public byte[] GetRowBytes(int rowIndex)
{
int rowLength = RowLength;
byte[] result = new byte[rowLength];
// hnidRows is set to zero if the TC contains no rows
if (m_tcInfo.hnidRows.IsEmpty)
{
throw new ArgumentException("Invalid row index, the table context is empty");
}
else if (m_tcInfo.hnidRows.IsHeapID)
{
// the row matrix is stored in the data tree
byte[] rows = m_heap.GetHeapItem(m_tcInfo.hnidRows.HeapID);
int offset = (int)rowIndex * rowLength;
Array.Copy(rows, offset, result, 0, rowLength);
return(result);
}
else
{
// indicates that the row matrix is stored in the subnode block, and the NID is the local NID under the subnode BTree
if (m_subnodeRows == null)
{
m_subnodeRows = m_subnodeBTree.GetSubnode(m_tcInfo.hnidRows.NodeID);
}
int blockIndex = (int)(rowIndex / m_rowsPerBlock);
int inBlockRowIndex = (int)(rowIndex % m_rowsPerBlock);
DataBlock block = m_subnodeRows.DataTree.GetDataBlock(blockIndex);
int offset = inBlockRowIndex * rowLength;
Array.Copy(block.Data, offset, result, 0, rowLength);
return(result);
}
}
public BTreeOnHeap(HeapOnNode heap, HeapID bTreeHeaderHeapID)
{
m_heap = heap;
m_bTreeHeaderHeapID = bTreeHeaderHeapID;
byte[] headerBytes = m_heap.GetHeapItem(bTreeHeaderHeapID);
BTreeHeader = new BTreeOnHeapHeader(headerBytes);
}
public static byte[] GetExternalPropertyBytes(HeapOnNode heap, SubnodeBTree subnodeBTree, HeapOrNodeID heapOrNodeID)
{
if (heapOrNodeID.IsEmpty)
{
return(new byte[0]);
}
else if (heapOrNodeID.IsHeapID)
{
byte[] result = heap.GetHeapItem(heapOrNodeID.HeapID);
return(result);
}
else
{
// indicates that the item is stored in the subnode block, and the NID is the local NID under the subnode
Subnode subnode = subnodeBTree.GetSubnode(heapOrNodeID.NodeID);
if (subnode != null)
{
if (subnode.DataTree == null)
{
return(new byte[0]);
}
else
{
return(subnode.DataTree.GetData());
}
}
else
{
throw new MissingSubnodeException();
}
}
}
private Subnode m_subnodeRows; // for buffering purposes
public TableContext(HeapOnNode heap, SubnodeBTree subnodeBTree)
{
m_heap = heap;
m_subnodeBTree = subnodeBTree;
m_tcInfo = new TableContextInfo(m_heap.GetHeapItem(m_heap.HeapHeader.hidUserRoot));
BTreeOnHeap <TableContextRowID> bTreeOnHeap = new BTreeOnHeap <TableContextRowID>(m_heap, m_tcInfo.hidRowIndex);
if (bTreeOnHeap.BTreeHeader.hidRoot.hidIndex > 0) // hidRoot is set to zero if the BTH is empty.
{
m_rowIndex = bTreeOnHeap.GetAll();
m_rowIndex.Sort(TableContextRowID.CompareByRowIndex);
}
m_rowsPerBlock = (int)Math.Floor((double)DataBlock.MaximumDataLength / RowLength);
}
public byte[] GetHeapItem(HeapID heapID)
{
return(m_heap.GetHeapItem(heapID));
}