mirror of
https://github.com/MariaDB/server.git
synced 2025-01-15 19:42:28 +01:00
285 lines
11 KiB
C
285 lines
11 KiB
C
/* Copyright (c) 2011, Oracle and/or its affiliates.
|
|
Copyright (c) 1991, 2021, MariaDB Corporation.
|
|
|
|
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 Street, Fifth Floor, Boston, MA 02110-1335 USA */
|
|
|
|
#ifndef _my_compare_h
|
|
#define _my_compare_h
|
|
|
|
#include "myisampack.h"
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#include "m_ctype.h" /* CHARSET_INFO */
|
|
|
|
/*
|
|
There is a hard limit for the maximum number of keys as there are only
|
|
8 bits in the index file header for the number of keys in a table.
|
|
This means that 0..255 keys can exist for a table. The idea of
|
|
HA_MAX_POSSIBLE_KEY is to ensure that one can use myisamchk & tools on
|
|
a MyISAM table for which one has more keys than MyISAM is normally
|
|
compiled for. If you don't have this, you will get a core dump when
|
|
running myisamchk compiled for 128 keys on a table with 255 keys.
|
|
*/
|
|
|
|
#define HA_MAX_POSSIBLE_KEY 255 /* For myisamchk */
|
|
/*
|
|
The following defines can be increased if necessary.
|
|
But beware the dependency of MI_MAX_POSSIBLE_KEY_BUFF and HA_MAX_KEY_LENGTH.
|
|
*/
|
|
|
|
#define HA_MAX_KEY_LENGTH 1000 /* Max length in bytes */
|
|
#define HA_MAX_KEY_SEG 32 /* Max segments for key */
|
|
|
|
#define HA_MAX_POSSIBLE_KEY_BUFF (HA_MAX_KEY_LENGTH + 24+ 6+6)
|
|
#define HA_MAX_KEY_BUFF (HA_MAX_KEY_LENGTH+HA_MAX_KEY_SEG*6+8+8)
|
|
|
|
typedef struct st_HA_KEYSEG /* Key-portion */
|
|
{
|
|
CHARSET_INFO *charset;
|
|
uint32 start; /* Start of key in record */
|
|
uint32 null_pos; /* position to NULL indicator */
|
|
uint16 bit_pos; /* Position to bit part */
|
|
uint16 flag;
|
|
uint16 length; /* Keylength */
|
|
uint16 language;
|
|
uint8 type; /* Type of key (for sort) */
|
|
uint8 null_bit; /* bitmask to test for NULL */
|
|
uint8 bit_start;
|
|
uint8 bit_length; /* Length of bit part */
|
|
} HA_KEYSEG;
|
|
|
|
#define get_key_length(length,key) \
|
|
{ if (*(const uchar*) (key) != 255) \
|
|
length= (uint) *(const uchar*) ((key)++); \
|
|
else \
|
|
{ length= mi_uint2korr((key)+1); (key)+=3; } \
|
|
}
|
|
|
|
#define get_key_length_rdonly(length,key) \
|
|
{ if (*(const uchar*) (key) != 255) \
|
|
length= ((uint) *(const uchar*) ((key))); \
|
|
else \
|
|
{ length= mi_uint2korr((key)+1); } \
|
|
}
|
|
|
|
#define get_key_pack_length(length,length_pack,key) \
|
|
{ if (*(const uchar*) (key) != 255) \
|
|
{ length= (uint) *(const uchar*) ((key)++); length_pack= 1; }\
|
|
else \
|
|
{ length=mi_uint2korr((key)+1); (key)+= 3; length_pack= 3; } \
|
|
}
|
|
|
|
#define store_key_length_inc(key,length) \
|
|
{ if ((length) < 255) \
|
|
{ *(key)++= (uchar)(length); } \
|
|
else \
|
|
{ *(key)=255; mi_int2store((key)+1,(length)); (key)+=3; } \
|
|
}
|
|
|
|
#define size_to_store_key_length(length) ((length) < 255 ? 1 : 3)
|
|
|
|
static inline uchar get_rec_bits(const uchar *ptr, uchar ofs, uint len)
|
|
{
|
|
uint16 val= ptr[0];
|
|
if (ofs + len > 8)
|
|
val|= (uint16)(((uint) ptr[1]) << 8);
|
|
return (uchar) ((val >> ofs) & ((1 << len) - 1));
|
|
}
|
|
|
|
static inline void set_rec_bits(uint16 bits, uchar *ptr, uchar ofs, uint len)
|
|
{
|
|
ptr[0]= (uchar) ((ptr[0] & ~(((1 << len) - 1) << ofs)) | (bits << ofs));
|
|
if (ofs + len > 8)
|
|
ptr[1]= (uchar) ((ptr[1] & ~((1 << (len - 8 + ofs)) - 1)) |
|
|
bits >> (8 - ofs));
|
|
}
|
|
|
|
#define clr_rec_bits(bit_ptr, bit_ofs, bit_len) \
|
|
set_rec_bits(0, bit_ptr, bit_ofs, bit_len)
|
|
|
|
|
|
/*
|
|
Compare two VARCHAR values.
