Merkle DAG

The DagNode is a directed acyclic graph whose edges are a DagLink. This means that links to objects can authenticate the objects themselves, and that every object contains a secure representation of its children.

Every Merkle node is a directed acyclic graph (DAG) because each child node is accessed via its CID, basically the hash of the child's dag node. It's ID is the hash of its local content (data and links). So after creation there is no way to edit a DagNode. This prevents cycles (assuming there are no hash collisions) since one can not link the first created node to the last node to create the last reference.

var a = Encoding.UTF8.GetBytes("a");
var anode = new DagNode(a);
var alink = anode.ToLink("a");

var b = Encoding.UTF8.GetBytes("b");
var bnode = new DagNode(b);
var blink = bnode.ToLink("b");

var node = new DagNode(null, new[] { alink, blink });
Assert.AreEqual(2, node.Links.Count());
Assert.AreEqual("QmbNgNPPykP4YTuAeSa3DsnBJWLVxccrqLUZDPNQfizGKs", (string)node.Id);