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+/* Copyright (c) 2000, 2016, Oracle and/or its affiliates.
+ Copyright (c) 2010, 2016, MariaDB
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
+
+/*
+ Code for handling red-black (balanced) binary trees.
+ key in tree is allocated accrding to following:
+
+ 1) If size < 0 then tree will not allocate keys and only a pointer to
+ each key is saved in tree.
+ compare and search functions uses and returns key-pointer
+
+ 2) If size == 0 then there are two options:
+ - key_size != 0 to tree_insert: The key will be stored in the tree.
+ - key_size == 0 to tree_insert: A pointer to the key is stored.
+ compare and search functions uses and returns key-pointer.
+
+ 3) if key_size is given to init_tree then each node will continue the
+ key and calls to insert_key may increase length of key.
+ if key_size > sizeof(pointer) and key_size is a multiple of 8 (double
+ align) then key will be put on a 8 aligned address. Else
+ the key will be on address (element+1). This is transparent for user
+ compare and search functions uses a pointer to given key-argument.
+
+ - If you use a free function for tree-elements and you are freeing
+ the element itself, you should use key_size = 0 to init_tree and
+ tree_search
+
+ The actual key in TREE_ELEMENT is saved as a pointer or after the
+ TREE_ELEMENT struct.
+ If one uses only pointers in tree one can use tree_set_pointer() to
+ change address of data.
+
+ Implemented by monty.
+*/
+
+/*
+ NOTE:
+ tree->compare function should be ALWAYS called as
+ (*tree->compare)(custom_arg, ELEMENT_KEY(tree,element), key)
+ and not other way around, as
+ (*tree->compare)(custom_arg, key, ELEMENT_KEY(tree,element))
+
+ ft_boolean_search.c (at least) relies on that.
+*/
+
+#include "mysys_priv.h"
+#include <m_string.h>
+#include <my_tree.h>
+#include "my_base.h"
+
+#define BLACK 1
+#define RED 0
+#define DEFAULT_ALLOC_SIZE 8192
+#define DEFAULT_ALIGN_SIZE 8192
+
+static int delete_tree_element(TREE *,TREE_ELEMENT *, my_bool abort);
+static int tree_walk_left_root_right(TREE *,TREE_ELEMENT *,
+ tree_walk_action,void *);
+static int tree_walk_right_root_left(TREE *,TREE_ELEMENT *,
+ tree_walk_action,void *);
+static void left_rotate(TREE_ELEMENT **parent,TREE_ELEMENT *leaf);
+static void right_rotate(TREE_ELEMENT **parent, TREE_ELEMENT *leaf);
+static void rb_insert(TREE *tree,TREE_ELEMENT ***parent,
+ TREE_ELEMENT *leaf);
+static void rb_delete_fixup(TREE *tree,TREE_ELEMENT ***parent);
+
+static TREE_ELEMENT null_element= { NULL, NULL, 0, BLACK };
+
+/* The actual code for handling binary trees */
+
+#ifndef DBUG_OFF
+static int test_rb_tree(TREE_ELEMENT *element);
+#endif
+
+void init_tree(TREE *tree, size_t default_alloc_size, size_t memory_limit,
+ int size, qsort_cmp2 compare,
+ tree_element_free free_element, void *custom_arg,
+ myf my_flags)
+{
+ DBUG_ENTER("init_tree");
+ DBUG_PRINT("enter",("tree: %p size: %d", tree, size));
+
+ if (default_alloc_size < DEFAULT_ALLOC_SIZE)
+ default_alloc_size= DEFAULT_ALLOC_SIZE;
+ default_alloc_size= MY_ALIGN(default_alloc_size, DEFAULT_ALIGN_SIZE);
+ tree->root= &null_element;
+ tree->compare=compare;
+ tree->size_of_element= size > 0 ? (uint) size : 0;
+ tree->memory_limit=memory_limit;
+ tree->free=free_element;
+ tree->allocated=0;
+ tree->elements_in_tree=0;
+ tree->custom_arg = custom_arg;
+ tree->my_flags= my_flags;
+ tree->flag= 0;
+ if (!free_element && size >= 0 &&
+ ((uint) size <= sizeof(void*) || ((uint) size & (sizeof(void*)-1))))
+ {
+ /*
+ We know that the data doesn't have to be aligned (like if the key
+ contains a double), so we can store the data combined with the
+ TREE_ELEMENT.
