Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 73500267 authored by Peter Jones's avatar Peter Jones Committed by Matt Fleming
Browse files

lib/ucs2_string: Add ucs2 -> utf8 helper functions 



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: default avatarPeter Jones <pjones@redhat.com>
Tested-by: default avatarLee, Chun-Yi <jlee@suse.com>
Acked-by: default avatarMatthew Garrett <mjg59@coreos.com>
Signed-off-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
parent 59fd1214

include/linux/ucs2_string.h

+4 −0
Original line number Diff line number Diff line
@@ -11,4 +11,8 @@ unsigned long ucs2_strlen(const ucs2_char_t *s); 
unsigned long ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength);

int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len);



unsigned long ucs2_utf8size(const ucs2_char_t *src);

unsigned long ucs2_as_utf8(u8 *dest, const ucs2_char_t *src,

			   unsigned long maxlength);



#endif /* _LINUX_UCS2_STRING_H_ */

lib/ucs2_string.c

+62 −0
Original line number Diff line number Diff line
@@ -49,3 +49,65 @@ ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t 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);