static inline void create_split()

in src/annoylib.h [759:792]

• 32 lines of code
• 12 McCabe index (conditional complexity)

  static inline void create_split(const vector<Node<S, T>*>& nodes, int f, size_t s, Random& random, Node<S, T>* n) {
    size_t cur_size = 0;
    size_t i = 0;
    int dim = f * 8 * sizeof(T);
    for (; i < max_iterations; i++) {
      // choose random position to split at
      n->v[0] = random.index(dim);
      cur_size = 0;
      for (typename vector<Node<S, T>*>::const_iterator it = nodes.begin(); it != nodes.end(); ++it) {
        if (margin(n, (*it)->v, f)) {
          cur_size++;
        }
      }
      if (cur_size > 0 && cur_size < nodes.size()) {
        break;
      }
    }
    // brute-force search for splitting coordinate
    if (i == max_iterations) {
      int j = 0;
      for (; j < dim; j++) {
        n->v[0] = j;
        cur_size = 0;
        for (typename vector<Node<S, T>*>::const_iterator it = nodes.begin(); it != nodes.end(); ++it) {
          if (margin(n, (*it)->v, f)) {
            cur_size++;
          }
        }
        if (cur_size > 0 && cur_size < nodes.size()) {
          break;
        }
      }
    }
  }