+ */
+ tree->offset_to_key=sizeof(TREE_ELEMENT); /* Put key after element */
+ /* Fix allocation size so that we don't lose any memory */
+ default_alloc_size/=(sizeof(TREE_ELEMENT)+size);
+ if (!default_alloc_size)
+ default_alloc_size=1;
+ default_alloc_size*=(sizeof(TREE_ELEMENT)+size);
+ }
+ else
+ {
+ tree->offset_to_key=0; /* use key through pointer */
+ tree->size_of_element+=sizeof(void*);
+ }
+ if (!(tree->with_delete= MY_TEST(my_flags & MY_TREE_WITH_DELETE)))
+ {
+ init_alloc_root(key_memory_TREE, &tree->mem_root, default_alloc_size, 0,
+ MYF(my_flags));
+ tree->mem_root.min_malloc= sizeof(TREE_ELEMENT)+tree->size_of_element;
+ }
+ DBUG_VOID_RETURN;
+}
+
+static int free_tree(TREE *tree, my_bool abort, myf free_flags)
+{
+ int error, first_error= 0;
+ DBUG_ENTER("free_tree");
+ DBUG_PRINT("enter",("tree: %p", tree));
+
+ if (tree->root) /* If initialized */
+ {
+ if (tree->with_delete)
+ {
+ if ((error= delete_tree_element(tree, tree->root, abort)))
+ {
+ first_error= first_error ? first_error : error;
+ abort= 1;
+ }
+ }
+ else
+ {
+ if (tree->free)
+ {
+ if (tree->memory_limit)
+ (*tree->free)(NULL, free_init, tree->custom_arg);
+ if ((error= delete_tree_element(tree, tree->root, abort)))
+ first_error= first_error ? first_error : error;
+ if (tree->memory_limit)
+ (*tree->free)(NULL, free_end, tree->custom_arg);
+ }
+ free_root(&tree->mem_root, free_flags);
+ }
+ }
+ tree->root= &null_element;
+ tree->elements_in_tree=0;
+ tree->allocated=0;
+
+ DBUG_RETURN(first_error);
+}
+
+
+/**
+ Delete tree.
+
+ @param tree Tree
+ @param abort 0 if normal, 1 if tree->free should not be called.
+
+ @return 0 ok
+ <> 0 Returns first <> 0 from (tree->free)(*,free_free,*)
+
+ @Notes
+ If one (tree->free)(,free_free,) returns <> 0, no future
+ tree->free(*,free_free,*) will be called.
+ Other tree->free operations (free_init, free_end) will be called
+*/
+
+
+int delete_tree(TREE* tree, my_bool abort)
+{
+ return free_tree(tree, abort, MYF(0)); /* my_free() mem_root if applicable */
+}
+
+int reset_tree(TREE* tree)
+{
+ /* do not free mem_root, just mark blocks as free */
+ return free_tree(tree, 0, MYF(MY_MARK_BLOCKS_FREE));
+}
+
+
+static int delete_tree_element(TREE *tree, TREE_ELEMENT *element,
+ my_bool abort)
+{
+ int error, first_error= 0;
+ if (element != &null_element)
+ {
+ if ((first_error= delete_tree_element(tree, element->left, abort)))
+ abort= 1;
+ if (!abort && tree->free)
+ {
+ if ((error= (*tree->free)(ELEMENT_KEY(tree,element), free_free,
+ tree->custom_arg)))
+ {
+ first_error= first_error ? first_error : error;
+ abort= 1;
+ }
+ }
+ if ((error= delete_tree_element(tree, element->right, abort)))
+ first_error= first_error ? first_error : error;
+ if (tree->with_delete)
+ my_free(element);
+ }
+ return first_error;
+}
+
+
+/*
+ insert, search and delete of elements
+
+ The following should be true:
+ parent[0] = & parent[-1][0]->left ||
+ parent[0] = & parent[-1][0]->right
+*/
+
+TREE_ELEMENT *tree_insert(TREE *tree, void *key, uint key_size,
+ void* custom_arg)
+{
+ int cmp;
+ TREE_ELEMENT *element,***parent;
+
+ parent= tree->parents;
+ *parent = &tree->root; element= tree->root;
+ for (;;)
+ {
+ if (element == &null_element ||
+ (cmp = (*tree->compare)(custom_arg, ELEMENT_KEY(tree,element),
+ key)) == 0)
+ break;
+ if (cmp < 0)
+ {
+ *++parent= &element->right; element= element->right;
+ }
+ else
+ {
+ *++parent = &element->left; element= element->left;
+ }
+ }
+ if (element == &null_element)
+ {
+ uint alloc_size;
+ if (tree->flag & TREE_ONLY_DUPS)
+ return TREE_ELEMENT_UNIQUE;
+ alloc_size=sizeof(TREE_ELEMENT)+key_size+tree->size_of_element;
