public static DatabaseRecord ReadFrom(byte[] buffer, int offset)
{
DatabaseRecord result = null;
if (Utilities.ToInt32BigEndian(buffer, offset + 0xC) != 0)
{
switch ((RecordType)(buffer[offset + 0x13] & 0xF))
{
case RecordType.Volume:
result = new VolumeRecord();
break;
case RecordType.Component:
result = new ComponentRecord();
break;
case RecordType.Extent:
result = new ExtentRecord();
break;
case RecordType.Disk:
result = new DiskRecord();
break;
case RecordType.DiskGroup:
result = new DiskGroupRecord();
break;
default:
throw new NotImplementedException("Unrecognized record type: " + buffer[offset + 0x13]);
}
result.DoReadFrom(buffer, offset);
}
return result;
}
private SparseStream OpenVolume(VolumeRecord volume)
{
List<SparseStream> cmpntStreams = new List<SparseStream>();
foreach (var component in _database.GetVolumeComponents(volume.Id))
{
cmpntStreams.Add(OpenComponent(component));
}
if (cmpntStreams.Count < 1)
{
throw new IOException("Volume with no associated components");
}
else if (cmpntStreams.Count == 1)
{
return cmpntStreams[0];
}
else
{
return new MirrorStream(Ownership.Dispose, cmpntStreams.ToArray());
}
}
private LogicalVolumeStatus GetVolumeStatus(VolumeRecord volume)
{
int numFailed = 0;
ulong numOK = 0;
LogicalVolumeStatus worst = LogicalVolumeStatus.Healthy;
foreach (var cmpnt in _database.GetVolumeComponents(volume.Id))
{
LogicalVolumeStatus cmpntStatus = GetComponentStatus(cmpnt);
worst = WorstOf(worst, cmpntStatus);
if (cmpntStatus == LogicalVolumeStatus.Failed)
{
numFailed++;
}
else
{
numOK++;
}
}
if (numOK < 1)
{
return LogicalVolumeStatus.Failed;
}
else if (numOK == volume.ComponentCount)
{
return worst;
}
else
{
return LogicalVolumeStatus.FailedRedundancy;
}
}