Current File : //usr/include/mysql/server/private/hash.h
/* Copyright (c) 2000, 2010, Oracle and/or its affiliates.
Copyright (c) 2011, 2013, Monty Program Ab.
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 */
/* Dynamic hashing of record with different key-length */
#ifndef _hash_h
#define _hash_h
#include "my_sys.h" /* DYNAMIC_ARRAY */
/*
This forward declaration is used from C files where the real
definition is included before. Since C does not allow repeated
typedef declarations, even when identical, the definition may not be
repeated.
*/
#ifdef __cplusplus
extern "C" {
#endif
/*
Overhead to store an element in hash
Can be used to approximate memory consumption for a hash
*/
#define HASH_OVERHEAD (sizeof(char*)*2)
/* flags for hash_init */
#define HASH_UNIQUE 1 /* hash_insert fails on duplicate key */
#define HASH_THREAD_SPECIFIC 2 /* Mark allocated memory THREAD_SPECIFIC */
typedef uint32 my_hash_value_type;
typedef uchar *(*my_hash_get_key)(const uchar *,size_t*,my_bool);
typedef my_hash_value_type (*my_hash_function)(CHARSET_INFO *,
const uchar *, size_t);
typedef void (*my_hash_free_key)(void *);
typedef my_bool (*my_hash_walk_action)(void *,void *);
typedef struct st_hash {
size_t key_offset,key_length; /* Length of key if const length */
size_t blength;
ulong records;
uint flags;
DYNAMIC_ARRAY array; /* Place for hash_keys */
my_hash_get_key get_key;
my_hash_function hash_function;
void (*free)(void *);
CHARSET_INFO *charset;
} HASH;
/* A search iterator state */
typedef uint HASH_SEARCH_STATE;
#define my_hash_init(A,B,C,D,E,F,G,H,I) my_hash_init2(A,B,0,C,D,E,F,G,0,H,I)
my_bool my_hash_init2(PSI_memory_key psi_key, HASH *hash, uint growth_size,
CHARSET_INFO *charset, ulong default_array_elements,
size_t key_offset, size_t key_length,
my_hash_get_key get_key, my_hash_function hash_function,
void (*free_element)(void*), uint flags);
void my_hash_free(HASH *tree);
void my_hash_reset(HASH *hash);
uchar *my_hash_element(HASH *hash, size_t idx);
uchar *my_hash_search(const HASH *info, const uchar *key, size_t length);
uchar *my_hash_search_using_hash_value(const HASH *info,
my_hash_value_type hash_value,
const uchar *key, size_t length);
my_hash_value_type my_hash_sort(CHARSET_INFO *cs,
const uchar *key, size_t length);
#define my_calc_hash(A, B, C) my_hash_sort((A)->charset, B, C)
uchar *my_hash_first(const HASH *info, const uchar *key, size_t length,
HASH_SEARCH_STATE *state);
uchar *my_hash_first_from_hash_value(const HASH *info,
my_hash_value_type hash_value,
const uchar *key,
size_t length,
HASH_SEARCH_STATE *state);
uchar *my_hash_next(const HASH *info, const uchar *key, size_t length,
HASH_SEARCH_STATE *state);
my_bool my_hash_insert(HASH *info, const uchar *data);
my_bool my_hash_delete(HASH *hash, uchar *record);
my_bool my_hash_update(HASH *hash, uchar *record, uchar *old_key,
size_t old_key_length);
void my_hash_replace(HASH *hash, HASH_SEARCH_STATE *state, uchar *new_row);
my_bool my_hash_check(HASH *hash); /* Only in debug library */
my_bool my_hash_iterate(HASH *hash, my_hash_walk_action action, void *argument);
#define my_hash_clear(H) bzero((char*) (H), sizeof(*(H)))
#define my_hash_inited(H) ((H)->blength != 0)
#define my_hash_init_opt(A,B,C,D,E,F,G,H,I) \
(!my_hash_inited(B) && my_hash_init(A,B,C,D,E,F,G,H,I))
#ifdef __cplusplus
}
#endif
#endif
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