~drizzle-trunk/drizzle/development

/* Copyright (C) 2003 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 */

#include <sys/types.h>

#include <sys/stat.h>

#include "transparent_file.h"

#define DEFAULT_CHAIN_LENGTH 512

/*

  Version for file format.

  1 - Initial Version. That is, the version when the metafile was introduced.

*/

#define TINA_VERSION 1

typedef struct st_tina_share {

  char *table_name;

  char data_file_name[FN_REFLEN];

  uint table_name_length, use_count;

  /*

    Below flag is needed to make log tables work with concurrent insert.

    For more details see comment to ha_tina::update_status.

  */

  my_bool is_log_table;

  /*

    Here we save the length of the file for readers. This is updated by

    inserts, updates and deletes. The var is initialized along with the

    share initialization.

  */

  off_t saved_data_file_length;

  pthread_mutex_t mutex;

  THR_LOCK lock;

  bool update_file_opened;

  bool tina_write_opened;

  File meta_file;           /* Meta file we use */

  File tina_write_filedes;  /* File handler for readers */

  bool crashed;             /* Meta file is crashed */

  ha_rows rows_recorded;    /* Number of rows in tables */

  uint data_file_version;   /* Version of the data file used */

} TINA_SHARE;

struct tina_set {

  off_t begin;

  off_t end;

};

class ha_tina: public handler

{

  THR_LOCK_DATA lock;      /* MySQL lock */

  TINA_SHARE *share;       /* Shared lock info */

  off_t current_position;  /* Current position in the file during a file scan */

  off_t next_position;     /* Next position in the file scan */

  off_t local_saved_data_file_length; /* save position for reads */

  off_t temp_file_length;

  uchar byte_buffer[IO_SIZE];

  Transparent_file *file_buff;

  File data_file;                   /* File handler for readers */

  File update_temp_file;

  String buffer;

  /*

    The chain contains "holes" in the file, occured because of

    deletes/updates. It is used in rnd_end() to get rid of them

    in the end of the query.

  */

  tina_set chain_buffer[DEFAULT_CHAIN_LENGTH];

  tina_set *chain;

  tina_set *chain_ptr;

  uchar chain_alloced;

  uint32_t chain_size;

  uint local_data_file_version;  /* Saved version of the data file used */

  bool records_is_known;

  MEM_ROOT blobroot;

private:

  bool get_write_pos(off_t *end_pos, tina_set *closest_hole);

  int open_update_temp_file_if_needed();

  int init_tina_writer();

  int init_data_file();

public:

  ha_tina(handlerton *hton, TABLE_SHARE *table_arg);

  ~ha_tina()

  {

    if (chain_alloced)

      my_free(chain, 0);

    if (file_buff)

      delete file_buff;

  }

  const char *table_type(void) const { return "CSV"; }

  const char *index_type(uint inx __attribute__((unused)))

  { return "NONE"; }

  const char **bas_ext() const;

  uint64_t table_flags() const

  {

    return (HA_NO_TRANSACTIONS | HA_REC_NOT_IN_SEQ | HA_NO_AUTO_INCREMENT |

            HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE);

  }

  uint32_t index_flags(uint idx __attribute__((unused)),

                       uint part __attribute__((unused)),

                       bool all_parts __attribute__((unused))) const

  {

    /*

      We will never have indexes so this will never be called(AKA we return

      zero)

    */

    return 0;

  }

  uint max_record_length() const { return HA_MAX_REC_LENGTH; }

  uint max_keys()          const { return 0; }

  uint max_key_parts()     const { return 0; }

  uint max_key_length()    const { return 0; }

  /*

     Called in test_quick_select to determine if indexes should be used.

   */

  virtual double scan_time() { return (double) (stats.records+stats.deleted) / 20.0+10; }

  /* The next method will never be called */

  virtual bool fast_key_read() { return 1;}

  /* 

    TODO: return actual upper bound of number of records in the table.

    (e.g. save number of records seen on full table scan and/or use file size

    as upper bound)

  */

  ha_rows estimate_rows_upper_bound() { return HA_POS_ERROR; }

  int open(const char *name, int mode, uint open_options);

  int close(void);

  int write_row(uchar * buf);

  int update_row(const uchar * old_data, uchar * new_data);

  int delete_row(const uchar * buf);

  int rnd_init(bool scan=1);

  int rnd_next(uchar *buf);

  int rnd_pos(uchar * buf, uchar *pos);

  bool check_and_repair(THD *thd);

  int check(THD* thd, HA_CHECK_OPT* check_opt);

  bool is_crashed() const;

  int rnd_end();

  int repair(THD* thd, HA_CHECK_OPT* check_opt);

  /* This is required for SQL layer to know that we support autorepair */

  bool auto_repair() const { return 1; }

  void position(const uchar *record);

  int info(uint);

  int delete_all_rows(void);

  int create(const char *name, TABLE *form, HA_CREATE_INFO *create_info);

  bool check_if_incompatible_data(HA_CREATE_INFO *info,

                                  uint table_changes);

  THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,

      enum thr_lock_type lock_type);

  /*

    These functions used to get/update status of the handler.

    Needed to enable concurrent inserts.

  */

  void get_status();

  void update_status();

  /* The following methods were added just for TINA */

  int encode_quote(uchar *buf);

  int find_current_row(uchar *buf);

  int chain_append();

};