forked from Minki/linux
73500267c9
This adds ucs2_utf8size(), which tells us how big our ucs2 string is in bytes, and ucs2_as_utf8, which translates from ucs2 to utf8.. Signed-off-by: Peter Jones <pjones@redhat.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
114 lines
2.4 KiB
C
114 lines
2.4 KiB
C
#include <linux/ucs2_string.h>
|
|
#include <linux/module.h>
|
|
|
|
/* Return the number of unicode characters in data */
|
|
unsigned long
|
|
ucs2_strnlen(const ucs2_char_t *s, size_t maxlength)
|
|
{
|
|
unsigned long length = 0;
|
|
|
|
while (*s++ != 0 && length < maxlength)
|
|
length++;
|
|
return length;
|
|
}
|
|
EXPORT_SYMBOL(ucs2_strnlen);
|
|
|
|
unsigned long
|
|
ucs2_strlen(const ucs2_char_t *s)
|
|
{
|
|
return ucs2_strnlen(s, ~0UL);
|
|
}
|
|
EXPORT_SYMBOL(ucs2_strlen);
|
|
|
|
/*
|
|
* Return the number of bytes is the length of this string
|
|
* Note: this is NOT the same as the number of unicode characters
|
|
*/
|
|
unsigned long
|
|
ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength)
|
|
{
|
|
return ucs2_strnlen(data, maxlength/sizeof(ucs2_char_t)) * sizeof(ucs2_char_t);
|
|
}
|
|
EXPORT_SYMBOL(ucs2_strsize);
|
|
|
|
int
|
|
ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len)
|
|
{
|
|
while (1) {
|
|
if (len == 0)
|
|
return 0;
|
|
if (*a < *b)
|
|
return -1;
|
|
if (*a > *b)
|
|
return 1;
|
|
if (*a == 0) /* implies *b == 0 */
|
|
return 0;
|
|
a++;
|
|
b++;
|
|
len--;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(ucs2_strncmp);
|
|
|
|
unsigned long
|
|
ucs2_utf8size(const ucs2_char_t *src)
|
|
{
|
|
unsigned long i;
|
|
unsigned long j = 0;
|
|
|
|
for (i = 0; i < ucs2_strlen(src); i++) {
|
|
u16 c = src[i];
|
|
|
|
if (c > 0x800)
|
|
j += 3;
|
|
else if (c > 0x80)
|
|
j += 2;
|
|
else
|
|
j += 1;
|
|
}
|
|
|
|
return j;
|
|
}
|
|
EXPORT_SYMBOL(ucs2_utf8size);
|
|
|
|
/*
|
|
* copy at most maxlength bytes of whole utf8 characters to dest from the
|
|
* ucs2 string src.
|
|
*
|
|
* The return value is the number of characters copied, not including the
|
|
* final NUL character.
|
|
*/
|
|
unsigned long
|
|
ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
|
|
{
|
|
unsigned int i;
|
|
unsigned long j = 0;
|
|
unsigned long limit = ucs2_strnlen(src, maxlength);
|
|
|
|
for (i = 0; maxlength && i < limit; i++) {
|
|
u16 c = src[i];
|
|
|
|
if (c > 0x800) {
|
|
if (maxlength < 3)
|
|
break;
|
|
maxlength -= 3;
|
|
dest[j++] = 0xe0 | (c & 0xf000) >> 12;
|
|
dest[j++] = 0x80 | (c & 0x0fc0) >> 8;
|
|
dest[j++] = 0x80 | (c & 0x003f);
|
|
} else if (c > 0x80) {
|
|
if (maxlength < 2)
|
|
break;
|
|
maxlength -= 2;
|
|
dest[j++] = 0xc0 | (c & 0xfe0) >> 5;
|
|
dest[j++] = 0x80 | (c & 0x01f);
|
|
} else {
|
|
maxlength -= 1;
|
|
dest[j++] = c & 0x7f;
|
|
}
|
|
}
|
|
if (maxlength)
|
|
dest[j] = '\0';
|
|
return j;
|
|
}
|
|
EXPORT_SYMBOL(ucs2_as_utf8);
|