1 /* Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
2 
3    This program is free software; you can redistribute it and/or modify
4    it under the terms of the GNU General Public License, version 2.0,
5    as published by the Free Software Foundation.
6 
7    This program is also distributed with certain software (including
8    but not limited to OpenSSL) that is licensed under separate terms,
9    as designated in a particular file or component or in included license
10    documentation.  The authors of MySQL hereby grant you an additional
11    permission to link the program and your derivative works with the
12    separately licensed software that they have included with MySQL.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License, version 2.0, for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
22 
23 #ifndef _tree_h
24 #define _tree_h
25 
26 /**
27   @file include/my_tree.h
28 */
29 
30 #include <stddef.h>
31 #include <sys/types.h>
32 
33 #include "my_alloc.h" /* MEM_ROOT */
34 #include "my_base.h"  /* get 'enum ha_rkey_function' */
35 #include "my_inttypes.h"
36 #include "my_sys.h" /* qsort2_cmp */
37 
38 /* Worst case tree is half full. This gives use 2^(MAX_TREE_HEIGHT/2) leafs */
39 #define MAX_TREE_HEIGHT 64
40 
41 #define ELEMENT_KEY(tree, element)                                        \
42   (tree->offset_to_key ? (void *)((uchar *)element + tree->offset_to_key) \
43                        : *((void **)(element + 1)))
44 
45 #define tree_set_pointer(element, ptr) \
46   *((uchar **)(element + 1)) = ((uchar *)(ptr))
47 
48 #define TREE_NO_DUPS 1
49 
50 typedef enum { left_root_right, right_root_left } TREE_WALK;
51 typedef uint32 element_count;
52 typedef int (*tree_walk_action)(void *, element_count, void *);
53 
54 typedef enum { free_init, free_free, free_end } TREE_FREE;
55 typedef void (*tree_element_free)(void *, TREE_FREE, const void *);
56 
57 struct TREE_ELEMENT {
TREE_ELEMENTTREE_ELEMENT58   TREE_ELEMENT() : count(0), colour(0) {}
59 
60   TREE_ELEMENT *left{nullptr}, *right{nullptr};
61   uint32 count : 31, colour : 1; /* black is marked as 1 */
62 };
63 
64 #define ELEMENT_CHILD(element, offs) \
65   (*(TREE_ELEMENT **)((char *)element + offs))
66 
67 struct TREE {
68   TREE_ELEMENT *root{nullptr}, null_element;
69   TREE_ELEMENT **parents[MAX_TREE_HEIGHT]{nullptr};
70   uint offset_to_key{0}, elements_in_tree{0}, size_of_element{0};
71   ulong memory_limit{0}, allocated{0};
72   qsort2_cmp compare{nullptr};
73   const void *custom_arg{nullptr};
74   MEM_ROOT mem_root;
75   bool with_delete{false};
76   tree_element_free free{nullptr};
77   uint flag{0};
78 };
79 
80 /* Functions on whole tree */
81 void init_tree(TREE *tree, ulong memory_limit, int element_size,
82                qsort2_cmp compare, bool with_delete,
83                tree_element_free free_element, const void *custom_arg);
84 void delete_tree(TREE *);
85 void reset_tree(TREE *);
86 /* similar to delete tree, except we do not my_free() blocks in mem_root
87  */
88 #define is_tree_inited(tree) ((tree)->root != 0)
89 
90 /* Functions on leafs */
91 TREE_ELEMENT *tree_insert(TREE *tree, void *key, uint key_size,
92                           const void *custom_arg);
93 void *tree_search(TREE *tree, void *key, const void *custom_arg);
94 int tree_walk(TREE *tree, tree_walk_action action, void *argument,
95               TREE_WALK visit);
96 int tree_delete(TREE *tree, void *key, uint key_size, const void *custom_arg);
97 void *tree_search_key(TREE *tree, const void *key, TREE_ELEMENT **parents,
98                       TREE_ELEMENT ***last_pos, enum ha_rkey_function flag,
99                       const void *custom_arg);
100 void *tree_search_edge(TREE *tree, TREE_ELEMENT **parents,
101                        TREE_ELEMENT ***last_pos, int child_offs);
102 void *tree_search_next(TREE *tree, TREE_ELEMENT ***last_pos, int l_offs,
103                        int r_offs);
104 ha_rows tree_record_pos(TREE *tree, const void *key,
105                         enum ha_rkey_function search_flag,
106                         const void *custom_arg);
107 
108 #define TREE_ELEMENT_EXTRA_SIZE (sizeof(TREE_ELEMENT) + sizeof(void *))
109 
110 #endif
111