Initial commit

packages/leann-backend-hnsw/third_party/faiss/c_api/faiss_c.h

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+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// -*- c -*-
+
+/// Macros and typedefs for C wrapper API declarations
+
+#ifndef FAISS_C_H
+#define FAISS_C_H
+
+#include <stdint.h>
+
+typedef int64_t faiss_idx_t; ///< all indices are this type
+typedef faiss_idx_t idx_t;
+typedef float faiss_component_t; ///< all vector components are this type
+typedef float faiss_distance_t; ///< all distances between vectors are this type
+
+/// Declare an opaque type for a class type `clazz`.
+#define FAISS_DECLARE_CLASS(clazz) typedef struct Faiss##clazz##_H Faiss##clazz;
+
+/// Declare an opaque type for a class type `clazz`, while
+/// actually aliasing it to an existing parent class type `parent`.
+#define FAISS_DECLARE_CLASS_INHERITED(clazz, parent) \
+    typedef struct Faiss##parent##_H Faiss##clazz;
+
+/// Declare a dynamic downcast operation from a base `FaissIndex*` pointer
+/// type to a more specific index type. The function returns the same pointer
+/// if the downcast is valid, and `NULL` otherwise.
+#define FAISS_DECLARE_INDEX_DOWNCAST(clazz) \
+    Faiss##clazz* faiss_##clazz##_cast(FaissIndex*);
+
+/// Declare a dynamic downcast operation from a base `FaissSearchParameters*`
+/// pointer type to a more specific search parameters type. The function returns
+/// the same pointer if the downcast is valid, and `NULL` otherwise.
+#define FAISS_DECLARE_SEARCH_PARAMETERS_DOWNCAST(clazz) \
+    Faiss##clazz* faiss_##clazz##_cast(FaissSearchParameters*);
+
+/// Declare a getter for the field `name` in class `clazz`,
+/// of return type `ty`
+#define FAISS_DECLARE_GETTER(clazz, ty, name) \
+    ty faiss_##clazz##_##name(const Faiss##clazz*);
+
+/// Declare a setter for the field `name` in class `clazz`,
+/// in which the user provides a value of type `ty`
+#define FAISS_DECLARE_SETTER(clazz, ty, name) \
+    void faiss_##clazz##_set_##name(Faiss##clazz*, ty);
+
+/// Declare a getter and setter for the field `name` in class `clazz`.
+#define FAISS_DECLARE_GETTER_SETTER(clazz, ty, name) \
+    FAISS_DECLARE_GETTER(clazz, ty, name)            \
+    FAISS_DECLARE_SETTER(clazz, ty, name)
+
+/// Declare a destructor function which frees an object of
+/// type `clazz`.
+#define FAISS_DECLARE_DESTRUCTOR(clazz) \
+    void faiss_##clazz##_free(Faiss##clazz* obj);
+
+#endif