+ tree->allocated+=alloc_size;
+
+ if (tree->memory_limit && tree->elements_in_tree
+ && tree->allocated > tree->memory_limit)
+ {
+ reset_tree(tree);
+ return tree_insert(tree, key, key_size, custom_arg);
+ }
+
+ key_size+=tree->size_of_element;
+ if (tree->with_delete)
+ element=(TREE_ELEMENT *) my_malloc(key_memory_TREE, alloc_size,
+ MYF(tree->my_flags | MY_WME));
+ else
+ element=(TREE_ELEMENT *) alloc_root(&tree->mem_root,alloc_size);
+ if (!element)
+ return(NULL);
+ **parent=element;
+ element->left=element->right= &null_element;
+ if (!tree->offset_to_key)
+ {
+ if (key_size == sizeof(void*)) /* no length, save pointer */
+ *((void**) (element+1))=key;
+ else
+ {
+ *((void**) (element+1))= (void*) ((void **) (element+1)+1);
+ memcpy((uchar*) *((void **) (element+1)),key,
+ (size_t) (key_size-sizeof(void*)));
+ }
+ }
+ else
+ memcpy((uchar*) element+tree->offset_to_key,key,(size_t) key_size);
+ element->count=1; /* May give warning in purify */
+ tree->elements_in_tree++;
+ rb_insert(tree,parent,element); /* rebalance tree */
+ }
+ else
+ {
+ if (tree->flag & TREE_NO_DUPS)
+ return(NULL);
+ element->count++;
+ /* Avoid a wrap over of the count. */
+ if (! element->count)
+ element->count--;
+ }
+ DBUG_EXECUTE("check_tree", test_rb_tree(tree->root););
+ return element;
+}
+
+int tree_delete(TREE *tree, void *key, uint key_size, void *custom_arg)
+{
+ int cmp,remove_colour;
+ TREE_ELEMENT *element,***parent, ***org_parent, *nod;
+ if (!tree->with_delete)
+ return 1; /* not allowed */
+
+ parent= tree->parents;
+ *parent= &tree->root; element= tree->root;
+ for (;;)
+ {
+ if (element == &null_element)
+ return 1; /* Was not in tree */
+ if ((cmp = (*tree->compare)(custom_arg, ELEMENT_KEY(tree,element),
+ key)) == 0)
+ break;
+ if (cmp < 0)
+ {
+ *++parent= &element->right; element= element->right;
+ }
+ else
+ {
+ *++parent = &element->left; element= element->left;
+ }
+ }
+ if (element->left == &null_element)
+ {
+ (**parent)=element->right;
+ remove_colour= element->colour;
+ }
+ else if (element->right == &null_element)
+ {
+ (**parent)=element->left;
+ remove_colour= element->colour;
+ }
+ else
+ {
+ org_parent= parent;
+ *++parent= &element->right; nod= element->right;
+ while (nod->left != &null_element)
+ {
+ *++parent= &nod->left; nod= nod->left;
+ }
+ (**parent)=nod->right; /* unlink nod from tree */
+ remove_colour= nod->colour;
+ org_parent[0][0]=nod; /* put y in place of element */
+ org_parent[1]= &nod->right;
+ nod->left=element->left;
+ nod->right=element->right;
+ nod->colour=element->colour;
+ }
+ if (remove_colour == BLACK)
+ rb_delete_fixup(tree,parent);
+ if (tree->free)
+ (*tree->free)(ELEMENT_KEY(tree,element), free_free, tree->custom_arg);
+ tree->allocated-= sizeof(TREE_ELEMENT) + tree->size_of_element + key_size;
+ my_free(element);
+ tree->elements_in_tree--;
+ return 0;
+}
+
+
+void *tree_search(TREE *tree, void *key, void *custom_arg)
+{
+ int cmp;
+ TREE_ELEMENT *element=tree->root;
+
+ for (;;)
+ {
+ if (element == &null_element)
+ return (void*) 0;
+ if ((cmp = (*tree->compare)(custom_arg, ELEMENT_KEY(tree,element),
+ key)) == 0)
+ return ELEMENT_KEY(tree,element);
+ if (cmp < 0)
+ element=element->right;
+ else
+ element=element->left;
+ }
+}
+
+void *tree_search_key(TREE *tree, const void *key,
+ TREE_ELEMENT **parents, TREE_ELEMENT ***last_pos,
+ enum ha_rkey_function flag, void *custom_arg)
+{
+ int cmp;
+ TREE_ELEMENT *element= tree->root;
+ TREE_ELEMENT **last_left_step_parent= NULL, **last_right_step_parent= NULL;
+ TREE_ELEMENT **last_equal_element= NULL;
+
+/*
+ TODO: support for HA_READ_KEY_OR_PREV, HA_READ_PREFIX flags if needed.
