1410.4.2
by Djellel E. Difallah
removing my |
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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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1802.10.2
by Monty Taylor
Update all of the copyright headers to include the correct address. |
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
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1410.4.2
by Djellel E. Difallah
removing my |
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/*
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Code for handling red-black (balanced) binary trees.
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2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
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key in tree is allocated according to following:
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1410.4.2
by Djellel E. Difallah
removing my |
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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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2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
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align) then key will be put on a 8 aligned address. Else
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the key will be on address (element+1). This is transparent for user
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1410.4.2
by Djellel E. Difallah
removing my |
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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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2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
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(*compare)(custom_arg, element_key(element), key)
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and NOT the other way around, as
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(*compare)(custom_arg, key, element_key(element))
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1410.4.2
by Djellel E. Difallah
removing my |
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*/
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2173.2.1
by Monty Taylor
Fixes incorrect usage of include |
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#include <config.h> |
1410.4.2
by Djellel E. Difallah
removing my |
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2173.2.1
by Monty Taylor
Fixes incorrect usage of include |
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#include <drizzled/tree.h> |
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#include <drizzled/internal/my_sys.h> |
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#include <drizzled/internal/m_string.h> |
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1410.4.2
by Djellel E. Difallah
removing my |
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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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namespace drizzled |
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{
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2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
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/**
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2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
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* Tree class public methods
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2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
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*/
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void Tree::init_tree(size_t default_alloc_size, uint32_t mem_limit, |
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uint32_t size, qsort_cmp2 compare_callback, bool free_with_tree, |
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tree_element_free free_callback, void *caller_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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memset(&this->null_element, 0, sizeof(this->null_element)); |
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root= &this->null_element; |
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compare= compare_callback; |
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size_of_element= size > 0 ? (uint32_t) size : 0; |
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memory_limit= mem_limit; |
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free= free_callback; |
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allocated= 0; |
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elements_in_tree= 0; |
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custom_arg = caller_arg; |
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null_element.colour= BLACK; |
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null_element.left=this->null_element.right= 0; |
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flag= 0; |
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if (!free_callback && |
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(size <= sizeof(void*) || ((uint32_t) 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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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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offset_to_key= 0; /* use key through pointer */ |
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size_of_element+= sizeof(void*); |
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}
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if (! (with_delete= free_with_tree)) |
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{
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mem_root.init(default_alloc_size); |
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mem_root.min_malloc= (sizeof(Tree_Element)+size_of_element); |
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}
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}
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void Tree::delete_tree() |
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{
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free_tree(MYF(0)); /* free() mem_root if applicable */ |
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}
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void Tree::reset_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(MYF(memory::MARK_BLOCKS_FREE)); |
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}
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Tree_Element* Tree::tree_insert(void* key, uint32_t key_size, void* caller_arg) |
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{
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int cmp; |
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Tree_Element *element,***parent; |
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parent= this->parents; |
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*parent = &this->root; element= this->root; |
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for (;;) |
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{
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if (element == &this->null_element || |
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2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
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(cmp = (*compare)(caller_arg, element_key(element), key)) == 0) |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
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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 == &this->null_element) |
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{
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size_t alloc_size= sizeof(Tree_Element)+key_size+this->size_of_element; |
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this->allocated+= alloc_size; |
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if (this->memory_limit && this->elements_in_tree |
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&& this->allocated > this->memory_limit) |
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{
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reset_tree(); |
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return tree_insert(key, key_size, caller_arg); |
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}
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key_size+= this->size_of_element; |
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if (this->with_delete) |
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element= (Tree_Element *) malloc(alloc_size); |
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else
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element= (Tree_Element *) this->mem_root.alloc(alloc_size); |
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**parent= element; |
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element->left= element->right= &this->null_element; |
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if (!this->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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memcpy(*((void **) (element+1)),key, key_size - sizeof(void*)); |
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}
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}
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else
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memcpy((unsigned char*) element + this->offset_to_key, key, key_size); |
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element->count= 1; /* May give warning in purify */ |
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this->elements_in_tree++; |
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rb_insert(parent,element); /* rebalance tree */ |
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}
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else
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{
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if (this->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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int Tree::tree_walk(tree_walk_action action, void *argument, TREE_WALK visit) |
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{
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switch (visit) { |
