/// <summary>
/// Removes redundant nodes (that contain only an 'End' entry).
/// </summary>
/// <param name="entryIndex">The index of the entry that may have a redundant child.</param>
/// <returns>An entry that needs to be promoted to the parent node (if any).</returns>
private IndexEntry LiftNode(int entryIndex)
{
if ((_entries[entryIndex].Flags & IndexEntryFlags.Node) != 0)
{
IndexNode childNode = _index.GetSubBlock(_entries[entryIndex]).Node;
if (childNode._entries.Count == 1)
{
long freeBlock = _entries[entryIndex].ChildrenVirtualCluster;
_entries[entryIndex].Flags = (_entries[entryIndex].Flags & ~IndexEntryFlags.Node) |
(childNode._entries[0].Flags & IndexEntryFlags.Node);
_entries[entryIndex].ChildrenVirtualCluster = childNode._entries[0].ChildrenVirtualCluster;
_index.FreeBlock(freeBlock);
}
if ((_entries[entryIndex].Flags & (IndexEntryFlags.Node | IndexEntryFlags.End)) == 0)
{
IndexEntry entry = _entries[entryIndex];
_entries.RemoveAt(entryIndex);
IndexNode nextNode = _index.GetSubBlock(_entries[entryIndex]).Node;
return(nextNode.AddEntry(entry));
}
}
return(null);
}
public IndexNode(IndexNodeSaveFn store, int storeOverhead, Index index, IndexNode parent, byte[] buffer, int offset)
{
_store = store;
_storageOverhead = storeOverhead;
_index = index;
_parent = parent;
_header = new IndexHeader(buffer, offset + 0);
_totalSpaceAvailable = _header.AllocatedSizeOfEntries;
_entries = new List<IndexEntry>();
int pos = (int)_header.OffsetToFirstEntry;
while (pos < _header.TotalSizeOfEntries)
{
IndexEntry entry = new IndexEntry(index.IsFileIndex);
entry.Read(buffer, offset + pos);
_entries.Add(entry);
if ((entry.Flags & IndexEntryFlags.End) != 0)
{
break;
}
pos += entry.Size;
}
}
public bool TryFindEntry(byte[] key, out IndexEntry entry, out IndexNode node)
{
foreach (IndexEntry focus in _entries)
{
if ((focus.Flags & IndexEntryFlags.End) != 0)
{
if ((focus.Flags & IndexEntryFlags.Node) != 0)
{
IndexBlock subNode = _index.GetSubBlock(focus);
return(subNode.Node.TryFindEntry(key, out entry, out node));
}
break;
}
int compVal = _index.Compare(key, focus.KeyBuffer);
if (compVal == 0)
{
entry = focus;
node = this;
return(true);
}
if (compVal < 0 && (focus.Flags & (IndexEntryFlags.End | IndexEntryFlags.Node)) != 0)
{
IndexBlock subNode = _index.GetSubBlock(focus);
return(subNode.Node.TryFindEntry(key, out entry, out node));
}
}
entry = null;
node = null;
return(false);
}
public Index(File file, string name, BiosParameterBlock bpb, UpperCase upCase)
{
_file = file;
_name = name;
_bpb = bpb;
_isFileIndex = name == "$I30";
_blockCache = new ObjectCache <long, IndexBlock>();
_root = _file.GetStream(AttributeType.IndexRoot, _name).GetContent <IndexRoot>();
_comparer = _root.GetCollator(upCase);
using (Stream s = _file.OpenStream(AttributeType.IndexRoot, _name, FileAccess.Read))
{
byte[] buffer = Utilities.ReadFully(s, (int)s.Length);
_rootNode = new IndexNode(WriteRootNodeToDisk, 0, this, true, buffer, IndexRoot.HeaderOffset);
// Give the attribute some room to breathe, so long as it doesn't squeeze others out
// BROKEN, BROKEN, BROKEN - how to figure this out? Query at the point of adding entries to the root node?
