void fts_icu_utf16_to_utf8(string_t *dest_utf8, const UChar *src_utf16,
unsigned int src_len)
{
int32_t dest_len = 0;
int32_t sub_num = 0;
char *dest_data, *retp = NULL;
UErrorCode err = U_ZERO_ERROR;
/* try to encode with the current buffer size */
dest_data = buffer_get_space_unsafe(dest_utf8, 0,
buffer_get_writable_size(dest_utf8));
retp = u_strToUTF8WithSub(dest_data, buffer_get_writable_size(dest_utf8),
&dest_len, src_utf16, src_len,
UNICODE_REPLACEMENT_CHAR, &sub_num, &err);
if (err == U_BUFFER_OVERFLOW_ERROR) {
/* try again with a larger buffer */
dest_data = buffer_get_space_unsafe(dest_utf8, 0, dest_len);
err = U_ZERO_ERROR;
retp = u_strToUTF8WithSub(dest_data, buffer_get_writable_size(dest_utf8), &dest_len,
src_utf16, src_len,
UNICODE_REPLACEMENT_CHAR,
&sub_num, &err);
}
if (U_FAILURE(err)) {
i_panic("LibICU u_strToUTF8WithSub() failed: %s",
u_errorName(err));
}
buffer_set_used_size(dest_utf8, dest_len);
i_assert(retp == dest_data);
}
/* {{{ intl_charFromString
* faster than doing intl_convert_utf16_to_utf8(&res, &res_len,
* from.getBuffer(), from.length(), &status),
* but consumes more memory */
int intl_charFromString(const UnicodeString &from, char **res, int *res_len, UErrorCode *status)
{
if (from.isBogus()) {
return FAILURE;
}
//the number of UTF-8 code units is not larger than that of UTF-16 code
//units * 3 + 1 for the terminator
int32_t capacity = from.length() * 3 + 1;
if (from.isEmpty()) {
*res = (char*)emalloc(1);
**res = '\0';
*res_len = 0;
return SUCCESS;
}
*res = (char*)emalloc(capacity);
*res_len = 0; //tbd
const UChar *utf16buf = from.getBuffer();
int32_t actual_len;
u_strToUTF8WithSub(*res, capacity - 1, &actual_len, utf16buf, from.length(),
U_SENTINEL, NULL, status);
if (U_FAILURE(*status)) {
efree(*res);
*res = NULL;
return FAILURE;
}
(*res)[actual_len] = '\0';
*res_len = (int)actual_len;
return SUCCESS;
}
