U_CAPI void U_EXPORT2
uiter_setUTF16BE(UCharIterator * iter, const char * s, int32_t length)
{
if (iter != NULL)
{
/* allow only even-length strings (the input length counts bytes) */
if (s != NULL && (length == -1 || (length >= 0 && IS_EVEN(length))))
{
/* length/=2, except that >>=1 also works for -1 (-1/2==0, -1>>1==-1) */
length >>= 1;
if (U_IS_BIG_ENDIAN && IS_POINTER_EVEN(s))
{
/* big-endian machine and 2-aligned UTF-16BE string: use normal UChar iterator */
uiter_setString(iter, (const UChar *)s, length);
return;
}
*iter = utf16BEIterator;
iter->context = s;
if (length >= 0)
{
iter->length = length;
}
else
{
iter->length = utf16BE_strlen(s);
}
iter->limit = iter->length;
}
else
{
/*
* Count the number of UChars in a UTF-16BE string before a terminating UChar NUL,
* i.e., before a pair of 0 bytes where the first 0 byte is at an even
* offset from s.
*/
static int32_t
utf16BE_strlen(const char *s) {
if(IS_POINTER_EVEN(s)) {
/*
* even-aligned, call u_strlen(s)
* we are probably on a little-endian machine, but searching for UChar NUL
* does not care about endianness
*/
return u_strlen((const UChar *)s);
} else {
/* odd-aligned, search for pair of 0 bytes */
const char *p=s;
while(!(*p==0 && p[1]==0)) {
p+=2;
}
return (int32_t)((p-s)/2);
}
}