_rootNode.TotalSpaceAvailable += _file.MftRecordFreeSpace(AttributeType.IndexRoot, _name) - 100;
}
if (_file.StreamExists(AttributeType.IndexAllocation, _name))
{
_indexStream = _file.OpenStream(AttributeType.IndexAllocation, _name, FileAccess.ReadWrite);
}
if (_file.StreamExists(AttributeType.Bitmap, _name))
{
_indexBitmap = new Bitmap(_file.OpenStream(AttributeType.Bitmap, _name, FileAccess.ReadWrite), long.MaxValue);
}
}
public Index(File file, string name, BiosParameterBlock bpb, UpperCase upCase)
{
_file = file;
_name = name;
_bpb = bpb;
_isFileIndex = name == "$I30";
_blockCache = new ObjectCache<long, IndexBlock>();
_root = _file.GetStream(AttributeType.IndexRoot, _name).GetContent<IndexRoot>();
_comparer = _root.GetCollator(upCase);
using (Stream s = _file.OpenStream(AttributeType.IndexRoot, _name, FileAccess.Read))
{
byte[] buffer = Utilities.ReadFully(s, (int)s.Length);
_rootNode = new IndexNode(WriteRootNodeToDisk, 0, this, true, buffer, IndexRoot.HeaderOffset);
// Give the attribute some room to breathe, so long as it doesn't squeeze others out
// BROKEN, BROKEN, BROKEN - how to figure this out? Query at the point of adding entries to the root node?
_rootNode.TotalSpaceAvailable += _file.MftRecordFreeSpace(AttributeType.IndexRoot, _name) - 100;
}
if (_file.StreamExists(AttributeType.IndexAllocation, _name))
{
_indexStream = _file.OpenStream(AttributeType.IndexAllocation, _name, FileAccess.ReadWrite);
}
if (_file.StreamExists(AttributeType.Bitmap, _name))
{
_indexBitmap = new Bitmap(_file.OpenStream(AttributeType.Bitmap, _name, FileAccess.ReadWrite), long.MaxValue);
}
}
/// <summary>
/// Removes redundant nodes (that contain only an 'End' entry).
/// </summary>
/// <param name="entryIndex">The index of the entry that may have a redundant child</param>
private void LiftNode(int entryIndex)
{
if ((_entries[entryIndex].Flags & IndexEntryFlags.Node) != 0)
{
IndexNode childNode = _index.GetSubBlock(this, _entries[entryIndex]).Node;
if (childNode._entries.Count == 1)
{
long freeBlock = _entries[entryIndex].ChildrenVirtualCluster;
_entries[entryIndex].Flags = (_entries[entryIndex].Flags & ~IndexEntryFlags.Node) | (childNode._entries[0].Flags & IndexEntryFlags.Node);
_entries[entryIndex].ChildrenVirtualCluster = childNode._entries[0].ChildrenVirtualCluster;
if ((_entries[entryIndex].Flags & IndexEntryFlags.Node) != 0)
{
IndexNode newChildNode = _index.GetSubBlock(this, _entries[entryIndex]).Node;
childNode._parent = this;
}
_index.FreeBlock(freeBlock);
}
if ((_entries[entryIndex].Flags & (IndexEntryFlags.Node | IndexEntryFlags.End)) == 0)
{
IndexEntry entry = _entries[entryIndex];
_entries.RemoveAt(entryIndex);
AddEntry(entry, false);
}
}
}
public IndexNode(IndexNodeSaveFn store, int storeOverhead, Index index, IndexNode parent, byte[] buffer, int offset)
{
_store = store;
_storageOverhead = storeOverhead;
_index = index;
_parent = parent;
_header = new IndexHeader(buffer, offset + 0);
_totalSpaceAvailable = _header.AllocatedSizeOfEntries;
_entries = new List <IndexEntry>();
int pos = (int)_header.OffsetToFirstEntry;
while (pos < _header.TotalSizeOfEntries)
{
IndexEntry entry = new IndexEntry(index.IsFileIndex);
entry.Read(buffer, offset + pos);
_entries.Add(entry);
if ((entry.Flags & IndexEntryFlags.End) != 0)
{
break;
}
pos += entry.Size;
}
}
protected override void Read(byte[] buffer, int offset)
{
// Skip FixupRecord fields...
