public BPlusTree(Configuration <T> cfg)
{
Order = cfg.BPTree_Order;
Alignment = cfg.Alignment;
Cluster_Data_Length = cfg.Clustering_Data_Length;
_key_Serializer = cfg.Key_Serializer;
_node_Factory = new Node_Factory <T>(_key_Serializer, Order, Alignment, Cluster_Data_Length);
_block_Size = _node_Factory.Size_In_Bytes(Order);
_data_Serializer = new Data_Serializer <T>(_key_Serializer, Alignment, 2, 1024);
_pending_Changes = new Pending_Changes <T>(_block_Size, _index_Pointer, _data_Pointer, _node_Factory, _data_Serializer);
_streamFactory = cfg.Stream_Factory;
Index_Stream = _streamFactory.Create_ReadWrite_Index_Stream();
Data_Stream = _streamFactory.Create_ReadWrite_Data_Stream();
Metadata_Stream = _streamFactory.Create_ReadWrite_Metadata_Stream();
Cached_Nodes = new Dictionary <long, Node <T> >();
_cache = new Cache_LRU <long, Node <T> >(() => this.Current_Time);
_metadata = new Metadata {
Order = Order
};
Init();
}
public BPlusTree(Stream metadataStream, Stream indexStream, Stream dataStream, int order, int alignment, int cluster_data_length, IKey_Serializer <T> serializer)
{
Order = order;
Alignment = alignment;
Cluster_Data_Length = cluster_data_length;
_key_Serializer = serializer;
_node_Factory = new Node_Factory <T>(_key_Serializer, Order, Alignment, Cluster_Data_Length);
_block_Size = _node_Factory.Size_In_Bytes(Order);
_data_Serializer = new Data_Serializer <T>(_key_Serializer, Alignment, 2, 1024);
_pending_Changes = new Pending_Changes <T>(_block_Size, _index_Pointer, _data_Pointer, _node_Factory, _data_Serializer);
Index_Stream = indexStream;
Data_Stream = dataStream;
Metadata_Stream = metadataStream;
Cached_Nodes = new Dictionary <long, Node <T> >();
_cache = new Cache_LRU <long, Node <T> >(() => this.Current_Time);
_metadata = new Metadata {
Order = Order
};
Init();
}
private void Init()
{
System.Threading.Tasks.Task.Factory.StartNew(() =>
{
while (true)
{
lock (this)
{
Current_Time = DateTime.Now;
System.Threading.Monitor.Wait(this, 100);
}
}
});
try
{
var buffer = new byte[512];
Metadata_Stream.Seek(0, SeekOrigin.Begin);
Metadata_Stream.Read(buffer, 0, buffer.Length);
var metadata = Metadata.From_Bytes(buffer);
Root = Read_Root(metadata.Root_Address);
if (Root.IsValid)
{
Order = metadata.Order;
_data_Pointer = metadata.DataStream_Length;
_index_Pointer = metadata.IndexStream_Length;
Cluster_Data_Length = metadata.Clustered_Data_Length;
Alignment = metadata.Alignment;
_node_Factory = new Node_Factory <T>(_key_Serializer, Order, Alignment, Cluster_Data_Length);
_block_Size = _node_Factory.Size_In_Bytes(Order);
_data_Serializer = new Data_Serializer <T>(_key_Serializer, Alignment, 2, 1024);
_pending_Changes = new Pending_Changes <T>(_block_Size, _index_Pointer, _data_Pointer, _node_Factory, _data_Serializer);
_metadata = metadata;
return;
}
}
catch (Exception) { }
var root = _node_Factory.Create_New(true);
Write_Node(root);
_pending_Changes.Append_New_Root(root);
}
public Node(Node_Factory <T> factory, int order, bool isLeaf, bool isClustered, int clustered_Data_Length)
{
_Factory = factory;
IsLeaf = isLeaf;
IsClustered = isClustered;
Pointers = new long[order + 1];
Keys = new T[order];
Versions = new int[order];
Children = new Node <T> [order + 1];
Is_Volatile = true;
if (isClustered)
{
Data = new byte[order + 1, clustered_Data_Length + 12];
_clustered_Data_Length = clustered_Data_Length;
}
else
{
Data = new byte[0, 0];
}
}
public Node_Split_Result <T> Split(Node_Factory <T> node_Factory)
{
int size = Keys.Length;
var node_Left = this;
var node_Right = node_Factory.Create_New(node_Left.IsLeaf);
node_Right.Parent = node_Left.Parent;
var mid_Key = node_Left.Keys[size / 2];
node_Right.Key_Num = size - size / 2 - 1;
for (int i = 0; i < node_Right.Key_Num; i++)
{
node_Right.Keys[i] = node_Left.Keys[i + (size / 2 + 1)];
node_Right.Pointers[i] = node_Left.Pointers[i + (size / 2 + 1)];
if (!IsLeaf)
{
node_Right.Children[i] = node_Left.Children[i + (size / 2 + 1)];
}
else
{
for (int j = 0; j < _clustered_Data_Length; j++)
{
node_Right.Data[i, j] = node_Left.Data[i + (size / 2 + 1), j];
}
}
if (node_Right.Children[i] != null)
{
node_Right.Children[i].Parent = node_Right;
}
}
node_Right.Pointers[node_Right.Key_Num] = node_Left.Pointers[size];
node_Right.Children[node_Right.Key_Num] = node_Left.Children[size];
for (int j = 0; j < _clustered_Data_Length; j++)
{
node_Right.Data[node_Right.Key_Num, j] = node_Left.Data[size, j];
}
if (node_Right.Children[node_Right.Key_Num] != null)
{
node_Right.Children[node_Right.Key_Num].Parent = node_Right;
}
node_Left.Key_Num = size / 2;
if (node_Left.IsLeaf)
{
node_Left.Key_Num++;
node_Right.Pointers[0] = node_Left.Pointers[0];
node_Right.Children[0] = node_Left.Children[0];
node_Left.Pointers[0] = node_Right.Address; //TODO double linked list
mid_Key = node_Left.Keys[size / 2 + 1];
}
return(new Node_Split_Result <T> {
Node_Left = node_Left, Node_Right = node_Right, Mid_Key = mid_Key
});
}