private int getPwned(byte[] hash, bool needCount)
{
if (hash == null)
{
throw new ArgumentNullException("hash");
}
if (hash.Length != 20)
{
throw new ArgumentException("The hash is expected to be 20 bytes long.", "hash");
}
if (_stream == null || _reader == null)
{
throw new ObjectDisposedException(nameof(PwnedChecker));
}
int prefix = (hash[0] << 16) + (hash[1] << 8) + hash[2];
_stream.Position = prefix * 5;
long pos = _reader.ReadUInt32();
pos += (long)_reader.ReadByte() << 32;
if (pos == 0)
{
return(0);
}
_stream.Position = pos;
int entryCount = _reader.Read7BitEncodedInt();
if (entryCount == 0)
{
return(0);
}
var bytes = _reader.ReadBytes(entryCount * 17);
int min = 0;
int max = entryCount - 1;
int cur = 0;
while (true)
{
cur = (min + max) / 2;
for (int i = 0; i < 17; i++)
{
int cmp = hash[3 + i] - bytes[cur * 17 + i];
if (cmp < 0)
{
max = cur - 1;
goto different;
}
else if (cmp > 0)
{
min = cur + 1;
goto different;
}
}
break; // match found; its index is in "cur"
different:
if (min > max)
{
return(0);
}
}
if (!needCount)
{
return(1);
}
for (int i = 0; i < cur; i++)
{
_reader.Read7BitEncodedInt();
}
return(_reader.Read7BitEncodedInt());
}
