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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems
*
* 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 02110-1301 USA
*/
/* Dynamic hashing of record with different key-length */
#ifndef MYSYS_HASH_H
#define MYSYS_HASH_H
#include <mysys/my_sys.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)
/* flags for hash_init */
#define HASH_UNIQUE 1 /* hash_insert fails on duplicate key */
typedef unsigned char *(*hash_get_key)(const unsigned char *,size_t*,bool);
typedef void (*hash_free_key)(void *);
typedef struct st_hash {
/* Length of key if const length */
size_t key_offset,key_length;
size_t blength;
uint32_t records;
uint32_t flags;
/* Place for hash_keys */
DYNAMIC_ARRAY array;
hash_get_key get_key;
void (*free)(void *);
const CHARSET_INFO *charset;
} HASH;
/* A search iterator state */
typedef uint32_t HASH_SEARCH_STATE;
bool _hash_init(HASH *hash, uint32_t growth_size,
const CHARSET_INFO * const charset,
uint32_t default_array_elements, size_t key_offset,
size_t key_length, hash_get_key get_key,
void (*free_element)(void*), uint32_t flags);
#define hash_init(A,B,C,D,E,F,G,H) _hash_init(A,0,B,C,D,E,F,G,H)
#define hash_init2(A,B,C,D,E,F,G,H,I) _hash_init(A,B,C,D,E,F,G,H,I)
void hash_free(HASH *tree);
void my_hash_reset(HASH *hash);
unsigned char *hash_element(HASH *hash,uint32_t idx);
unsigned char *hash_search(const HASH *info, const unsigned char *key,
size_t length);
unsigned char *hash_first(const HASH *info, const unsigned char *key,
size_t length, HASH_SEARCH_STATE *state);
unsigned char *hash_next(const HASH *info, const unsigned char *key,
size_t length, HASH_SEARCH_STATE *state);
bool my_hash_insert(HASH *info,const unsigned char *data);
bool hash_delete(HASH *hash,unsigned char *record);
bool hash_update(HASH *hash,unsigned char *record, unsigned char *old_key,
size_t old_key_length);
void hash_replace(HASH *hash, HASH_SEARCH_STATE *state, unsigned char *new_row);
#define hash_clear(H) memset((H), 0, sizeof(*(H)))
#define hash_inited(H) ((H)->array.buffer != 0)
#define hash_init_opt(A,B,C,D,E,F,G,H) \
(!hash_inited(A) && _hash_init(A,0,B,C,D,E,F,G, H))
#ifdef __cplusplus
}
#endif
#endif
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