1 /* Copyright (c) 2000, 2010, Oracle and/or its affiliates.
2    Copyright (c) 2011, 2013, Monty Program Ab.
3 
4    This program is free software; you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; version 2 of the License.
7 
8    This program is distributed in the hope that it will be useful,
9    but WITHOUT ANY WARRANTY; without even the implied warranty of
10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11    GNU General Public License for more details.
12 
13    You should have received a copy of the GNU General Public License
14    along with this program; if not, write to the Free Software
15    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
16 
17 /* Dynamic hashing of record with different key-length */
18 
19 #ifndef _hash_h
20 #define _hash_h
21 
22 #include "my_sys.h"                             /* DYNAMIC_ARRAY */
23 
24 /*
25   This forward declaration is used from C files where the real
26   definition is included before.  Since C does not allow repeated
27   typedef declarations, even when identical, the definition may not be
28   repeated.
29 */
30 #ifdef	__cplusplus
31 extern "C" {
32 #endif
33 
34 /*
35   Overhead to store an element in hash
36   Can be used to approximate memory consumption for a hash
37  */
38 #define HASH_OVERHEAD (sizeof(char*)*2)
39 
40 /* flags for hash_init */
41 #define HASH_UNIQUE     1       /* hash_insert fails on duplicate key */
42 #define HASH_THREAD_SPECIFIC 2  /* Mark allocated memory THREAD_SPECIFIC */
43 
44 typedef uint32 my_hash_value_type;
45 typedef uchar *(*my_hash_get_key)(const uchar *,size_t*,my_bool);
46 typedef my_hash_value_type (*my_hash_function)(CHARSET_INFO *,
47                                                const uchar *, size_t);
48 typedef void (*my_hash_free_key)(void *);
49 typedef my_bool (*my_hash_walk_action)(void *,void *);
50 
51 typedef struct st_hash {
52   size_t key_offset,key_length;		/* Length of key if const length */
53   size_t blength;
54   ulong records;
55   uint flags;
56   DYNAMIC_ARRAY array;				/* Place for hash_keys */
57   my_hash_get_key get_key;
58   my_hash_function hash_function;
59   void (*free)(void *);
60   CHARSET_INFO *charset;
61 } HASH;
62 
63 /* A search iterator state */
64 typedef uint HASH_SEARCH_STATE;
65 
66 #define my_hash_init(A,B,C,D,E,F,G,H) my_hash_init2(A,0,B,C,D,E,F,0,G,H)
67 my_bool my_hash_init2(HASH *hash, uint growth_size, CHARSET_INFO *charset,
68                       ulong default_array_elements, size_t key_offset,
69                       size_t key_length, my_hash_get_key get_key,
70                       my_hash_function hash_function,
71                       void (*free_element)(void*),
72                       uint flags);
73 void my_hash_free(HASH *tree);
74 void my_hash_reset(HASH *hash);
75 uchar *my_hash_element(HASH *hash, size_t idx);
76 uchar *my_hash_search(const HASH *info, const uchar *key, size_t length);
77 uchar *my_hash_search_using_hash_value(const HASH *info,
78                                        my_hash_value_type hash_value,
79                                        const uchar *key, size_t length);
80 my_hash_value_type my_hash_sort(CHARSET_INFO *cs,
81                                 const uchar *key, size_t length);
82 #define my_calc_hash(A, B, C) my_hash_sort((A)->charset, B, C)
83 uchar *my_hash_first(const HASH *info, const uchar *key, size_t length,
84                      HASH_SEARCH_STATE *state);
85 uchar *my_hash_first_from_hash_value(const HASH *info,
86                                      my_hash_value_type hash_value,
87                                      const uchar *key,
88                                      size_t length,
89                                      HASH_SEARCH_STATE *state);
90 uchar *my_hash_next(const HASH *info, const uchar *key, size_t length,
91                     HASH_SEARCH_STATE *state);
92 my_bool my_hash_insert(HASH *info, const uchar *data);
93 my_bool my_hash_delete(HASH *hash, uchar *record);
94 my_bool my_hash_update(HASH *hash, uchar *record, uchar *old_key,
95                        size_t old_key_length);
96 void my_hash_replace(HASH *hash, HASH_SEARCH_STATE *state, uchar *new_row);
97 my_bool my_hash_check(HASH *hash); /* Only in debug library */
98 my_bool my_hash_iterate(HASH *hash, my_hash_walk_action action, void *argument);
99 
100 #define my_hash_clear(H) bzero((char*) (H), sizeof(*(H)))
101 #define my_hash_inited(H) ((H)->blength != 0)
102 #define my_hash_init_opt(A,B,C,D,E,F,G,H) \
103           (!my_hash_inited(A) && my_hash_init(A,B,C,D,E,F,G,H))
104 
105 #ifdef	__cplusplus
106 }
107 #endif
108 #endif
109