private List <ArrayPosition> TranslateSectors(long startSectorIndex, int sectorCount)
{
List <ArrayPosition> result = new List <ArrayPosition>();
int numberOfDisks = m_extents.Count;
int sectorsLeft = sectorCount;
long currentSectorIndex = startSectorIndex;
while (sectorsLeft > 0)
{
long extentStartSectorInColumn = 0;
long nextExtentStartSectorInColumn = 0;
for (int index = 0; index < m_extents.Count; index++)
{
DynamicDiskExtent extent = m_extents[index];
extentStartSectorInColumn = nextExtentStartSectorInColumn;
nextExtentStartSectorInColumn += extent.TotalSectors;
if (currentSectorIndex >= extentStartSectorInColumn && currentSectorIndex < nextExtentStartSectorInColumn)
{
long sectorIndexInExtent = currentSectorIndex - extentStartSectorInColumn;
int sectorCountInExtent = (int)Math.Min(extent.TotalSectors - sectorIndexInExtent, sectorsLeft);
ArrayPosition position = new ArrayPosition(index, sectorIndexInExtent, sectorCountInExtent);
result.Add(position);
currentSectorIndex += sectorCountInExtent;
sectorsLeft -= sectorCountInExtent;
}
}
}
return(result);
}
public List <ArrayPosition> TranslateSectors(long startSectorIndex, int sectorCount)
{
List <ArrayPosition> result = new List <ArrayPosition>();
int numberOfColumns = m_columns.Count;
int sectorsLeft = sectorCount;
long currentSectorIndex = startSectorIndex;
while (sectorsLeft > 0)
{
long stripeIndexInVolume = currentSectorIndex / m_sectorsPerStripe;
long stripeIndexInColumn = stripeIndexInVolume / numberOfColumns;
int diskIndex = (int)(stripeIndexInVolume % numberOfColumns);
long columnSectorIndex = stripeIndexInColumn * m_sectorsPerStripe + (currentSectorIndex % m_sectorsPerStripe);
int sectorsToReadFromCurrentColumnStripe = Math.Min(m_sectorsPerStripe - (int)(columnSectorIndex % m_sectorsPerStripe), sectorsLeft);
// e.g. :
// Column 0: 0 3 6 ...
// Column 1: 1 4 7 ...
// Column 2: 2 5 8 ...
ArrayPosition position = new ArrayPosition(diskIndex, columnSectorIndex, sectorsToReadFromCurrentColumnStripe);
result.Add(position);
currentSectorIndex += sectorsToReadFromCurrentColumnStripe;
sectorsLeft -= sectorsToReadFromCurrentColumnStripe;
}
return(result);
}
// Each ArrayPosition is within a single stripe
public List <ArrayPosition> TranslateSectors(long startSectorIndex, int sectorCount)
{
List <ArrayPosition> result = new List <ArrayPosition>();
int numberOfColumns = m_columns.Count;
int sectorsLeft = sectorCount;
long currentSectorIndex = startSectorIndex;
while (sectorsLeft > 0)
{
long dataStripeIndexInVolume = currentSectorIndex / m_sectorsPerStripe; // stripe index if we don't count parity stripes
long stripeIndexInColumn = dataStripeIndexInVolume / (numberOfColumns - 1);
int parityColumnIndex = (numberOfColumns - 1) - (int)(stripeIndexInColumn % numberOfColumns);
int columnIndex = (int)(dataStripeIndexInVolume % numberOfColumns);
// Another way to calculate columnIndex:
//int stripeVerticalIndex = (int)(dataStripeIndexInVolume % (numberOfColumns - 1));
//int columnIndex2 = (parityColumnIndex + 1 + stripeVerticalIndex) % numberOfColumns;
long columnSectorIndex = stripeIndexInColumn * m_sectorsPerStripe + (currentSectorIndex % m_sectorsPerStripe);
int sectorsToReadFromCurrentColumnStripe = Math.Min(m_sectorsPerStripe - (int)(columnSectorIndex % m_sectorsPerStripe), sectorsLeft);
// e.g. :
// Column 0: 0 3 P ...
// Column 1: 1 P 4 ...
// Column 2: P 2 5 ...
// Column 0: 0 4 8 P ...
// Column 1: 1 5 P 09 ...
// Column 2: 2 P 6 10 ...
// Column 3: P 3 7 11 ...
ArrayPosition position = new ArrayPosition(columnIndex, columnSectorIndex, sectorsToReadFromCurrentColumnStripe);
result.Add(position);
currentSectorIndex += sectorsToReadFromCurrentColumnStripe;
sectorsLeft -= sectorsToReadFromCurrentColumnStripe;
}
return(result);
}