+*/
+
+ *parents = &null_element;
+ while (element != &null_element)
+ {
+ *++parents= element;
+ if ((cmp= (*tree->compare)(custom_arg, ELEMENT_KEY(tree, element),
+ key)) == 0)
+ {
+ switch (flag) {
+ case HA_READ_KEY_EXACT:
+ case HA_READ_KEY_OR_NEXT:
+ case HA_READ_BEFORE_KEY:
+ case HA_READ_KEY_OR_PREV:
+ last_equal_element= parents;
+ cmp= 1;
+ break;
+ case HA_READ_AFTER_KEY:
+ cmp= -1;
+ break;
+ case HA_READ_PREFIX_LAST:
+ case HA_READ_PREFIX_LAST_OR_PREV:
+ last_equal_element= parents;
+ cmp= -1;
+ break;
+ default:
+ return NULL;
+ }
+ }
+ if (cmp < 0) /* element < key */
+ {
+ last_right_step_parent= parents;
+ element= element->right;
+ }
+ else
+ {
+ last_left_step_parent= parents;
+ element= element->left;
+ }
+ }
+ switch (flag) {
+ case HA_READ_KEY_EXACT:
+ case HA_READ_PREFIX_LAST:
+ *last_pos= last_equal_element;
+ break;
+ case HA_READ_KEY_OR_NEXT:
+ *last_pos= last_equal_element ? last_equal_element : last_left_step_parent;
+ break;
+ case HA_READ_AFTER_KEY:
+ *last_pos= last_left_step_parent;
+ break;
+ case HA_READ_PREFIX_LAST_OR_PREV:
+ *last_pos= last_equal_element ? last_equal_element : last_right_step_parent;
+ break;
+ case HA_READ_BEFORE_KEY:
+ *last_pos= last_right_step_parent;
+ break;
+ case HA_READ_KEY_OR_PREV:
+ *last_pos= last_equal_element ? last_equal_element : last_right_step_parent;
+ break;
+ default:
+ return NULL;
+ }
+ return *last_pos ? ELEMENT_KEY(tree, **last_pos) : NULL;
+}
+
+/*
+ Search first (the most left) or last (the most right) tree element
+*/
+void *tree_search_edge(TREE *tree, TREE_ELEMENT **parents,
+ TREE_ELEMENT ***last_pos, int child_offs)
+{
+ TREE_ELEMENT *element= tree->root;
+
+ *parents= &null_element;
+ while (element != &null_element)
+ {
+ *++parents= element;
+ element= ELEMENT_CHILD(element, child_offs);
+ }
+ *last_pos= parents;
+ return **last_pos != &null_element ?
