/// <summary>
///
/// </summary>
/// <param name="pageid"></param>
/// <param name="result"></param>
protected override sealed void DoRead(uint pageid, byte[] result)
{
IRRFrame irrframe;
//if not in hash map
if (!map.TryGetValue(pageid, out irrframe))
{
//add to hash map
irrframe = new IRRFrame(pageid, pool.AllocSlot());
map[pageid] = irrframe;
//load the page
dev.Read(pageid, pool[irrframe.DataSlotId]);
pool[irrframe.DataSlotId].CopyTo(result, 0);
//add to IRR queue
Frame frame = new Frame(pageid);
frame.Dirty = false;
irrQueue.Enqueue(frame);
//(to be added) if the queue exceed a certain threshold, one frame should be kicked off.
}
else//in hash map
{
irrframe = map[pageid];
if (!irrframe.Resident) //miss non resident
{
irrframe.DataSlotId = pool.AllocSlot();
dev.Read(pageid, pool[irrframe.DataSlotId]);
pool[irrframe.DataSlotId].CopyTo(result, 0);
}
//update IRR
uint irr = irrQueue.accessIRR(pageid, false);
irrframe.ReadIRR = irr; //possiblely 0, no effect
if (irr == 0)
{
Frame frame = new Frame(pageid);
frame.Dirty = false;
irrQueue.Enqueue(frame);
}
}
}
/// <summary>
///
/// </summary>
/// <param name="pageid"></param>
/// <param name="data"></param>
protected override sealed void DoWrite(uint pageid, byte[] data)
{
IRRFrame irrframe;
//if not in hash map
if (!map.TryGetValue(pageid, out irrframe))
{
//add to hash map
irrframe = new IRRFrame(pageid, pool.AllocSlot());
map[pageid] = irrframe;
//add to IRR queue
Frame frame = new Frame(pageid);
frame.Dirty = true;
irrQueue.Enqueue(frame);
//(to be added) if the queue exceed a certain threshold, one frame should be kicked off.
}
else//in hash map
{
irrframe = map[pageid];
if (!irrframe.Resident) //miss non resident allocate a slot
{
irrframe.DataSlotId = pool.AllocSlot();
}
//update IRR
uint irr = irrQueue.accessIRR(pageid, true);
irrframe.WriteIRR = irr; //0 doesn't matter.
if (irr == 0)
{
Frame frame = new Frame(pageid);
frame.Dirty = true;
irrQueue.Enqueue(frame);
}
}
irrframe.Dirty = true;
data.CopyTo(pool[irrframe.DataSlotId], 0);
}
