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by brian
clean slate |
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/* Copyright (C) 2000 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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/*
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Code for handling red-black (balanced) binary trees.
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key in tree is allocated accrding to following:
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1) If size < 0 then tree will not allocate keys and only a pointer to
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each key is saved in tree.
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compare and search functions uses and returns key-pointer
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2) If size == 0 then there are two options:
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- key_size != 0 to tree_insert: The key will be stored in the tree.
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- key_size == 0 to tree_insert: A pointer to the key is stored.
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compare and search functions uses and returns key-pointer.
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3) if key_size is given to init_tree then each node will continue the
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key and calls to insert_key may increase length of key.
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if key_size > sizeof(pointer) and key_size is a multiple of 8 (double
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allign) then key will be put on a 8 alligned adress. Else
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the key will be on adress (element+1). This is transparent for user
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compare and search functions uses a pointer to given key-argument.
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- If you use a free function for tree-elements and you are freeing
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the element itself, you should use key_size = 0 to init_tree and
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tree_search
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The actual key in TREE_ELEMENT is saved as a pointer or after the
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TREE_ELEMENT struct.
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If one uses only pointers in tree one can use tree_set_pointer() to
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change address of data.
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Implemented by monty.
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*/
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/*
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NOTE:
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tree->compare function should be ALWAYS called as
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(*tree->compare)(custom_arg, ELEMENT_KEY(tree,element), key)
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and not other way around, as
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(*tree->compare)(custom_arg, key, ELEMENT_KEY(tree,element))
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*/
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#include "mysys_priv.h" |
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212.5.18
by Monty Taylor
Moved m_ctype, m_string and my_bitmap. Removed t_ctype. |
57 |
#include <mystrings/m_string.h> |
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212.5.15
by Monty Taylor
Moved my_tree. |
58 |
#include <mysys/my_tree.h> |
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1
by brian
clean slate |
59 |
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#define BLACK 1
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#define RED 0
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#define DEFAULT_ALLOC_SIZE 8192
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#define DEFAULT_ALIGN_SIZE 8192
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static void delete_tree_element(TREE *,TREE_ELEMENT *); |
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static int tree_walk_left_root_right(TREE *,TREE_ELEMENT *, |
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tree_walk_action,void *); |
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static int tree_walk_right_root_left(TREE *,TREE_ELEMENT *, |
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tree_walk_action,void *); |
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static void left_rotate(TREE_ELEMENT **parent,TREE_ELEMENT *leaf); |
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static void right_rotate(TREE_ELEMENT **parent, TREE_ELEMENT *leaf); |
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static void rb_insert(TREE *tree,TREE_ELEMENT ***parent, |
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TREE_ELEMENT *leaf); |
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static void rb_delete_fixup(TREE *tree,TREE_ELEMENT ***parent); |
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||
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298
by Brian Aker
ulong conversion. |
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void init_tree(TREE *tree, uint32_t default_alloc_size, uint32_t memory_limit, |
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146
by Brian Aker
my_bool cleanup. |
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int size, qsort_cmp2 compare, bool with_delete, |
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1
by brian
clean slate |
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tree_element_free free_element, void *custom_arg) |
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{
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if (default_alloc_size < DEFAULT_ALLOC_SIZE) |
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default_alloc_size= DEFAULT_ALLOC_SIZE; |
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default_alloc_size= MY_ALIGN(default_alloc_size, DEFAULT_ALIGN_SIZE); |
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212.6.14
by Mats Kindahl
Removing redundant use of casts in mysys for memcmp(), memcpy(), memset(), and memmove(). |
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memset(&tree->null_element, 0, sizeof(tree->null_element)); |
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1
by brian
clean slate |
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tree->root= &tree->null_element; |
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tree->compare=compare; |
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tree->size_of_element=size > 0 ? (uint) size : 0; |
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tree->memory_limit=memory_limit; |
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tree->free=free_element; |
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tree->allocated=0; |
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tree->elements_in_tree=0; |
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tree->custom_arg = custom_arg; |
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tree->null_element.colour=BLACK; |
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tree->null_element.left=tree->null_element.right=0; |
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tree->flag= 0; |
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if (!free_element && size >= 0 && |
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((uint) size <= sizeof(void*) || ((uint) size & (sizeof(void*)-1)))) |
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{
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/*
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We know that the data doesn't have to be aligned (like if the key
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contains a double), so we can store the data combined with the
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TREE_ELEMENT.
