private unsafe void BufferAndLoad(long currentAddress, long currentPage, long currentFrame)
{
if (first || (currentAddress & hlog.PageSizeMask) == 0)
{
// Prefetch pages based on buffering mode
if (frameSize == 1)
{
if (!first)
{
hlog.AsyncReadPagesFromDeviceToFrame(currentAddress >> hlog.LogPageSizeBits, 1, endAddress, AsyncReadPagesCallback, Empty.Default, frame, out loaded[currentFrame]);
}
}
else
{
var endPage = endAddress >> hlog.LogPageSizeBits;
if ((endPage > currentPage) &&
((endPage > currentPage + 1) || ((endAddress & hlog.PageSizeMask) != 0)))
{
hlog.AsyncReadPagesFromDeviceToFrame(1 + (currentAddress >> hlog.LogPageSizeBits), 1, endAddress, AsyncReadPagesCallback, Empty.Default, frame, out loaded[(currentPage + 1) % frameSize]);
}
}
first = false;
}
loaded[currentFrame].Wait();
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="hlog"></param>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
public unsafe GenericScanIterator(GenericAllocator <Key, Value> hlog, long beginAddress, long endAddress, ScanBufferingMode scanBufferingMode)
{
this.hlog = hlog;
this.beginAddress = beginAddress;
this.endAddress = endAddress;
recordSize = hlog.GetRecordSize(0);
currentAddress = beginAddress;
if (scanBufferingMode == ScanBufferingMode.SinglePageBuffering)
{
frameSize = 1;
}
else
{
frameSize = 2;
}
frame = new GenericFrame <Key, Value>(frameSize, hlog.PageSize);
loaded = new CountdownEvent[frameSize];
var frameNumber = (currentAddress >> hlog.LogPageSizeBits) % frameSize;
hlog.AsyncReadPagesFromDeviceToFrame
(currentAddress >> hlog.LogPageSizeBits,
1, AsyncReadPagesCallback, Empty.Default,
frame, out loaded[frameNumber]);
}
/// <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 GenericScanIterator(GenericAllocator <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;
recordSize = hlog.GetRecordSize(0).Item2;
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 GenericFrame <Key, Value>(frameSize, hlog.PageSize);
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>
/// Constructor
/// </summary>
/// <param name="hlog"></param>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
public unsafe GenericScanIterator(GenericAllocator <Key, Value> hlog, long beginAddress, long endAddress, ScanBufferingMode scanBufferingMode)
{
this.hlog = hlog;
if (beginAddress == 0)
{
beginAddress = hlog.GetFirstValidLogicalAddress(0);
}
this.beginAddress = beginAddress;
this.endAddress = endAddress;
recordSize = hlog.GetRecordSize(0);
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 GenericFrame <Key, Value>(frameSize, hlog.PageSize);
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]);
}
}
internal override void AsyncReadPagesFromDeviceToFrame <TContext>(long readPageStart, int numPages, long untilAddress, TContext context, out CountdownEvent completed, long devicePageOffset = 0, IDevice device = null, IDevice objectLogDevice = null, CancellationTokenSource cts = null) => hlog.AsyncReadPagesFromDeviceToFrame(readPageStart, numPages, untilAddress, AsyncReadPagesCallback, context, frame, out completed, devicePageOffset, device, objectLogDevice);