public LfsRecord WriteRecord(int clientIndex, LfsRecordType recordType, ulong clientPreviousLsn, ulong clientUndoNextLsn, uint transactionId, byte[] clientData, bool flushToDisk)
{
if (m_restartPage == null)
{
m_restartPage = ReadRestartPage();
}
// It's perfectly valid to clear the CleanDismount flag after writing the transfer.
// Note that CurrentLsn is used to determine which is restart page recent so we should not update the restart page without incrementing CurrentLsn first.
ushort clientSeqNumber = m_restartPage.RestartArea.LogClientArray[clientIndex].SeqNumber;
LfsRecord record = new LfsRecord();
record.ClientSeqNumber = clientSeqNumber;
record.ClientIndex = (ushort)clientIndex;
record.RecordType = recordType;
record.ClientPreviousLsn = clientPreviousLsn;
record.ClientUndoNextLsn = clientUndoNextLsn;
record.TransactionId = transactionId;
record.ClientDataLength = (uint)clientData.Length;
record.Data = clientData;
record.ThisLsn = GetNextLsn();
m_recordsPendingWrite.Add(record);
bool endOfTransferRecorded = false;
if (flushToDisk)
{
FlushRecords(m_recordsPendingWrite, out endOfTransferRecorded);
m_recordsPendingWrite.Clear();
}
// Update CurrentLsn / LastLsnDataLength
m_restartPage.RestartArea.CurrentLsn = record.ThisLsn;
m_restartPage.RestartArea.LastLsnDataLength = (uint)record.Data.Length;
// If the client is writing a ClientRestart, the call to write a restart page (when updating the client record) is imminent, so no need to write a restart page now.
// Note that CurrentLsn is used to determine which restart page is more recent so we should not update the restart page without incrementing CurrentLsn.
if (recordType != LfsRecordType.ClientRestart && endOfTransferRecorded)
{
// When the NTFS v5.1 driver restarts a dirty log file, it does not expect to find more than one transfer after the last flushed LSN.
// If more than one transfer is encountered, it is treated as a fatal error and the driver will report STATUS_DISK_CORRUPT_ERROR.
// Updating the CurrentLsn / LastLsnDataLength in the restart area will make the NTFS driver see the next page we write as the only transfer after the flushed LSN.
WriteRestartPage(false);
}
return(record);
}
public LfsRecord(byte[] buffer, int offset)
{
ThisLsn = LittleEndianConverter.ToUInt64(buffer, offset + 0x00);
ClientPreviousLsn = LittleEndianConverter.ToUInt64(buffer, offset + 0x08);
ClientUndoNextLsn = LittleEndianConverter.ToUInt64(buffer, offset + 0x10);
ClientDataLength = LittleEndianConverter.ToUInt32(buffer, offset + 0x18);
ClientSeqNumber = LittleEndianConverter.ToUInt16(buffer, offset + 0x1C);
ClientIndex = LittleEndianConverter.ToUInt16(buffer, offset + 0x1E);
RecordType = (LfsRecordType)LittleEndianConverter.ToUInt32(buffer, offset + 0x20);
TransactionId = LittleEndianConverter.ToUInt32(buffer, offset + 0x24);
Flags = (LfsRecordFlags)LittleEndianConverter.ToUInt16(buffer, offset + 0x28);
if (IsMultiPageRecord)
{
Data = ByteReader.ReadBytes(buffer, offset + HeaderLength, buffer.Length - (offset + HeaderLength));
}
else
{
Data = ByteReader.ReadBytes(buffer, offset + HeaderLength, (int)ClientDataLength);
}
}
public LfsRecord WriteRecord(int clientIndex, LfsRecordType recordType, ulong clientPreviousLsn, ulong clientUndoNextLsn, uint transactionId, byte[] clientData)
{
if (m_restartPage == null)
{
m_restartPage = ReadRestartPage();
}
if (m_restartPage.LogRestartArea.IsClean)
{
// We should clear the CleanDismount flag before making changes to the log file
WriteRestartPage(false);
}
ushort clientSeqNumber = m_restartPage.LogRestartArea.LogClientArray[clientIndex].SeqNumber;
LfsRecord record = new LfsRecord();
record.ClientSeqNumber = clientSeqNumber;
record.ClientIndex = (ushort)clientIndex;
record.RecordType = recordType;
record.ClientPreviousLsn = clientPreviousLsn;
record.ClientUndoNextLsn = clientUndoNextLsn;
record.TransactionId = transactionId;
record.ClientDataLength = (uint)clientData.Length;
record.Data = clientData;
record.ThisLsn = GetNextLsn();
WriteRecord(record);
// Update CurrentLsn / LastLsnDataLength
m_restartPage.LogRestartArea.CurrentLsn = record.ThisLsn;
m_restartPage.LogRestartArea.LastLsnDataLength = (uint)record.Data.Length;
if (record.IsMultiPageRecord)
{
// We can optimize by only writing the restart page if we already had one transfer after the last flushed LSN.
WriteRestartPage(false);
}
return(record);
}