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*/
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tree->offset_to_key=sizeof(TREE_ELEMENT); /* Put key after element */ |
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/* Fix allocation size so that we don't lose any memory */
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default_alloc_size/=(sizeof(TREE_ELEMENT)+size); |
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if (!default_alloc_size) |
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default_alloc_size=1; |
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default_alloc_size*=(sizeof(TREE_ELEMENT)+size); |
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}
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else
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{
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tree->offset_to_key=0; /* use key through pointer */ |
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tree->size_of_element+=sizeof(void*); |
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}
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if (!(tree->with_delete=with_delete)) |
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{
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init_alloc_root(&tree->mem_root, (uint) default_alloc_size, 0); |
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tree->mem_root.min_malloc=(sizeof(TREE_ELEMENT)+tree->size_of_element); |
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}
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51.3.14
by Jay Pipes
Phase 2 removal of DBUG in mysys |
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return; |
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1
by brian
clean slate |
122 |
}
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static void free_tree(TREE *tree, myf free_flags) |
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{
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if (tree->root) /* If initialized */ |
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{
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if (tree->with_delete) |
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delete_tree_element(tree,tree->root); |
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else
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{
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if (tree->free) |
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{
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if (tree->memory_limit) |
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(*tree->free)(NULL, free_init, tree->custom_arg); |
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delete_tree_element(tree,tree->root); |
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if (tree->memory_limit) |
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(*tree->free)(NULL, free_end, tree->custom_arg); |
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}
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free_root(&tree->mem_root, free_flags); |
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}
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}
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tree->root= &tree->null_element; |
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tree->elements_in_tree=0; |
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tree->allocated=0; |
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||
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51.3.14
by Jay Pipes
Phase 2 removal of DBUG in mysys |
147 |
return; |
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1
by brian
clean slate |
148 |
}
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void delete_tree(TREE* tree) |
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{
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477
by Monty Taylor
Removed my_free(). It turns out that it had been def'd to ignore the flags passed to it in the second arg anyway. Gotta love that. |
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free_tree(tree, MYF(0)); /* free() mem_root if applicable */ |
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1
by brian
clean slate |
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}
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void reset_tree(TREE* tree) |
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{
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/* do not free mem_root, just mark blocks as free */
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free_tree(tree, MYF(MY_MARK_BLOCKS_FREE)); |
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}
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static void delete_tree_element(TREE *tree, TREE_ELEMENT *element) |
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{
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if (element != &tree->null_element) |
