private int DoReplace(ref AListSparseOperation <T> op, int index, out AListNode <int, T> splitLeft, out AListNode <int, T> splitRight)
{
if (op.WriteEmpty)
{
int i1, i2;
uint leftToReplace = (uint)(op.SourceCount - op.SourceIndex);
uint startAt = (uint)(index + op.SourceIndex);
i1 = GetSectionRange(startAt, leftToReplace, out i2);
_list.RemoveRange(i1, i2 - i1);
uint amtReplaced = System.Math.Min(leftToReplace, _totalCount - startAt);
op.SourceIndex += (int)amtReplaced;
splitLeft = splitRight = null;
if (IsUndersized)
{
splitLeft = this;
}
return(0);
}
// Currently there is only one other replacement operation exposed on
// SparseAList, namely changing the value of a single item. I'll
// include code for changing multiple items at once, but not optimize
// that case. And no sparse support.
Debug.Assert(op.SparseSource == null);
splitLeft = splitRight = null;
if (op.Source != null)
{
for (; op.SourceIndex < op.SourceCount; op.SourceIndex++)
{
op.Item = op.Source[op.SourceIndex];
if (!ReplaceSingleItem(ref op, (uint)(index + op.SourceIndex)))
{
SplitLeaf(out splitLeft, out splitRight);
return(0);
}
}
}
else
{
Debug.Assert(op.SourceIndex == 0 && op.SourceCount == 1);
if (!ReplaceSingleItem(ref op, (uint)(index + op.SourceIndex)))
{
SplitLeaf(out splitLeft, out splitRight);
return(0);
}
op.SourceIndex++;
}
return(0);
}
internal override int DoSparseOperation(ref AListSparseOperation <T> op, int index, out AListNode <int, T> splitLeft, out AListNode <int, T> splitRight)
{
Debug.Assert(!IsFrozen);
if (op.IsInsert)
{
return(DoInsert(ref op, index, out splitLeft, out splitRight));
}
else
{
return(DoReplace(ref op, index, out splitLeft, out splitRight));
}
}
private bool ReplaceSingleItem(ref AListSparseOperation <T> op, uint index)
{
int i;
if (BinarySearch(index, out i))
{
_list.InternalArray[_list.Internalize(i)].Item = op.Item;
}
else
{
if (_list.Count >= _maxNodeSize)
{
return(false);
}
_list.Insert(i, new Entry(index, op.Item));
}
return(true);
}
internal override int DoSparseOperation(ref AListSparseOperation <T> op, int index, out AListNode <int, T> splitLeft, out AListNode <int, T> splitRight)
{
Debug.Assert(!IsFrozen);
Debug.Assert(op.Source == null || op.SourceCount == op.Source.Count);
AssertValid();
Entry e = default(Entry);
// Perform the insert/replace
int change = 0, i = 0;
do
{
if (change == 0)
{
// runs once for insert operations, once or multiple times for replace
i = BinarySearchI((uint)(index + op.SourceIndex));
AutoClone(ref _children[i].Node, this, op.tob);
e = _children[i];
}
change += e.Node.DoSparseOperation(ref op, index - (int)e.Index, out splitLeft, out splitRight);
} while (op.SourceIndex < op.SourceCount && splitLeft == null && index + op.SourceIndex < TotalCount);
// Adjust base index of nodes that follow
if (change != 0)
{
AdjustIndexesAfter(i, change);
}
// Handle child split/undersize
if (splitLeft == null)
{
return(change);
}
else if (splitRight != null)
{
splitLeft = HandleChildSplit(i, splitLeft, ref splitRight, op.tob);
return(change);
}
else
{
splitLeft = HandleUndersized(i, op.tob) ? this : null;
return(change);
}
}
/// <summary>Performs an insert or replace operation in a <see cref="SparseAList{T}"/>.</summary>
/// <param name="op">Describes the operation to be performed</param>
/// <param name="index">Relative index in child node where the sparse
/// operation began; <c>index + op.SourceIndex</c> is where the next
/// insertion or replacement must occur. For example if the child
