Function CountUtf8Bytes

Bcore/src/main/cpp/dex/utf.cc:239–268

}

size_t CountUtf8Bytes(const uint16_t* chars, size_t char_count) {
  size_t result = 0;
  const uint16_t *end = chars + char_count;
  while (chars < end) {
    const uint16_t ch = *chars++;
    if (LIKELY(ch != 0 && ch < 0x80)) {
      result++;
      continue;
    }
    if (ch < 0x800) {
      result += 2;
      continue;
    }
    if (ch >= 0xd800 && ch < 0xdc00) {
      if (chars < end) {
        const uint16_t ch2 = *chars;
        // If we find a properly paired surrogate, we emit it as a 4 byte
        // UTF sequence. If we find an unpaired leading or trailing surrogate,
        // we emit it as a 3 byte sequence like would have done earlier.
        if (ch2 >= 0xdc00 && ch2 < 0xe000) {
          chars++;
          result += 4;
          continue;
        }
      }
    }
    result += 3;
  }
  return result;
}

static inline constexpr bool NeedsEscaping(uint16_t ch) {
  return (ch < ' ' || ch > '~');