Viewing file:  hash.h (2.51 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* Copyright (C) 2000 MySQL 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; either version 2 of the License, or
(at your option) any later version.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
/* Dynamic hashing of record with different key-length */
#ifndef _hash_h
#define _hash_h
#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)
typedef byte *(*hash_get_key)(const byte *,uint*,my_bool);
typedef void (*hash_free_key)(void *);
typedef struct st_hash {
uint key_offset,key_length; /* Length of key if const length */
uint records, blength;
uint flags;
DYNAMIC_ARRAY array; /* Place for hash_keys */
hash_get_key get_key;
void (*free)(void *);
CHARSET_INFO *charset;
} HASH;
/* A search iterator state */
typedef uint HASH_SEARCH_STATE;
#define hash_init(A,B,C,D,E,F,G,H) _hash_init(A,B,C,D,E,F,G, H CALLER_INFO)
my_bool _hash_init(HASH *hash, CHARSET_INFO *charset,
uint default_array_elements, uint key_offset,
uint key_length, hash_get_key get_key,
void (*free_element)(void*), uint flags CALLER_INFO_PROTO);
void hash_free(HASH *tree);
void my_hash_reset(HASH *hash);
byte *hash_element(HASH *hash,uint idx);
gptr hash_search(const HASH *info, const byte *key, uint length);
gptr hash_first(const HASH *info, const byte *key, uint length,
HASH_SEARCH_STATE *state);
gptr hash_next(const HASH *info, const byte *key, uint length,
HASH_SEARCH_STATE *state);
my_bool my_hash_insert(HASH *info,const byte *data);
my_bool hash_delete(HASH *hash,byte *record);
my_bool hash_update(HASH *hash,byte *record,byte *old_key,uint old_key_length);
void hash_replace(HASH *hash, HASH_SEARCH_STATE *state, byte *new_row);
my_bool hash_check(HASH *hash); /* Only in debug library */
#define hash_clear(H) bzero((char*) (H),sizeof(*(H)))
#define hash_inited(H) ((H)->array.buffer != 0)
#ifdef __cplusplus
}
#endif
#endif
|