private unsafe void BufferAndLoad(long currentAddress, long currentPage, long currentFrame)
{
if (loadedPage[currentFrame] != currentPage)
{
if (loadedPage[currentFrame] != -1)
{
WaitForFrameLoad(currentFrame);
}
allocator.AsyncReadPagesFromDeviceToFrame(currentAddress >> allocator.LogPageSizeBits, 1, endAddress, AsyncReadPagesCallback, Empty.Default, frame, out loaded[currentFrame], 0, null, null, loadedCancel[currentFrame]);
loadedPage[currentFrame] = currentAddress >> allocator.LogPageSizeBits;
}
if (frameSize == 2)
{
var nextPage = currentPage + 1;
var nextFrame = (currentFrame + 1) % frameSize;
if (loadedPage[nextFrame] != nextPage)
{
if (loadedPage[nextFrame] != -1)
{
WaitForFrameLoad(nextFrame);
}
allocator.AsyncReadPagesFromDeviceToFrame(1 + (currentAddress >> allocator.LogPageSizeBits), 1, endAddress, AsyncReadPagesCallback, Empty.Default, frame, out loaded[nextFrame], 0, null, null, loadedCancel[nextFrame]);
loadedPage[nextFrame] = 1 + (currentAddress >> allocator.LogPageSizeBits);
}
}
WaitForFrameLoad(currentFrame);
}
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();
}
private unsafe bool BufferAndLoad(long currentAddress, long currentPage, long currentFrame, long headAddress)
{
for (int i = 0; i < frameSize; i++)
{
var nextPage = currentPage + i;
// Cannot load page if its not fully written to storage
if (headAddress < (nextPage + 1) << allocator.LogPageSizeBits)
{
continue;
}
var nextFrame = (currentFrame + i) % frameSize;
long val;
while ((val = nextLoadedPage[nextFrame]) < nextPage || loadedPage[nextFrame] < nextPage)
{
if (val < nextPage && Interlocked.CompareExchange(ref nextLoadedPage[nextFrame], nextPage, val) == val)
{
var tmp_i = i;
epoch.BumpCurrentEpoch(() =>
{
allocator.AsyncReadPagesFromDeviceToFrame(tmp_i + (currentAddress >> allocator.LogPageSizeBits), 1, endAddress, AsyncReadPagesCallback, Empty.Default, frame, out loaded[nextFrame], 0, null, null, loadedCancel[nextFrame]);
loadedPage[nextFrame] = nextPage;
});
}
else
{
epoch.ProtectAndDrain();
}
}
}
return(WaitForFrameLoad(currentAddress, currentFrame));
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="hlog"></param>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
public unsafe BlittableScanIterator(BlittableAllocator <Key, Value> hlog, long beginAddress, long endAddress, ScanBufferingMode scanBufferingMode)
{
this.hlog = hlog;
this.beginAddress = beginAddress;
this.endAddress = endAddress;
currentAddress = beginAddress;
if (scanBufferingMode == ScanBufferingMode.SinglePageBuffering)
{
frameSize = 1;
}
else
{
frameSize = 2;
}
frame = new BlittableFrame(frameSize, hlog.PageSize, hlog.GetDeviceSectorSize());
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>
/// <param name="forceInMemory">Provided address range is known by caller to be in memory, even if less than HeadAddress</param>
public unsafe BlittableScanIterator(BlittableAllocator <Key, Value> hlog, long beginAddress, long endAddress, ScanBufferingMode scanBufferingMode, LightEpoch epoch, bool forceInMemory = false)
{
this.hlog = hlog;
this.forceInMemory = forceInMemory;
// 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 && !forceInMemory)
{
var frameNumber = (nextAddress >> hlog.LogPageSizeBits) % frameSize;
hlog.AsyncReadPagesFromDeviceToFrame
(nextAddress >> hlog.LogPageSizeBits,
1, endAddress, AsyncReadPagesCallback, Empty.Default,
frame, out loaded[frameNumber]);
}
}
private unsafe bool BufferAndLoad(long currentAddress, long currentPage, long currentFrame, long headAddress)
{
for (int i = 0; i < frameSize; i++)
{
var nextPage = currentPage + i;
var pageEndAddress = (nextPage + 1) << allocator.LogPageSizeBits;
if (fasterLog.readOnlyMode)
{
// Support partial page reads of committed data
var _flush = fasterLog.CommittedUntilAddress;
if (_flush < pageEndAddress)
{
pageEndAddress = _flush;
}
}
// Cannot load page if its not fully written to storage
if (headAddress < pageEndAddress)
{
continue;
}
var nextFrame = (currentFrame + i) % frameSize;
long val;
while ((val = nextLoadedPage[nextFrame]) < pageEndAddress || loadedPage[nextFrame] < pageEndAddress)
{
if (val < pageEndAddress && Interlocked.CompareExchange(ref nextLoadedPage[nextFrame], pageEndAddress, val) == val)
{
var tmp_i = i;
epoch.BumpCurrentEpoch(() =>
{
allocator.AsyncReadPagesFromDeviceToFrame(tmp_i + (currentAddress >> allocator.LogPageSizeBits), 1, endAddress, AsyncReadPagesCallback, Empty.Default, frame, out loaded[nextFrame], 0, null, null, loadedCancel[nextFrame]);
loadedPage[nextFrame] = pageEndAddress;
});
}
else
{
epoch.ProtectAndDrain();
}
}
}
return(WaitForFrameLoad(currentAddress, currentFrame));
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="hlog"></param>
/// <param name="beginAddress"></param>
/// <param name="endAddress"></param>
/// <param name="scanBufferingMode"></param>
public unsafe BlittableScanIterator(BlittableAllocator <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;
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]);
}
}
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) => allocator.AsyncReadPagesFromDeviceToFrame(readPageStart, numPages, untilAddress, AsyncReadPagesCallback, context, frame, out completed, devicePageOffset, device, objectLogDevice, cts);