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{
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delete_tree_element(tree,element->left); |
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if (tree->free) |
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(*tree->free)(ELEMENT_KEY(tree,element), free_free, tree->custom_arg); |
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delete_tree_element(tree,element->right); |
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if (tree->with_delete) |
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477
by Monty Taylor
Removed my_free(). It turns out that it had been def'd to ignore the flags passed to it in the second arg anyway. Gotta love that. |
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free((char*) element); |
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1
by brian
clean slate |
172 |
}
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}
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/*
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insert, search and delete of elements
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The following should be true:
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parent[0] = & parent[-1][0]->left ||
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parent[0] = & parent[-1][0]->right
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*/
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||
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660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
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TREE_ELEMENT *tree_insert(TREE *tree, void *key, uint32_t key_size, |
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1
by brian
clean slate |
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void* custom_arg) |
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{
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int cmp; |
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TREE_ELEMENT *element,***parent; |
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parent= tree->parents; |
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*parent = &tree->root; element= tree->root; |
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for (;;) |
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{
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if (element == &tree->null_element || |
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(cmp = (*tree->compare)(custom_arg, ELEMENT_KEY(tree,element), |
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key)) == 0) |
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break; |
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if (cmp < 0) |
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{
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*++parent= &element->right; element= element->right; |
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}
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else
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{
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*++parent = &element->left; element= element->left; |
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}
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}
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if (element == &tree->null_element) |
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{
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482
by Brian Aker
Remove uint. |
209 |
uint32_t alloc_size=sizeof(TREE_ELEMENT)+key_size+tree->size_of_element; |
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1
by brian
clean slate |
210 |
tree->allocated+=alloc_size; |
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if (tree->memory_limit && tree->elements_in_tree |
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&& tree->allocated > tree->memory_limit) |
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{
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reset_tree(tree); |
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return tree_insert(tree, key, key_size, custom_arg); |
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}
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key_size+=tree->size_of_element; |
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if (tree->with_delete) |
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656.1.26
by Monty Taylor
Finally removed all of the my_malloc stuff. |
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element=(TREE_ELEMENT *) malloc(alloc_size); |
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1
by brian
clean slate |
222 |
else
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element=(TREE_ELEMENT *) alloc_root(&tree->mem_root,alloc_size); |
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if (!element) |
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return(NULL); |
