~drizzle-trunk/drizzle/development

/* 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; 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., 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)

/* flags for hash_init */

#define HASH_UNIQUE     1       /* hash_insert fails on duplicate key */

typedef uchar *(*hash_get_key)(const uchar *,size_t*,bool);

typedef void (*hash_free_key)(void *);

typedef struct st_hash {

  size_t key_offset,key_length;		/* Length of key if const length */

  size_t blength;

  uint32_t records;

  uint flags;

  DYNAMIC_ARRAY array;				/* Place for hash_keys */

  hash_get_key get_key;

  void (*free)(void *);

  const 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,0,B,C,D,E,F,G,H CALLER_INFO)

#define hash_init2(A,B,C,D,E,F,G,H,I) _hash_init(A,B,C,D,E,F,G,H,I CALLER_INFO)

bool _hash_init(HASH *hash, uint 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*), uint flags CALLER_INFO_PROTO);

void hash_free(HASH *tree);

void my_hash_reset(HASH *hash);

uchar *hash_element(HASH *hash,uint32_t idx);

uchar *hash_search(const HASH *info, const uchar *key, size_t length);

uchar *hash_first(const HASH *info, const uchar *key, size_t length,

                HASH_SEARCH_STATE *state);

uchar *hash_next(const HASH *info, const uchar *key, size_t length,

                 HASH_SEARCH_STATE *state);

bool my_hash_insert(HASH *info,const uchar *data);

bool hash_delete(HASH *hash,uchar *record);

bool hash_update(HASH *hash,uchar *record,uchar *old_key,size_t old_key_length);

void hash_replace(HASH *hash, HASH_SEARCH_STATE *state, uchar *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 CALLER_INFO))

#ifdef	__cplusplus

}

#endif

#endif