public void Generate(uint[] valsTable, uint n)
{
uint i;
// lengths: represents lengths of encoded values
var lengths = new uint[n];
_n = n;
_totalLength = 0;
for (i = 0; i < _n; i++)
{
if (valsTable[i] == 0)
{
lengths[i] = 0;
}
else
{
lengths[i] = ILog2(valsTable[i] + 1);
_totalLength += lengths[i];
}
}
_storeTable = new uint[(_totalLength + 31) >> 5];
_totalLength = 0;
for (i = 0; i < _n; i++)
{
if (valsTable[i] == 0)
{
continue;
}
var storedValue = valsTable[i] - ((1U << (int)lengths[i]) - 1U);
BitBool.SetBitsAtPos(_storeTable, _totalLength, storedValue, lengths[i]);
_totalLength += lengths[i];
}
_remR = ILog2(_totalLength / _n);
if (_remR == 0)
{
_remR = 1;
}
_lengthRems = new uint[((_n * _remR) + 0x1f) >> 5];
var remsMask = (1U << (int)_remR) - 1U;
_totalLength = 0;
for (i = 0; i < _n; i++)
{
_totalLength += lengths[i];
BitBool.SetBitsValue(_lengthRems, i, _totalLength & remsMask, _remR, remsMask);
lengths[i] = _totalLength >> (int)_remR;
}
_sel = new Select();
_sel.Generate(lengths, _n, (_totalLength >> (int)_remR));
}
public uint Query(uint idx)
{
uint selRes;
uint encIdx;
var remsMask = (uint)((1 << (int)_remR) - 1);
if (idx == 0)
{
encIdx = 0;
selRes = _sel.Query(idx);
}
else
{
selRes = _sel.Query(idx - 1);
encIdx = (selRes - (idx - 1)) << (int)_remR;
encIdx += BitBool.GetBitsValue(_lengthRems, idx - 1, _remR, remsMask);
selRes = _sel.NextQuery(selRes);
}
var encLength = (selRes - idx) << (int)_remR;
encLength += BitBool.GetBitsValue(_lengthRems, idx, _remR, remsMask);
encLength -= encIdx;
if (encLength == 0)
{
return(0);
}
return(BitBool.GetBitsAtPos(_storeTable, encIdx, encLength) + ((uint)((1 << (int)encLength) - 1)));
}
