private ImmutableIdDispenser(ImmutableIdDispenser left, ImmutableIdDispenser right, int used, int size, uint bitmap)
{
_left = left;
_right = right;
_used = used;
_size = size;
_bitmap = bitmap;
CheckInvariants();
}
private ImmutableIdDispenser(ImmutableIdDispenser left, ImmutableIdDispenser right, int used, int size, uint bitmap)
{
_left = left;
_right = right;
_used = used;
_size = size;
_bitmap = bitmap;
CheckInvariants();
}
public ImmutableIdDispenser AllocateId(out int id)
{
if (_used == _size)
{
id = _size;
return(new ImmutableIdDispenser(this, null, _size + 1, checked (2 * _size + BitsPerNode), 1));
}
var bitmap = _bitmap;
var left = _left;
var right = _right;
// Any free bits in current node?
if (bitmap != uint.MaxValue)
{
int bit = 0;
while ((bitmap & (uint)(1 << bit)) != 0)
{
bit++;
}
bitmap |= (uint)(1 << bit);
id = ChildSize + bit;
}
else
{
Debug.Assert(ChildSize > 0);
if (left == null)
{
left = new ImmutableIdDispenser(null, null, 1, ChildSize, 1);
id = left.ChildSize;
}
else
if (right == null)
{
right = new ImmutableIdDispenser(null, null, 1, ChildSize, 1);
id = ChildSize + BitsPerNode + right.ChildSize;
}
else
{
if (left._used < right._used)
{
Debug.Assert(left._used < left._size);
left = left.AllocateId(out id);
}
else
{
Debug.Assert(right._used < right._size);
right = right.AllocateId(out id);
id += (ChildSize + BitsPerNode);
}
}
}
return(new ImmutableIdDispenser(left, right, _used + 1, _size, bitmap));
}
public ImmutableIdDispenser AllocateId(out int id)
{
if (_used == _size)
{
id = _size;
return new ImmutableIdDispenser(this, null, _size + 1, checked(2 * _size + BitsPerNode), 1);
}
var bitmap = _bitmap;
var left = _left;
var right = _right;
// Any free bits in current node?
if (bitmap != UInt32.MaxValue)
{
int bit = 0;
while ((bitmap & (uint)(1 << bit)) != 0)
bit++;
bitmap |= (uint)(1 << bit);
id = ChildSize + bit;
}
else
{
Debug.Assert(ChildSize > 0);
if (left == null)
{
left = new ImmutableIdDispenser(null, null, 1, ChildSize, 1);
id = left.ChildSize;
}
else
if (right == null)
{
right = new ImmutableIdDispenser(null, null, 1, ChildSize, 1);
id = ChildSize + BitsPerNode + right.ChildSize;
}
else
{
if (left._used < right._used)
{
Debug.Assert(left._used < left._size);
left = left.AllocateId(out id);
}
else
{
Debug.Assert(right._used < right._size);
right = right.AllocateId(out id);
id += (ChildSize + BitsPerNode);
}
}
}
return new ImmutableIdDispenser(left, right, _used + 1, _size, bitmap);
}