~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

 */

#ifndef DRIZZLED_HANDLER_STRUCTS_H

#define DRIZZLED_HANDLER_STRUCTS_H

#include <stdint.h>

#include <time.h>

#include <drizzled/base.h>

#include <drizzled/structs.h>

#include <drizzled/definitions.h>

#include <drizzled/lex_string.h>

class Ha_trx_info;

struct st_key;

typedef struct st_key KEY;

struct st_key_cache;

typedef struct st_key_cache KEY_CACHE;

namespace drizzled

{

namespace plugin

{

class StorageEngine;

}

}

struct Session_TRANS

{

  Session_TRANS() {};

  /* true is not all entries in the engines[] support 2pc */

  bool        no_2pc;

  /* storage engines that registered in this transaction */

  Ha_trx_info *ha_list;

  /*

    The purpose of this flag is to keep track of non-transactional

    tables that were modified in scope of:

    - transaction, when the variable is a member of

    Session::transaction.all

    - top-level statement or sub-statement, when the variable is a

    member of Session::transaction.stmt

    This member has the following life cycle:

    * stmt.modified_non_trans_table is used to keep track of

    modified non-transactional tables of top-level statements. At

    the end of the previous statement and at the beginning of the session,

    it is reset to false.  If such functions

    as mysql_insert, mysql_update, mysql_delete etc modify a

    non-transactional table, they set this flag to true.  At the

    end of the statement, the value of stmt.modified_non_trans_table

    is merged with all.modified_non_trans_table and gets reset.

    * all.modified_non_trans_table is reset at the end of transaction

    * Since we do not have a dedicated context for execution of a

    sub-statement, to keep track of non-transactional changes in a

    sub-statement, we re-use stmt.modified_non_trans_table.

    At entrance into a sub-statement, a copy of the value of

    stmt.modified_non_trans_table (containing the changes of the

    outer statement) is saved on stack. Then

    stmt.modified_non_trans_table is reset to false and the

    substatement is executed. Then the new value is merged with the

    saved value.

  */

  bool modified_non_trans_table;

  void reset() { no_2pc= false; modified_non_trans_table= false; }

};

typedef struct st_ha_create_information

{

  const CHARSET_INFO *table_charset, *default_table_charset;

  const char *alias;

  uint64_t auto_increment_value;

  uint32_t table_options;

  uint32_t used_fields;

  enum row_type row_type;

  drizzled::plugin::StorageEngine *db_type;

  bool table_existed;			/* 1 in create if table existed */

} HA_CREATE_INFO;

typedef struct st_ha_alter_information

{

  KEY  *key_info_buffer;

  uint32_t key_count;

  uint32_t index_drop_count;

  uint32_t *index_drop_buffer;

  uint32_t index_add_count;

  uint32_t *index_add_buffer;

  void *data;

} HA_ALTER_INFO;

typedef struct st_key_create_information

{

  enum ha_key_alg algorithm;

  uint32_t block_size;

  LEX_STRING comment;

} KEY_CREATE_INFO;

typedef struct st_ha_check_opt

{

  st_ha_check_opt() {}                        /* Remove gcc warning */

} HA_CHECK_OPT;

typedef struct st_range_seq_if

{

  /*

    Initialize the traversal of range sequence

    SYNOPSIS

    init()

    init_params  The seq_init_param parameter

    n_ranges     The number of ranges obtained

    flags        A combination of HA_MRR_SINGLE_POINT, HA_MRR_FIXED_KEY

    RETURN

    An opaque value to be used as RANGE_SEQ_IF::next() parameter

  */

  range_seq_t (*init)(void *init_params, uint32_t n_ranges, uint32_t flags);

  /*

    Get the next range in the range sequence

    SYNOPSIS

    next()

    seq    The value returned by RANGE_SEQ_IF::init()

    range  OUT Information about the next range

    RETURN

    0 - Ok, the range structure filled with info about the next range

    1 - No more ranges

  */

  uint32_t (*next) (range_seq_t seq, KEY_MULTI_RANGE *range);

} RANGE_SEQ_IF;

/*

  This is a buffer area that the handler can use to store rows.

  'end_of_used_area' should be kept updated after calls to

  read-functions so that other parts of the code can use the

  remaining area (until next read calls is issued).

*/

typedef struct st_handler_buffer

{

  unsigned char *buffer;         /* Buffer one can start using */

  unsigned char *buffer_end;     /* End of buffer */

  unsigned char *end_of_used_area;     /* End of area that was used by handler */

} HANDLER_BUFFER;

#endif /* DRIZZLED_HANDLER_STRUCTS_H */