private void LoadBufferPage(BufferEntry buffer)
{
buffer.Page = new Page(new byte[Constants.PageSize]);
//buffer.Page = PageManager.ReadPage(buffer.Position);
buffer.State = BufferState.Clean;
buffer.Latch.ExitWriteScope();
}
private void Remove(BufferEntry entry)
{
if (entry.Prev == null &&
entry.Next == null &&
entry != _first)
{
return;
}
if (entry.Prev == entry)
{
_first = null;
}
else if (_first == entry)
{
entry.Next.Prev = entry.Prev;
entry.Prev.Next = entry.Next;
_first = entry.Next;
}
else
{
entry.Next.Prev = entry.Prev;
entry.Prev.Next = entry.Next;
}
_count--;
_version++;
}
private void AddLRUEntry(BufferEntry buffer)
{
if (LRU.Count >= Options.LRULimit)
{
//FLUSH
}
LRU.AddFirst(buffer);
}
public void MoveToLast(BufferEntry entry)
{
if (entry == null)
{
throw new ArgumentNullException(nameof(entry));
}
Remove(entry);
AddLast(entry);
}
public void AddLast(BufferEntry entry)
{
if (_first == null)
{
_first = entry;
_version++;
_count++;
entry.Prev = entry;
entry.Next = entry;
}
else
{
InsertBefore(_first, entry);
}
}
private void InsertBefore(BufferEntry beforeEntry, BufferEntry entry)
{
if (entry == null)
{
throw new ArgumentNullException(nameof(entry));
}
if (beforeEntry == null)
{
throw new ArgumentNullException(nameof(beforeEntry));
}
_count++;
_version++;
entry.Next = beforeEntry;
entry.Prev = beforeEntry.Prev;
beforeEntry.Prev.Next = entry;
beforeEntry.Prev = entry;
}
private void MoveLRUEntry(BufferEntry buffer)
{
LRU.MoveToFirst(buffer);
}
public void AddFlushEntry(BufferEntry buffer)
{
Flush.AddFirst(buffer);
}
public void Clear()
{
_first = null;
_count = 0;
_version++;
}
