internal static int SizeOfMetaData(IInternalPersistent parent)
{
if (parent == null)
{
throw new ArgumentNullException("parent");
}
if (!(parent is CollectionOnDisk))
{
throw new ArgumentException("Parent is not CollectionOnDisk type.");
}
if (Encoding != ((CollectionOnDisk)parent).File.Server.Encoding)
{
Encoding = ((CollectionOnDisk)parent).File.Server.Encoding;
_sizeOf = 0;
}
if (_sizeOf == 0)
{
var o = new LinkedItemOnDisk
{
DiskBuffer = ((CollectionOnDisk)parent).DataBlockDriver.
CreateBlock(((CollectionOnDisk)parent).File.DataBlockSize),
Data = new byte[0]
};
var w = new OnDiskBinaryWriter(Encoding)
{
DataBlock = o.DiskBuffer
};
WritePersistentData(parent, o, w);
_sizeOf = (int)w.BaseStream.Position;
w.Close();
}
return(_sizeOf);
}
public override void Clear()
{
if (Count <= 0)
{
return;
}
FirstItem = new LinkedItemOnDisk(File.DataBlockSize);
this.CurrentItem = FirstItem;
LastItem = new LinkedItemOnDisk(File.DataBlockSize);
base.Clear();
}
/// <summary>
/// Add 'Value' to the Collection
/// </summary>
public long Add(object value)
{
var o = new LinkedItemOnDisk(this.DataBlockSize)
{
Data = value
};
WriteToDisk(o, false);
UpdateCount(UpdateCountType.Increment);
//*** update Current, Last & First
if (LastItem.DiskBuffer.DataAddress != -1)
{
o.PreviousItemAddress = LastItem.DiskBuffer.DataAddress;
WriteToDisk(o, false);
LinkedItemOnDisk biod = CurrentItem;
biod.NextItemAddress = o.DiskBuffer.DataAddress;
Sop.DataBlock db = DataBlockDriver.ReadBlockFromDisk(this, LastItem.DiskBuffer.DataAddress, true);
if (CurrentItem.DiskBuffer.DataAddress != LastItem.DiskBuffer.DataAddress)
{
biod = (LinkedItemOnDisk)ReadFromBlock(db);
biod.NextItemAddress = o.DiskBuffer.DataAddress;
}
else
{
PurifyMeta(biod, db);
if (db.SizeOccupied > 0)
{
biod.DiskBuffer = db;
}
}
WriteToDisk(biod, false);
}
else
{
FirstItem.DiskBuffer.DataAddress = o.DiskBuffer.DataAddress;
}
currentEntry = null;
CurrentItem = o;
CurrentEntryDataAddress = o.DiskBuffer.DataAddress;
currentDataBlock = o.DiskBuffer;
LastItem.DiskBuffer.DataAddress = o.DiskBuffer.DataAddress;
MruManager.Add(CurrentEntryDataAddress, o);
//** update the header
RegisterChange(true);
//IsDirty = true;
return(o.DiskBuffer.DataAddress);
}
/// <summary>
/// Shared Block on Disk purifies data and only saves one
/// copy of Meta data in it.
/// </summary>
/// <param name="biod"></param>
/// <param name="db"></param>
protected override void PurifyMeta(LinkedItemOnDisk biod, Sop.DataBlock db)
{
if (db.SizeOccupied > 0)
{
//** purify data by separating meta data from it so meta data won't be serialized more than once
int metaDataSize = LinkedListOnDisk.SizeOfMetaData(this);
int newSize = db.SizeOccupied - metaDataSize;
byte[] newData = new byte[newSize];
Array.Copy(db.Data, metaDataSize, newData, 0, newSize);
//** assign data to block for serialization
biod.Data = newData;
}
}
public override void Unpack(IInternalPersistent parent, BinaryReader reader)
{
if (CurrentItem == null)
{
FirstItem = new LinkedItemOnDisk(File.DataBlockSize);
LastItem = new LinkedItemOnDisk(File.DataBlockSize);
}
CurrentItem = FirstItem;
long firstItemDataAddress = reader.ReadInt64();
long lastItemDataAddress = reader.ReadInt64();
FirstItem.DiskBuffer.DataAddress = firstItemDataAddress;
LastItem.DiskBuffer.DataAddress = lastItemDataAddress;
base.Unpack(parent, reader);
}
/// <summary>
/// MoveFirst makes the first entry in the Collection the current one
/// </summary>
public override bool MoveFirst()
{
if (Count > 0 && CurrentItem != null)
{
if (FirstItem.DiskBuffer.DataAddress != CurrentEntryDataAddress ||
FirstItem.DiskBuffer.DataAddress != CurrentItem.DiskBuffer.DataAddress)
{
CurrentEntryDataAddress = -1;
this.DataBlockDriver.MoveTo(this, FirstItem.DiskBuffer.DataAddress);
Sop.DataBlock db = DataBlockDriver.ReadBlockFromDisk(this, FirstItem.DiskBuffer.DataAddress, false);
this.currentDataBlock = db;
CurrentItem = (LinkedItemOnDisk)ReadFromBlock(db);
}
return(true);
}
return(false);
}
protected internal override void Initialize(File.IFile file, params KeyValuePair <string, object>[] parameters)
{
base.Initialize(file, parameters);
if (FirstItem == null)
{
FirstItem = new LinkedItemOnDisk(file.DataBlockSize);
}
if (CurrentItem == null)
{
CurrentItem = FirstItem;
}
if (LastItem == null)
{
LastItem = new LinkedItemOnDisk(file.DataBlockSize);
}
//** don't call open here, let caller code do it to ensure proper "state" when Open is called!!
