uuid.cpp

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#include "utils/uuid.h"
 
// TODO: Should unit test whether this is correct
FLASHMEM
void utils::UUID::toCharArray(char *_buffer) const {
  //  process 16 bytes build up the char array.
  for (uint8_t i = 0, j = 0; i < 16; i++) {
    //  multiples of 4 between 8 and 20 get a -.
    //  note we are processing 2 digits in one loop.
    if ((i & 0x1) == 0) {
      if ((4 <= i) && (i <= 10)) {
        _buffer[j++] = '-';
      }
    }
 
    // uint8_t nr   = i / 4;
    uint8_t xx = ar[i];
    uint8_t ch = xx & 0x0F;
    _buffer[j++] = (ch < 10) ? '0' + ch : ('a' - 10) + ch;
 
    ch = (xx >> 4) & 0x0F;
    // ar[nr] >>= 8;
    _buffer[j++] = (ch < 10) ? '0' + ch : ('a' - 10) + ch;
  }
 
  //  if (_upperCase)
  //  {
  //    for (int i = 0; i < 37; i++)
  //    {
  //      _buffer[i] = toUpper(_buffer[i]);
  //    }
  //  }
  _buffer[36] = 0;
}
 
FLASHMEM
String utils::UUID::toString() const {
  char _buffer[37];
  toCharArray(_buffer);
  return String(_buffer);
}
 
FLASHMEM
size_t utils::UUID::printTo(Print &p) const {
  //  UUID in string format
  char _buffer[37];
  toCharArray(_buffer);
  return p.print(_buffer);
}
 
FLASHMEM
uint8_t chartoi(char X) {
  if ('0' <= X && X <= '9')
    return X - '0';
  if ('a' <= X && X <= 'f')
    return X - 'a' + 10;
  if ('A' <= X && X <= 'F')
    return X - 'A' + 10;
  return 0;
}
 
// TODO: Should unit test whether this is correct
FLASHMEM
utils::UUID utils::UUID::fromString(const char *str) {
  UUID data; // all zero by default
 
  if (strlen(str) != 36)
    return data;
 
  // implementation follows
  // https://github.com/mariusbancila/stduuid/blob/3afe7193facd5d674de709fccc44d5055e144d7a/include/uuid.h#L503
  bool firstDigit = true;
  size_t index = 0;
  for (size_t i = 0; i < 36; i++) {
    if (str[i] == '-')
      continue;
    if (firstDigit) {
      data.ar[index] = chartoi(str[i]) << 4;
      firstDigit = false;
    } else {
      data.ar[index] |= chartoi(str[i]);
      index++;
      firstDigit = true;
    }
  }
  return data;
}