Add serialization API to brute-force

cpp/include/cuvs/neighbors/brute_force.hpp

@@ -47,6 +47,14 @@ struct index : cuvs::neighbors::index {
   index& operator=(index&&)      = default;
   ~index()                       = default;
 
+  /**
+   * @brief Construct an empty index.
+   *
+   * Constructs an empty index. This index will either need to be trained with `build`
+   * or loaded from a saved copy with `deserialize`
+   */
+  index(raft::resources const& handle);
+
   /** Construct a brute force index from dataset
    *
    * Constructs a brute force index from a dataset. This lets us precompute norms for
@@ -371,6 +379,124 @@ void search(raft::resources const& handle,
             raft::device_matrix_view<float, int64_t, raft::row_major> distances,
             const cuvs::neighbors::filtering::base_filter& sample_filter =
               cuvs::neighbors::filtering::none_sample_filter{});
+
+/**
+ * Save the index to file.
+ *
+ * Experimental, both the API and the serialization format are subject to change.
+ *
+ * @code{.cpp}
+ * #include <raft/core/resources.hpp>
+ * #include <cuvs/neighbors/brute_force.hpp>
+ *
+ * raft::resources handle;
+ *
+ * // create a string with a filepath
+ * std::string filename("/path/to/index");
+ * // create an index with `auto index = brute_force::build(...);`
+ * cuvs::neighbors::brute_force::serialize(handle, filename, index);
+ * @endcode
+ *
+ * @tparam T data element type
+ *
+ * @param[in] handle the raft handle
+ * @param[in] filename the file name for saving the index
+ * @param[in] index brute force index
+ * @param[in] include_dataset whether to include the dataset in the serialized
+ * output
+ *
+ */
+void serialize(raft::resources const& handle,
+               const std::string& filename,
+               const cuvs::neighbors::brute_force::index<half, float>& index,
+               bool include_dataset = true);
+/**
+ * Save the index to file.
+ *
+ * Experimental, both the API and the serialization format are subject to change.
+ *
+ * @code{.cpp}
+ * #include <raft/core/resources.hpp>
+ * #include <cuvs/neighbors/brute_force.hpp>
+ *
+ * raft::resources handle;
+ *
+ * // create a string with a filepath
+ * std::string filename("/path/to/index");
+ * // create an index with `auto index = brute_force::build(...);`
+ * cuvs::neighbors::brute_force::serialize(handle, filename, index);
+ * @endcode
+ *
+ * @tparam T data element type
+ *
+ * @param[in] handle the raft handle
+ * @param[in] filename the file name for saving the index
+ * @param[in] index brute force index
+ * @param[in] include_dataset whether to include the dataset in the serialized
+ * output
+ *
+ */
+void serialize(raft::resources const& handle,
+               const std::string& filename,
+               const cuvs::neighbors::brute_force::index<float, float>& index,
+               bool include_dataset = true);
+/**
+ * Load index from file.
+ *
+ * Experimental, both the API and the serialization format are subject to change.
+ *
+ * @code{.cpp}
+ * #include <raft/core/resources.hpp>
+ * #include <cuvs/neighbors/brute_force.hpp>
+ *
+ * raft::resources handle;
+ *
+ * // create a string with a filepath
+ * std::string filename("/path/to/index");
+ * using T    = half; // data element type
+ * brute_force::index<T, float> index(handle);
+ * cuvs::neighbors::brute_force::deserialize(handle, filename, index);
+ * @endcode
+ *
+ * @param[in] handle the raft handle
+ * @param[in] filename the name of the file that stores the index
+ * @param[out] index brute force index
+ *
+ */
+void deserialize(raft::resources const& handle,
+                 const std::string& filename,
+                 cuvs::neighbors::brute_force::index<half, float>* index);
+/**
+ * Load index from file.
+ *
+ * Experimental, both the API and the serialization format are subject to change.
+ *
+ * @code{.cpp}
+ * #include <raft/core/resources.hpp>
+ * #include <raft/neighbors/brute_force_serialize.cuh>
+ *
+ * raft::resources handle;
+ *
+ * // create a string with a filepath
+ * std::string filename("/path/to/index");
+ * using T    = float; // data element type
+ * brute_force::index<T, float> index(handle);
+ * cuvs::neighbors::brute_force::deserialize(handle, filename, index);
+ * @endcode
+ *
+ * @param[in] handle the raft handle
+ * @param[in] filename the name of the file that stores the index
+ * @param[out] index brute force index
+ *
+ */
+void deserialize(raft::resources const& handle,
+                 const std::string& filename,
+                 cuvs::neighbors::brute_force::index<float, float>* index);
+
+/**@}*/
+
+}  // namespace raft::neighbors::brute_force
+
 /**
  * @}
  */