/// <param name="count">Maximum number of clusters to read</param>
public byte[] ReadDataClusters(NTFSVolume volume, long firstClusterVCN, int count)
{
long lastClusterVcnToRead = firstClusterVCN + count - 1;
if (firstClusterVCN < LowestVCN || firstClusterVCN > HighestVCN)
{
string message = String.Format("Cluster VCN {0}-{1} is not within the valid range ({2}-{3})", firstClusterVCN, lastClusterVcnToRead, LowestVCN, HighestVCN);
throw new ArgumentOutOfRangeException(message);
}
if (lastClusterVcnToRead > HighestVCN)
{
lastClusterVcnToRead = HighestVCN;
}
byte[] result = new byte[count * volume.BytesPerCluster];
KeyValuePairList <long, int> sequence = m_dataRunSequence.TranslateToLCN(firstClusterVCN - LowestVCN, count);
long bytesRead = 0;
foreach (KeyValuePair <long, int> run in sequence)
{
byte[] clusters = volume.ReadClusters(run.Key, run.Value);
Array.Copy(clusters, 0, result, bytesRead, clusters.Length);
bytesRead += clusters.Length;
}
// If the last cluster is only partially used or we have been asked to read clusters beyond the last cluster, trim result.
// (Either of those cases could only be true if we have just read the last cluster).
if (lastClusterVcnToRead == (long)HighestVCN)
{
long bytesToUse = (long)(FileSize - (ulong)firstClusterVCN * (uint)volume.BytesPerCluster);
if (bytesToUse < result.Length)
{
byte[] resultTrimmed = new byte[bytesToUse];
Array.Copy(result, resultTrimmed, bytesToUse);
return(resultTrimmed);
}
}
return(result);
}