+ ELEMENT_KEY(tree, **last_pos) : NULL;
+}
+
+void *tree_search_next(TREE *tree, TREE_ELEMENT ***last_pos, int l_offs,
+ int r_offs)
+{
+ TREE_ELEMENT *x= **last_pos;
+
+ if (ELEMENT_CHILD(x, r_offs) != &null_element)
+ {
+ x= ELEMENT_CHILD(x, r_offs);
+ *++*last_pos= x;
+ while (ELEMENT_CHILD(x, l_offs) != &null_element)
+ {
+ x= ELEMENT_CHILD(x, l_offs);
+ *++*last_pos= x;
+ }
+ return ELEMENT_KEY(tree, x);
+ }
+ else
+ {
+ TREE_ELEMENT *y= *--*last_pos;
+ while (y != &null_element && x == ELEMENT_CHILD(y, r_offs))
+ {
+ x= y;
+ y= *--*last_pos;
+ }
+ return y == &null_element ? NULL : ELEMENT_KEY(tree, y);
+ }
+}
+
+/*
+ Expected that tree is fully balanced
+ (each path from root to leaf has the same length)
+*/
+ha_rows tree_record_pos(TREE *tree, const void *key,
+ enum ha_rkey_function flag, void *custom_arg)
+{
+ int cmp;
+ TREE_ELEMENT *element= tree->root;
+ double left= 1;
+ double right= tree->elements_in_tree;
+
+ while (element != &null_element)
+ {
+ if ((cmp= (*tree->compare)(custom_arg, ELEMENT_KEY(tree, element),
+ key)) == 0)
+ {
+ switch (flag) {
+ case HA_READ_KEY_EXACT:
+ case HA_READ_BEFORE_KEY:
+ cmp= 1;
+ break;
+ case HA_READ_AFTER_KEY:
+ cmp= -1;
+ break;
+ default:
+ return HA_POS_ERROR;
+ }
+ }
+ if (cmp < 0) /* element < key */
+ {
+ element= element->right;
+ left= (left + right) / 2;
+ }
+ else
+ {
+ element= element->left;
+ right= (left + right) / 2;
+ }
+ }
+ switch (flag) {
+ case HA_READ_KEY_EXACT:
+ case HA_READ_BEFORE_KEY:
+ return (ha_rows) right;
+ case HA_READ_AFTER_KEY:
+ return (ha_rows) left;
+ default:
+ return HA_POS_ERROR;
+ }
+}
+
+int tree_walk(TREE *tree, tree_walk_action action, void *argument, TREE_WALK visit)
+{
+ switch (visit) {
+ case left_root_right:
+ return tree_walk_left_root_right(tree,tree->root,action,argument);
+ case right_root_left:
+ return tree_walk_right_root_left(tree,tree->root,action,argument);
+ }
+ return 0; /* Keep gcc happy */
+}
+
+static int tree_walk_left_root_right(TREE *tree, TREE_ELEMENT *element, tree_walk_action action, void *argument)
+{
+ int error;
+ if (element->left) /* Not null_element */
+ {
+ if ((error=tree_walk_left_root_right(tree,element->left,action,
+ argument)) == 0 &&
+ (error=(*action)(ELEMENT_KEY(tree,element),
+ (element_count) element->count,
+ argument)) == 0)
+ error=tree_walk_left_root_right(tree,element->right,action,argument);
+ return error;
+ }
+ return 0;
+}
+
+static int tree_walk_right_root_left(TREE *tree, TREE_ELEMENT *element, tree_walk_action action, void *argument)
+{
+ int error;
+ if (element->right) /* Not null_element */
+ {
+ if ((error=tree_walk_right_root_left(tree,element->right,action,
+ argument)) == 0 &&
+ (error=(*action)(ELEMENT_KEY(tree,element),
+ (element_count) element->count,
+ argument)) == 0)
+ error=tree_walk_right_root_left(tree,element->left,action,argument);
+ return error;
+ }
+ return 0;
+}
+
+
+ /* Functions to fix up the tree after insert and delete */
+
+static void left_rotate(TREE_ELEMENT **parent, TREE_ELEMENT *leaf)
+{
+ TREE_ELEMENT *y;
+
+ y=leaf->right;
+ leaf->right=y->left;
+ parent[0]=y;
+ y->left=leaf;
+}
+
+static void right_rotate(TREE_ELEMENT **parent, TREE_ELEMENT *leaf)