}
public override void Close()
{
if (!IsOpen)
{
return;
}
base.Close();
if (OnDiskBinaryWriter != null)
{
OnDiskBinaryWriter.Close();
OnDiskBinaryWriter = null;
}
if (OnDiskBinaryReader != null)
{
OnDiskBinaryReader.Close();
OnDiskBinaryReader = null;
}
FirstItem = new LinkedItemOnDisk(File.DataBlockSize);
this.CurrentItem = FirstItem;
LastItem = new LinkedItemOnDisk(File.DataBlockSize);
}
//internal override bool RemoveInMemory(long DataAddress, Transaction.ITransactionLogger Transaction)
//{
// if (LastItem != null)
// LastItem.Clear();
// if (FirstItem != null)
// FirstItem.Clear();
// CurrentItem = null;
// base.RemoveInMemory(DataAddress, Transaction);
// return true;
//}
private void RemoveAt(long dataAddress, bool willMove)
{
if (willMove && !MoveTo(dataAddress))
{
return;
}
if (IsDeletedBlocksList && Count == 1)
{
return;
}
Sop.DataBlock currBlock = this.GetCurrentDataBlock(true);
if (FirstItem.DiskBuffer.DataAddress == dataAddress)
{
MoveFirst();
if (MoveNext())
{
FirstItem.DiskBuffer.DataAddress = CurrentItem.DiskBuffer.DataAddress;
CurrentItem.PreviousItemAddress = -1;
Sop.DataBlock db = WriteToBlock(CurrentItem, CurrentItem.DiskBuffer);
DataBlockDriver.SetDiskBlock(this, db, false);
}
else
{
long address = FirstItem.DiskBuffer.DataAddress;
FirstItem.DiskBuffer.DataAddress = LastItem.DiskBuffer.DataAddress = -1;
CurrentItem = FirstItem;
Sop.DataBlock db = WriteToBlock(CurrentItem, CurrentItem.DiskBuffer);
db.DataAddress = address;
DataBlockDriver.SetDiskBlock(this, db, false);
db.DataAddress = -1;
}
}
else if (LastItem.DiskBuffer.DataAddress == dataAddress)
{
if (MovePrevious() || FirstItem.DiskBuffer.DataAddress == CurrentItem.DiskBuffer.DataAddress)
{
LastItem.DiskBuffer.DataAddress = CurrentItem.DiskBuffer.DataAddress;
CurrentItem.NextItemAddress = -1;
Sop.DataBlock db = WriteToBlock(CurrentItem, CurrentItem.DiskBuffer);
DataBlockDriver.SetDiskBlock(this, db, false);
}
else
{
throw new InvalidOperationException("Can't go previous but First is not the only item.");
}
}
else
{
LinkedItemOnDisk curr = CurrentItem;
LinkedItemOnDisk prev = null, next = null;
if (MoveTo(curr.PreviousItemAddress))
{
prev = CurrentItem;
}
if (MoveTo(curr.NextItemAddress))
{
next = CurrentItem;
}
if (prev != null && next != null)
{
prev.NextItemAddress = curr.NextItemAddress;
next.PreviousItemAddress = curr.PreviousItemAddress;
Sop.DataBlock db = WriteToBlock(prev, prev.DiskBuffer);
DataBlockDriver.SetDiskBlock(this, db, false);
db = WriteToBlock(next, next.DiskBuffer);
DataBlockDriver.SetDiskBlock(this, db, false);
}
}
if (MruManager.Count > 0)
{
MruManager.Remove(dataAddress, true);
}
DataBlockDriver.Remove(this, currBlock);
}
/// <summary>
/// Allows child class to purify Meta data from data
/// </summary>
/// <param name="biod"></param>
/// <param name="db"></param>
protected virtual void PurifyMeta(LinkedItemOnDisk biod, Sop.DataBlock db)
{
}
