/// <summary>
/// Returns the Current Sop.DataBlock with option not to put it on cache
/// </summary>
/// <param name="getForRemoval"></param>
/// <returns></returns>
protected internal Sop.DataBlock GetCurrentDataBlock(bool getForRemoval)
{
if (currentDataBlock == null || DataBlockDriver.GetId(currentDataBlock) == -1)
{
currentDataBlock = DataBlockDriver.ReadBlockFromDisk(this, getForRemoval);
}
return(currentDataBlock);
}
/// <summary>
/// Clear contents of this Collection.
/// Changes will be saved right after clearing the contents.
/// </summary>
public virtual void Clear()
{
if (HeaderData.OccupiedBlocksHead != null && HeaderData.OccupiedBlocksTail != null)
{
HeaderData.DiskBuffer.IsDirty = true;
HeaderData.OccupiedBlocksTail.DataAddress =
HeaderData.NextAllocatableAddress =
HeaderData.StartAllocatableAddress = HeaderData.OccupiedBlocksHead.DataAddress;
int segmentSize = File.GetSegmentSize();
if (HeaderData.OccupiedBlocksHead.DataAddress + segmentSize != HeaderData.EndAllocatableAddress)
{
//**** add to File.DeletedCollections the next _region for reuse...
//** read next segment of deleted collection
var dbi = new DeletedBlockInfo();
Sop.DataBlock db;
db = DataBlockDriver.ReadBlockFromDisk(this,
HeaderData.OccupiedBlocksHead.DataAddress + segmentSize -
(int)File.DataBlockSize, true);
if (db.InternalNextBlockAddress >= 0)
{
dbi.StartBlockAddress = db.InternalNextBlockAddress;
dbi.EndBlockAddress = db.InternalNextBlockAddress + segmentSize;
if (File.DeletedCollections != null)
{
bool oc = ((CollectionOnDisk)File.DeletedCollections).ChangeRegistry;
((CollectionOnDisk)File.DeletedCollections).ChangeRegistry = ChangeRegistry;
File.DeletedCollections.Add(dbi);
((CollectionOnDisk)File.DeletedCollections).ChangeRegistry = oc;
}
HeaderData.EndAllocatableAddress = HeaderData.OccupiedBlocksHead.DataAddress + segmentSize;
}
}
}
HeaderData.Count = 0;
if (HeaderData.diskBuffer != null)
{
HeaderData.diskBuffer.ClearData();
}
if (deletedBlocks != null)
{
deletedBlocks.Clear();
}
//if (MruManager != null)
// MruManager.Clear();
//if (this.DataBlockDriver != null)
// this.DataBlockDriver.MruManager.Clear();
//Blocks.Clear();
currentDataBlock = null;
currentEntry = null;
_currentEntryDataAddress = -1;
RegisterChange();
Flush();
}
/// <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>
/// 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);
}
/// <summary>
/// OnRead gets called to read Object from Disk
/// </summary>
/// <param name="address">Address of Object on disk</param>
/// <returns></returns>
protected internal virtual object OnRead(long address)
{
//** read Node including Keys
Sop.DataBlock d = DataBlockDriver.ReadBlockFromDisk(this, address, false);
return(ReadFromBlock(d));
}