/// <summary>
/// Create a new snapshot from scratch
/// </summary>
private void Create()
{
DateTime start = DateTime.Now;
// TO DO: check free space on parity drive here?
UInt32 totalBlocks = 1; // make it one so no chance of divide-by-zero below
foreach (DataDrive d in drives) {
d.BeginFileEnum();
UInt32 scanBlocks = d.TotalScanBlocks;
if (scanBlocks > totalBlocks)
totalBlocks = scanBlocks;
}
try {
ParityBlock parityBlock = new ParityBlock(parity);
byte[] dataBuf = new byte[Parity.BLOCK_SIZE];
UInt32 block = 0;
bool done = false;
while (!done) {
done = true;
foreach (DataDrive d in drives)
if (d.GetNextBlock(done ? parityBlock.Data : dataBuf))
if (done)
done = false;
else
parityBlock.Add(dataBuf);
if (!done)
parityBlock.Write(block);
Progress = (double)block / totalBlocks;
block++;
if (cancel) {
// we can't salvage an initial update that was cancelled so we'll have to start again from scratch next time.
LogFile.Log("Initial update cancelled. Resetting parity to empty.");
Erase();
return;
}
}
}
catch (Exception e) {
LogFile.Log("Fatal error on initial update: " + e.Message);
LogFile.Log(e.StackTrace);
// can't recover from errors either, must also start over from scratch
Erase();
throw new UpdateFailedException(e.Message);
}
finally {
foreach (DataDrive d in drives)
d.EndFileEnum();
parity.Close();
if (!cancel)
Empty = false;
}
}
