internal static UInt128 CreateNew(int firstTrue)
{
var newInstance = new UInt128();
for (int i = firstTrue; i < BITS_PER_TRANSACTION; i++)
{
newInstance.SetBit(i);
}
return newInstance;
}
/// <summary>
/// Returns the MSB most significant bit.
/// </summary>
public static int LastSetBit(UInt128 value)
{
if (value == 0) return 0;
if(value._second != 0)
{
return LastSetBit(value._second) + UInt128.BITS_PER_ONE_TRANSACTION_PART;
}
return LastSetBit(value._first);
}
/// <summary>
/// Returns the first set bit (FFS), or 0 if no bits are set.
/// </summary>
public static int FirstSetBit(UInt128 value)
{
if (value._first != 0)
{
return FirstSetBit(value._first);
}
else
{
return FirstSetBit(value._second) + UInt128.BITS_PER_ONE_TRANSACTION_PART;
}
}
public Bitmap128(UInt128[] bitmaps, int support)
{
SequencesCount = bitmaps.Length;
_bitmaps = bitmaps;
_support = support;
}
/// <summary>
/// Creates a new bitmap by S-Step with a given item-bitmap.
/// </summary>
public Bitmap128 CreateNewBySStep(Bitmap128 itemBitmap)
{
// A new bitmap for S-Step will be create by ANDing transformed sequence-bitmap with item-bitmap.
// During creating a new bitmap also counts the support for a new bitmap.
var support = 0;
var newBitmaps = new UInt128[SequencesCount];
var itemBitmaps = itemBitmap._bitmaps;
for (var sid = 0; sid < SequencesCount; ++sid)
{
if (_bitmaps[sid] == 0) continue;
var tid = DeBruijn.FirstSetBit(_bitmaps[sid]);
if ((newBitmaps[sid] = (TransformedBitmap[tid] & itemBitmaps[sid])) == 0) continue;
++support;
}
return support > 0 ? new Bitmap128(newBitmaps, support) : null;
}
/// <summary>
/// Creates a new bitmap by I-Step with a given item-bitmap.
/// </summary>
public Bitmap128 CreateNewByIStep(Bitmap128 itemBitmap)
{
// A new bitmap for I-Step will be create by ANDing sequence-bitmap with item-bitmap.
// During creating a new bitmap also counts the support for a new bitmap.
var support = 0;
var newBitmaps = new UInt128[SequencesCount];
var itemBitmaps = itemBitmap._bitmaps;
for (var sid = 0; sid < SequencesCount; ++sid)
{
if ((newBitmaps[sid] = (_bitmaps[sid] & itemBitmaps[sid])) == 0) continue;
++support;
}
return support > 0 ? new Bitmap128(newBitmaps, support) : null;
}
public bool Equals(UInt128 other)
{
return other._first == _first && other._second == _second;
}
