public Index(string fileName, string indexName, int mainPageSize = 0, Mode mode = Mode.Read)
{
MainPageSize = mainPageSize;
_indexPath = indexName;
_filePath = fileName;
IndexUnit.Path = indexName;
MainReader = new MainReader(fileName, MainPageSize, mode);
MainWriter = new MainWriter(fileName, MainPageSize, mode);
FilePage.PageSize = mainPageSize;
if (mode == Mode.New)
{
Initialize();
}
if (mode == Mode.Read)
{
MetaData.Read();
IndexUnit.Init(false);
IndexUnit.ReadIndex();
FilePage.PageSize = MainPageSize;
MainReader = new MainReader(fileName, MainPageSize, mode);
MainWriter = new MainWriter(fileName, MainPageSize, mode);
IndexUnit.WriteIndex();
}
MetaData.Save();
}
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();
}
