Current File : //usr/include/mysql/server/private/my_compare.h
/* Copyright (c) 2011, Oracle and/or its affiliates.
Copyright (c) Monty Program Ab; 1991-2011
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)(ptr[1]) << 8;
return (val >> ofs) & ((1 << len) - 1);
}
static inline void set_rec_bits(uint16 bits, uchar *ptr, uchar ofs, uint len)
{
ptr[0]= (ptr[0] & ~(((1 << len) - 1) << ofs)) | (bits << ofs);
if (ofs + len > 8)
ptr[1]= (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)
extern int ha_compare_text(CHARSET_INFO *, const uchar *, size_t,
const uchar *, size_t , my_bool);
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 of index_cond_func_xxx functions.
0=ICP_NO_MATCH - index tuple doesn't satisfy the pushed index condition (the
engine should discard the tuple and go to the next one)
1=ICP_MATCH - index tuple satisfies the pushed index condition (the
engine should fetch and return the record)
2=ICP_OUT_OF_RANGE - index tuple is out range that we're scanning, e.g. this
if we're scanning "t.key BETWEEN 10 AND 20" and got a
"t.key=21" tuple (the engine should stop scanning and
return HA_ERR_END_OF_FILE right away).
3=ICP_ABORTED_BY_USER - engine must stop scanning and should return
HA_ERR_ABORTED_BY_USER right away
-1= ICP_ERROR - Reserved for internal errors in engines. Should not be
returned by index_cond_func_xxx
*/
typedef enum icp_result {
ICP_ERROR=-1,
ICP_NO_MATCH=0,
ICP_MATCH=1,
ICP_OUT_OF_RANGE=2,
ICP_ABORTED_BY_USER=3
} ICP_RESULT;
typedef ICP_RESULT (*index_cond_func_t)(void *param);
#endif /* _my_compare_h */
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