LogSequenceNumber = Utilities.ToUInt64LittleEndian(buffer, offset + 0x08);
IndexBlockVcn = Utilities.ToUInt64LittleEndian(buffer, offset + 0x10);
_node = new IndexNode(WriteToDisk, UpdateSequenceSize, _index, _parentNode, buffer, offset + FieldSize);
}
protected override void Read(byte[] buffer, int offset)
{
// Skip FixupRecord fields...
LogSequenceNumber = Utilities.ToUInt64LittleEndian(buffer, offset + 0x08);
IndexBlockVcn = Utilities.ToUInt64LittleEndian(buffer, offset + 0x10);
_node = new IndexNode(WriteToDisk, UpdateSequenceSize, _index, _parentNode, buffer, offset + FieldSize);
}
internal IndexBlock GetSubBlock(IndexNode parentNode, IndexEntry parentEntry)
{
IndexBlock block = _blockCache[parentEntry.ChildrenVirtualCluster];
if (block == null)
{
block = new IndexBlock(this, parentNode, parentEntry, _bpb);
_blockCache[parentEntry.ChildrenVirtualCluster] = block;
}
return(block);
}
public IndexBlock(Index index, IndexNode parentNode, IndexEntry parentEntry, BiosParameterBlock bpb)
: base("INDX", bpb.BytesPerSector)
{
_index = index;
_parentNode = parentNode;
Stream stream = index.AllocationStream;
_streamPosition = parentEntry.ChildrenVirtualCluster * bpb.BytesPerSector * bpb.SectorsPerCluster;
stream.Position = _streamPosition;
byte[] buffer = Utilities.ReadFully(stream, (int)index.IndexBufferSize);
FromBytes(buffer, 0);
}
public IndexBlock(Index index, IndexNode parentNode, IndexEntry parentEntry, BiosParameterBlock bpb)
: base("INDX", bpb.BytesPerSector)
{
_index = index;
_parentNode = parentNode;
Stream stream = index.AllocationStream;
_streamPosition = parentEntry.ChildrenVirtualCluster * bpb.BytesPerSector * bpb.SectorsPerCluster;
stream.Position = _streamPosition;
byte[] buffer = Utilities.ReadFully(stream, (int)index.IndexBufferSize);
FromBytes(buffer, 0);
}
private IndexBlock(Index index, bool isRoot, long vcn, BiosParameterBlock bpb)
: base("INDX", bpb.BytesPerSector, bpb.IndexBufferSize)
{
_index = index;
_isRoot = isRoot;
_indexBlockVcn = (ulong)vcn;
_streamPosition = vcn * bpb.BytesPerSector * bpb.SectorsPerCluster;
_node = new IndexNode(WriteToDisk, UpdateSequenceSize, _index, isRoot, (uint)bpb.IndexBufferSize - FieldSize);
WriteToDisk();
}
private IndexBlock(Index index, bool isRoot, long vcn, BiosParameterBlock bpb)
: base("INDX", bpb.BytesPerSector, bpb.IndexBufferSize)
{
_index = index;
_isRoot = isRoot;
_indexBlockVcn = (ulong)vcn;
_streamPosition = vcn * bpb.BytesPerSector * bpb.SectorsPerCluster;
_node = new IndexNode(WriteToDisk, UpdateSequenceSize, _index, isRoot, (uint)bpb.IndexBufferSize - FieldSize);
WriteToDisk();
}
private IEnumerable <IndexEntry> FindAllIn(IComparable <byte[]> query, IndexNode node)
{
lock (_lock)
{
foreach (IndexEntry focus in node.Entries)
{
bool searchChildren = true;
bool matches = false;
bool keepIterating = true;
if ((focus.Flags & IndexEntryFlags.End) == 0)
{
int compVal = query.CompareTo(focus.KeyBuffer);
if (compVal == 0)
{
matches = true;
}
else if (compVal > 0)
{
searchChildren = false;
}
else if (compVal < 0)
{
keepIterating = false;
}
}
if (searchChildren && (focus.Flags & IndexEntryFlags.Node) != 0)
{
IndexBlock block = GetSubBlock(focus);
foreach (IndexEntry entry in FindAllIn(query, block.Node))
{
yield return(entry);
}
}
if (matches)
{
