Function decode

test/benchmark/base64.c:40–70

#define next_char(x) char x = decode_table[(unsigned char)*str++]; if (x < 0) return 1;

int decode(int size, const char* str, int* out_size, char** output) {
  *output = (char*) malloc( decode_size(size) );
  char *out = *output;
  while (size > 0 && (str[size - 1] == '\n' || str[size - 1] == '\r' || str[size - 1] == '=')) size--;
  const char* ends = str + size - 4;
  while (1) {
    if (str > ends) break;
    while (*str == '\n' || *str == '\r') str++;

    if (str > ends) break;
    next_char(a); next_char(b); next_char(c); next_char(d);

    *out++ = (char)(a << 2 | b >> 4);
    *out++ = (char)(b << 4 | c >> 2);
    *out++ = (char)(c << 6 | d >> 0);
  }

  int mod = (str - ends) % 4;
  if (mod == 2) {
    next_char(a); next_char(b);
    *out++ = (char)(a << 2 | b >> 4);
  } else if (mod == 3) {
    next_char(a); next_char(b); next_char(c);
    *out++ = (char)(a << 2 | b >> 4);
    *out++ = (char)(b << 4 | c >> 2);
  }

  *out = '\0';
  *out_size = out - *output;
  return 0;
}

void encode(int size, const char* str, int* out_size, char** output) {
  *output = (char*) malloc( encode_size(size) );