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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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 */
/* classes to use when handling where clause */
#ifndef _opt_range_h
#define _opt_range_h
#ifdef __GNUC__
#pragma interface /* gcc class implementation */
#endif
#define NO_MIN_RANGE 1
#define NO_MAX_RANGE 2
#define NEAR_MIN 4
#define NEAR_MAX 8
#define UNIQUE_RANGE 16
#define EQ_RANGE 32
typedef struct st_key_part {
uint16 key,part,part_length;
uint8 null_bit;
Field *field;
} KEY_PART;
class QUICK_RANGE :public Sql_alloc {
public:
char *min_key,*max_key;
uint16 min_length,max_length,flag;
QUICK_RANGE(); /* Full range */
QUICK_RANGE(const char *min_key_arg,uint min_length_arg,
const char *max_key_arg,uint max_length_arg,
uint flag_arg)
: min_key((char*) sql_memdup(min_key_arg,min_length_arg+1)),
max_key((char*) sql_memdup(max_key_arg,max_length_arg+1)),
min_length(min_length_arg),
max_length(max_length_arg),
flag(flag_arg)
{}
};
class QUICK_SELECT {
public:
bool next;
int error;
uint index,max_used_key_length;
TABLE *head;
handler *file;
byte *record;
List<QUICK_RANGE> ranges;
List_iterator<QUICK_RANGE> it;
QUICK_RANGE *range;
MEM_ROOT alloc;
KEY_PART *key_parts;
ha_rows records;
double read_time;
QUICK_SELECT(TABLE *table,uint index_arg,bool no_alloc=0);
~QUICK_SELECT();
void reset(void) { next=0; it.rewind(); }
int get_next();
int cmp_next(QUICK_RANGE *range);
bool unique_key_range();
};
class SQL_SELECT :public Sql_alloc {
public:
QUICK_SELECT *quick; // If quick-select used
COND *cond; // where condition
TABLE *head;
IO_CACHE file; // Positions to used records
ha_rows records; // Records in use if read from file
double read_time; // Time to read rows
key_map quick_keys; // Possible quick keys
key_map needed_reg; // Possible quick keys after prev tables.
table_map const_tables,read_tables;
bool free_cond;
SQL_SELECT();
~SQL_SELECT();
bool check_quick(bool force_quick_range=0, ha_rows limit = HA_POS_ERROR)
{ return test_quick_select(~0L,0,limit, force_quick_range) < 0; }
inline bool skipp_record() { return cond ? cond->val_int() == 0 : 0; }
int test_quick_select(key_map keys,table_map prev_tables,ha_rows limit,
bool force_quick_range=0);
};
QUICK_SELECT *get_quick_select_for_ref(TABLE *table, struct st_table_ref *ref);
#endif
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