yield return(focus);
}
if (!keepIterating)
{
yield break;
}
}
}
}
public IndexNode(IndexNodeSaveFn store, int storeOverhead, Index index, IndexNode parent, uint allocatedSize)
{
_store = store;
_storageOverhead = storeOverhead;
_index = index;
_parent = parent;
_header = new IndexHeader(allocatedSize);
_totalSpaceAvailable = allocatedSize;
IndexEntry endEntry = new IndexEntry(_index.IsFileIndex);
endEntry.Flags |= IndexEntryFlags.End;
_entries = new List<IndexEntry>();
_entries.Add(endEntry);
_header.OffsetToFirstEntry = (uint)(IndexHeader.Size + storeOverhead);
_header.TotalSizeOfEntries = (uint)(_header.OffsetToFirstEntry + endEntry.Size);
}
public IndexNode(IndexNodeSaveFn store, int storeOverhead, Index index, IndexNode parent, uint allocatedSize)
{
_store = store;
_storageOverhead = storeOverhead;
_index = index;
_parent = parent;
_header = new IndexHeader(allocatedSize);
_totalSpaceAvailable = allocatedSize;
IndexEntry endEntry = new IndexEntry(_index.IsFileIndex);
endEntry.Flags |= IndexEntryFlags.End;
_entries = new List <IndexEntry>();
_entries.Add(endEntry);
_header.OffsetToFirstEntry = (uint)(IndexHeader.Size + storeOverhead);
_header.TotalSizeOfEntries = (uint)(_header.OffsetToFirstEntry + endEntry.Size);
}
protected IEnumerable <IndexEntry> Enumerate(IndexNode node)
{
foreach (IndexEntry focus in node.Entries)
{
if ((focus.Flags & IndexEntryFlags.Node) != 0)
{
IndexBlock block = GetSubBlock(focus);
foreach (IndexEntry subEntry in Enumerate(block.Node))
{
yield return(subEntry);
}
}
if ((focus.Flags & IndexEntryFlags.End) == 0)
{
yield return(focus);
}
}
}
private void NodeAsString(TextWriter writer, string prefix, IndexNode node, string id)
{
writer.WriteLine(prefix + id + ":");
foreach (var entry in node.Entries)
{
if ((entry.Flags & IndexEntryFlags.End) != 0)
{
writer.WriteLine(prefix + " E");
}
else
{
writer.WriteLine(prefix + " " + EntryAsString(entry, _file.BestName, _name));
}
if ((entry.Flags & IndexEntryFlags.Node) != 0)
{
NodeAsString(writer, prefix + " ", GetSubBlock(node, entry).Node, ":i" + entry.ChildrenVirtualCluster);
}
}
}
private Index(AttributeType attrType, AttributeCollationRule collationRule, File file, string name, BiosParameterBlock bpb, UpperCase upCase)
{
_file = file;
_name = name;
_bpb = bpb;
_isFileIndex = (name == "$I30");
_blockCache = new ObjectCache <long, IndexBlock>();
_file.CreateStream(AttributeType.IndexRoot, _name);
_root = new IndexRoot()
{
AttributeType = (uint)attrType,
CollationRule = collationRule,
IndexAllocationSize = (uint)bpb.IndexBufferSize,
RawClustersPerIndexRecord = bpb.RawIndexBufferSize
};
_comparer = _root.GetCollator(upCase);
_rootNode = new IndexNode(WriteRootNodeToDisk, 0, this, null, 32);
}
internal IndexBlock AllocateBlock(IndexNode parentNode, IndexEntry parentEntry)
{
if (_indexStream == null)
{
_file.CreateStream(AttributeType.IndexAllocation, _name);
_indexStream = _file.OpenStream(AttributeType.IndexAllocation, _name, FileAccess.ReadWrite);
}
if (_indexBitmap == null)
{
_file.CreateStream(AttributeType.Bitmap, _name);
_indexBitmap = new Bitmap(_file.OpenStream(AttributeType.Bitmap, _name, FileAccess.ReadWrite), long.MaxValue);
}
long idx = _indexBitmap.AllocateFirstAvailable(0);
