests/neighbors/ann_cagra/test_half_uint32_t.cu

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright (c) 2023-2024, NVIDIA CORPORATION.
+ * SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION.
  * SPDX-License-Identifier: Apache-2.0
  */
 
@@ -13,11 +13,17 @@ typedef AnnCagraTest<float, half, std::uint32_t> AnnCagraTestF16_U32;
 TEST_P(AnnCagraTestF16_U32, AnnCagra_U32) { this->testCagra<uint32_t>(); }
 TEST_P(AnnCagraTestF16_U32, AnnCagra_I64) { this->testCagra<int64_t>(); }
 
+typedef AnnCagraAddNodesTest<float, half, std::uint32_t> AnnCagraAddNodesTestF16_U32;
+TEST_P(AnnCagraAddNodesTestF16_U32, AnnCagraAddNodes) { this->testCagra(); }
+
 typedef AnnCagraIndexMergeTest<float, half, std::uint32_t> AnnCagraIndexMergeTestF16_U32;
 TEST_P(AnnCagraIndexMergeTestF16_U32, AnnCagraIndexMerge_U32) { this->testCagra<uint32_t>(); }
 TEST_P(AnnCagraIndexMergeTestF16_U32, AnnCagraIndexMerge_I64) { this->testCagra<int64_t>(); }
 
 INSTANTIATE_TEST_CASE_P(AnnCagraTest, AnnCagraTestF16_U32, ::testing::ValuesIn(inputs));
+INSTANTIATE_TEST_CASE_P(AnnCagraAddNodesTest,
+                        AnnCagraAddNodesTestF16_U32,
+                        ::testing::ValuesIn(inputs_addnode));
 INSTANTIATE_TEST_CASE_P(AnnCagraIndexMergeTest,
                         AnnCagraIndexMergeTestF16_U32,
                         ::testing::ValuesIn(inputs));

python/cuvs/cuvs/tests/test_cagra.py

@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: Copyright (c) 2024-2025, NVIDIA CORPORATION.
+# SPDX-FileCopyrightText: Copyright (c) 2024-2026, NVIDIA CORPORATION.
 # SPDX-License-Identifier: Apache-2.0
 #
 
@@ -182,6 +182,7 @@ def test_filtered_cagra(sparsity):
     "params",
     [
         {
+            "dtype": np.int8,
             "intermediate_graph_degree": 64,
             "graph_degree": 32,
             "test_extend": False,
@@ -190,6 +191,7 @@ def test_filtered_cagra(sparsity):
             "build_algo": "ivf_pq",
         },
         {
+            "dtype": np.float32,
             "intermediate_graph_degree": 32,
             "graph_degree": 16,
             "test_extend": True,
@@ -198,6 +200,7 @@ def test_filtered_cagra(sparsity):
             "build_algo": "ivf_pq",
         },
         {
+            "dtype": np.float32,
             "intermediate_graph_degree": 128,
             "graph_degree": 32,
             "test_extend": False,
@@ -206,6 +209,7 @@ def test_filtered_cagra(sparsity):
             "build_algo": "nn_descent",
         },
         {
+            "dtype": np.float16,
             "intermediate_graph_degree": 64,
             "graph_degree": 32,
             "test_extend": True,
@@ -219,6 +223,7 @@ def test_cagra_index_params(params):
     # Note that inner_product tests use normalized input which we cannot
     # represent in int8, therefore we test only sqeuclidean metric here.
     run_cagra_build_search_test(
+        dtype=params["dtype"],
         test_extend=params["test_extend"],
         k=params["k"],
         metric=params["metric"],