ha_tina.h
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:5k
- /* 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; either version 2 of the License, or
- (at your option) any later version.
- 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 <my_dir.h>
- #define DEFAULT_CHAIN_LENGTH 512
- typedef struct st_tina_share {
- char *table_name;
- byte *mapped_file; /* mapped region of file */
- uint table_name_length,use_count;
- MY_STAT file_stat; /* Stat information for the data file */
- File data_file; /* Current open data file */
- pthread_mutex_t mutex;
- THR_LOCK lock;
- } TINA_SHARE;
- typedef 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 */
- byte byte_buffer[IO_SIZE];
- String buffer;
- tina_set chain_buffer[DEFAULT_CHAIN_LENGTH];
- tina_set *chain;
- tina_set *chain_ptr;
- byte chain_alloced;
- uint32 chain_size;
- public:
- ha_tina(TABLE *table): handler(table),
- /*
- These definitions are found in hanler.h
- Theses are not probably completely right.
- */
- current_position(0), next_position(0), chain_alloced(0), chain_size(DEFAULT_CHAIN_LENGTH)
- {
- /* Set our original buffers from pre-allocated memory */
- buffer.set(byte_buffer, IO_SIZE, system_charset_info);
- chain = chain_buffer;
- }
- ~ha_tina()
- {
- if (chain_alloced)
- my_free((gptr)chain,0);
- }
- const char *table_type() const { return "CSV"; }
- const char *index_type(uint inx) { return "NONE"; }
- const char **bas_ext() const;
- ulong table_flags() const
- {
- return (HA_REC_NOT_IN_SEQ | HA_NOT_EXACT_COUNT |
- HA_NO_AUTO_INCREMENT );
- }
- ulong index_flags(uint idx, uint part, bool all_parts) 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) (records+deleted) / 20.0+10; }
- /* The next method will never be called */
- virtual double read_time(ha_rows rows) { DBUG_ASSERT(0); return((double) rows / 20.0+1); }
- 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 test_if_locked);
- int close(void);
- int write_row(byte * buf);
- int update_row(const byte * old_data, byte * new_data);
- int delete_row(const byte * buf);
- int index_read(byte * buf, const byte * key,
- uint key_len, enum ha_rkey_function find_flag);
- int index_read_idx(byte * buf, uint idx, const byte * key,
- uint key_len, enum ha_rkey_function find_flag);
- int index_next(byte * buf);
- int index_prev(byte * buf);
- int index_first(byte * buf);
- int index_last(byte * buf);
- int rnd_init(bool scan=1);
- int rnd_next(byte *buf);
- int rnd_pos(byte * buf, byte *pos);
- int rnd_end();
- void position(const byte *record);
- void info(uint);
- int extra(enum ha_extra_function operation);
- int reset(void);
- int external_lock(THD *thd, int lock_type);
- int delete_all_rows(void);
- ha_rows records_in_range(int inx, const byte *start_key,uint start_key_len,
- enum ha_rkey_function start_search_flag,
- const byte *end_key,uint end_key_len,
- enum ha_rkey_function end_search_flag);
- // int delete_table(const char *from);
- // int rename_table(const char * from, const char * to);
- int create(const char *name, TABLE *form, HA_CREATE_INFO *create_info);
- THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
- enum thr_lock_type lock_type);
- /* The following methods were added just for TINA */
- int encode_quote(byte *buf);
- int find_current_row(byte *buf);
- int chain_append();
- };