protected override sealed void DoRead(uint pageid, byte[] result)
{
RWFrame frame = null;
//////////////////////////////////by cat
if (!map.TryGetValue(pageid, out frame))
{
frame = new RWFrame(pageid);
map[pageid] = frame;
}
if (!frame.Resident)
{
frame.DataSlotId = pool.AllocSlot();
dev.Read(pageid, pool[frame.DataSlotId]);
pool[frame.DataSlotId].CopyTo(result, 0);
}
pool[frame.DataSlotId].CopyTo(result, 0);
//////////////////////////////////////////////////////
readList.updateFrame(frame, false);
writeList.updateFrame(frame, false);
}
protected override sealed void DoWrite(uint pageid, byte[] data)
{
RWFrame frame = null;
if (!map.TryGetValue(pageid, out frame))
{
frame = new RWFrame(pageid);
map[pageid] = frame;
}
if (!frame.Resident)
{
frame.DataSlotId = pool.AllocSlot();
}
data.CopyTo(pool[frame.DataSlotId], 0);
frame.Dirty = true;
//////////////////////////////////////////////////////
readList.updateFrame(frame, true);
writeList.updateFrame(frame, true);
}
private void updateFrameNode(RWFrame frame, bool isWriteQueue, bool isWriteOperation, LinkedListNode<RWQuery> node)
{
if (isWriteQueue)
{
if (isWriteOperation)
{
frame.NodeOfWriteInWriteQueue = node;
}
else
{
frame.NodeOfReadInWriteQueue = node;
}
}
else
{
if (isWriteOperation)
{
frame.NodeOfWriteInReadQueue = node;
}
else
{
frame.NodeOfReadInReadQueue = node;
}
}
}
private LinkedListNode<RWQuery> getNode(RWFrame frame, bool isWriteQueue, bool isWriteOperation)
{
if (isWriteQueue)
{
if (isWriteOperation)
{
return frame.NodeOfWriteInWriteQueue;
}
else
{
return frame.NodeOfReadInWriteQueue;
}
}
else
{
if (isWriteOperation)
{
return frame.NodeOfWriteInReadQueue;
}
else
{
return frame.NodeOfReadInReadQueue;
}
}
}
public LinkedListNode<RWQuery> updateFrame(RWFrame frame, bool isWrite)
{
if (getNode(frame, isWriteQueue, isWrite) == null)
{
return Enqueue(frame, isWrite);
}
else
{
return AccessFrame(frame, isWrite);
}
}
public LinkedListNode<RWQuery> Enqueue(RWFrame frame, bool isWrite)
{
LinkedListNode<RWQuery> newNode = queue.AddFirst(new RWQuery(frame.Id, isWrite));
updateFrameNode(frame, isWriteQueue, isWrite, newNode);
return newNode;
}
public LinkedListNode<RWQuery> AccessFrame(RWFrame frame, bool isWrite)
{
LinkedListNode<RWQuery> node = getNode(frame, isWriteQueue, isWrite);
queue.Remove(node);
LinkedListNode<RWQuery> newNode = queue.AddFirst(new RWQuery(frame.Id, isWrite));
updateFrameNode(frame, isWriteQueue, node.Value.Type == AccessType.Write, newNode);
return newNode;
}
