A high performance, immutable, light-weight, dependency-free, ring consistent hash library.

💻 Usage

Construction

varnodeToWeight=newDictionary<string,int>(){{"NodeA",100},{"NodeB",150},};varhasher=ConsistentHash.Create(nodeToWeight);

Hashing

varnode=hasher.Hash(Guid.NewGuid());// node = "NodeB"

AddOrSet / AddOrSetRange

// {NodeA: 100, NodeB: 150}hasher=hasher.AddOrSet(node:"NodeA",weight:200);// {NodeA: 200, NodeB: 150}hasher=hasher.AddOrSetRange(newDictionary<string,int>(){{"NodeC",500},{"NodeD",35}});// {NodeA: 200, NodeB: 150, NodeC: 500, NodeD: 35}hasher=hasher.AddOrSet(node:"NodeC",weight:0);// {NodeA: 200, NodeB: 150, NodeD: 35}hasher=hasher.AddOrSet(node:"NodeD",weight:-100);// {NodeA: 200, NodeB: 150}

Remove / RemoveRange

// {NodeA: 200, NodeB: 150, NodeC: 500, NodeD: 35}hasher=hasher.Remove("NodeA");// {NodeB: 150, NodeC: 500, NodeD: 35}hasher=hasher.Remove("NonExistingNode");// {NodeB: 150, NodeC: 500, NodeD: 35}hasher=hasher.RemoveRange(new[]{"NodeC","NodeD"});// {NodeB: 150}

🌟 Features

• High performance - Internally uses GetHashCode and XxHash for mapping nodes to values, and RadixSort for sorting
• Deterministic - Given particular node/weight pairs, and hash key, the hash result will be identical.
• Immutable
• Handles collisions in a deterministic manner (WIP)
• Thoroughly tested
• Zero dependencies
• Super light weight

⚡️ Performance

📉 API runtime and memory

Operation	Runtime	Memory usage	Details
Hash	O(log(N))	n/a	N = Number of nodes
Construction	O(∑ni=0Ni)	O(∑ni=0Ni)	Ni = Weight defined for node i
AddOrSetRange	O(∑ni=0Ni)	O(∑ni=0Ni)	Ni = Weight defined for node i
RemoveRange	O(∑ni=0Ni)	O(∑ni=0Ni)	Ni = Weight defined for node i
Update	O(∑ni=0Ni)	O(∑ni=0Ni)	Ni = Weight defined for node i
Contains	O(1)	n/a
TryGetWeight	O(1)	n/a
Equals	O(N)	n/a	N = Number of nodes

NOTE: Any altering call creates a new instance, so costing sum of all weights.

📊 Distribution Benchmarks (WIP)

📃 License

ConsistentHash🪐 is free and open-source software licensed under the GNU General Public License