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);
}
}
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();
}
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;
}
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;
}
}
}
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, _isRoot, buffer, offset + FieldSize);
}