/// <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);
}
}
}
protected override void DoAccess(uint pageid, byte[] resultOrData, AccessType type)
{
LinkedListNode<IFrame> node;
IFrame frame;
if (map.TryGetValue(pageid, out node))
{
frame = node.Value;
list.Remove(node);
}
else
{
frame = new Frame(pageid);
}
PerformAccess(frame, resultOrData, type);
node = list.AddFirst(frame);
map[pageid] = node;
}
/// <summary>
///
/// </summary>
/// <param name="pageid"></param>
/// <param name="data"></param>
protected override sealed void DoWrite(uint pageid, byte[] data)
{
Frame frame;
//if not in hash map
if (!map.TryGetValue(pageid, out frame))
{
//add to hash map
frame = new Frame(pageid, pool.AllocSlot());
map[pageid] = frame;
//add to wirte queue
writeQueue.Insert(0, pageid);
//(to be added) if the queue exceed a certain threshold, one frame should be kicked off.
}
else//in hash map
{
frame = map[pageid];
//update
if (IsInWriteWindow(pageid))
{
changeLimit(-3);//TODO
}
if (!frame.Resident) //miss non resident allocate a slot
{
//在readQueue里前移到resident里
int index = readQueue.IndexOf(pageid);
if (index != -1)
{
readQueue.RemoveAt(index);
}
frame.DataSlotId = pool.AllocSlot();
//移到resident的末尾
if (index != -1)
{
int lastReadResident = LastIndexOfResident(readQueue);
Debug.Assert(index > lastReadResident);
readQueue.Insert(lastReadResident + 1, pageid);
}
}
writeQueue.Remove(pageid);
writeQueue.Insert(0, pageid);
}
frame.Dirty = true;
data.CopyTo(pool[frame.DataSlotId], 0);
//if (writeQueue.Count > 2 * pool.NPages)
//{
// uint removeId = writeQueue[writeQueue.Count - 1];
// writeQueue.RemoveAt(writeQueue.Count - 1);
// int index = readQueue.IndexOf(removeId);
// if (index < 0)
// map.Remove(removeId);
//}
}
/// <summary>
///
/// </summary>
/// <param name="pageid"></param>
/// <param name="result"></param>
protected override sealed void DoRead(uint pageid, byte[] result)
{
Frame frame;
//if not in hash map
if (!map.TryGetValue(pageid, out frame))
{
//add to hash map
frame = new Frame(pageid, pool.AllocSlot());
map[pageid] = frame;
//load the page
dev.Read(pageid, pool[frame.DataSlotId]);
pool[frame.DataSlotId].CopyTo(result, 0);
//add to queue;
readQueue.Insert(0, pageid);
//(to be added) if the queue exceed a certain threshold, one frame should be kicked off.
}
else//in hash map
{
frame = map[pageid];
//update
if (IsInReadWindow(pageid))
{
changeLimit(1);
}
if (!frame.Resident) //miss non resident
{
//在writeQueue里前移到resident里
int index = writeQueue.IndexOf(pageid);
if (index != -1)
{
writeQueue.RemoveAt(index);
}
frame.DataSlotId = pool.AllocSlot();
dev.Read(pageid, pool[frame.DataSlotId]);
pool[frame.DataSlotId].CopyTo(result, 0);
//移到resident的末尾
if (index != -1)
{
int lastWriteResident = LastIndexOfResident(writeQueue);
Debug.Assert(index > lastWriteResident);
writeQueue.Insert(lastWriteResident + 1, pageid);
}
}
readQueue.Remove(pageid);
readQueue.Insert(0, pageid);
//if (readQueue.Count > 2 * pool.NPages)
//{
// uint removeId = readQueue[readQueue.Count - 1];
// readQueue.RemoveAt(readQueue.Count - 1);
// int index = writeQueue.IndexOf(removeId);
// if (index < 0)
// map.Remove(removeId);
//}
}
}
/// <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);
}
