public PoolPointer Allocate(long size)
{
if (size > PoolSize)
{
return(null);
}
long currentScanOffset = 0;
lock (PoolPointers)
{
foreach (var pointer in PoolPointers.OrderBy(x => x.Offset).ToArray())
{
if (pointer.Offset - currentScanOffset >= size)
{
var newPointer = new PoolPointer(this, currentScanOffset, size, DefaultFixed);
PoolPointers.Add(newPointer);
return(newPointer);
}
currentScanOffset = pointer.Offset + pointer.Length;
}
if (PoolSize - currentScanOffset >= size)
{
var newPointer = new PoolPointer(this, currentScanOffset, size, DefaultFixed);
PoolPointers.Add(newPointer);
return(newPointer);
}
}
return(null);
}
public long GetTotalAllocatedSize()
{
lock (PoolPointers)
{
return(PoolPointers.Sum(x => x.Length));
}
}
public void Release(PoolPointer poolPointer)
{
lock (PoolPointers)
{
if (PinnedPointers.Contains(poolPointer))
{
throw new InvalidOperationException("Cannot release a pool pointer that is currently pinned");
}
PoolPointers.Remove(poolPointer);
}
}
public void Compact()
{
lock (PoolPointers)
{
long currentScanOffset = 0;
int currentPinnedPointerIndex = 0;
var pinnedPointers = PinnedPointers
.Concat(PoolPointers.Where(x => x.Fixed))
.OrderBy(x => x.Offset)
.ToArray();
var movablePointers = PoolPointers
.Except(pinnedPointers)
.OrderBy(x => x.Offset);
foreach (var pointer in movablePointers)
{
if (currentScanOffset == pointer.Offset)
{
// Block is already in optimal position
currentScanOffset += pointer.Length;
continue;
}
while (pinnedPointers[currentPinnedPointerIndex].Offset - currentScanOffset < pointer.Length)
{
// There is a pinned pointer in the way. Skip over it
currentScanOffset = pinnedPointers[currentPinnedPointerIndex].Offset +
pinnedPointers[currentPinnedPointerIndex].Length;
currentPinnedPointerIndex++;
}
var originalPosition = UnderlyingMemory.Slice((int)pointer.Offset, (int)pointer.Length);
var newPosition = UnderlyingMemory.Slice((int)currentScanOffset, (int)pointer.Length);
originalPosition.CopyTo(newPosition);
pointer.Offset = currentScanOffset;
currentScanOffset += pointer.Length;
}
}
}
