void Encoding::string_reverse(uint8_t* start, uint8_t* end, OnigEncodingType* enc) {
ssize_t len = end - start;
if(len <= 0) return;
uint8_t stack_buf[STACK_BUF_SZ];
uint8_t* malloc_buf = 0;
uint8_t* buf = stack_buf;
if(len > STACK_BUF_SZ) {
malloc_buf = (uint8_t*)malloc(len);
buf = malloc_buf;
}
uint8_t* p = buf + len;
uint8_t* s = start;
while(s < end) {
int clen = mbclen(s, end, enc);
p -= clen;
memcpy(p, s, clen);
s += clen;
}
memcpy(start, buf, len);
if(malloc_buf) free(malloc_buf);
}
native_int Encoding::find_character_byte_index(const uint8_t* start, const uint8_t* end, native_int index, OnigEncodingType* enc) {
uint8_t* p = (uint8_t*) start;
while(p < end && index--) {
p += mbclen(p, end, enc);
}
if(p > end) p = (uint8_t*) end;
return p - start;
}
native_int Encoding::find_byte_character_index(const uint8_t* start, const uint8_t* end, native_int index, OnigEncodingType* enc) {
uint8_t* p = (uint8_t*) start;
native_int char_index = 0;
while(p < end && index > 0) {
native_int char_len = mbclen(p, end, enc);
p += char_len;
index -= char_len;
char_index++;
}
return char_index;
}