cpython/Modules/rotatingtree.c

#include "Python.h"
#include "rotatingtree.h"

#define KEY_LOWER_THAN(key1, key2) …

/* The randombits() function below is a fast-and-dirty generator that
 * is probably irregular enough for our purposes.  Note that it's biased:
 * I think that ones are slightly more probable than zeroes.  It's not
 * important here, though.
 */

static unsigned int random_value = …;
static unsigned int random_stream = …;
static PyMutex random_mutex = …;

static int
randombits(int bits)
{ … }


/* Insert a new node into the tree.
   (*root) is modified to point to the new root. */
void
RotatingTree_Add(rotating_node_t **root, rotating_node_t *node)
{ … }

/* Locate the node with the given key.  This is the most complicated
   function because it occasionally rebalances the tree to move the
   resulting node closer to the root. */
rotating_node_t *
RotatingTree_Get(rotating_node_t **root, void *key)
{ … }

/* Enumerate all nodes in the tree.  The callback enumfn() should return
   zero to continue the enumeration, or non-zero to interrupt it.
   A non-zero value is directly returned by RotatingTree_Enum(). */
int
RotatingTree_Enum(rotating_node_t *root, rotating_tree_enum_fn enumfn,
                  void *arg)
{ … }