* Authors:
* Florian octo Forster <octo at verplant.org>
**/
+
+#include "config.h"
+
#include <stdlib.h>
#include <stdio.h>
+#include <string.h>
#include <assert.h>
#include "utils_avltree.h"
/*
* private data types
*/
-struct avl_node_s
+struct c_avl_node_s
{
void *key;
void *value;
int height;
- struct avl_node_s *left;
- struct avl_node_s *right;
- struct avl_node_s *parent;
+ struct c_avl_node_s *left;
+ struct c_avl_node_s *right;
+ struct c_avl_node_s *parent;
};
-typedef struct avl_node_s avl_node_t;
+typedef struct c_avl_node_s c_avl_node_t;
-struct avl_tree_s
+struct c_avl_tree_s
{
- avl_node_t *root;
+ c_avl_node_t *root;
int (*compare) (const void *, const void *);
};
-struct avl_iterator_s
+struct c_avl_iterator_s
{
- avl_tree_t *tree;
- avl_node_t *node;
+ c_avl_tree_t *tree;
+ c_avl_node_t *node;
};
/*
* private functions
*/
#if 0
-static void verify_tree (avl_node_t *n)
+static void verify_tree (c_avl_node_t *n)
{
if (n == NULL)
return;
# define verify_tree(n) /**/
#endif
-static void free_node (avl_node_t *n)
+static void free_node (c_avl_node_t *n)
{
if (n == NULL)
return;
free (n);
}
-static int calc_height (avl_node_t *n)
+static int calc_height (c_avl_node_t *n)
{
int height_left;
int height_right;
: height_right) + 1);
} /* int calc_height */
-static avl_node_t *search (avl_tree_t *t, const void *key)
+static c_avl_node_t *search (c_avl_tree_t *t, const void *key)
{
- avl_node_t *n;
+ c_avl_node_t *n;
int cmp;
n = t->root;
* / a\ /_b\ /_b\ /_c\
* /____\
*/
-static avl_node_t *rotate_right (avl_tree_t *t, avl_node_t *x)
+static c_avl_node_t *rotate_right (c_avl_tree_t *t, c_avl_node_t *x)
{
- avl_node_t *p;
- avl_node_t *y;
- avl_node_t *b;
+ c_avl_node_t *p;
+ c_avl_node_t *y;
+ c_avl_node_t *b;
p = x->parent;
y = x->left;
* /_b\ / c\ /_a\ /_b\
* /____\
*/
-static avl_node_t *rotate_left (avl_tree_t *t, avl_node_t *x)
+static c_avl_node_t *rotate_left (c_avl_tree_t *t, c_avl_node_t *x)
{
- avl_node_t *p;
- avl_node_t *y;
- avl_node_t *b;
+ c_avl_node_t *p;
+ c_avl_node_t *y;
+ c_avl_node_t *b;
p = x->parent;
y = x->right;
return (y);
} /* void rotate_left */
-static avl_node_t *rotate_left_right (avl_tree_t *t, avl_node_t *x)
+static c_avl_node_t *rotate_left_right (c_avl_tree_t *t, c_avl_node_t *x)
{
rotate_left (t, x->left);
return (rotate_right (t, x));
} /* void rotate_left_right */
-static avl_node_t *rotate_right_left (avl_tree_t *t, avl_node_t *x)
+static c_avl_node_t *rotate_right_left (c_avl_tree_t *t, c_avl_node_t *x)
{
rotate_right (t, x->right);
return (rotate_left (t, x));
} /* void rotate_right_left */
-static void rebalance (avl_tree_t *t, avl_node_t *n)
+static void rebalance (c_avl_tree_t *t, c_avl_node_t *n)
{
int b_top;
int b_bottom;
} /* while (n != NULL) */
} /* void rebalance */
-static avl_iterator_t *avl_create_iterator (avl_tree_t *t, avl_node_t *n)
-{
- avl_iterator_t *iter;
-
- iter = (avl_iterator_t *) malloc (sizeof (avl_iterator_t));
- if (iter == NULL)
- return (NULL);
-
- iter->tree = t;
- iter->node = n;
-
- return (iter);
-}
-
-void *avl_node_next (avl_tree_t *t, avl_node_t *n)
+static c_avl_node_t *c_avl_node_next (c_avl_node_t *n)
{
- avl_node_t *r; /* return node */
+ c_avl_node_t *r; /* return node */
if (n == NULL)
{
return (NULL);
}
- else if (n->right == NULL)
- {
+ /* If we can't descent any further, we have to backtrack to the first
