public void AddEntry(MftSegmentReference fileReference, byte[] key)
{
IndexEntry entry = new IndexEntry();
entry.FileReference = fileReference;
entry.Key = key;
if (!m_rootRecord.IsParentNode)
{
int insertIndex = CollationHelper.FindIndexForSortedInsert(m_rootRecord.IndexEntries, key, m_rootRecord.CollationRule);
m_rootRecord.IndexEntries.Insert(insertIndex, entry);
if (m_rootRecord.RecordLength >= m_volume.AttributeRecordLengthToMakeNonResident)
{
if (m_indexAllocationRecord == null)
{
m_indexAllocationRecord = (IndexAllocationRecord)m_fileRecord.CreateAttributeRecord(AttributeType.IndexAllocation, m_indexName);
m_indexAllocationData = new NonResidentAttributeData(m_volume, m_fileRecord, m_indexAllocationRecord);
m_bitmapRecord = m_fileRecord.CreateAttributeRecord(AttributeType.Bitmap, m_indexName);
m_bitmapData = new BitmapData(m_volume, m_fileRecord, m_bitmapRecord, 0);
}
SplitRootIndexRecord();
}
else
{
m_volume.UpdateFileRecord(m_fileRecord);
}
}
else
{
KeyValuePairList <int, IndexRecord> path = FindInsertPath(key);
IndexRecord leafRecord = path[path.Count - 1].Value;
long leafRecordVBN = leafRecord.RecordVBN;
int insertIndex = CollationHelper.FindIndexForSortedInsert(leafRecord.IndexEntries, key, m_rootRecord.CollationRule);
leafRecord.IndexEntries.Insert(insertIndex, entry);
long leafRecordIndex = ConvertToRecordIndex(leafRecordVBN);
if (leafRecord.DoesFit((int)m_rootRecord.BytesPerIndexRecord))
{
WriteIndexRecord(leafRecordIndex, leafRecord);
}
else
{
// Split index record
SplitIndexRecord(path);
}
}
}
/// <param name="path">Key is index in parent node</param>
private void SplitIndexRecord(KeyValuePairList <int, IndexRecord> path)
{
int indexInParentRecord = path[path.Count - 1].Key;
// We will treat the record we want to split as the right node, and create a left node
IndexRecord rightNode = path[path.Count - 1].Value;
long rightNodeVBN = rightNode.RecordVBN;
long rightNodeIndex = ConvertToRecordIndex(rightNodeVBN);
List <IndexEntry> rightNodeEntries = rightNode.IndexEntries;
int splitIndex = rightNodeEntries.Count / 2;
IndexEntry middleEntry = rightNodeEntries[splitIndex];
IndexRecord leftNode = new IndexRecord();
leftNode.IsParentNode = rightNode.IsParentNode;
leftNode.IndexEntries = rightNodeEntries.GetRange(0, splitIndex);
rightNodeEntries.RemoveRange(0, splitIndex + 1);
if (rightNode.IsParentNode)
{
// A parent node has n keys and points to (n + 1) subnodes,
// When splitting it to two nodes we will take the pointer from the entry we wish to push to the parent node,
// and use it as the last pointer in the left node.
IndexEntry leftNodeLastEntry = new IndexEntry();
leftNodeLastEntry.ParentNodeForm = true;
leftNodeLastEntry.IsLastEntry = true;
leftNodeLastEntry.SubnodeVBN = middleEntry.SubnodeVBN;
leftNode.IndexEntries.Add(leftNodeLastEntry);
}
long leftNodeIndex = AllocateIndexRecord();
leftNode.RecordVBN = ConvertToVirtualBlockNumber(leftNodeIndex);
IndexEntry newParentEntry = new IndexEntry(middleEntry.FileReference, middleEntry.Key);
newParentEntry.ParentNodeForm = true;
newParentEntry.SubnodeVBN = leftNode.RecordVBN;
WriteIndexRecord(rightNodeIndex, rightNode);
WriteIndexRecord(leftNodeIndex, leftNode);
if (path.Count > 1)
{
IndexRecord parentRecord = path[path.Count - 2].Value;
long parentRecordIndex = ConvertToRecordIndex(parentRecord.RecordVBN);
List <IndexEntry> parentEntries = parentRecord.IndexEntries;
parentEntries.Insert(indexInParentRecord, newParentEntry);
if (parentRecord.DoesFit((int)m_rootRecord.BytesPerIndexRecord))
{
WriteIndexRecord(parentRecordIndex, parentRecord);
}
else
{
// Split parent index record
path.RemoveAt(path.Count - 1);
SplitIndexRecord(path);
}
}
else
{
m_rootRecord.IndexEntries.Insert(indexInParentRecord, newParentEntry);
if (m_rootRecord.RecordLength >= m_volume.AttributeRecordLengthToMakeNonResident)
{
SplitRootIndexRecord();
}
else
{
m_volume.UpdateFileRecord(m_fileRecord);
}
}
}
