private KeyValuePairList <int, IndexRecord> FindRemovalPath(byte[] key, out int indexOfEntryToRemove)
{
bool isParentNode = true;
List <IndexEntry> entries = m_rootRecord.IndexEntries;
KeyValuePairList <int, IndexRecord> path = new KeyValuePairList <int, IndexRecord>();
while (isParentNode)
{
int index = CollationHelper.FindIndexInParentNode(entries, key, m_rootRecord.CollationRule);
if (!entries[index].IsLastEntry && CollationHelper.Compare(entries[index].Key, key, m_rootRecord.CollationRule) == 0)
{
indexOfEntryToRemove = index;
return(path);
}
long subnodeVBN = entries[index].SubnodeVBN;
IndexRecord indexRecord = ReadIndexRecord(subnodeVBN);
isParentNode = indexRecord.IsParentNode;
entries = indexRecord.IndexEntries;
path.Add(index, indexRecord);
}
indexOfEntryToRemove = CollationHelper.FindIndexInLeafNode(entries, key, m_rootRecord.CollationRule);
if (indexOfEntryToRemove >= 0)
{
return(path);
}
else
{
return(null);
}
}
public KeyValuePair <MftSegmentReference, byte[]>?FindEntry(byte[] key)
{
if (!m_rootRecord.IsParentNode)
{
int index = CollationHelper.FindIndexInLeafNode(m_rootRecord.IndexEntries, key, m_rootRecord.CollationRule);
if (index >= 0)
{
IndexEntry entry = m_rootRecord.IndexEntries[index];
return(new KeyValuePair <MftSegmentReference, byte[]>(entry.FileReference, entry.Key));
}
else
{
return(null);
}
}
else
{
bool isParentNode = true;
List <IndexEntry> entries = m_rootRecord.IndexEntries;
int index;
while (isParentNode)
{
index = CollationHelper.FindIndexInParentNode(entries, key, m_rootRecord.CollationRule);
IndexEntry entry = entries[index];
if (!entry.IsLastEntry && CollationHelper.Compare(entry.Key, key, m_rootRecord.CollationRule) == 0)
{
return(new KeyValuePair <MftSegmentReference, byte[]>(entry.FileReference, entry.Key));
}
else
{
long subnodeVBN = entry.SubnodeVBN;
IndexRecord indexRecord = ReadIndexRecord(subnodeVBN);
isParentNode = indexRecord.IsParentNode;
entries = indexRecord.IndexEntries;
}
}
index = CollationHelper.FindIndexInLeafNode(entries, key, m_rootRecord.CollationRule);
if (index >= 0)
{
IndexEntry entry = entries[index];
return(new KeyValuePair <MftSegmentReference, byte[]>(entry.FileReference, entry.Key));
}
else
{
return(null);
}
}
}
private KeyValuePairList <int, IndexRecord> FindInsertPath(byte[] key)
{
bool isParentNode = true;
List <IndexEntry> entries = m_rootRecord.IndexEntries;
KeyValuePairList <int, IndexRecord> path = new KeyValuePairList <int, IndexRecord>();
while (isParentNode)
{
int index = CollationHelper.FindIndexInParentNode(entries, key, m_rootRecord.CollationRule);
long subnodeVBN = entries[index].SubnodeVBN;
IndexRecord indexRecord = ReadIndexRecord(subnodeVBN);
isParentNode = indexRecord.IsParentNode;
entries = indexRecord.IndexEntries;
path.Add(index, indexRecord);
}
return(path);
}
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);
}
}
}
public void RemoveEntry(byte[] key)
{
if (!m_rootRecord.IsParentNode)
{
int index = CollationHelper.FindIndexInLeafNode(m_rootRecord.IndexEntries, key, m_rootRecord.CollationRule);
if (index >= 0)
{
m_rootRecord.IndexEntries.RemoveAt(index);
}
m_volume.UpdateFileRecord(m_fileRecord);
}
else
{
int indexOfEntryToRemove;
KeyValuePairList <int, IndexRecord> path = FindRemovalPath(key, out indexOfEntryToRemove);
if (path == null)
{
return;
}
if ((path.Count > 0 && path[path.Count - 1].Value.IsParentNode) || path.Count == 0)
{
// We find the rightmost leaf entry in the left branch and put it instead.
// Note: Excluding the root of the branch, the rightmost leaf entry in the branch collates last.