|
|
@param charset_info - The character set and collation
|
|
@param a - The pointer to the first string
|
|
@param a_length - The length of the first string
|
|
@param b - The pointer to the second string
|
|
@param b_length - The length of the second string
|
|
@param b_is_prefix - Whether "b" is a prefix of "a",
|
|
e.g. in a prefix key (partial length key).
|
|
@returns - The result of comparison
|
|
|
|
- If "b_is_prefix" is FALSE, then the two strings are compared
|
|
taking into account the PAD SPACE/NO PAD attribute of the collation.
|
|
|
|
- If "b_is_prefix" is TRUE, then trailing spaces are compared in NO PAD style.
|
|
This is done e.g. when we compare a column value to its prefix key value
|
|
(the value of "a" to the value of "key_a"):
|
|
CREATE TABLE t1 (a VARCHAR(10), KEY(key_a(5));
|
|
*/
|
|
static inline int ha_compare_char_varying(CHARSET_INFO *charset_info,
|
|
const uchar *a, size_t a_length,
|
|
const uchar *b, size_t b_length,
|
|
my_bool b_is_prefix)
|
|
{
|
|
if (!b_is_prefix)
|
|
return charset_info->coll->strnncollsp(charset_info, a, a_length,
|
|
b, b_length);
|
|
return charset_info->coll->strnncoll(charset_info,
|
|
a, a_length,
|
|
b, b_length, TRUE/*prefix*/);
|
|
}
|
|
|
|
|
|
/*
|
|
Compare two CHAR values of the same declared character length,
|
|
e.g. CHAR(5) to CHAR(5).
|
|
|
|
@param charset_info - The character set and collation
|
|
@param a - The pointer to the first string
|
|
@param a_length - The length of the first string
|
|
@param b - The pointer to the second string
|
|
@param b_length - The length of the second string
|
|
@param nchars - The declared length (in characters)
|
|
@param b_is_prefix - Whether "b" is a prefix of "a",
|
|
e.g. in a prefix key (partial length key).
|
|
@returns - The result of comparison
|
|
|
|
- If "b_is_prefix" is FALSE, then the two strings are compared
|
|
taking into account the PAD SPACE/NO PAD attribute of the collation.
|
|
Additionally, this function assumes that the underlying storage could
|
|
optionally apply trailing space compression, so values can come into this
|
|
comparison function in different states:
|
|
- all trailing spaces removed
|
|
- some trailing spaced removed
|
|
- no trailing spaces removed (exactly "nchars" characters on the two sides)
|
|
This function virtually reconstructs trailing spaces up to the defined
|
|
length specified in "nchars".
|
|
If either of the sides have more than "nchar" characters,
|
|
then only leftmost "nchar" characters are compared.
|
|
|
|
- If "b_is_prefix" is TRUE, then trailing spaces are compared in NO PAD style.
|
|
This is done e.g. when we compare a column value to its prefix key value
|
|
(the value of "a" to the value of "key_a"):
|
|
CREATE TABLE t1 (a CHAR(10), KEY(key_a(5));
|
|
*/
|
|
static inline int ha_compare_char_fixed(CHARSET_INFO *charset_info,
|
|
const uchar *a, size_t a_length,
|
|
const uchar *b, size_t b_length,
|
|
size_t nchars,
|
|
my_bool b_is_prefix)
|
|
{
|
|
if (!b_is_prefix)
|
|
return charset_info->coll->strnncollsp_nchars(charset_info,
|
|
a, a_length,
|
|
b, b_length,
|
|
nchars,
|
|
MY_STRNNCOLLSP_NCHARS_EMULATE_TRIMMED_TRAILING_SPACES);
|
|
return charset_info->coll->strnncoll(charset_info,
|
|
a, a_length,
|
|
b, b_length, TRUE/*prefix*/);
|
|
}
|
|
|
|
|
|
/*
|
|
A function to compare words of a text.
