public void Extend(ulong additionalLengthInBytes)
{
ulong currentSize = this.Length;
if (m_attributeRecord is NonResidentAttributeRecord)
{
NonResidentAttributeData attributeData = new NonResidentAttributeData(m_volume, m_fileRecord, (NonResidentAttributeRecord)m_attributeRecord);
attributeData.Extend(additionalLengthInBytes);
}
else
{
byte[] data = ((ResidentAttributeRecord)m_attributeRecord).Data;
ulong finalDataLength = (uint)data.Length + additionalLengthInBytes;
ulong finalRecordLength = (uint)m_attributeRecord.RecordLength + additionalLengthInBytes;
if (finalRecordLength >= (ulong)m_volume.AttributeRecordLengthToMakeNonResident &&
m_attributeRecord.AttributeType != AttributeType.AttributeList) // We will create an attribute list with the right attribute form in advance.
{
// Convert the attribute to non-resident
long clustersToAllocate = (long)Math.Ceiling((double)finalDataLength / m_volume.BytesPerCluster);
if (clustersToAllocate > m_volume.NumberOfFreeClusters)
{
throw new DiskFullException();
}
NonResidentAttributeRecord attributeRecord = NonResidentAttributeRecord.Create(m_attributeRecord.AttributeType, m_attributeRecord.Name);
NonResidentAttributeData attributeData = new NonResidentAttributeData(m_volume, null, attributeRecord);
attributeData.Extend(finalDataLength);
if (data.Length % m_volume.BytesPerCluster > 0)
{
int fillDataLength = m_volume.BytesPerCluster - (data.Length % m_volume.BytesPerCluster);
if ((uint)data.Length + (uint)fillDataLength < finalDataLength)
{
// Only the last cluster can be partially used, if this is not the last cluster, zero-fill it
data = ByteUtils.Concatenate(data, new byte[fillDataLength]);
}
}
attributeData.WriteClusters(0, data);
// Note that we overwrite the old attribute only after writing the non-resident data
if (m_fileRecord != null)
{
m_fileRecord.RemoveAttributeRecord(m_attributeRecord.AttributeType, m_attributeRecord.Name);
FileRecordHelper.InsertSorted(m_fileRecord.Attributes, attributeRecord);
}
m_attributeRecord = attributeRecord;
}
else
{
int currentLength = data.Length;
byte[] temp = new byte[currentLength + (int)additionalLengthInBytes];
Array.Copy(data, temp, data.Length);
((ResidentAttributeRecord)m_attributeRecord).Data = temp;
}
if (m_fileRecord != null)
{
m_volume.UpdateFileRecord(m_fileRecord);
}
}
}
/// <returns>Record Index</returns>
private long AllocateIndexRecord()
{
long?indexRecord = m_bitmapData.AllocateRecord();
if (indexRecord == null)
{
long numberOfUsableBits = m_bitmapData.NumberOfUsableBits;
m_indexAllocationData.Extend(m_rootRecord.BytesPerIndexRecord * ExtendGranularity);
m_bitmapData.ExtendBitmap(ExtendGranularity);
indexRecord = m_bitmapData.AllocateRecord(numberOfUsableBits);
}
return(indexRecord.Value);
}
/// <returns>Record Index</returns>
private long AllocateIndexRecord()
{
uint transactionID = m_volume.LogClient.AllocateTransactionID();
long?indexRecord = m_bitmapData.AllocateRecord(transactionID);
if (indexRecord == null)
{
long numberOfUsableBits = m_bitmapData.NumberOfUsableBits;
m_indexAllocationData.Extend(m_rootRecord.BytesPerIndexRecord * ExtendGranularity);
m_bitmapData.ExtendBitmap(ExtendGranularity);
indexRecord = m_bitmapData.AllocateRecord(numberOfUsableBits, transactionID);
}
m_volume.LogClient.WriteForgetTransactionRecord(transactionID);
return(indexRecord.Value);
}