/// <summary>
/// Reads the middle table of many-to-many relationship. Bad performance currently, because it reads the
/// middle file everytime a record is read.
/// </summary>
/// <param name="rec"></param>
public void ReadMTM(BaseClass rec)
{
foreach (MTMRelationInfo mtmInfo in rec.MTMInfoList())
{
String filepath = Path.Combine(ctx.DatabaseFolder, mtmInfo.tableName) + ".dat"; //mtm middle tablo yolu
Stream mtmStream = File.OpenRead(filepath);
int line = Convert.ToInt32(mtmStream.Length / (sizeof(int) * 3));
List <MTMRec> mtmRecs = new List <MTMRec>(); //middle tablo kayıtları
for (int i = 0; i < line; i++)
{
Tuple <DKDB.BaseClass, Dictionary <PropertyInfo, int> > fillingLog;
fillingLog = FileOps.ReadSingleRecord(mtmStream, i + 1, typeof(MTMRec));
mtmRecs.Add((MTMRec)fillingLog.Item1);
}
mtmStream.Close();
int my_id_column = WhoAmI(mtmInfo.tableName); //MTMRec içinde id1 mi benim sütunum yoksa id2 mi? ctx'teki sıraya göre kontrol edilir
MTMReq mtmReq = new MTMReq(rec, mtmInfo.OwnMTMProp);
foreach (MTMRec mtmRec in mtmRecs) //her bir middle tablo kaydı için:
{
if (my_id_column == 1 && mtmRec.id_1 == rec.id)
{
mtmReq.AddOppId(mtmRec.id_2);//opposite id
}
else if (my_id_column == 2 && mtmRec.id_2 == rec.id)
{
mtmReq.AddOppId(mtmRec.id_1);//opposite id
}
}
KeyValuePair <string, Tuple <Type, Type> > kp = BaseClass.AllMTMRelations.FirstOrDefault(r => r.Key == mtmInfo.tableName);
object opposite_dbset = ctx.GetDBSetByType(my_id_column == 1 ? kp.Value.Item2 : kp.Value.Item1);
object[] parameters = new object[1];
parameters[0] = mtmReq; //list of ids of the records that we want to read from opposite db
PropertyInfo fi = opposite_dbset.GetType().GetProperty("MTMReqList");
List <MTMReq> rtbfMTM = fi.GetValue(opposite_dbset) as List <MTMReq>;
rtbfMTM.GetType().GetMethod("Add").Invoke(rtbfMTM, parameters);
}
}
/// <summary>
/// Completes changes in the dbset chosen by the command.
/// </summary>
/// <param name="command">AddDirectly, AddChilds, Update, Remove</param>
public bool SaveChanges(char[] com)
{
String command = new string(com);
bool result = false;
if (command == "AddOTM")
{
while (recordsToAddAsOTM.Count() != 0)
{
Tuple <object, object, PropertyInfo> rec = recordsToAddAsOTM[0];
OpenMainWrite();
rec.Item3.SetValue(rec.Item2, rec.Item1);
int fk = FileOps.Add(mainFile, removedIndexes, (BaseClass)rec.Item2);
rec.Item2.GetType().GetProperty(rec.Item3.Name).SetValue(rec.Item2, fk);
result = true;
}
}
else if (command == "AddDirectly")
{
//0. elemanlar ile işlem yapma nedeni:
//Bir ekleme işlemi yapılırken, içinde çocuk nesne var ise, bir şekilde üzerinde çalışılan
//listenin sonuna yeni kayıt eklenmesine neden olabilir.
OpenMainWrite();
while (recordsToAddDirectly.Count() != 0)
{
result = true;
int id = FileOps.Add(mainFile, removedIndexes, recordsToAddDirectly[0]);
recordsToAddDirectly[0].id = id;
allRecords.Add(recordsToAddDirectly[0]);
recordsToAddDirectly.RemoveAt(0);
}
mainFile.Close();
}
else if (command == "AddChilds")
{
OpenMainWrite();
while (recordsToAddAsOTO.Count() != 0)
{
result = true;
//item1=parent, item2=child
T record = (T)recordsToAddAsOTO[0].Item2;
int fk = FileOps.Add(mainFile, removedIndexes, record);
record.id = fk;
Type ownerType = recordsToAddAsOTO[0].Item1.GetType();
Type ownerDbSetType = ctx.dbsetTypes.Where(a => a.ToString().Equals(ownerType.ToString())).ElementAt(0);
object ownerDbSet = ctx.GetDBSetByType(ownerDbSetType);
object[] parameters = new object[1];
parameters[0] = (BaseClass)recordsToAddAsOTO[0].Item1;
//Explained under recordsToAddAsOTO declaration.
ownerDbSet.GetType().GetMethod("Update").Invoke(ownerDbSet, parameters);
allRecords.Add(record);
recordsToAddAsOTO.RemoveAt(0);
}
mainFile.Close();
}
else if (command == "Update")
{
OpenMainWrite();
while (Updates.Count() != 0)
{
result = true;
T record = Updates[0];
FileOps.Overwrite(mainFile, record);
Updates.RemoveAt(0);
}
mainFile.Close();
}
else if (command == "Remove")
{
OpenMainWrite();
while (recordsToRemove.Count() != 0)
{
result = true;
recordsToRemove[0].GetType().GetProperty("removed").SetValue(recordsToRemove[0], true);
FileOps.Remove(mainFile, metaFile, recordsToRemove[0]);
if (!ctx.removed.Any(kp => kp.Key == typeof(T)))
{
ctx.removed.Add(typeof(T), new List <int>());
}
ctx.removed.FirstOrDefault(kp => kp.Key == typeof(T)).Value
.Add((int)recordsToRemove[0].id);
recordsToRemove.RemoveAt(0);
}
mainFile.Close();
}
else if (command == "UpdateAfterRemoval") //silinmiş bir kayda referans olanların foreign keylerini -1 yapacak
{
List <PropertyInfo> toChangeColumns = new List <PropertyInfo>();
Dictionary <int, List <int> > toChange = new Dictionary <int, List <int> >();
foreach (KeyValuePair <Type, List <int> > kp in ctx.removed)
{
List <PropertyInfo> props = this.GetType().GetGenericArguments()[0].GetProperties().ToList();
foreach (PropertyInfo info in props)
{
if (!info.PropertyType.IsGenericType && info.PropertyType.Name.Equals(kp.Key.Name))
{
toChangeColumns.Add(info);
foreach (int id in kp.Value) //null yapılacak id
{
toChange.Add(id, new List <int>());
}
}
else if (info.PropertyType.IsGenericType && info.PropertyType.GetGenericArguments()[0].Name == kp.Key.Name)
{
//remove from mtm
}
}
}
foreach (T rec in allRecords)
{
foreach (PropertyInfo column in toChangeColumns)
{
foreach (KeyValuePair <int, List <int> > kp in toChange)
{
BaseClass child_rec = (BaseClass)rec.GetType().GetProperty(column.Name).GetValue(rec);
if (child_rec.id == kp.Key)
{
rec.GetType().GetProperty(column.Name).SetValue(rec, null);
kp.Value.Add(rec.id);
}
}
}
}
foreach (PropertyInfo column in toChangeColumns)
{
OpenMainWrite();
FileOps.MakeReferenceNull(mainFile, column, typeof(T), toChange);
mainFile.Close();
}
}
return(result);
}
