static FExtent GetFExtent(int srcLength, int weightsLength)
{
FExtentKey key = new FExtentKey(srcLength, weightsLength);
FExtent extent;
lock (fCache)
{
extent = (FExtent)fCache[key];
}
int fOffset = -weightsLength / 2;
if (extent == null)
{
extent = new FExtent();
extent.fStarts = new int[srcLength];
extent.fEnds = new int[srcLength];
for (int dst = 0; dst < srcLength; ++dst)
{
int startSrc = dst + fOffset;
if (startSrc < 0)
{
extent.fStarts[dst] = -startSrc;
}
else
{
extent.fStarts[dst] = 0;
}
int end = startSrc + weightsLength;
int endDelta = srcLength - end;
if (endDelta < 0)
{
extent.fEnds[dst] = weightsLength + endDelta;
}
else
{
extent.fEnds[dst] = weightsLength;
}
}
lock (fCache)
{
if (fCache.Count > 16)
{
object top = fCacheQ.Dequeue();
fCache.Remove(top);
}
fCache[key] = extent;
fCacheQ.Enqueue(key);
}
}
return(extent);
}
private static FExtent GetFExtent(int srcLength, int weightsLength)
{
FExtentKey key = new FExtentKey(srcLength, weightsLength);
FExtent extent;
lock (fCache)
{
extent = (FExtent)fCache[key];
}
int fOffset = -weightsLength / 2;
if (extent == null)
{
extent = new FExtent();
extent.fStarts = new int[srcLength];
extent.fEnds = new int[srcLength];
for (int dst = 0; dst < srcLength; ++dst)
{
int startSrc = dst + fOffset;
if (startSrc < 0)
{
extent.fStarts[dst] = -startSrc;
}
else
{
extent.fStarts[dst] = 0;
}
int end = startSrc + weightsLength;
int endDelta = srcLength - end;
if (endDelta < 0)
{
extent.fEnds[dst] = weightsLength + endDelta;
}
else
{
extent.fEnds[dst] = weightsLength;
}
}
lock (fCache)
{
if (fCache.Count > 16)
{
object top = fCacheQ.Dequeue();
fCache.Remove(top);
}
fCache[key] = extent;
fCacheQ.Enqueue(key);
}
}
return extent;
}
public override bool Equals(object obj)
{
FExtentKey fek = (FExtentKey)obj;
return(srcLength == fek.srcLength && weightsLength == fek.weightsLength);
}