+ * parent that's bigger than we, i. e. who's _left_ child we are. */
+ if (n->right == NULL)
+ {
r = n->parent;
- while (r != NULL)
+ while ((r != NULL) && (r->parent != NULL))
{
- /* stop if a bigger node is found */
- if (t->compare (n, r) < 0) /* n < r */
+ if (r->left == n)
break;
- r = r->parent;
+ n = r;
+ r = n->parent;
+ }
+
+ /* n->right == NULL && r == NULL => t is root and has no next
+ * r->left != n => r->right = n => r->parent == NULL */
+ if ((r == NULL) || (r->left != n))
+ {
+ assert ((r == NULL) || (r->parent == NULL));
+ return (NULL);
+ }
+ else
+ {
+ assert (r->left == n);
+ return (r);
}
}
else
}
return (r);
-}
+} /* c_avl_node_t *c_avl_node_next */
-void *avl_node_prev (avl_tree_t *t, avl_node_t *n)
+static c_avl_node_t *c_avl_node_prev (c_avl_node_t *n)
{
- avl_node_t *r; /* return node */
+ c_avl_node_t *r; /* return node */
if (n == NULL)
{
return (NULL);
}
- else if (n->left == NULL)
- {
+ /* If we can't descent any further, we have to backtrack to the first
+ * parent that's smaller than we, i. e. who's _right_ child we are. */
+ if (n->left == NULL)
+ {
r = n->parent;
- while (r != NULL)
+ while ((r != NULL) && (r->parent != NULL))
{
- /* stop if a smaller node is found */
- if (t->compare (n, r) > 0) /* n > r */
+ if (r->right == n)
break;
- r = r->parent;
+ n = r;
+ r = n->parent;
+ }
+
+ /* n->left == NULL && r == NULL => t is root and has no next
+ * r->right != n => r->left = n => r->parent == NULL */
+ if ((r == NULL) || (r->right != n))
+ {
+ assert ((r == NULL) || (r->parent == NULL));
+ return (NULL);
+ }
+ else
+ {
+ assert (r->right == n);
+ return (r);
}
}
else
}
return (r);
-} /* void *avl_node_prev */
+} /* c_avl_node_t *c_avl_node_prev */
-static int _remove (avl_tree_t *t, avl_node_t *n)
+static int _remove (c_avl_tree_t *t, c_avl_node_t *n)
{
assert ((t != NULL) && (n != NULL));
if ((n->left != NULL) && (n->right != NULL))
{
- avl_node_t *r; /* replacement node */
+ c_avl_node_t *r; /* replacement node */
if (BALANCE (n) > 0) /* left subtree is higher */
{
assert (n->left != NULL);
- r = avl_node_prev (t, n);
+ r = c_avl_node_prev (n);
}
else /* right subtree is higher */
{
assert (n->right != NULL);
- r = avl_node_next (t, n);
+ r = c_avl_node_next (n);
}
assert ((r->left == NULL) || (r->right == NULL));
/*
* public functions
*/
-avl_tree_t *avl_create (int (*compare) (const void *, const void *))
+c_avl_tree_t *c_avl_create (int (*compare) (const void *, const void *))
{
- avl_tree_t *t;
+ c_avl_tree_t *t;
- if ((t = (avl_tree_t *) malloc (sizeof (avl_tree_t))) == NULL)
+ if (compare == NULL)
+ return (NULL);
+
+ if ((t = (c_avl_tree_t *) malloc (sizeof (c_avl_tree_t))) == NULL)
return (NULL);
t->root = NULL;
return (t);
}
-void avl_destroy (avl_tree_t *t)
+void c_avl_destroy (c_avl_tree_t *t)
{
free_node (t->root);
free (t);
}
-int avl_insert (avl_tree_t *t, void *key, void *value)
+int c_avl_insert (c_avl_tree_t *t, void *key, void *value)
{
- avl_node_t *new;
- avl_node_t *nptr;
+ c_avl_node_t *new;
+ c_avl_node_t *nptr;
int cmp;
- if ((new = (avl_node_t *) malloc (sizeof (avl_node_t))) == NULL)
+ if ((new = (c_avl_node_t *) malloc (sizeof (c_avl_node_t))) == NULL)
return (-1);
new->key = key;
if (cmp == 0)
{
free_node (new);
- return (-1);
+ return (1);
}
else if (cmp < 0)
{
verify_tree (t->root);
