/// <summary>
/// Constructor
/// </summary>
/// <param name="fasterLog"></param>
/// <param name="hlog"></param>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
/// <param name="epoch"></param>
/// <param name="headerSize"></param>
/// <param name="name"></param>
/// <param name="getMemory"></param>
internal unsafe FasterLogScanIterator(FasterLog fasterLog, BlittableAllocator <Empty, byte> hlog, long beginAddress, long endAddress, GetMemory getMemory, ScanBufferingMode scanBufferingMode, LightEpoch epoch, int headerSize, string name)
{
this.fasterLog = fasterLog;
this.allocator = hlog;
this.getMemory = getMemory;
this.epoch = epoch;
this.headerSize = headerSize;
if (beginAddress == 0)
{
beginAddress = hlog.GetFirstValidLogicalAddress(0);
}
this.name = name;
this.endAddress = endAddress;
NextAddress = CompletedUntilAddress = beginAddress;
if (scanBufferingMode == ScanBufferingMode.SinglePageBuffering)
{
frameSize = 1;
}
else if (scanBufferingMode == ScanBufferingMode.DoublePageBuffering)
{
frameSize = 2;
}
else if (scanBufferingMode == ScanBufferingMode.NoBuffering)
{
frameSize = 0;
return;
}
frame = new BlittableFrame(frameSize, hlog.PageSize, hlog.GetDeviceSectorSize());
loaded = new CountdownEvent[frameSize];
loadedCancel = new CancellationTokenSource[frameSize];
loadedPage = new long[frameSize];
nextLoadedPage = new long[frameSize];
for (int i = 0; i < frameSize; i++)
{
loadedPage[i] = -1;
nextLoadedPage[i] = -1;
loadedCancel[i] = new CancellationTokenSource();
}
}
/// <summary>
/// Wait for ongoing checkpoint to complete
/// </summary>
/// <returns></returns>
public async ValueTask CompleteCheckpointAsync(CancellationToken token = default)
{
if (LightEpoch.AnyInstanceProtected())
{
throw new FasterException("Cannot use CompleteCheckpointAsync when using legacy or non-async sessions");
}
token.ThrowIfCancellationRequested();
while (true)
{
var systemState = _systemState;
if (systemState.phase == Phase.REST || systemState.phase == Phase.PREPARE_GROW || systemState.phase == Phase.IN_PROGRESS_GROW)
{
return;
}
await HandleCheckpointingPhasesAsync(null, null);
}
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
/// <param name="epoch"></param>
/// <param name="logPageSizeBits"></param>
public unsafe ScanIteratorBase(long beginAddress, long endAddress, ScanBufferingMode scanBufferingMode, LightEpoch epoch, int logPageSizeBits)
{
// If we are protected when creating the iterator, we do not need per-GetNext protection
if (!epoch.ThisInstanceProtected())
{
this.epoch = epoch;
}
this.beginAddress = beginAddress;
this.endAddress = endAddress;
this.logPageSizeBits = logPageSizeBits;
currentAddress = -1;
nextAddress = beginAddress;
if (scanBufferingMode == ScanBufferingMode.SinglePageBuffering)
{
frameSize = 1;
}
else if (scanBufferingMode == ScanBufferingMode.DoublePageBuffering)
{
frameSize = 2;
}
else if (scanBufferingMode == ScanBufferingMode.NoBuffering)
{
frameSize = 0;
return;
}
loaded = new CountdownEvent[frameSize];
loadedCancel = new CancellationTokenSource[frameSize];
loadedPage = new long[frameSize];
nextLoadedPage = new long[frameSize];
for (int i = 0; i < frameSize; i++)
{
loadedPage[i] = -1;
nextLoadedPage[i] = -1;
loadedCancel[i] = new CancellationTokenSource();
}
}
/// <summary>
/// Initialize device
/// </summary>
/// <param name="segmentSize"></param>
/// <param name="epoch"></param>
public virtual void Initialize(long segmentSize, LightEpoch epoch = null)
{
// TODO(Tianyu): Alternatively, we can adjust capacity based on the segment size: given a phsyical upper limit of capacity,
// we only make use of (Capacity / segmentSize * segmentSize) many bytes.
Debug.Assert(Capacity == -1 || Capacity % segmentSize == 0, "capacity must be a multiple of segment sizes");
this.segmentSize = segmentSize;
this.epoch = epoch;
if (!Utility.IsPowerOfTwo(segmentSize))
{
if (segmentSize != -1)
{
throw new Exception("Invalid segment size: " + segmentSize);
}
segmentSizeBits = 64;
segmentSizeMask = ~0UL;
}
else
{
segmentSizeBits = Utility.GetLogBase2((ulong)segmentSize);
segmentSizeMask = (ulong)segmentSize - 1;
}
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="hlog"></param>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
/// <param name="epoch"></param>
public GenericScanIterator(GenericAllocator <Key, Value> hlog, long beginAddress, long endAddress, ScanBufferingMode scanBufferingMode, LightEpoch epoch)
: base(beginAddress == 0 ? hlog.GetFirstValidLogicalAddress(0) : beginAddress, endAddress, scanBufferingMode, epoch, hlog.LogPageSizeBits)
{
this.hlog = hlog;
recordSize = hlog.GetRecordSize(0).Item2;
if (frameSize > 0)
{
frame = new GenericFrame <Key, Value>(frameSize, hlog.PageSize);
}
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="hlog"></param>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
/// <param name="epoch"></param>
public unsafe BlittableScanIterator(BlittableAllocator <Key, Value> hlog, long beginAddress, long endAddress, ScanBufferingMode scanBufferingMode, LightEpoch epoch)
{
this.hlog = hlog;
// If we are protected when creating the iterator, we do not need per-GetNext protection
if (!epoch.ThisInstanceProtected())
{
this.epoch = epoch;
}
if (beginAddress == 0)
{
beginAddress = hlog.GetFirstValidLogicalAddress(0);
}
this.endAddress = endAddress;
currentAddress = -1;
nextAddress = beginAddress;
if (scanBufferingMode == ScanBufferingMode.SinglePageBuffering)
{
frameSize = 1;
}
else if (scanBufferingMode == ScanBufferingMode.DoublePageBuffering)
{
frameSize = 2;
}
else if (scanBufferingMode == ScanBufferingMode.NoBuffering)
{
frameSize = 0;
return;
}
frame = new BlittableFrame(frameSize, hlog.PageSize, hlog.GetDeviceSectorSize());
loaded = new CountdownEvent[frameSize];
// Only load addresses flushed to disk
if (nextAddress < hlog.HeadAddress)
{
var frameNumber = (nextAddress >> hlog.LogPageSizeBits) % frameSize;
hlog.AsyncReadPagesFromDeviceToFrame
(nextAddress >> hlog.LogPageSizeBits,
1, endAddress, AsyncReadPagesCallback, Empty.Default,
frame, out loaded[frameNumber]);
}
}
/// <summary>
/// Creates a new SimpleVersionScheme
/// </summary>
public SimpleVersionScheme()
{
epoch = new LightEpoch();
}
