/// <summary>
/// Get next record in iterator
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
/// <returns></returns>
public bool GetNext(out Key key, out Value value)
{
key = default(Key);
value = default(Value);
while (true)
{
// Check for boundary conditions
if (currentAddress >= endAddress)
{
return(false);
}
if (currentAddress < hlog.BeginAddress)
{
throw new Exception("Iterator address is less than log BeginAddress " + hlog.BeginAddress);
}
var currentPage = currentAddress >> hlog.LogPageSizeBits;
var currentFrame = currentPage % frameSize;
var offset = currentAddress & hlog.PageSizeMask;
if (currentAddress < hlog.HeadAddress)
{
BufferAndLoad(currentAddress, currentPage, currentFrame);
}
var recordSize = hlog.GetRecordSize(hlog.GetPhysicalAddress(currentAddress));
// Check if record fits on page, if not skip to next page
if ((currentAddress & hlog.PageSizeMask) + recordSize > hlog.PageSize)
{
currentAddress = (1 + (currentAddress >> hlog.LogPageSizeBits)) << hlog.LogPageSizeBits;
continue;
}
if (currentAddress >= hlog.HeadAddress)
{
// Read record from cached page memory
var _physicalAddress = hlog.GetPhysicalAddress(currentAddress);
key = hlog.GetKey(_physicalAddress);
value = hlog.GetValue(_physicalAddress);
currentAddress += hlog.GetRecordSize(_physicalAddress);
return(true);
}
var physicalAddress = frame.GetPhysicalAddress(currentFrame, offset);
key = hlog.GetKey(physicalAddress);
value = hlog.GetValue(physicalAddress);
currentAddress += hlog.GetRecordSize(physicalAddress);
return(true);
}
}
/// <summary>
/// Get next record
/// </summary>
/// <param name="recordInfo"></param>
/// <returns>True if record found, false if end of scan</returns>
public bool GetNext(out RecordInfo recordInfo)
{
recordInfo = default;
while (true)
{
currentAddress = nextAddress;
// Check for boundary conditions
if (currentAddress >= endAddress)
{
return(false);
}
epoch?.Resume();
var headAddress = hlog.HeadAddress;
if (currentAddress < hlog.BeginAddress && !forceInMemory)
{
epoch?.Suspend();
throw new FasterException("Iterator address is less than log BeginAddress " + hlog.BeginAddress);
}
if (frameSize == 0 && currentAddress < headAddress && !forceInMemory)
{
epoch?.Suspend();
throw new FasterException("Iterator address is less than log HeadAddress in memory-scan mode");
}
var currentPage = currentAddress >> hlog.LogPageSizeBits;
var offset = currentAddress & hlog.PageSizeMask;
if (currentAddress < headAddress && !forceInMemory)
{
BufferAndLoad(currentAddress, currentPage, currentPage % frameSize, headAddress, endAddress);
}
long physicalAddress;
if (currentAddress >= headAddress || forceInMemory)
{
physicalAddress = hlog.GetPhysicalAddress(currentAddress);
currentPhysicalAddress = 0;
}
else
{
currentPhysicalAddress = physicalAddress = frame.GetPhysicalAddress(currentPage % frameSize, offset);
}
// Check if record fits on page, if not skip to next page
var recordSize = hlog.GetRecordSize(physicalAddress).Item2;
if ((currentAddress & hlog.PageSizeMask) + recordSize > hlog.PageSize)
{
nextAddress = (1 + (currentAddress >> hlog.LogPageSizeBits)) << hlog.LogPageSizeBits;
epoch?.Suspend();
continue;
}
nextAddress = currentAddress + recordSize;
ref var info = ref hlog.GetInfo(physicalAddress);
if (info.SkipOnScan || info.IsNull())
{
epoch?.Suspend();
continue;
}
recordInfo = info;
if (currentPhysicalAddress == 0)
{
currentKey = hlog.GetKey(physicalAddress);
currentValue = hlog.GetValue(physicalAddress);
}
epoch?.Suspend();
return(true);
}