mysql5/mysql-5.7.27/sql/sql_lex_hash.cc

107 lines
3.6 KiB
C++

/*
Copyright (c) 2015 Oracle and/or its affiliates. All rights reserved.
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,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
#include "lex_hash.h"
#include "sql_lex_hash.h"
#include "lex.h"
const Lex_hash Lex_hash::sql_keywords(sql_keywords_map, sql_keywords_max_len);
const Lex_hash Lex_hash::sql_keywords_and_funcs(sql_keywords_and_funcs_map,
sql_keywords_and_funcs_max_len);
const Lex_hash Lex_hash::hint_keywords(hint_keywords_map,
hint_keywords_max_len);
/*
The following data is based on the latin1 character set, and is only
used when comparing keywords
*/
static const uchar to_upper_lex[]=
{
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
96, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,123,124,125,126,127,
128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,
176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,
192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
208,209,210,211,212,213,214,247,216,217,218,219,220,221,222,255
};
inline int lex_casecmp(const char *s, const char *t, uint len)
{
while (len-- != 0 &&
to_upper_lex[(uchar) *s++] == to_upper_lex[(uchar) *t++]) ;
return (int) len + 1;
}
const SYMBOL *Lex_hash::get_hash_symbol(const char *s, unsigned int len) const
{
const char *cur_str= s;
if (len == 0)
{
DBUG_PRINT("warning",
("get_hash_symbol() received a request for a zero-length symbol,"
" which is probably a mistake."));
return NULL;
}
if (len > entry_max_len)
return NULL;
uint32 cur_struct= uint4korr(hash_map + ((len - 1) * 4));
for (;;)
{
uchar first_char= (uchar) cur_struct;
if (first_char == 0)
{
uint16 ires= (uint16) (cur_struct >> 16);
if (ires == array_elements(symbols))
return NULL;
const SYMBOL *res= symbols + ires;
uint count= (uint) (cur_str - s);
return lex_casecmp(cur_str, res->name + count, len - count) ? NULL : res;
}
uchar cur_char= (uchar) to_upper_lex[(uchar) *cur_str];
if (cur_char < first_char)
return NULL;
cur_struct>>= 8;
if (cur_char > (uchar) cur_struct)
return NULL;
cur_struct>>= 8;
cur_struct= uint4korr(hash_map +
(((uint16) cur_struct + cur_char - first_char) * 4));
cur_str++;
}
}