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case left_root_right: |
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return tree_walk_left_root_right(root,action,argument); |
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case right_root_left: |
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return tree_walk_right_root_left(root,action,argument); |
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}
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return 0; /* Keep gcc happy */ |
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}
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2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
213 |
/**
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* Tree class private methods
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*/
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void Tree::free_tree(myf free_flags) |
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{
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if (root) /* If initialized */ |
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{
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if (with_delete) |
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delete_tree_element(root); |
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else
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{
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if (free) |
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{
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if (memory_limit) |
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(*free)(NULL, free_init, custom_arg); |
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delete_tree_element(root); |
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if (memory_limit) |
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(*free)(NULL, free_end, custom_arg); |
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}
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mem_root.free_root(free_flags); |
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}
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}
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root= &null_element; |
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elements_in_tree= 0; |
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allocated= 0; |
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}
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void* Tree::element_key(Tree_Element* element) |
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{
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return offset_to_key ? (void*)((unsigned char*) element + offset_to_key) |
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: *((void**)(element + 1)); |
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}
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void Tree::delete_tree_element(Tree_Element *element) |
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{
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if (element != &null_element) |
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{
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delete_tree_element(element->left); |
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if (free) |
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(*free)(element_key(element), free_free, custom_arg); |
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delete_tree_element(element->right); |
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if (with_delete) |
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delete element; |
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}
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}
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259 |
||
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
260 |
int Tree::tree_walk_left_root_right(Tree_Element *element, tree_walk_action action, void *argument) |
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{
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int error; |
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if (element->left) /* Not null_element */ |
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{
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if ((error=tree_walk_left_root_right(element->left,action, |
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argument)) == 0 && |
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2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
267 |
(error=(*action)(element_key(element), element->count, argument)) == 0) |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
268 |
error=tree_walk_left_root_right(element->right,action,argument); |
269 |
return error; |
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}
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return 0; |
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}
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275 |
int Tree::tree_walk_right_root_left(Tree_Element *element, tree_walk_action action, void *argument) |
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{
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int error; |
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if (element->right) /* Not null_element */ |
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{
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280 |
if ((error=tree_walk_right_root_left(element->right,action, |
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argument)) == 0 && |
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2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
282 |
(error=(*action)(element_key(element), |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
283 |
element->count, |
284 |
argument)) == 0) |
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285 |
error=tree_walk_right_root_left(element->left,action,argument); |
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286 |
return error; |
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287 |
}
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288 |
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289 |
return 0; |
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290 |
}
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291 |
||
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
292 |
void Tree::left_rotate(Tree_Element **parent, Tree_Element *element) |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
293 |
{
|
294 |
Tree_Element *y; |
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295 |
||
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
296 |
y= element->right; |
297 |
element->right= y->left; |
|
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
298 |
parent[0]= y; |
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
299 |
y->left= element; |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
300 |
}
|
301 |
||
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
302 |
void Tree::right_rotate(Tree_Element **parent, Tree_Element *element) |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
303 |
{
|
304 |
Tree_Element *x; |
|
305 |
||
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
306 |
x= element->left; |
307 |
element->left= x->right; |
|
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
308 |
parent[0]= x; |
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
309 |
x->right= element; |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
310 |
}
|
311 |
||
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
312 |
void Tree::rb_insert(Tree_Element ***parent, Tree_Element *element) |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
313 |
{
|
314 |
Tree_Element *y,*par,*par2; |
|
315 |
||
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
316 |
element->colour=RED; |
317 |
while (element != root && (par=parent[-1][0])->colour == RED) |
|
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
318 |
{
|
319 |
if (par == (par2=parent[-2][0])->left) |
|
320 |
{
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321 |
y= par2->right; |
|
322 |
if (y->colour == RED) |
|
323 |
{
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324 |
par->colour= BLACK; |
|
325 |
y->colour= BLACK; |
|
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
326 |
element= par2; |
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
327 |
parent-= 2; |
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
328 |
element->colour= RED; /* And the loop continues */ |
1410.4.2
by Djellel E. Difallah
removing my |
329 |
}
|
330 |
else
|
|
331 |
{
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|
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
332 |
if (element == par->right) |
1410.4.2
by Djellel E. Difallah
removing my |
333 |
{
|
334 |
left_rotate(parent[-1],par); |
|
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
335 |
par= element; /* element is now parent to old element */ |
1410.4.2
by Djellel E. Difallah
removing my |
336 |
}
|
337 |
par->colour= BLACK; |
|
338 |
par2->colour= RED; |
|
339 |
right_rotate(parent[-2],par2); |
|
340 |
break; |
|
341 |
}
|
|
342 |
}
|
|
343 |
else
|
|
344 |
{
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|
345 |
y= par2->left; |
|
346 |
if (y->colour == RED) |
|
347 |
{
|
|
348 |
par->colour= BLACK; |
|
349 |
y->colour= BLACK; |
|
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
350 |
element= par2; |
1410.4.2
by Djellel E. Difallah
removing my |
351 |
parent-= 2; |
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
352 |
element->colour= RED; /* And the loop continues */ |
1410.4.2
by Djellel E. Difallah
removing my |
353 |
}
|
354 |
else
|
|
355 |
{
|
|
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
356 |
if (element == par->left) |
1410.4.2
by Djellel E. Difallah
removing my |
357 |
{
|
358 |
right_rotate(parent[-1],par); |
|
2455.1.2
by Ivo Roper
cleaned up versions of tree.h and tree.cc |
359 |
par= element; |
1410.4.2
by Djellel E. Difallah
removing my |
360 |
}
|
361 |
par->colour= BLACK; |
|
362 |
par2->colour= RED; |
|
363 |
left_rotate(parent[-2],par2); |
|
364 |
break; |
|
365 |
}
|
|
366 |
}
|
|
367 |
}
|
|
2455.1.1
by Ivo Roper
refactoring of TREE and TREE_ELEMENT structs into Tree and Tree_Element classes |
368 |
root->colour=BLACK; |
1410.4.2
by Djellel E. Difallah
removing my |
369 |
}
|
370 |
||
371 |
} /* namespace drizzled */ |