/// <summary>
/// read as a d-gaps list </summary>
private void ReadSetDgaps(IndexInput input)
{
Size_Renamed = input.ReadInt(); // (re)read size
Count_Renamed = input.ReadInt(); // read count
Bits = new byte[GetNumBytes(Size_Renamed)]; // allocate bits
int last = 0;
int n = Count();
while (n > 0)
{
last += input.ReadVInt();
Bits[last] = input.ReadByte();
n -= BitUtil.BitCount(Bits[last]);
Debug.Assert(n >= 0);
}
}
/// <summary>
/// Returns the total number of one bits in this vector. this is efficiently
/// computed and cached, so that, if the vector is not changed, no
/// recomputation is done for repeated calls.
/// </summary>
public int Count()
{
// if the vector has been modified
if (Count_Renamed == -1)
{
int c = 0;
int end = Bits.Length;
for (int i = 0; i < end; i++)
{
c += BitUtil.BitCount(Bits[i]); // sum bits per byte
}
Count_Renamed = c;
}
Debug.Assert(Count_Renamed <= Size_Renamed, "count=" + Count_Renamed + " size=" + Size_Renamed);
return(Count_Renamed);
}
/// <summary>
/// Write as a d-gaps list </summary>
private void WriteClearedDgaps(IndexOutput output)
{
output.WriteInt(-1); // mark using d-gaps
output.WriteInt(Size()); // write size
output.WriteInt(Count()); // write count
int last = 0;
int numCleared = Size() - Count();
for (int i = 0; i < Bits.Length && numCleared > 0; i++)
{
if (Bits[i] != unchecked ((byte)0xff))
{
output.WriteVInt(i - last);
output.WriteByte(Bits[i]);
last = i;
numCleared -= (8 - BitUtil.BitCount(Bits[i]));
Debug.Assert(numCleared >= 0 || (i == (Bits.Length - 1) && numCleared == -(8 - (Size_Renamed & 7))));
}
}
}
/// <summary>
/// read as a d-gaps cleared bits list </summary>
private void ReadClearedDgaps(IndexInput input)
{
Size_Renamed = input.ReadInt(); // (re)read size
Count_Renamed = input.ReadInt(); // read count
Bits = new byte[GetNumBytes(Size_Renamed)]; // allocate bits
for (int i = 0; i < Bits.Length; ++i)
{
Bits[i] = 0xff;
}
ClearUnusedBits();
int last = 0;
int numCleared = Size() - Count();
while (numCleared > 0)
{
last += input.ReadVInt();
Bits[last] = input.ReadByte();
numCleared -= 8 - BitUtil.BitCount(Bits[last]);
Debug.Assert(numCleared >= 0 || (last == (Bits.Length - 1) && numCleared == -(8 - (Size_Renamed & 7))));
}
}
internal virtual void AddWord(int wordNum, byte word)
{
Debug.Assert(wordNum > lastWordNum);
Debug.Assert(word != 0);
if (!reverse)
{
if (lastWordNum == -1)
{
clean = 2 + wordNum; // special case for the 1st sequence
dirtyWords.WriteByte(word);
}
else
{
switch (wordNum - lastWordNum)
{
case 1:
if (word == 0xFF && (byte)dirtyWords.Bytes[dirtyWords.Length - 1] == 0xFF)
{
--dirtyWords.Length;
WriteSequence();
reverse = true;
clean = 2;
}
else
{
dirtyWords.WriteByte(word);
}
break;
case 2:
dirtyWords.WriteByte(0);
dirtyWords.WriteByte(word);
break;
default:
WriteSequence();
clean = wordNum - lastWordNum - 1;
dirtyWords.WriteByte(word);
break;
}
}
}
else
{
Debug.Assert(lastWordNum >= 0);
switch (wordNum - lastWordNum)
{
case 1:
if (word == 0xFF)
{
if (dirtyWords.Length == 0)
{
++clean;
}
else if ((byte)dirtyWords.Bytes[dirtyWords.Length - 1] == 0xFF)
{
--dirtyWords.Length;
WriteSequence();
clean = 2;
}
else
{
dirtyWords.WriteByte(word);
}
}
else
{
dirtyWords.WriteByte(word);
}
break;
case 2:
dirtyWords.WriteByte(0);
dirtyWords.WriteByte(word);
break;
default:
WriteSequence();
reverse = false;
clean = wordNum - lastWordNum - 1;
dirtyWords.WriteByte(word);
break;
}
}
lastWordNum = wordNum;
cardinality += BitUtil.BitCount(word);
}