|
|
This is a common operation in full-text search:
|
|
SELECT MATCH (title) AGAINST ('word') FROM t1;
|
|
*/
|
|
static inline int ha_compare_word(CHARSET_INFO *charset_info,
|
|
const uchar *a, size_t a_length,
|
|
const uchar *b, size_t b_length)
|
|
{
|
|
return charset_info->coll->strnncollsp(charset_info,
|
|
a, a_length,
|
|
b, b_length);
|
|
}
|
|
|
|
|
|
/*
|
|
A function to compare a word of a text to a word prefix.
|
|
This is a common operation in full-text search:
|
|
SELECT MATCH (title) AGAINST ('wor*' IN BOOLEAN MODE) FROM t1;
|
|
*/
|
|
static inline int ha_compare_word_prefix(CHARSET_INFO *charset_info,
|
|
const uchar *a, size_t a_length,
|
|
const uchar *b, size_t b_length)
|
|
{
|
|
return charset_info->coll->strnncoll(charset_info,
|
|
a, a_length,
|
|
b, b_length,
|
|
TRUE/*b_is_prefix*/);
|
|
}
|
|
|
|
|
|
/*
|
|
Compare words (full match or prefix match), e.g. for full-text search.
|
|
*/
|
|
static inline int ha_compare_word_or_prefix(CHARSET_INFO *charset_info,
|
|
const uchar *a, size_t a_length,
|
|
const uchar *b, size_t b_length,
|
|
my_bool b_is_prefix)
|
|
{
|
|
if (!b_is_prefix)
|
|
return ha_compare_word(charset_info, a, a_length, b, b_length);
|
|
return ha_compare_word_prefix(charset_info, a, a_length, b, b_length);
|
|
}
|
|
|
|
|
|
extern int ha_key_cmp(HA_KEYSEG *keyseg, const uchar *a,
|
|
const uchar *b, uint key_length, uint nextflag,
|
|
uint *diff_pos);
|
|
extern HA_KEYSEG *ha_find_null(HA_KEYSEG *keyseg, const uchar *a);
|
|
|
|
/*
|
|
Inside an in-memory data record, memory pointers to pieces of the
|
|
record (like BLOBs) are stored in their native byte order and in
|
|
this amount of bytes.
|
|
*/
|
|
#define portable_sizeof_char_ptr 8
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
Return values for pushed index condition or rowid filter check functions.
|
|
|
|
0=CHECK_NEG - The filter is not satisfied. The engine should discard this
|
|
index tuple and continue the scan.
|
|
1=CHECK_POS - The filter is satisfied. Current index tuple should be
|
|
returned to the SQL layer.
|
|
2=CHECK_OUT_OF_RANGE - the index tuple is outside of the range that we're
|
|
scanning. (Example: if we're scanning "t.key BETWEEN 10 AND
|
|
20" and got a "t.key=21" tuple) Tthe engine should stop
|
|
scanning and return HA_ERR_END_OF_FILE right away).
|
|
3=CHECK_ABORTED_BY_USER - the engine must stop scanning and should return
|
|
HA_ERR_ABORTED_BY_USER right away
|
|
-1=CHECK_ERROR - Reserved for internal errors in engines. Should not be
|
|
returned by ICP or rowid filter check functions.
|
|
*/
|
|
|
|
typedef enum check_result {
|
|
CHECK_ERROR=-1,
|
|
CHECK_NEG=0,
|
|
CHECK_POS=1,
|
|
CHECK_OUT_OF_RANGE=2,
|
|
CHECK_ABORTED_BY_USER=3
|
|
} check_result_t;
|
|
|
|
typedef check_result_t (*index_cond_func_t)(void *param);
|
|
typedef check_result_t (*rowid_filter_func_t)(void *param);
|
|
|
|
#endif /* _my_compare_h */
|