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**parent=element; |
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element->left=element->right= &tree->null_element; |
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if (!tree->offset_to_key) |
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{
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if (key_size == sizeof(void*)) /* no length, save pointer */ |
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*((void**) (element+1))=key; |
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else
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{
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*((void**) (element+1))= (void*) ((void **) (element+1)+1); |
|
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212.6.14
by Mats Kindahl
Removing redundant use of casts in mysys for memcmp(), memcpy(), memset(), and memmove(). |
235 |
memcpy(*((void **) (element+1)),key, key_size - sizeof(void*)); |
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1
by brian
clean slate |
236 |
}
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}
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else
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481
by Brian Aker
Remove all of uchar. |
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memcpy((unsigned char*) element + tree->offset_to_key, key, key_size); |
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1
by brian
clean slate |
240 |
element->count=1; /* May give warning in purify */ |
241 |
tree->elements_in_tree++; |
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rb_insert(tree,parent,element); /* rebalance tree */ |
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}
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else
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{
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if (tree->flag & TREE_NO_DUPS) |
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return(NULL); |
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element->count++; |
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/* Avoid a wrap over of the count. */
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if (! element->count) |
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element->count--; |
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}
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return element; |
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}
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255 |
||
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482
by Brian Aker
Remove uint. |
256 |
int tree_delete(TREE *tree, void *key, uint32_t key_size, void *custom_arg) |
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1
by brian
clean slate |
257 |
{
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int cmp,remove_colour; |
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TREE_ELEMENT *element,***parent, ***org_parent, *nod; |
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if (!tree->with_delete) |
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return 1; /* not allowed */ |
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||
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parent= tree->parents; |
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*parent= &tree->root; element= tree->root; |
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for (;;) |
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{
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if (element == &tree->null_element) |
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return 1; /* Was not in tree */ |
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if ((cmp = (*tree->compare)(custom_arg, ELEMENT_KEY(tree,element), |
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key)) == 0) |
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break; |
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if (cmp < 0) |
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{
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*++parent= &element->right; element= element->right; |
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}
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276 |
else
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277 |
{
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278 |
*++parent = &element->left; element= element->left; |
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}
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280 |
}
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281 |
if (element->left == &tree->null_element) |
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282 |
{
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(**parent)=element->right; |
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284 |
remove_colour= element->colour; |