/// node represents items 100-200, and op.SourceIndex is 7, and
/// the absolute index of the start of the operation (op.AbsoluteIndex)
/// is 98, then <c>index</c> will be -2 (98-100) and the next insertion
/// or replacement will occur at index 5 in the child. <c>index</c> may
/// be negative but <c>index + op.SourceIndex >= 0</c>.</param>
/// <param name="splitLeft">If the node needs to split, splitLeft and
/// splitRight are set to the new pieces. If the node is undersized,
/// splitLeft is set to <c>this</c> (the called node) and splitRight
/// is set to null.</param>
/// <returns>Size change (always 0 for a replacement operation)</returns>
/// <remarks>In a language with templates, I would change a couple
/// of elements of <see cref="AListSparseOperation{T}"/> into
/// template parameters.</remarks>
internal virtual int DoSparseOperation(ref AListSparseOperation <T> op, int index, out AListNode <K, T> splitLeft, out AListNode <K, T> splitRight)
{
throw new NotSupportedException();
}
private int DoInsert(ref AListSparseOperation <T> op, int index0, out AListNode <int, T> splitLeft, out AListNode <int, T> splitRight)
{
Debug.Assert(_totalCount + op.SourceCount >= _totalCount); // caller ensures list size does not overflow
if (op.WriteEmpty)
{
// SourceIndex will be 0 because inserting empty space always finishes on the first try.
Debug.Assert(op.SourceIndex == 0);
InsertSpace((uint)index0, op.SourceCount);
op.SourceIndex = op.SourceCount;
splitLeft = splitRight = null;
return(op.SourceCount);
}
int leftHere = _maxNodeSize - _list.Count;
if (leftHere == 0)
{
SplitLeaf(out splitLeft, out splitRight);
return(0); // return without inserting anything
}
uint index = (uint)(index0 + op.SourceIndex);
int i;
BinarySearch(index, out i);
if (op.Source == null)
{
// Special case: insert a single item
Debug.Assert(op.SourceCount == 1);
_list.AutoRaiseCapacity(1, _maxNodeSize);
_list.Insert(i, new Entry(index, op.Item));
AdjustOffsetsStartingAt(i + 1, ref _list, 1);
_totalCount++;
op.SourceIndex++;
splitLeft = splitRight = null;
return(1);
}
splitLeft = splitRight = null;
if (op.SparseSource != null)
{
var source = op.SparseSource;
var tempList = new InternalList <Entry>(leftHere);
int?si;
T item;
for (int prev = op.SourceIndex - 1; ; prev = si.Value)
{
si = prev;
item = source.NextHigherItem(ref si);
if (si == null)
{
break;
}
tempList.Add(new Entry {
Offset = (uint)(index0 + si.Value),
Item = item
});
if (tempList.Count == leftHere)
{
break;
}
}
_list.InsertRangeHelper(i, tempList.Count);
for (int j = 0; j < tempList.Count; j++)
{
_list[i + j] = tempList[j];
}
int newSourceIndex = si == null ? source.Count : si.Value + 1;
int virtualItemsInserted = newSourceIndex - op.SourceIndex;
op.SourceIndex = newSourceIndex;
AdjustOffsetsStartingAt(i + tempList.Count, ref _list, virtualItemsInserted);
_totalCount += (uint)virtualItemsInserted;
return(virtualItemsInserted);
}
else
{
int c = op.SourceCount;
int leftToInsert = c - op.SourceIndex;
Debug.Assert(leftToInsert > 0);
int amtToIns = System.Math.Min(leftHere, leftToInsert);
_list.AutoRaiseCapacity(amtToIns, _maxNodeSize);
_list.InsertRangeHelper(i, amtToIns);
for (int j = 0; j < amtToIns; j++)
{
_list[i + j] = new Entry(index + (uint)j, op.Source[op.SourceIndex + j]);
}
AdjustOffsetsStartingAt(i + amtToIns, ref _list, amtToIns);
_totalCount += (uint)amtToIns;
op.SourceIndex += amtToIns;
//if (tob != null) tob.AddingItems(slice, this, false);
return(amtToIns);
}
}
