//todo
public void Reorganize()
{
Console.WriteLine("###REORGANIZATION###");
var NewMainReader = new MainReader("newmain", MainPageSize, Mode.New);
var NewMainWriter = new MainWriter("newmain", MainPageSize, Mode.New);
TempLong = OverflowAddress;
ResetVariables();
AllocateEmptyPageAtTheEnd(ref NewMainWriter);
MainPages++;
FilePage newPage = NewMainReader.ReadNextPage();
Tuple <Record, long> entry;
MainReader.Reader.Position = 0;
//MainReader._count = false;
while ((entry = MainReader.ReadNextEntryWithChaining()) != null)
{
if (entry.Item1.Key == long.MaxValue)
{
continue;
}
if (entry.Item1.Deleted)
{
continue;
}
if (newPage.Count >= Alpha * MainPageSize)
{
// insert new element to index
// allocate new page
NewMainWriter.WritePage(newPage);
AllocateEmptyPageAtTheEnd(ref NewMainWriter);
newPage = NewMainReader.ReadNextPage();
MainPages++;
if (entry.Item1.Key != long.MaxValue)
{
IndexUnit.Entries.Add(new Tuple <long, long>(entry.Item1.Key, MainPages - 1));
}
}
newPage.Entries[(int)newPage.Count++] = new Tuple <Record, long>(entry.Item1, -1);
MainRecordCount++;
}
NewMainWriter.WritePage(newPage);
OverflowAddress = NewMainWriter.Writer.Position;
AllocateEmptyPageAtTheEnd(ref NewMainWriter); // allocate overflow
OverflowPages++;
IndexUnit.Sort();
IndexUnit.WriteIndex();
MetaData.Save();
MainReader.Dispose();
MainWriter.Dispose();
NewMainReader.Dispose();
NewMainWriter.Dispose();
File.Delete(_filePath);
File.Move("newmain", _filePath);
MainReader = new MainReader(_filePath, MainPageSize, Mode.Read);
MainWriter = new MainWriter(_filePath, MainPageSize, Mode.Read);
}
private void AllocateEmptyPageAtTheEnd(ref MainWriter mw)
{
mw.Writer.Position = mw.Writer.Length;
var page = new FilePage {
Address = MainReader.PageNumberFromAddress(mw.Writer.Position)
};
mw.WritePage(page);
}
private void Initialize()
{
//fill primary area with empty pages
//set overflow area address
long addrI = 0L, addrM = 0L;
try
{
File.Delete("meta");
}
catch
{
}
IndexUnit.Init(true);
var firstMainPage = new FilePage {
Address = addrM++, Count = 1
};
firstMainPage.Entries[0] = new Tuple <Record, long>(new Record(), -1);
MainWriter.WritePage(firstMainPage);
MainPages = 1;
MainRecordCount = 1;
OverflowAddress = MainWriter.Writer.Position;
OverflowFirstPageNumber = MainReader.PageNumberFromAddress(MainWriter.Writer.Position);
var newPage = new FilePage {
Address = addrM
};
MainWriter.WritePage(newPage);
OverflowEndAddress = MainWriter.Writer.Position;
OverflowPages = 1;
MainWriter.Reset();
Program.MainWrites = 0L;
MetaData.Save();
IndexUnit.WriteIndex();
}