public override void Load(CacheNode <TKey, TValue>[] nodes)
{
_nodes = nodes;
_actNodes = nodes.Length;
_ranges = new long[nodes.Length, nodes.Length];
float sum = 0;
for (int i = 0; i < nodes.Length; i++)//приводим усредненные частоты к вероятностям
{
var node = nodes[i];
var prob = node.GetProbability();
sum += prob;
_ranges[i, i] =
new RangeDesc
{
Range = prob,
Root = i
};
}
for (int i = 0; i < nodes.Length; i++) //приводим усредненные частоты к вероятностям
{
var r = (RangeDesc)_ranges[i, i];
r.Range /= sum;
_ranges[i, i] = r;
}
}
private unsafe void RebalanceStep(int start, int diff)
{
var ranges = _uRanges;
int end = start + diff;// *(float*)& - вытаскивает поле Range из записи
float levelShiftSum = *(float *)&ranges[start * _actNodes + start]
+ *(float *)&ranges[end * _actNodes + end];
float minRange;
int minRoot;
var onlyRightBestTime = *(float *)&ranges[(start + 1) * _actNodes + end];
var onlyLeftBestTime = *(float *)&ranges[start * _actNodes + end - 1];
if (onlyRightBestTime > onlyLeftBestTime)
{
minRange = onlyLeftBestTime;
minRoot = end;
}
else
{
minRange = onlyRightBestTime;
minRoot = start;
}
/* нижеследующий код является оптимизированной в плане вычислений версией данного
* for (var possRoot = start + 1; possRoot < end; possRoot++)
* {
* var leftSubTreeBestTime =
*(float*)&ranges[start * _actNodes + possRoot - 1];
* //от start*_actNodes+start, до start*_actNodes+end-1, шаг +1
* var rightSubTreeBestTime =
*(float*)&ranges[(possRoot + 1) * _actNodes + end];
* //от (start+2)*_actNodes+end, до (end+1)*_actNodes+end,шаг +_actNodes
* var newPossBestTime = leftSubTreeBestTime + rightSubTreeBestTime;
*
* if (minRange > newPossBestTime)
* {
* minRange = newPossBestTime;
* minRoot = possRoot;
* }
* levelShiftSum +=
*(float*)&ranges[possRoot * _actNodes + possRoot];
* //от (start+1)*_actNodes+start+1, до end*_actNodes+end, шаг +_actNodes+1
* }*/
int leftSubTreeShift = start * _actNodes + start;
int rightSubTreeShift = (start + 2) * _actNodes + end;
int resultShift = (start + 1) * _actNodes + start + 1;
for (var possRoot = start + 1; possRoot < end; possRoot++)
{
var leftSubTreeBestTime = *(float *)&ranges[leftSubTreeShift];
var rightSubTreeBestTime = *(float *)&ranges[rightSubTreeShift];
var newPossBestTime = leftSubTreeBestTime + rightSubTreeBestTime;
if (minRange > newPossBestTime)
{
minRange = newPossBestTime;
minRoot = possRoot;
}
levelShiftSum += *(float *)&ranges[resultShift];
leftSubTreeShift += 1;
rightSubTreeShift += _actNodes;
resultShift += (_actNodes + 1);
}
ranges[start * _actNodes + end] = new RangeDesc
{
Range = levelShiftSum + minRange,
Root = minRoot
};
}