1#include <linux/ucs2_string.h>
2#include <linux/module.h>
3
4/* Return the number of unicode characters in data */
5unsigned long
6ucs2_strnlen(const ucs2_char_t *s, size_t maxlength)
7{
8        unsigned long length = 0;
9
10        while (*s++ != 0 && length < maxlength)
11                length++;
12        return length;
13}
14EXPORT_SYMBOL(ucs2_strnlen);
15
16unsigned long
17ucs2_strlen(const ucs2_char_t *s)
18{
19        return ucs2_strnlen(s, ~0UL);
20}
21EXPORT_SYMBOL(ucs2_strlen);
22
23/*
24 * Return the number of bytes is the length of this string
25 * Note: this is NOT the same as the number of unicode characters
26 */
27unsigned long
28ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength)
29{
30        return ucs2_strnlen(data, maxlength/sizeof(ucs2_char_t)) * sizeof(ucs2_char_t);
31}
32EXPORT_SYMBOL(ucs2_strsize);
33
34int
35ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len)
36{
37        while (1) {
38                if (len == 0)
39                        return 0;
40                if (*a < *b)
41                        return -1;
42                if (*a > *b)
43                        return 1;
44                if (*a == 0) /* implies *b == 0 */
45                        return 0;
46                a++;
47                b++;
48                len--;
49        }
50}
51EXPORT_SYMBOL(ucs2_strncmp);
52
53unsigned long
54ucs2_utf8size(const ucs2_char_t *src)
55{
56	unsigned long i;
57	unsigned long j = 0;
58
59	for (i = 0; i < ucs2_strlen(src); i++) {
60		u16 c = src[i];
61
62		if (c >= 0x800)
63			j += 3;
64		else if (c >= 0x80)
65			j += 2;
66		else
67			j += 1;
68	}
69
70	return j;
71}
72EXPORT_SYMBOL(ucs2_utf8size);
73
74/*
75 * copy at most maxlength bytes of whole utf8 characters to dest from the
76 * ucs2 string src.
77 *
78 * The return value is the number of characters copied, not including the
79 * final NUL character.
80 */
81unsigned long
82ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
83{
84	unsigned int i;
85	unsigned long j = 0;
86	unsigned long limit = ucs2_strnlen(src, maxlength);
87
88	for (i = 0; maxlength && i < limit; i++) {
89		u16 c = src[i];
90
91		if (c >= 0x800) {
92			if (maxlength < 3)
93				break;
94			maxlength -= 3;
95			dest[j++] = 0xe0 | (c & 0xf000) >> 12;
96			dest[j++] = 0x80 | (c & 0x0fc0) >> 6;
97			dest[j++] = 0x80 | (c & 0x003f);
98		} else if (c >= 0x80) {
99			if (maxlength < 2)
100				break;
101			maxlength -= 2;
102			dest[j++] = 0xc0 | (c & 0x7c0) >> 6;
103			dest[j++] = 0x80 | (c & 0x03f);
104		} else {
105			maxlength -= 1;
106			dest[j++] = c & 0x7f;
107		}
108	}
109	if (maxlength)
110		dest[j] = '\0';
111	return j;
112}
113EXPORT_SYMBOL(ucs2_as_utf8);
114