public object Read(uint index)
{
if ((options & StreamOptions.SingleObject) != 0)
{
if (index != 0)
{
return(null);
}
if (objectAddress == 0)
{
return(null);
}
// We read it.
BlockStream stream = BlockStream.FromBase(objectAddress, journal.ReadService);
return(stream.Read(objectSize));
}
else
{
// We have to find it in B+ tree first.
BPlusTree tree = new BPlusTree(objectAddress);
ObjectInfo info = tree.Find(journal.ReadService, index);
if (info == null)
{
return(null);
}
// We read it.
BlockStream stream = BlockStream.FromBase(info.Address, journal.ReadService);
return(stream.Read(info.Size));
}
}
public unsafe IDriverNode Find(string path)
{
// 1) Locate children TS first.
ulong childrenTS;
Block block = journal.ReadService.Read(BlockType.NodeHeaderBlock, commonAddress);
fixed(byte *p = block.Data)
{
NodeCommonHeader *header = (NodeCommonHeader *)p;
childrenTS = header->ChildrenBTree;
}
// 2) Search in B+ tree.
BPlusTree tree = new BPlusTree(childrenTS);
ObjectInfo info = tree.Find(journal.ReadService, (uint)path.GetHashCode());
if (info == null)
{
return(null);
}
// 3) Find the actual object address.
BlockStream stream = BlockStream.FromBase(info.Address, journal.ReadService);
ChildTag childTag = Common.DeserializeFromArray(stream.Read(info.Size)) as ChildTag;
ulong? address = childTag.Find(path);
if (!address.HasValue)
{
return(null); // May only match hash value.
}
// Return the physical node (most current version).
return(new PhysicalNode(path, address.Value, journal));
}
public unsafe void DeleteChild(string name)
{
// 1) Find children TS.
ulong childTS = 0;
Block block = journal.ReadService.Read(BlockType.NodeHeaderBlock, commonAddress);
fixed(byte *p = block.Data)
{
NodeCommonHeader *header = (NodeCommonHeader *)p;
childTS = header->ChildrenBTree;
}
// 2) Find child.
BPlusTree tree = new BPlusTree(childTS);
ObjectInfo info = tree.Find(journal.ReadService, (uint)name.GetHashCode());
BlockStream stream = BlockStream.FromBase(info.Address, journal.ReadService);
ChildTag tag = Common.DeserializeFromArray(stream.Read(info.Size)) as ChildTag;
ulong? childAddress = tag.Find(name);
// Execute operation
Operations.DeleteChild deleteChild = new DeleteChild(childAddress.Value, childTS, name);
journal.Execute(deleteChild);
}
public unsafe IDriverNode GetVersion(ulong version)
{
// 1) Extract version typed stream.
ulong versionTS;
Block block = journal.ReadService.Read(BlockType.NodeHeaderBlock, commonAddress);
fixed(byte *p = block.Data)
{
NodeCommonHeader *header = (NodeCommonHeader *)p;
versionTS = header->VersionsBTree;
}
// 2) Search for version
BPlusTree versionTree = new BPlusTree(versionTS);
ObjectInfo info = versionTree.Find(journal.ReadService, (uint)version.GetHashCode());
if (info == null)
{
return(null);
}
// 3) Locate the version.
BlockStream versionTagStream = BlockStream.FromBase(info.Address, journal.ReadService);
VersionTag versionTag = Common.DeserializeFromArray(versionTagStream.Read(info.Size)) as VersionTag;
ulong?rVersionAddress = versionTag.Find(version);
if (!rVersionAddress.HasValue)
{
return(null);
}
// 4) Return the node.
return(new PhysicalNode(name, commonAddress, rVersionAddress.Value, journal));
}