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285 |
}
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286 |
else if (element->right == &tree->null_element) |
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{
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288 |
(**parent)=element->left; |
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remove_colour= element->colour; |
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290 |
}
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291 |
else
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292 |
{
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293 |
org_parent= parent; |
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294 |
*++parent= &element->right; nod= element->right; |
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295 |
while (nod->left != &tree->null_element) |
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296 |
{
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297 |
*++parent= &nod->left; nod= nod->left; |
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298 |
}
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299 |
(**parent)=nod->right; /* unlink nod from tree */ |
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300 |
remove_colour= nod->colour; |
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301 |
org_parent[0][0]=nod; /* put y in place of element */ |
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302 |
org_parent[1]= &nod->right; |
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nod->left=element->left; |
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304 |
nod->right=element->right; |
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305 |
nod->colour=element->colour; |
|
306 |
}
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307 |
if (remove_colour == BLACK) |
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308 |
rb_delete_fixup(tree,parent); |
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309 |
if (tree->free) |
|
310 |
(*tree->free)(ELEMENT_KEY(tree,element), free_free, tree->custom_arg); |
|
311 |
tree->allocated-= sizeof(TREE_ELEMENT) + tree->size_of_element + key_size; |
|
|
481
by Brian Aker
Remove all of uchar. |
312 |
free((unsigned char*) element); |
|
1
by brian
clean slate |
313 |
tree->elements_in_tree--; |
314 |
return 0; |
|
315 |
}
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316 |
||
317 |
||
318 |
void *tree_search(TREE *tree, void *key, void *custom_arg) |
|
319 |
{
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|
320 |
int cmp; |
|
321 |
TREE_ELEMENT *element=tree->root; |
|
322 |
||
323 |
for (;;) |
|
324 |
{
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|
325 |
if (element == &tree->null_element) |
|
326 |
return (void*) 0; |
|
327 |
if ((cmp = (*tree->compare)(custom_arg, ELEMENT_KEY(tree,element), |
|
328 |
key)) == 0) |
|
329 |
return ELEMENT_KEY(tree,element); |
|
330 |
if (cmp < 0) |
|
331 |
element=element->right; |
|
332 |
else
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|
333 |
element=element->left; |
|
334 |
}
|
|
335 |
}
|
|
336 |
||
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
337 |
void *tree_search_key(TREE *tree, const void *key, |
|
1
by brian
clean slate |
338 |
TREE_ELEMENT **parents, TREE_ELEMENT ***last_pos, |
339 |
enum ha_rkey_function flag, void *custom_arg) |
|
340 |
{
|
|
341 |
int cmp; |
|
342 |
TREE_ELEMENT *element= tree->root; |
|
343 |
TREE_ELEMENT **last_left_step_parent= NULL, **last_right_step_parent= NULL; |
|
344 |
TREE_ELEMENT **last_equal_element= NULL; |
|
345 |
||
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
346 |
/*
|
|
1
by brian
clean slate |
347 |
TODO: support for HA_READ_KEY_OR_PREV, HA_READ_PREFIX flags if needed.
|
348 |
*/
|
|
349 |
||
350 |
*parents = &tree->null_element; |
|
351 |
while (element != &tree->null_element) |
|
352 |
{
|
|
353 |
*++parents= element; |
|
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
354 |
if ((cmp= (*tree->compare)(custom_arg, ELEMENT_KEY(tree, element), |
|
1
by brian
clean slate |
355 |
key)) == 0) |
356 |
{
|
|
357 |
switch (flag) { |
|
358 |
case HA_READ_KEY_EXACT: |
|
359 |
case HA_READ_KEY_OR_NEXT: |
|
360 |
case HA_READ_BEFORE_KEY: |
|
361 |
last_equal_element= parents; |
|
362 |
cmp= 1; |
|
363 |
break; |
|
364 |
case HA_READ_AFTER_KEY: |
|
365 |
cmp= -1; |
|
366 |
break; |
|
367 |
case HA_READ_PREFIX_LAST: |
|
368 |
case HA_READ_PREFIX_LAST_OR_PREV: |
|
369 |
last_equal_element= parents; |
|
370 |
cmp= -1; |
|
371 |
break; |
|
372 |
default: |
|
373 |
return NULL; |
|
374 |
}
|
|
375 |
}
|
|
376 |
if (cmp < 0) /* element < key */ |
|
377 |
{
|
|
378 |
last_right_step_parent= parents; |
|
379 |
element= element->right; |
|
380 |
}
|
|
381 |
else
|
|
382 |
{
|
|
383 |
last_left_step_parent= parents; |
|
384 |
element= element->left; |
|
385 |
}
|
|
386 |
}
|
|
387 |
switch (flag) { |
|
388 |
case HA_READ_KEY_EXACT: |
|
389 |