parentEntry.ChildrenVirtualCluster = idx * Utilities.Ceil(_bpb.IndexBufferSize, _bpb.SectorsPerCluster * _bpb.BytesPerSector);
parentEntry.Flags |= IndexEntryFlags.Node;
IndexBlock block = IndexBlock.Initialize(this, parentNode, parentEntry, _bpb);
_blockCache[parentEntry.ChildrenVirtualCluster] = block;
return(block);
}
internal static IndexBlock Initialize(Index index, IndexNode parentNode, IndexEntry parentEntry, BiosParameterBlock bpb)
{
return(new IndexBlock(index, parentNode, parentEntry.ChildrenVirtualCluster, bpb));
}
public bool RemoveEntry(byte[] key)
{
bool exactMatch;
int entryIndex = GetEntry(key, out exactMatch);
IndexEntry entry = _entries[entryIndex];
if (exactMatch)
{
if ((entry.Flags & IndexEntryFlags.Node) != 0)
{
// Get the next biggest entry in the index, which may be sibling or descendant of sibling
IndexEntry replacementLeaf = _entries[entryIndex + 1];
if ((replacementLeaf.Flags & (IndexEntryFlags.End | IndexEntryFlags.Node)) == IndexEntryFlags.End)
{
entry.KeyBuffer = null;
entry.DataBuffer = null;
entry.Flags |= IndexEntryFlags.End;
_entries.RemoveAt(entryIndex + 1);
}
else
{
if ((replacementLeaf.Flags & IndexEntryFlags.Node) != 0)
{
IndexNode giftingNode = _index.GetSubBlock(this, replacementLeaf).Node;
replacementLeaf = giftingNode.FindSmallestLeaf();
}
// Take a reference to the byte arrays because in the recursive case, these arrays
// may be changed as a new node is promoted.
byte[] newKey = replacementLeaf.KeyBuffer;
byte[] newData = replacementLeaf.DataBuffer;
RemoveEntry(newKey);
// Just over-write our key & data with the replacement
entry.KeyBuffer = newKey;
entry.DataBuffer = newData;
LiftNode(entryIndex + 1);
}
}
else
{
_entries.RemoveAt(entryIndex);
}
_store();
return(true);
}
else
{
if ((entry.Flags & IndexEntryFlags.Node) != 0)
{
IndexNode childNode = _index.GetSubBlock(this, entry).Node;
if (childNode.RemoveEntry(key))
{
LiftNode(entryIndex);
_store();
return(true);
}
}
else
{
return(false);
}
}
return(false);
}
internal static IndexBlock Initialize(Index index, IndexNode parentNode, IndexEntry parentEntry, BiosParameterBlock bpb)
{
return new IndexBlock(index, parentNode, parentEntry.ChildrenVirtualCluster, bpb);
}
private Index(AttributeType attrType, AttributeCollationRule collationRule, File file, string name, BiosParameterBlock bpb, UpperCase upCase)
{
_file = file;
_name = name;
_bpb = bpb;
_isFileIndex = name == "$I30";
_blockCache = new ObjectCache<long, IndexBlock>();
_file.CreateStream(AttributeType.IndexRoot, _name);
_root = new IndexRoot()
{
AttributeType = (uint)attrType,
CollationRule = collationRule,
IndexAllocationSize = (uint)bpb.IndexBufferSize,
RawClustersPerIndexRecord = bpb.RawIndexBufferSize
};
_comparer = _root.GetCollator(upCase);
_rootNode = new IndexNode(WriteRootNodeToDisk, 0, this, true, 32);
}
private void NodeAsString(TextWriter writer, string prefix, IndexNode node, string id)
{
writer.WriteLine(prefix + id + ":");
foreach (var entry in node.Entries)
{
if ((entry.Flags & IndexEntryFlags.End) != 0)
{
writer.WriteLine(prefix + " E");
}
else
{
writer.WriteLine(prefix + " " + EntryAsString(entry, _file.BestName, _name));
}
if ((entry.Flags & IndexEntryFlags.Node) != 0)
{
NodeAsString(writer, prefix + " ", GetSubBlock(entry).Node, ":i" + entry.ChildrenVirtualCluster);
}
}
}
