/// <summary>
/// Remove Block from the Collection.
/// NOTE: this is used by BTreeAlgorithm when deleting a node's and/or
/// a node's item's data block(s) on disk.
/// </summary>
public bool Remove(Algorithm.Collection.ICollectionOnDisk parent, Sop.DataBlock block, bool clearBlock = true)
{
if (!parent.File.Server.HasTrashBin)
{
return(false);
}
// remove block and linked blocks from MRU
Sop.DataBlock d = block;
long contiguousBlockStartAddress = -1;
long currentBlockAddress = -1;
int contiguousBlockCount = 0;
var deletedBlocks = ((CollectionOnDisk)parent).DeletedBlocks;
IDictionary <long, Sop.DataBlock> blocks = ((CollectionOnDisk)parent).Blocks;
if (!d.IsFolded)
{
d.Fold();
}
if (d.IsFolded)
{
if (clearBlock && d.SizeOccupied > 0)
{
d.SizeOccupied = 0;
}
foreach (var segment in d.foldedDataAddresses)
{
if (deletedBlocks != null)
{
RegisterRemovedBlock((CollectionOnDisk)parent, segment.Address, segment.BlockCount * (int)parent.DataBlockSize);
// add removed block to the recycle Store for reuse later on Add operation
deletedBlocks.AddAvailableBlock(segment.Address, segment.BlockCount * (int)parent.DataBlockSize);
}
}
}
else
{
#region Legacy code for removing unfolded Blocks
do
{
if (d.DataAddress >= 0)
{
blocks.Remove(d.DataAddress);
}
if (currentBlockAddress >= 0 && currentBlockAddress + (int)parent.DataBlockSize == d.DataAddress)
{
// if current block is part of a single contiguous block
contiguousBlockCount++;
currentBlockAddress = d.DataAddress;
}
else
{
if (currentBlockAddress != -1)
{
// recycle segment
if (deletedBlocks != null)
{
RegisterRemovedBlock((CollectionOnDisk)parent, contiguousBlockStartAddress, contiguousBlockCount * (int)parent.DataBlockSize);
// add removed block to the recycle Store for reuse later on Add operation
deletedBlocks.AddAvailableBlock(contiguousBlockStartAddress,
contiguousBlockCount * (int)parent.DataBlockSize);
}
}
currentBlockAddress = d.DataAddress;
contiguousBlockStartAddress = d.DataAddress;
contiguousBlockCount = 1;
}
// clear block's data
if (clearBlock && d.SizeOccupied > 0)
{
d.SizeOccupied = 0;
}
if (d.Next == null && d.NextItemAddress >= 0)
{
//load the next datablock to get its next block address...
d.Next = ReadBlockFromDisk(parent, parent.FileStream.Position, true, true,
CreateBlock(parent.DataBlockSize));
}
d = d.Next;
} while (d != null);
// add to deleted blocks store any deleted block haven't added yet
if (contiguousBlockStartAddress != -1)
{
if (deletedBlocks != null)
{
RegisterRemovedBlock((CollectionOnDisk)parent, contiguousBlockStartAddress, contiguousBlockCount * (int)parent.DataBlockSize);
// add removed block to the recycle Store for reuse later on Add operation
deletedBlocks.AddAvailableBlock(contiguousBlockStartAddress,
contiguousBlockCount * (int)parent.DataBlockSize);
}
}
#endregion
}
parent.RegisterChange(true);
return(true);
}