case HA_READ_PREFIX_LAST: |
|
390 |
*last_pos= last_equal_element; |
|
391 |
break; |
|
392 |
case HA_READ_KEY_OR_NEXT: |
|
393 |
*last_pos= last_equal_element ? last_equal_element : last_left_step_parent; |
|
394 |
break; |
|
395 |
case HA_READ_AFTER_KEY: |
|
396 |
*last_pos= last_left_step_parent; |
|
397 |
break; |
|
398 |
case HA_READ_PREFIX_LAST_OR_PREV: |
|
399 |
*last_pos= last_equal_element ? last_equal_element : last_right_step_parent; |
|
400 |
break; |
|
401 |
case HA_READ_BEFORE_KEY: |
|
402 |
*last_pos= last_right_step_parent; |
|
403 |
break; |
|
404 |
default: |
|
405 |
return NULL; |
|
406 |
}
|
|
407 |
return *last_pos ? ELEMENT_KEY(tree, **last_pos) : NULL; |
|
408 |
}
|
|
409 |
||
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
410 |
/*
|
411 |
Search first (the most left) or last (the most right) tree element
|
|
|
1
by brian
clean slate |
412 |
*/
|
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
413 |
void *tree_search_edge(TREE *tree, TREE_ELEMENT **parents, |
|
1
by brian
clean slate |
414 |
TREE_ELEMENT ***last_pos, int child_offs) |
415 |
{
|
|
416 |
TREE_ELEMENT *element= tree->root; |
|
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
417 |
|
|
1
by brian
clean slate |
418 |
*parents= &tree->null_element; |
419 |
while (element != &tree->null_element) |
|
420 |
{
|
|
421 |
*++parents= element; |
|
422 |
element= ELEMENT_CHILD(element, child_offs); |
|
423 |
}
|
|
424 |
*last_pos= parents; |
|
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
425 |
return **last_pos != &tree->null_element ? |
|
1
by brian
clean slate |
426 |
ELEMENT_KEY(tree, **last_pos) : NULL; |
427 |
}
|
|
428 |
||
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
429 |
void *tree_search_next(TREE *tree, TREE_ELEMENT ***last_pos, int l_offs, |
|
1
by brian
clean slate |
430 |
int r_offs) |
431 |
{
|
|
432 |
TREE_ELEMENT *x= **last_pos; |
|
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
433 |
|
|
1
by brian
clean slate |
434 |
if (ELEMENT_CHILD(x, r_offs) != &tree->null_element) |
435 |
{
|
|
436 |
x= ELEMENT_CHILD(x, r_offs); |
|
437 |
*++*last_pos= x; |
|
438 |
while (ELEMENT_CHILD(x, l_offs) != &tree->null_element) |
|
439 |
{
|
|
440 |
x= ELEMENT_CHILD(x, l_offs); |
|
441 |
*++*last_pos= x; |
|
442 |
}
|
|
443 |
return ELEMENT_KEY(tree, x); |
|
444 |
}
|
|
445 |
else
|
|
446 |
{
|
|
447 |
TREE_ELEMENT *y= *--*last_pos; |
|
448 |
while (y != &tree->null_element && x == ELEMENT_CHILD(y, r_offs)) |
|
449 |
{
|
|
450 |
x= y; |
|
451 |
y= *--*last_pos; |
|
452 |
}
|
|
453 |
return y == &tree->null_element ? NULL : ELEMENT_KEY(tree, y); |
|
454 |
}
|
|
455 |
}
|
|
456 |
||
457 |
/*
|
|
458 |
Expected that tree is fully balanced
|
|
459 |
(each path from root to leaf has the same length)
|
|
460 |
*/
|
|
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
461 |
ha_rows tree_record_pos(TREE *tree, const void *key, |
|
1
by brian
clean slate |
462 |
enum ha_rkey_function flag, void *custom_arg) |
463 |
{
|
|
464 |
int cmp; |
|
465 |
TREE_ELEMENT *element= tree->root; |
|
466 |
double left= 1; |
|
467 |
double right= tree->elements_in_tree; |
|
468 |
||
469 |
while (element != &tree->null_element) |
|
470 |
{
|
|
|
660.1.3
by Eric Herman
removed trailing whitespace with simple script: |
471 |
if ((cmp= (*tree->compare)(custom_arg, ELEMENT_KEY(tree, element), |
|
1
by brian
clean slate |
472 |
key)) == 0) |
473 |
{
|
|
474 |
switch (flag) { |
|
475 |
case HA_READ_KEY_EXACT: |
|
476 |
case HA_READ_BEFORE_KEY: |
|
477 |
cmp= 1; |
|
478 |
break; |
|
479 |
case HA_READ_AFTER_KEY: |
|
480 |
cmp= -1; |
|
481 |
break; |
|
482 |
default: |
|
483 |
return HA_POS_ERROR; |
|
484 |
}
|
|
485 |
}
|
|
486 |
if (cmp < 0) /* element < key */ |
|
487 |
{
|
|
488 |
element= element->right; |
|
489 |
left= (left + right) / 2; |
|
490 |
}
|
|
491 |
else
|
|
492 |
{
|
|
493 |
element= element->left; |
|
494 |
right= (left + right) / 2; |
|
495 |
}
|
|
496 |
}
|
|
497 |
switch (flag) { |
|
498 |
case HA_READ_KEY_EXACT: |
|
499 |
case HA_READ_BEFORE_KEY: |
|
500 |
return (ha_rows) right; |
|
501 |
case HA_READ_AFTER_KEY: |
|
502 |
return (ha_rows) left; |
|
503 |
default: |
|
504 |
return HA_POS_ERROR; |
|
505 |
}
|
|
506 |
}
|
|
507 |
||
508 |
int tree_walk(TREE *tree, tree_walk_action action, void *argument, TREE_WALK visit) |
|
509 |
{
|
|
510 |
switch (visit) { |
|
511 |
case left_root_right: |
|
512 |
return tree_walk_left_root_right(tree,tree->root,action,argument); |
|
513 |
case right_root_left: |
|
514 |
return tree_walk_right_root_left(tree,tree->root,action,argument); |
|
515 |
}
|
|
516 |
return 0; /* Keep gcc happy */ |
|
517 |
}
|
|
518 |
||
519 |
static int tree_walk_left_root_right(TREE *tree, TREE_ELEMENT *element, tree_walk_action action, void *argument) |
|
520 |
{
|
|
521 |
int error; |
|
522 |
if (element->left) /* Not null_element */ |
|
523 |
{
|
|
524 |
if ((error=tree_walk_left_root_right(tree,element->left,action, |
|
525 |
argument)) == 0 && |
|
526 |
