/// <summary>
/// Removes a node from the hash ring.
///
/// Note that <see cref="ConsistentHash{T}"/> is immutable and
/// this operation returns a new instance.
/// </summary>
public static ConsistentHash <T> operator -(ConsistentHash <T> hash, T node)
{
var nodeHash = ConsistentHash.HashFor(node.ToString());
return(new ConsistentHash <T>(hash._nodes.CopyAndRemove(Enumerable.Range(1, hash._virtualNodesFactor).Select(r => new KeyValuePair <int, T>(ConsistentHash.ConcatenateNodeHash(nodeHash, r), node))),
hash._virtualNodesFactor));
}
/// <summary>
/// Get the node responsible for the data key.
/// Can only be used if nodes exist in the node ring.
/// Otherwise throws <see cref="ArgumentException"/>.
/// </summary>
public T NodeFor(string key)
{
if (IsEmpty)
{
throw new InvalidOperationException(string.Format("Can't get node for [{0}] from an empty node ring", key));
}
return(NodeRing[Idx(Array.BinarySearch(NodeHashRing, ConsistentHash.HashFor(key)))]);
}
/// <summary>
/// Get the node responsible for the data key.
/// Can only be used if nodes exist in the node ring.
/// </summary>
/// <exception cref="InvalidOperationException">
/// This exception is thrown if the node ring is empty.
/// </exception>
public T NodeFor(byte[] key)
{
if (IsEmpty)
{
throw new InvalidOperationException($"Can't get node for [{key}] from an empty node ring");
}
return(NodeRing[Idx(Array.BinarySearch(NodeHashRing, ConsistentHash.HashFor(key)))]);
}