~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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */

#ifndef PLUGIN_CSV_HA_TINA_H

#define PLUGIN_CSV_HA_TINA_H

#include <drizzled/cursor.h>

#include <drizzled/thr_lock.h>

#include <sys/types.h>

#include <sys/stat.h>

#include "transparent_file.h"

/*

  Version for file format.

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

*/

#define TINA_VERSION 1

class TinaShare

{

  TinaShare();

  TinaShare(const TinaShare &);

  TinaShare& operator=(const TinaShare &);

public:

  explicit TinaShare(const std::string &name);

  ~TinaShare();

  std::string table_name;

  std::string data_file_name;

  uint32_t use_count;

  /*

    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;

  bool update_file_opened;

  bool tina_write_opened;

  int meta_file;           /* Meta file we use */

  int tina_write_filedes;  /* File Cursor for readers */

  bool crashed;             /* Meta file is crashed */

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

  uint32_t data_file_version;   /* Version of the data file used */

};

class ha_tina: public drizzled::Cursor

{

  drizzled::THR_LOCK_DATA lock;      /* MySQL lock */

  TinaShare *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;

  unsigned char byte_buffer[IO_SIZE];

  Transparent_file *file_buff;

  int data_file;                   /* File Cursor for readers */

  int update_temp_file;

  drizzled::String buffer;

  /*

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

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

    in the end of the query.

  */

  std::vector< std::pair<off_t, off_t> > chain;

  uint32_t local_data_file_version;  /* Saved version of the data file used */

  bool records_is_known;

  drizzled::memory::Root blobroot;

  bool get_write_pos(off_t *end_pos,

                     std::vector< std::pair<off_t, off_t> >::iterator &closest_hole);

  int open_update_temp_file_if_needed();

  int init_tina_writer();

  int init_data_file();

public:

  ha_tina(drizzled::plugin::StorageEngine &engine, drizzled::Table &table_arg);

  ~ha_tina()

  {

    if (file_buff)

      delete file_buff;

  }

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

  const char *index_type(uint32_t)

  { return "NONE"; }

  /*

     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)

  */

  drizzled::ha_rows estimate_rows_upper_bound() { return HA_POS_ERROR; }

  int doOpen(const drizzled::TableIdentifier &identifier, int mode, uint32_t test_if_locked);

  int open(const char *, int , uint32_t ) { assert(0); return -1; }

  int close(void);

  int doInsertRecord(unsigned char * buf);

  int doUpdateRecord(const unsigned char * old_data, unsigned char * new_data);

  int doDeleteRecord(const unsigned char * buf);

  int doStartTableScan(bool scan=1);

  int rnd_next(unsigned char *buf);

  int rnd_pos(unsigned char * buf, unsigned char *pos);

  int doEndTableScan();

  TinaShare *get_share(const std::string &table_name);

  int free_share();

  int repair(drizzled::Session* session, drizzled::HA_CHECK_OPT* check_opt);

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

  void position(const unsigned char *record);

  int info(uint);

  int delete_all_rows(void);

  void get_auto_increment(uint64_t, uint64_t,

                          uint64_t,

                          uint64_t *,

                          uint64_t *)

  {}

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

  int encode_quote(unsigned char *buf);

  int find_current_row(unsigned char *buf);

  int chain_append();

};

#endif /* PLUGIN_CSV_HA_TINA_H */