KeyValuePairList <int, IndexRecord> pathToLeaf = FindPathToRightmostLeaf(path, indexOfEntryToRemove);
IndexRecord leaf = pathToLeaf[pathToLeaf.Count - 1].Value;
IndexEntry entryToRemoveFromLeaf = leaf.IndexEntries[leaf.IndexEntries.Count - 1];
leaf.IndexEntries.RemoveAt(leaf.IndexEntries.Count - 1);
long leafRecordIndex = ConvertToRecordIndex(leaf.RecordVBN);
// Note: CHKDSK does not accept an empty IndexRecord, however, we must not call RemovePointer just yet because it might affect the parent as well.
WriteIndexRecord(leafRecordIndex, leaf);
if (path.Count == 0)
{
m_rootRecord.IndexEntries[indexOfEntryToRemove].FileReference = entryToRemoveFromLeaf.FileReference;
m_rootRecord.IndexEntries[indexOfEntryToRemove].Key = entryToRemoveFromLeaf.Key;
m_volume.UpdateFileRecord(m_fileRecord);
}
else
{
path[path.Count - 1].Value.IndexEntries[indexOfEntryToRemove].FileReference = entryToRemoveFromLeaf.FileReference;
path[path.Count - 1].Value.IndexEntries[indexOfEntryToRemove].Key = entryToRemoveFromLeaf.Key;
long recordIndex = ConvertToRecordIndex(path[path.Count - 1].Value.RecordVBN);
WriteIndexRecord(recordIndex, path[path.Count - 1].Value);
}
if (leaf.IndexEntries.Count == 0)
{
int indexOfLeafPointer = pathToLeaf[pathToLeaf.Count - 1].Key;
RemovePointer(pathToLeaf.GetRange(0, pathToLeaf.Count - 1), indexOfLeafPointer);
DeallocateIndexRecord(leafRecordIndex);
}
}
else
{
int indexInParentRecord = path[path.Count - 1].Key;
IndexRecord leaf = path[path.Count - 1].Value;
leaf.IndexEntries.RemoveAt(indexOfEntryToRemove);
long recordIndex = ConvertToRecordIndex(leaf.RecordVBN);
if (leaf.IndexEntries.Count > 0)
{
WriteIndexRecord(recordIndex, leaf);
}
else
{
path.RemoveAt(path.Count - 1);
RemovePointer(path, indexInParentRecord);
DeallocateIndexRecord(recordIndex);
}
}
}
}
public bool UpdateFileNameRecord(FileNameRecord fileNameRecord)
{
byte[] key = fileNameRecord.GetBytes();
if (!m_rootRecord.IsParentNode)
{
int index = CollationHelper.FindIndexInLeafNode(m_rootRecord.IndexEntries, key, m_rootRecord.CollationRule);
if (index >= 0)
{
m_rootRecord.IndexEntries[index].Key = key;
m_volume.UpdateFileRecord(m_fileRecord);
return(true);
}
}
else
{
IndexRecord indexRecord = null;
bool isParentNode = true;
List <IndexEntry> entries = m_rootRecord.IndexEntries;
int index;
while (isParentNode)
{
index = CollationHelper.FindIndexInParentNode(entries, key, m_rootRecord.CollationRule);
IndexEntry entry = entries[index];
if (!entry.IsLastEntry && CollationHelper.Compare(entry.Key, key, m_rootRecord.CollationRule) == 0)
{
entries[index].Key = key;
if (indexRecord == null)
{
m_volume.UpdateFileRecord(m_fileRecord);
}
else
{
long recordIndex = ConvertToRecordIndex(indexRecord.RecordVBN);
WriteIndexRecord(recordIndex, indexRecord);
}
return(true);
}
else
{
long subnodeVBN = entry.SubnodeVBN;
indexRecord = ReadIndexRecord(subnodeVBN);
isParentNode = indexRecord.IsParentNode;
entries = indexRecord.IndexEntries;
}
}
index = CollationHelper.FindIndexInLeafNode(entries, key, m_rootRecord.CollationRule);
if (index >= 0)
{
entries[index].Key = key;
if (indexRecord == null)
{
m_volume.UpdateFileRecord(m_fileRecord);
}
else
{
long recordIndex = ConvertToRecordIndex(indexRecord.RecordVBN);
WriteIndexRecord(recordIndex, indexRecord);
}
return(true);
}
}
return(false);
}
