Merge pull request 'static weight algorithm' (#15) from JoYang/pcm-coordinator:master into master

Former-commit-id: 40d527663f2d944da898002620d6b8183fe206d7

api/internal/scheduler/entity/entity.go

@@ -11,3 +11,9 @@ type Participant struct {
 	Name           string
 	Participant_id int64
 }
+
+type WeightP struct {
+	Participant_id int64
+	Weight         int32
+	Name           string
+}

api/internal/scheduler/strategy/staticWeight.go

@@ -1,10 +1,69 @@
 package strategy
 
+import (
+	"errors"
+	"gitlink.org.cn/jcce-pcm/pcm-coordinator/api/internal/scheduler/entity"
+)
+
 type StaticWeightStrategy struct {
 	// TODO: add fields
+
+	//每个
+	num     int32
+	weights []entity.WeightP
 }
 
 func (ps *StaticWeightStrategy) Schedule() ([]*AssignedCluster, error) {
 	// TODO: implement the scheduling logic	return nil, nil
-	return nil, nil
+
+	if ps.num < 1 {
+		return nil, errors.New("numbers must be greater than 0")
+	}
+
+	if ps.weights == nil {
+		return nil, errors.New("weight must be set")
+	}
+
+	var weightSum int32
+	weightSum = 0
+	for _, w := range ps.weights {
+		weightSum += w.Weight
+	}
+
+	weightRatio := make([]float64, len(ps.weights))
+	for i, w := range ps.weights {
+		weightRatio[i] = float64(w.Weight) / float64(weightSum)
+	}
+
+	var rest = ps.num
+	var results []*AssignedCluster
+
+	for i := 0; i < len(ps.weights); i++ {
+
+		var n = int(float64(ps.num) * weightRatio[i])
+		rest -= int32(n)
+
+		cluster := &AssignedCluster{ParticipantId: ps.weights[i].Participant_id, Name: ps.weights[i].Name, Replicas: int32(n)}
+		results = append(results, cluster)
+	}
+
+	if rest != 0 {
+		if rest < 0 { // 如果差值小于0，需要增加某些元素的值
+			for i := len(ps.weights) - 1; rest < 0 && i >= 0; i-- {
+				if results[i].Replicas < ps.weights[i].Weight {
+					results[i].Replicas++
+					rest++
+				}
+			}
+		} else {
+			for i := len(ps.weights) - 1; rest > 0 && i >= 0; i-- {
+				if results[i].Replicas < ps.weights[i].Weight {
+					results[i].Replicas--
+					rest--
+				}
+			}
+		}
+	}
+
+	return results, nil
 }