~drizzle-trunk/drizzle/development

/* -*- 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