quoracle-go\quorumSystem.go

func (qs QuorumSystem) loadOptimalStrategy(
	optimize OptimizeType,
	readQuorums []ExprSet,
	writeQuorums []ExprSet,
	readFraction DistributionValues,
	loadLimit *float64,
	networkLimit *float64,
	latencyLimit *float64) (*Strategy, error) {

  ...

	buildLatencyDef := func(latencyLimit *float64) (lpDefinition, error) {
		def := newDefinitionWithVarsAndConstraints(readQuorumVars, writeQuorumVars)

		// building latency objs | -inf <= latency_def <= inf
		objExpr := make([]float64, len(def.Vars))

		for _, v := range readQuorumVars {
			nodes := make([]Node, 0)

			for x := range v.Quorum {
				q := qs.GetNodeByName(x.String())
				nodes = append(nodes, q)
			}

			l, err := qs.readQuorumLatency(nodes)

			if err != nil {
				return lpDefinition{}, fmt.Errorf("error on readQuorumLatency %s", err)
			}

			objExpr[v.Index] = fr * v.Value * float64(l)
		}

		for _, v := range writeQuorumVars {
			nodes := make([]Node, 0)

			for x := range v.Quorum {
				q := qs.GetNodeByName(x.String())
				nodes = append(nodes, q)
			}

			l, err := qs.writeQuorumLatency(nodes)

			if err != nil {
				return lpDefinition{}, fmt.Errorf("error on writeQuorumLatency %s", err)
			}

			objExpr[v.Index] = (1 - fr) * v.Value * float64(l)
		}

		objExpr = append([]float64{ninf}, objExpr...)

		if latencyLimit == nil {
			objExpr = append(objExpr, pinf)
		} else {
			objExpr = append(objExpr, *latencyLimit)
		}
		def.Objectives = append(def.Objectives, objExpr)

		return def, nil
	}

	...
  
	return &newStrategy, nil
}