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/*
Copyright (c) 2018 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _CTYPE_UTF16_H
#define _CTYPE_UTF16_H
/*
D800..DB7F - Non-provate surrogate high (896 pages)
DB80..DBFF - Private surrogate high (128 pages)
DC00..DFFF - Surrogate low (1024 codes in a page)
*/
#define MY_UTF16_SURROGATE_HIGH_FIRST 0xD800
#define MY_UTF16_SURROGATE_HIGH_LAST 0xDBFF
#define MY_UTF16_SURROGATE_LOW_FIRST 0xDC00
#define MY_UTF16_SURROGATE_LOW_LAST 0xDFFF
#define MY_UTF16_HIGH_HEAD(x) ((((uchar) (x)) & 0xFC) == 0xD8)
#define MY_UTF16_LOW_HEAD(x) ((((uchar) (x)) & 0xFC) == 0xDC)
/* Test if a byte is a leading byte of a high or low surrogate head: */
#define MY_UTF16_SURROGATE_HEAD(x) ((((uchar) (x)) & 0xF8) == 0xD8)
/* Test if a Unicode code point is a high or low surrogate head */
#define MY_UTF16_SURROGATE(x) (((x) & 0xF800) == 0xD800)
#define MY_UTF16_WC2(a, b) ((a << 8) + b)
/*
a= 110110?? (<< 18)
b= ???????? (<< 10)
c= 110111?? (<< 8)
d= ???????? (<< 0)
*/
#define MY_UTF16_WC4(a, b, c, d) (((a & 3) << 18) + (b << 10) + \
((c & 3) << 8) + d + 0x10000)
static inline int
my_mb_wc_utf16_quick(my_wc_t *pwc, const uchar *s, const uchar *e)
{
if (s + 2 > e)
return MY_CS_TOOSMALL2;
/*
High bytes: 0xD[89AB] = B'110110??'
Low bytes: 0xD[CDEF] = B'110111??'
Surrogate mask: 0xFC = B'11111100'
*/
if (MY_UTF16_HIGH_HEAD(*s)) /* Surrogate head */
{
if (s + 4 > e)
return MY_CS_TOOSMALL4;
if (!MY_UTF16_LOW_HEAD(s[2])) /* Broken surrigate pair */
return MY_CS_ILSEQ;
*pwc= MY_UTF16_WC4(s[0], s[1], s[2], s[3]);
return 4;
}
if (MY_UTF16_LOW_HEAD(*s)) /* Low surrogate part without high part */
return MY_CS_ILSEQ;
*pwc= MY_UTF16_WC2(s[0], s[1]);
return 2;
}
#endif /* _CTYPE_UTF16_H */
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