return (0);
-} /* int avl_insert */
+} /* int c_avl_insert */
-int avl_remove (avl_tree_t *t, void *key, void **rkey, void **rvalue)
+int c_avl_remove (c_avl_tree_t *t, const void *key, void **rkey, void **rvalue)
{
- avl_node_t *n;
+ c_avl_node_t *n;
int status;
assert (t != NULL);
status = _remove (t, n);
verify_tree (t->root);
return (status);
-} /* void *avl_remove */
+} /* void *c_avl_remove */
-int avl_get (avl_tree_t *t, const void *key, void **value)
+int c_avl_get (c_avl_tree_t *t, const void *key, void **value)
{
- avl_node_t *n;
+ c_avl_node_t *n;
- assert (value != NULL);
+ assert (t != NULL);
n = search (t, key);
if (n == NULL)
return (-1);
- *value = n->value;
+ if (value != NULL)
+ *value = n->value;
return (0);
}
-avl_iterator_t *avl_get_iterator (avl_tree_t *t)
+int c_avl_pick (c_avl_tree_t *t, void **key, void **value)
{
- avl_node_t *n;
-
- if (t == NULL)
- return (NULL);
-
- for (n = t->root; n != NULL; n = n->left)
- if (n->left == NULL)
- break;
+ c_avl_node_t *n;
+ c_avl_node_t *p;
- return (avl_create_iterator (t, n));
-} /* avl_iterator_t *avl_get_iterator */
-
-int avl_pick (avl_tree_t *t, void **key, void **value)
-{
- avl_node_t *n;
- avl_node_t *p;
-
- assert ((key != NULL) && (value != NULL));
+ if ((key == NULL) || (value == NULL))
+ return (-1);
if (t->root == NULL)
return (-1);
rebalance (t, p);
return (0);
-} /* int avl_pick */
+} /* int c_avl_pick */
-void *avl_iterator_next (avl_iterator_t *iter)
+c_avl_iterator_t *c_avl_get_iterator (c_avl_tree_t *t)
{
- avl_node_t *n;
+ c_avl_iterator_t *iter;
+
+ if (t == NULL)
+ return (NULL);
- if ((iter == NULL) || (iter->node == NULL))
+ iter = (c_avl_iterator_t *) malloc (sizeof (c_avl_iterator_t));
+ if (iter == NULL)
return (NULL);
+ memset (iter, '\0', sizeof (c_avl_iterator_t));
+ iter->tree = t;
+
+ return (iter);
+} /* c_avl_iterator_t *c_avl_get_iterator */
- n = avl_node_next (iter->tree, iter->node);
+int c_avl_iterator_next (c_avl_iterator_t *iter, void **key, void **value)
+{
+ c_avl_node_t *n;
+
+ if ((iter == NULL) || (key == NULL) || (value == NULL))
+ return (-1);
+
+ if (iter->node == NULL)
+ {
+ for (n = iter->tree->root; n != NULL; n = n->left)
+ if (n->left == NULL)
+ break;
+ iter->node = n;
+ }
+ else
+ {
+ n = c_avl_node_next (iter->node);
+ }
if (n == NULL)
- return (NULL);
+ return (-1);
iter->node = n;
- return (n);
+ *key = n->key;
+ *value = n->value;
-}
+ return (0);
+} /* int c_avl_iterator_next */
-void *avl_iterator_prev (avl_iterator_t *iter)
+int c_avl_iterator_prev (c_avl_iterator_t *iter, void **key, void **value)
{
- avl_node_t *n;
+ c_avl_node_t *n;
- if ((iter == NULL) || (iter->node == NULL))
- return (NULL);
+ if ((iter == NULL) || (key == NULL) || (value == NULL))
+ return (-1);
- n = avl_node_prev (iter->tree, iter->node);
+ if (iter->node == NULL)
+ {
+ for (n = iter->tree->root; n != NULL; n = n->left)
+ if (n->right == NULL)
+ break;
+ iter->node = n;
+ }
+ else
+ {
+ n = c_avl_node_prev (iter->node);
+ }
if (n == NULL)
- return (NULL);
+ return (-1);
iter->node = n;
- return (n);
+ *key = n->key;
+ *value = n->value;
-}
+ return (0);
+} /* int c_avl_iterator_prev */
-void avl_iterator_destroy (avl_iterator_t *iter)
+void c_avl_iterator_destroy (c_avl_iterator_t *iter)
{
free (iter);
}
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