+{
+ TREE_ELEMENT *x;
+
+ x=leaf->left;
+ leaf->left=x->right;
+ parent[0]=x;
+ x->right=leaf;
+}
+
+static void rb_insert(TREE *tree, TREE_ELEMENT ***parent, TREE_ELEMENT *leaf)
+{
+ TREE_ELEMENT *y,*par,*par2;
+
+ leaf->colour=RED;
+ while (leaf != tree->root && (par=parent[-1][0])->colour == RED)
+ {
+ if (par == (par2=parent[-2][0])->left)
+ {
+ y= par2->right;
+ if (y->colour == RED)
+ {
+ par->colour=BLACK;
+ y->colour=BLACK;
+ leaf=par2;
+ parent-=2;
+ leaf->colour=RED; /* And the loop continues */
+ }
+ else
+ {
+ if (leaf == par->right)
+ {
+ left_rotate(parent[-1],par);
+ par=leaf; /* leaf is now parent to old leaf */
+ }
+ par->colour=BLACK;
+ par2->colour=RED;
+ right_rotate(parent[-2],par2);
+ break;
+ }
+ }
+ else
+ {
+ y= par2->left;
+ if (y->colour == RED)
+ {
+ par->colour=BLACK;
+ y->colour=BLACK;
+ leaf=par2;
+ parent-=2;
+ leaf->colour=RED; /* And the loop continues */
+ }
+ else
+ {
+ if (leaf == par->left)
+ {
+ right_rotate(parent[-1],par);
+ par=leaf;
+ }
+ par->colour=BLACK;
+ par2->colour=RED;
+ left_rotate(parent[-2],par2);
+ break;
+ }
+ }
+ }
+ tree->root->colour=BLACK;
+}
+
+static void rb_delete_fixup(TREE *tree, TREE_ELEMENT ***parent)
+{
+ TREE_ELEMENT *x,*w,*par;
+
+ x= **parent;
+ while (x != tree->root && x->colour == BLACK)
+ {
+ if (x == (par=parent[-1][0])->left)
+ {
+ w=par->right;
+ if (w->colour == RED)
+ {
+ w->colour=BLACK;
+ par->colour=RED;
+ left_rotate(parent[-1],par);
+ parent[0]= &w->left;
+ *++parent= &par->left;
+ w=par->right;
+ }
+ if (w->left->colour == BLACK && w->right->colour == BLACK)
+ {
+ w->colour=RED;
+ x=par;
+ parent--;
+ }
+ else
+ {
+ if (w->right->colour == BLACK)
+ {
+ w->left->colour=BLACK;
+ w->colour=RED;
+ right_rotate(&par->right,w);
+ w=par->right;
+ }
+ w->colour=par->colour;
+ par->colour=BLACK;
+ w->right->colour=BLACK;
+ left_rotate(parent[-1],par);
+ x=tree->root;
+ break;
+ }
+ }
+ else
+ {
+ w=par->left;
+ if (w->colour == RED)
+ {
+ w->colour=BLACK;
+ par->colour=RED;
+ right_rotate(parent[-1],par);
+ parent[0]= &w->right;
+ *++parent= &par->right;
+ w=par->left;
+ }
+ if (w->right->colour == BLACK && w->left->colour == BLACK)
+ {
+ w->colour=RED;
+ x=par;
+ parent--;
+ }
+ else
+ {
+ if (w->left->colour == BLACK)
+ {
+ w->right->colour=BLACK;
+ w->colour=RED;
+ left_rotate(&par->left,w);
+ w=par->left;
+ }
+ w->colour=par->colour;
+ par->colour=BLACK;
+ w->left->colour=BLACK;
+ right_rotate(parent[-1],par);
+ x=tree->root;
+ break;
+ }
+ }
+ }
+ x->colour=BLACK;
+}
+
+#ifndef DBUG_OFF
+
+ /* Test that the proporties for a red-black tree holds */
+
+static int test_rb_tree(TREE_ELEMENT *element)
+{
+ int count_l,count_r;
+
+ if (!element->left)
+ return 0; /* Found end of tree */
+ if (element->colour == RED &&
+ (element->left->colour == RED || element->right->colour == RED))
+ {
+ printf("Wrong tree: Found two red in a row\n");
+ return -1;
+ }
+ count_l=test_rb_tree(element->left);
+ count_r=test_rb_tree(element->right);
+ if (count_l >= 0 && count_r >= 0)
+ {
+ if (count_l == count_r)
+ return count_l+(element->colour == BLACK);
+ printf("Wrong tree: Incorrect black-count: %d - %d\n",count_l,count_r);
+ }
+ return -1;
+}
+#endif