// The maximum NTFS file size is 2^64 bytes, so total number of file clusters can be represented using long
public void AllocateAdditionalClusters(NTFSVolume volume, long clustersToAllocate)
{
ulong desiredStartLCN = (ulong)DataRunSequence.DataLastLCN;
KeyValuePairList <ulong, long> freeClusterRunList = volume.AllocateClusters(desiredStartLCN, clustersToAllocate);
for (int index = 0; index < freeClusterRunList.Count; index++)
{
ulong runStartLCN = freeClusterRunList[index].Key;
long runLength = freeClusterRunList[index].Value;
bool mergeWithLastRun = (index == 0 && runStartLCN == desiredStartLCN);
if (mergeWithLastRun)
{
// we append this run to the last run
DataRun lastRun = DataRunSequence[DataRunSequence.Count - 1];
lastRun.RunLength += (long)runLength;
HighestVCN += (long)runLength;
}
else
{
DataRun run = new DataRun();
ulong previousLCN = (ulong)DataRunSequence.LastDataRunStartLCN;
run.RunOffset = (long)(runStartLCN - previousLCN);
run.RunLength = (long)runLength;
HighestVCN += runLength;
DataRunSequence.Add(run);
}
}
}
private void AllocateAdditionalClusters(long clustersToAllocate)
{
KeyValuePairList <long, long> freeClusterRunList;
DataRunSequence dataRuns = m_attributeRecord.DataRunSequence;
if (dataRuns.Count == 0)
{
freeClusterRunList = m_volume.AllocateClusters(clustersToAllocate);
}
else
{
long desiredStartLCN = dataRuns.DataLastLCN + 1;
freeClusterRunList = m_volume.AllocateClusters(desiredStartLCN, clustersToAllocate);
long firstRunStartLCN = freeClusterRunList[0].Key;
long firstRunLength = freeClusterRunList[0].Value;
if (firstRunStartLCN == desiredStartLCN)
{
// Merge with last run
DataRun lastRun = dataRuns[dataRuns.Count - 1];
lastRun.RunLength += firstRunLength;
m_attributeRecord.HighestVCN += (long)firstRunLength;
freeClusterRunList.RemoveAt(0);
}
}
for (int index = 0; index < freeClusterRunList.Count; index++)
{
long runStartLCN = freeClusterRunList[index].Key;
long runLength = freeClusterRunList[index].Value;
DataRun run = new DataRun();
long previousLCN = m_attributeRecord.DataRunSequence.LastDataRunStartLCN;
run.RunOffset = runStartLCN - previousLCN;
run.RunLength = runLength;
m_attributeRecord.HighestVCN += runLength;
m_attributeRecord.DataRunSequence.Add(run);
}
// Extend() will update the FileRecord
m_attributeRecord.AllocatedLength += (ulong)(clustersToAllocate * m_volume.BytesPerCluster);
}