private IEnumerable<IndexEntry> FindAllIn(IComparable<byte[]> query, IndexNode node)
{
foreach (var focus in node.Entries)
{
bool searchChildren = true;
bool matches = false;
bool keepIterating = true;
if ((focus.Flags & IndexEntryFlags.End) == 0)
{
int compVal = query.CompareTo(focus.KeyBuffer);
if (compVal == 0)
{
matches = true;
}
else if (compVal > 0)
{
searchChildren = false;
}
else if (compVal < 0)
{
keepIterating = false;
}
}
if (searchChildren && (focus.Flags & IndexEntryFlags.Node) != 0)
{
IndexBlock block = GetSubBlock(focus);
foreach (var entry in FindAllIn(query, block.Node))
{
yield return entry;
}
}
if (matches)
{
yield return focus;
}
if (!keepIterating)
{
yield break;
}
}
}
protected IEnumerable<IndexEntry> Enumerate(IndexNode node)
{
foreach (var focus in node.Entries)
{
if ((focus.Flags & IndexEntryFlags.Node) != 0)
{
IndexBlock block = GetSubBlock(focus);
foreach (var subEntry in Enumerate(block.Node))
{
yield return subEntry;
}
}
if ((focus.Flags & IndexEntryFlags.End) == 0)
{
yield return focus;
}
}
}
public bool RemoveEntry(byte[] key, out IndexEntry newParentEntry)
{
bool exactMatch;
int entryIndex = GetEntry(key, out exactMatch);
IndexEntry entry = _entries[entryIndex];
if (exactMatch)
{
if ((entry.Flags & IndexEntryFlags.Node) != 0)
{
IndexNode childNode = _index.GetSubBlock(entry).Node;
IndexEntry rLeaf = childNode.FindLargestLeaf();
byte[] newKey = rLeaf.KeyBuffer;
byte[] newData = rLeaf.DataBuffer;
IndexEntry newEntry;
childNode.RemoveEntry(newKey, out newEntry);
entry.KeyBuffer = newKey;
entry.DataBuffer = newData;
if (newEntry != null)
{
InsertEntryThisNode(newEntry);
}
newEntry = LiftNode(entryIndex);
if (newEntry != null)
{
InsertEntryThisNode(newEntry);
}
newEntry = PopulateEnd();
if (newEntry != null)
{
InsertEntryThisNode(newEntry);
}
// New entry could be larger than old, so may need
// to divide this node...
newParentEntry = EnsureNodeSize();
}
else
{
_entries.RemoveAt(entryIndex);
newParentEntry = null;
}
_store();
return(true);
}
else if ((entry.Flags & IndexEntryFlags.Node) != 0)
{
IndexNode childNode = _index.GetSubBlock(entry).Node;
IndexEntry newEntry;
if (childNode.RemoveEntry(key, out newEntry))
{
if (newEntry != null)
{
InsertEntryThisNode(newEntry);
}
newEntry = LiftNode(entryIndex);
if (newEntry != null)
{
InsertEntryThisNode(newEntry);
}
newEntry = PopulateEnd();
if (newEntry != null)
{
InsertEntryThisNode(newEntry);
}
// New entry could be larger than old, so may need
// to divide this node...
newParentEntry = EnsureNodeSize();
_store();
return(true);
}
}
newParentEntry = null;
return(false);
}
public bool TryFindEntry(byte[] key, out IndexEntry entry, out IndexNode node)
{
foreach (var focus in _entries)
{
if ((focus.Flags & IndexEntryFlags.End) != 0)
{
if ((focus.Flags & IndexEntryFlags.Node) != 0)
{
IndexBlock subNode = _index.GetSubBlock(focus);
return subNode.Node.TryFindEntry(key, out entry, out node);
}
break;
}
else
{
int compVal = _index.Compare(key, focus.KeyBuffer);
if (compVal == 0)
{
entry = focus;
node = this;
return true;
}
else if (compVal < 0 && (focus.Flags & (IndexEntryFlags.End | IndexEntryFlags.Node)) != 0)
{
IndexBlock subNode = _index.GetSubBlock(focus);
return subNode.Node.TryFindEntry(key, out entry, out node);
}
}
}
entry = null;
node = null;
return false;
}
