hash.h
上传用户:romrleung
上传日期:2022-05-23
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文件大小:2k
- /* 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,current_record;
- uint flags;
- DYNAMIC_ARRAY array; /* Place for hash_keys */
- hash_get_key get_key;
- void (*free)(void *);
- CHARSET_INFO *charset;
- } HASH;
- #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(HASH *info,const byte *key,uint length);
- gptr hash_next(HASH *info,const byte *key,uint length);
- 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, uint idx, 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