(error=(*action)(ELEMENT_KEY(tree,element), |
|
527 |
(element_count) element->count, |
|
528 |
argument)) == 0) |
|
529 |
error=tree_walk_left_root_right(tree,element->right,action,argument); |
|
530 |
return error; |
|
531 |
}
|
|
532 |
return 0; |
|
533 |
}
|
|
534 |
||
535 |
static int tree_walk_right_root_left(TREE *tree, TREE_ELEMENT *element, tree_walk_action action, void *argument) |
|
536 |
{
|
|
537 |
int error; |
|
538 |
if (element->right) /* Not null_element */ |
|
539 |
{
|
|
540 |
if ((error=tree_walk_right_root_left(tree,element->right,action, |
|
541 |
argument)) == 0 && |
|
542 |
(error=(*action)(ELEMENT_KEY(tree,element), |
|
543 |
(element_count) element->count, |
|
544 |
argument)) == 0) |
|
545 |
error=tree_walk_right_root_left(tree,element->left,action,argument); |
|
546 |
return error; |
|
547 |
}
|
|
548 |
return 0; |
|
549 |
}
|
|
550 |
||
551 |
||
552 |
/* Functions to fix up the tree after insert and delete */
|
|
553 |
||
554 |
static void left_rotate(TREE_ELEMENT **parent, TREE_ELEMENT *leaf) |
|
555 |
{
|
|
556 |
TREE_ELEMENT *y; |
|
557 |
||
558 |
y=leaf->right; |
|
559 |
leaf->right=y->left; |
|
560 |
parent[0]=y; |
|
561 |
y->left=leaf; |
|
562 |
}
|
|
563 |
||
564 |
static void right_rotate(TREE_ELEMENT **parent, TREE_ELEMENT *leaf) |
|
565 |
{
|
|
566 |
TREE_ELEMENT *x; |
|
567 |
||
568 |
x=leaf->left; |
|
569 |
leaf->left=x->right; |
|
570 |
parent[0]=x; |
|
571 |
x->right=leaf; |
|
572 |
}
|
|
573 |
||
574 |
static void rb_insert(TREE *tree, TREE_ELEMENT ***parent, TREE_ELEMENT *leaf) |
|
575 |
{
|
|
576 |
TREE_ELEMENT *y,*par,*par2; |
|
577 |
||
578 |
leaf->colour=RED; |
|
579 |
while (leaf != tree->root && (par=parent[-1][0])->colour == RED) |
|
580 |
{
|
|
581 |
if (par == (par2=parent[-2][0])->left) |
|
582 |
{
|
|
583 |
y= par2->right; |
|
584 |
if (y->colour == RED) |
|
585 |
{
|
|
586 |
par->colour=BLACK; |
|
587 |
y->colour=BLACK; |
|
588 |
leaf=par2; |
|
589 |
parent-=2; |
|
590 |
leaf->colour=RED; /* And the loop continues */ |
|
591 |
}
|
|
592 |
else
|
|
593 |
{
|
|
594 |
if (leaf == par->right) |
|
595 |
{
|
|
596 |
left_rotate(parent[-1],par); |
|
597 |
par=leaf; /* leaf is now parent to old leaf */ |
|
598 |
}
|
|
599 |
par->colour=BLACK; |
|
600 |
par2->colour=RED; |
|
601 |
right_rotate(parent[-2],par2); |
|
602 |
break; |
|
603 |
}
|
|
604 |
}
|
|
605 |
else
|
|
606 |
{
|
|
607 |
y= par2->left; |
|
608 |
if (y->colour == RED) |
|
609 |
{
|
|
610 |
par->colour=BLACK; |
|
611 |
y->colour=BLACK; |
|
612 |
leaf=par2; |
|
613 |
parent-=2; |
|
614 |
leaf->colour=RED; /* And the loop continues */ |
|
615 |
}
|
|
616 |
else
|
|
617 |
{
|
|
618 |
if (leaf == par->left) |
|
619 |
{
|
|
620 |
right_rotate(parent[-1],par); |
|
621 |
par=leaf; |
|
622 |
}
|
|
623 |
par->colour=BLACK; |
|
624 |
par2->colour=RED; |
|
625 |
left_rotate(parent[-2],par2); |
|
626 |
break; |
|
627 |
}
|
|
628 |
}
|
|
629 |
}
|
|
630 |
tree->root->colour=BLACK; |
|
631 |
}
|
|
632 |
||
633 |
static void rb_delete_fixup(TREE *tree, TREE_ELEMENT ***parent) |
|
634 |
{
|
|
635 |
TREE_ELEMENT *x,*w,*par; |
|
636 |
||
637 |
x= **parent; |
|
638 |
while (x != tree->root && x->colour == BLACK) |
|
639 |
{
|
|
640 |
if (x == (par=parent[-1][0])->left) |
|
641 |
{
|
|
642 |
w=par->right; |
|
643 |
if (w->colour == RED) |
|
644 |
{
|
|
645 |
w->colour=BLACK; |
|
646 |
par->colour=RED; |
|
647 |
left_rotate(parent[-1],par); |
|
648 |
parent[0]= &w->left; |
|
649 |
*++parent= &par->left; |
|
650 |
w=par->right; |
|
651 |
}
|
|
652 |
if (w->left->colour == BLACK && w->right->colour == BLACK) |
|
653 |
{
|
|
654 |
w->colour=RED; |
|
655 |
x=par; |
|
656 |
parent--; |
|
657 |
}
|
|
658 |
else
|
|
659 |
{
|
|
660 |
if (w->right->colour == BLACK) |
|
661 |
{
|
|
662 |
w->left->colour=BLACK; |
|
663 |
w->colour=RED; |
|
664 |
right_rotate(&par->right,w); |
|
665 |
w=par->right; |
|
666 |
}
|
|
667 |
w->colour=par->colour; |
|
668 |
par->colour=BLACK; |
|
669 |
w->right->colour=BLACK; |
|
670 |
left_rotate(parent[-1],par); |
|
671 |
x=tree->root; |
|
672 |
break; |
|
673 |
}
|
|
674 |
}
|
|
675 |
else
|
|
676 |
{
|
|
677 |
w=par->left; |
|
678 |
if (w->colour == RED) |
|
679 |
{
|
|
680 |
w->colour=BLACK; |
|
681 |
par->colour=RED; |
|
682 |
right_rotate(parent[-1],par); |
|
683 |
parent[0]= &w->right; |
|
684 |
*++parent= &par->right; |
|
685 |
w=par->left; |
|
686 |
}
|
|
687 |
if (w->right->colour == BLACK && w->left->colour == BLACK) |
|
688 |
{
|
|
689 |
w->colour=RED; |
|
690 |
x=par; |
|
691 |
parent--; |
|
692 |
}
|
|
693 |
else
|
|
694 |
{
|
|
695 |
if (w->left->colour == BLACK) |
|
696 |
{
|
|
697 |
w->right->colour=BLACK; |
|
698 |
w->colour=RED; |
|
699 |
left_rotate(&par->left,w); |
|
700 |
w=par->left; |
|
701 |
}
|
|
702 |
w->colour=par->colour; |
|
703 |
par->colour=BLACK; |
|
704 |
w->left->colour=BLACK; |
|
705 |
right_rotate(parent[-1],par); |
|
706 |
x=tree->root; |
|
707 |
break; |
|
708 |
}
|
|
709 |
}
|
|
710 |
}
|
|
711 |
x->colour=BLACK; |
|
712 |
}
|