public static void MoveExtentDataLeft(Volume volume, DiskExtent sourceExtent, DiskExtent relocatedExtent, MoveExtentOperationBootRecord resumeRecord, ref long bytesCopied)
{
// we make sure no data will be overwritten too soon:
long distanceLBA = (long)(resumeRecord.OldStartSector - resumeRecord.NewStartSector);
bool bufferedMode = false;
if (distanceLBA < BufferedModeThresholdLBA)
{
bufferedMode = true;
}
int transferSizeLBA;
if (bufferedMode)
{
transferSizeLBA = (int)resumeRecord.BackupBufferSizeLBA;;
}
else
{
transferSizeLBA = (int)Math.Min(Settings.MaximumTransferSizeLBA, distanceLBA);
}
// move the data
for (long sectorIndex = (long)resumeRecord.NumberOfCommittedSectors; sectorIndex < relocatedExtent.TotalSectors; sectorIndex += transferSizeLBA)
{
long sectorsLeft = relocatedExtent.TotalSectors - sectorIndex;
int sectorsToRead = (int)Math.Min(transferSizeLBA, sectorsLeft);
byte[] data = sourceExtent.ReadSectors(sectorIndex, sectorsToRead);
if (bufferedMode)
{
// we write the data to the buffer for recovery purposes
relocatedExtent.Disk.WriteSectors((long)resumeRecord.BackupBufferStartSector, data);
resumeRecord.RestoreFromBuffer = true;
relocatedExtent.WriteSectors(0, resumeRecord.GetBytes());
}
relocatedExtent.WriteSectors(sectorIndex, data);
// update the resume record
resumeRecord.RestoreFromBuffer = false;
resumeRecord.NumberOfCommittedSectors += (ulong)sectorsToRead;
volume.WriteSectors(0, resumeRecord.GetBytes());
bytesCopied = (long)resumeRecord.NumberOfCommittedSectors * sourceExtent.BytesPerSector;
}
}
public static void MoveExtentDataRight(Volume volume, DiskExtent sourceExtent, DiskExtent relocatedExtent, MoveExtentOperationBootRecord resumeRecord, ref long bytesCopied)
{
// we make sure no data will be overwritten too soon:
long distanceLBA = (long)(resumeRecord.NewStartSector - resumeRecord.OldStartSector);
bool bufferedMode = false;
if (distanceLBA < BufferedModeThresholdLBA)
{
bufferedMode = true;
}
int transferSizeLBA;
if (bufferedMode)
{
transferSizeLBA = (int)resumeRecord.BackupBufferSizeLBA;
}
else
{
transferSizeLBA = (int)Math.Min(Settings.MaximumTransferSizeLBA, distanceLBA);
}
// move the data
for (long readCount = (long)resumeRecord.NumberOfCommittedSectors; readCount < relocatedExtent.TotalSectors; readCount += transferSizeLBA)
{
// we read (and write) from the end of the extent and progress to the left
long sectorsLeft = relocatedExtent.TotalSectors - readCount;
int sectorsToRead = (int)Math.Min(transferSizeLBA, sectorsLeft);
long sectorIndex = relocatedExtent.TotalSectors - readCount - sectorsToRead;
byte[] data = sourceExtent.ReadSectors(sectorIndex, sectorsToRead);
if (bufferedMode)
{
// we write the data to the buffer for recovery purposes
relocatedExtent.Disk.WriteSectors((long)resumeRecord.BackupBufferStartSector, data);
resumeRecord.RestoreFromBuffer = true;
// Note: if the extent we move is the first in the volume, we will write the resume record to
// the source extent, which is the one that the database is still referring to
volume.WriteSectors(0, resumeRecord.GetBytes());
}
relocatedExtent.WriteSectors(sectorIndex, data);
// update the resume record
resumeRecord.RestoreFromBuffer = false;
resumeRecord.NumberOfCommittedSectors += (ulong)sectorsToRead;
volume.WriteSectors(0, resumeRecord.GetBytes());
bytesCopied = (long)resumeRecord.NumberOfCommittedSectors * sourceExtent.BytesPerSector;
}
}
