text: /**
   * Copyright (c) Facebook, Inc. and its affiliates.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */
  
  // Copyright 2004-present Facebook. All Rights Reserved.
  // -*- c -*-
  
  #ifndef FAISS_AUTO_TUNE_C_H
  #define FAISS_AUTO_TUNE_C_H
  
  #include "faiss_c.h"
  #include "Index_c.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /// possible values of a parameter, sorted from least to most expensive/accurate
  FAISS_DECLARE_CLASS(ParameterRange)
  
  FAISS_DECLARE_GETTER(ParameterRange, const char*, name)
  
  /// Getter for the values in the range. The output values are invalidated
  /// upon any other modification of the range.
  void faiss_ParameterRange_values(FaissParameterRange*, double**, size_t*);
  
  /** Uses a-priori knowledge on the Faiss indexes to extract tunable parameters.
   */
  FAISS_DECLARE_CLASS(ParameterSpace)
  
  FAISS_DECLARE_DESTRUCTOR(ParameterSpace)
  
  /// Parameter space default constructor
  int faiss_ParameterSpace_new(FaissParameterSpace** space);
  
  /// nb of combinations, = product of values sizes
  size_t faiss_ParameterSpace_n_combinations(const FaissParameterSpace*);
  
  /// get string representation of the combination
  /// by writing it to the given character buffer.
  /// A buffer size of 1000 ensures that the full name is collected.
  int faiss_ParameterSpace_combination_name(const FaissParameterSpace*, size_t, char*, size_t);
  
  /// set a combination of parameters described by a string
  int faiss_ParameterSpace_set_index_parameters(const FaissParameterSpace*, FaissIndex*, const char *);
  
  /// set a combination of parameters on an index
  int faiss_ParameterSpace_set_index_parameters_cno(const FaissParameterSpace*, FaissIndex*, size_t);
  
  /// set one of the parameters
  int faiss_ParameterSpace_set_index_parameter(const FaissParameterSpace*, FaissIndex*, const char *, double);
  
  /// print a description on stdout
  void faiss_ParameterSpace_display(const FaissParameterSpace*);
  
  /// add a new parameter (or return it if it exists)
  int faiss_ParameterSpace_add_range(FaissParameterSpace*, const char*, FaissParameterRange**);
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif