public BTree(int Degree, string FilePath, IFixedLengthFactory <T> ContentFactory, IFixedLengthFactory <TKey> KeyFactory)
{
FileName = FilePath;
TFactory = ContentFactory;
TKeyFactory = KeyFactory;
File = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.ReadWrite,
FileShare.Read);
RootPointer = FileManagment.ReadLine(File, 0);
FirstAvailablePointer = FileManagment.ReadLine(File, 1);
this.Degree = FileManagment.ReadLine(File, 2);
if (FirstAvailablePointer == int.MinValue)
{
FirstAvailablePointer = 0;
}
if (this.Degree == int.MinValue)
{
this.Degree = Degree;
}
if (RootPointer == int.MinValue)
{
BNode <T, TKey> Root = new BNode <T, TKey>(this.Degree, FirstAvailablePointer, int.MinValue,
TFactory, TKeyFactory);
FirstAvailablePointer++;
RootPointer = Root.Pointer;
Root.DiskWrite(File, SizesNSpecialCharacters.HeaderSizeInBytes);
}
UpdateHeader();
}
internal BNode(int Degree, int Pointer, int Parent, IFixedLengthFactory <T> ContentFactory, IFixedLengthFactory <TKey> KeyFactory)
{
this.Degree = Degree;
this.Pointer = Pointer;
this.Parent = Parent;
this.KeyFactory = KeyFactory;
this.ContentFactory = ContentFactory;
Clear(ContentFactory, KeyFactory);
}
private void Clear(IFixedLengthFactory <T> ContentFactory, IFixedLengthFactory <TKey> KeyFactory)
{
Keys = new List <TKey>();
Values = new List <T>();
for (int i = 0; i < Degree - 1; i++)
{
Keys.Add(KeyFactory.CreateNull());
Values.Add(ContentFactory.CreateNull());
}
ChildrenPointers = new List <int>();
for (int i = 0; i < Degree; i++)
{
ChildrenPointers.Add(SizesNSpecialCharacters.NullPointer);
}
}
public void Clear(FileStream File, IFixedLengthFactory <T> ContentFactory, IFixedLengthFactory <TKey> KeyFactory)
{
Clear(ContentFactory, KeyFactory);
DiskWrite(File, SizesNSpecialCharacters.HeaderSizeInBytes);
}
public static BNode <T, TKey> DiskRead(FileStream File, int Degreee, int Pointer, IFixedLengthFactory <T> ContentFactory, IFixedLengthFactory <TKey> KeyFactory)
{
BNode <T, TKey> NewNode = new BNode <T, TKey>(Degreee, Pointer, 0, ContentFactory, KeyFactory);
byte[] BytesArray = new byte[NewNode.SizeInBytes];
int FieldsIndex = 0;
File.Seek(NewNode.DiskPosition(), SeekOrigin.Begin);
File.Read(BytesArray, 0, NewNode.SizeInBytes);
string[] Fields = Encoding.UTF8.GetString(BytesArray).Replace(Environment.NewLine, "").Replace("".PadRight(3, SizesNSpecialCharacters.GroupSeparator[0]), SizesNSpecialCharacters.GroupSeparator.ToString()).Split(SizesNSpecialCharacters.GroupSeparator[0]);
NewNode.Parent = int.Parse(Fields[FieldsIndex]);
FieldsIndex++;
for (int i = 0; i < NewNode.ChildrenPointers.Count; i++)
{
NewNode.ChildrenPointers[i] = int.Parse(Fields[FieldsIndex]);
FieldsIndex++;
}
for (int i = 0; i < NewNode.Keys.Count; i++)
{
NewNode.Keys[i] = KeyFactory.Create(Fields[FieldsIndex]);
FieldsIndex++;
}
for (int i = 0; i < NewNode.Values.Count; i++)
{
NewNode.Values[i] = ContentFactory.Create(Fields[FieldsIndex]);
FieldsIndex++;
}
return(NewNode);
}
