/// <summary>
/// Add node to tree. Returns false if node cannot be added because tree would get higher than allowed.
/// </summary>
/// <param name="node">Node to be added</param>
/// <param name="metadata">Metadata node</param>
/// <param name="blidnginMaskNode">Blinding mask node</param>
/// <returns>false if node cannot be added because tree would get higher than allowed, true otherwise.</returns>
public bool AddNode(TreeNode node, IdentityMetadata metadata = null, TreeNode blidnginMaskNode = null)
{
if (node == null)
{
throw new ArgumentNullException(nameof(node));
}
if (metadata != null)
{
node = AddMetadata(node, metadata);
}
if (blidnginMaskNode != null)
{
node = CreateParentNode(blidnginMaskNode, node);
}
if (_heads.Count == 0)
{
if (node.Level > _maxTreeHeight)
{
return(false);
}
}
else if (CalcNewTreeHeight(node) > _maxTreeHeight)
{
return(false);
}
AddNodeToForest(node, _heads);
return(true);
}
/// <summary>
/// Create aggregation tree node instance.
/// </summary>
/// <param name="metadata">Metadata to be added to hash chain</param>
/// <param name="level">the level value of the aggregation tree node</param>
public TreeNode(IdentityMetadata metadata, uint level = 0)
{
if (metadata == null)
{
throw new ArgumentNullException(nameof(metadata));
}
Metadata = metadata;
Level = level;
}
/// <summary>
/// Add a data hash to be signed. Returns false if the hash cannot be added because tree would get higher than allowed.
/// </summary>
/// <param name="dataHash">Data hash to be added</param>
/// <param name="metadata">Metadata to be added together with data hash</param>
/// <param name="level">the level value of the aggregation tree node</param>
/// <returns>false if data hash cannot be added because tree would get higher than allowed, true otherwise.</returns>
public bool Add(DataHash dataHash, IdentityMetadata metadata = null, uint level = 0)
{
if (!_canAddItems)
{
throw new BlockSigningException("Signing process is started. Cannot add new items.");
}
if (dataHash == null)
{
throw new ArgumentNullException(nameof(dataHash));
}
TreeNode node = new TreeNode(dataHash, level);
if (!_treeBuilder.AddNode(node, metadata, _useBlindingMasks ? GetBlindingMaskNode(node) : null))
{
return(false);
}
_leafNodes.Add(node);
return(true);
}
private TreeNode AddMetadata(TreeNode node, IdentityMetadata metadata)
{
DataHash nodeHash = DataHasher
.AddData(node.Hash.Imprint)
.AddData(metadata.AggregationHashChainMetadata.EncodeValue())
.AddData(Util.EncodeUnsignedLong(node.Level + 1))
.GetHash();
TreeNode metadataNode = new TreeNode(metadata, node.Level);
TreeNode parent = new TreeNode(node.Level + 1)
{
Hash = nodeHash,
Left = node,
Right = metadataNode
};
node.IsLeftNode = true;
metadataNode.IsLeftNode = false;
node.Parent = metadataNode.Parent = parent;
node = parent;
return(node);
}
