A simple example of a hash ring using go.

hash_ring.go

import (
	jump "github.com/anachronistic/jump-consistent-hash"
)

type Ring struct {
	VirtualNodes uint64
	RealNodes    []string
	Replication  int32
}

type Location struct {
	Key         uint64
	VirtualNode uint64
	RealNodes   []string
}

func (ring *Ring) getVirtualNode(key uint64) uint64 {
	return key % ring.VirtualNodes
}

func (ring *Ring) getRealNodes(virtualNode uint64) []string {
	startIndex := jump.Hash(virtualNode, int32(len(ring.RealNodes)))
	realNodes := make([]string, ring.Replication)
	var i int32
	for i = 0; i < ring.Replication; i++ {
		realNodes[i] = ring.RealNodes[(startIndex+i)%int32(len(ring.RealNodes))]
	}
	return realNodes
}

func (ring *Ring) GetKeyLocation(key uint64) Location {
	virtualNode := ring.getVirtualNode(key)
	realNodes := ring.getRealNodes(virtualNode)

	return Location{
		key,
		virtualNode,
		realNodes,
	}
}