/// <summary>
/// 创建文件
/// </summary>
public static void Create(DataFileEntity model)
{
FileStream fs = new FileStream(model.FilePath, FileMode.CreateNew);
model.FileStream = fs;
model.MaxPageID = 2;
//写入0页
DataPageManage.Write(new DataPageEntity { DataFile = model, ID = Config.DATABASE_PAGE_ID, Content = model.Database.ToBytes() });
//写入1页
DataPageManage.Write(new DataPageEntity { DataFile = model, ID = Config.DATAFILE_PAGE_ID, Content = model.ToBytes() });
//写入2页
TablePageEntity modelTP = new TablePageEntity { Tables = new List<DataTable.DataTableEntity>() };
DataPageEntity modelDP= new DataPageEntity { DataFile = model, ID = Config.DATATABLE_PAGE_ID, Content = modelTP.ToBytes() };
DataPageManage.Write(modelDP);
//赋值
modelTP.DataPage = modelDP;
model.TablePage = modelTP;
}
/// <summary>
/// 获取空分页编号
/// </summary>
/// <param name="model"></param>
public static long GetEmptyPageID(DataFileEntity model)
{
//遍历已有页找空页（0-2必定不为空）
for (int i = 3; i <= model.MaxPageID; i++)
{
model.FileStream.Seek(i * Config.PAGE_SIZE, SeekOrigin.Begin);
byte[] arr = new byte[1];
model.FileStream.Read(arr, 0, 1);
if (arr[0] == Convert.ToInt32(EPageType.Empty))
{
return i;
}
}
//没有空页，添加新页
model.MaxPageID++;
Update(model);
return model.MaxPageID;
}
/// <summary>
/// 读文件
/// </summary>
/// <param name="modelDF"></param>
public static void Read(DataFileEntity model)
{
model.FileStream = new FileStream(model.FilePath, FileMode.Open);
//读文件信息
DataPageEntity modelDP = new DataPageEntity { DataFile = model, ID = Config.DATAFILE_PAGE_ID };
DataPageManage.Read(modelDP);
model.FromBytes(modelDP.Content);
//读表信息
DataPageEntity modelDPT = new DataPageEntity { DataFile = model, ID = Config.DATATABLE_PAGE_ID };
DataPageManage.Read(modelDPT);
model.TablePage = new TablePageEntity();
model.TablePage.DataPage = modelDPT;
model.TablePage.FromBytes(modelDPT.Content);
//读取列
foreach (DataTableEntity modelDT in model.TablePage.Tables)
{
DataPageEntity modelDPTemp = new DataPageEntity { DataFile = model, ID = modelDT.ColumnPageID };
DataPageManage.Read(modelDPTemp);
modelDT.ColumnPage = new ColumnPageEntity();
modelDT.ColumnPage.DataPage = modelDPTemp;
modelDT.ColumnPage.Table = modelDT;
modelDT.ColumnPage.FromBytes(modelDPTemp.Content);
//表用户列
modelDT.UserColumns = new List<DataColumnEntity>();
modelDT.UserColumns.AddRange(modelDT.ColumnPage.Columns.Where(info => info.Type == EColumnType.User));
}
}
/// <summary>
/// 删除文件
/// </summary>
public static void Delete(DataFileEntity model)
{
if (model.FileStream != null) model.FileStream.Close();
File.Delete(model.FilePath);
}
/// <summary>
/// 修改
/// </summary>
public static void Update(DataFileEntity model)
{
DataPageManage.Write(new DataPageEntity { DataFile = model, ID = Config.DATAFILE_PAGE_ID, Content = model.ToBytes() });
}
