feature(domain): 增加对于互斥域的支持

distributor/distributor.go

@@ -254,6 +254,11 @@ func (v *VariantsDistributor) tabExperimentVariant(c *config.ProductConfig, expe
 	if !ok {
 		return e.Variant{}, fmt.Errorf("no layer[%s] exist in config", experiment.LayerID)
 	}
+	// check 互斥域
+	hitDomain := layer.HitDomain(decisionId)
+	if !hitDomain {
+		return e.Variant{}, nil
+	}
 	eid, err := v.tabLayerExperimentId(layer, decisionId)
 	if err != nil || len(eid) == 0 || eid != experiment.Id {
 		return e.Variant{}, err

entities/domain.go

@@ -0,0 +1,28 @@
+package entities
+
+import (
+	"strings"
+
+	"github.com/volcengine/datatester-go-sdk/distributor/bucketer"
+)
+
+type Domain struct {
+	ID           string `json:"id"`
+	Name         string `json:"name"`
+	HashStrategy string `json:"hash_strategy"`
+	Begin        uint32 `json:"begin"`
+	Length       uint32 `json:"length"`
+}
+
+// Hit 方法检查给定的 decisionID 是否在当前 Domain 的索引范围内
+func (d Domain) Hit(decisionID string) bool {
+	// 通过连接 decisionID 和 d.Name 获取流量桶索引
+	index, err := bucketer.NewMmh3BucketService().GetTrafficBucketIndex(
+		strings.Join([]string{decisionID, d.Name}, ":"))
+	// 如果获取索引过程中出现错误，返回 false
+	if err != nil {
+		return false
+	}
+	// 如果索引值在 d.Begin 和 d.Begin + d.Length 之间，返回 true，否则返回 false
+	return index >= d.Begin && index < d.Begin+d.Length
+}

entities/layer.go

@@ -14,4 +14,25 @@ type Layer struct {
 	Name              string                      `json:"name"`
 	TrafficAllocation []release.TrafficAllocation `json:"traffic_allocation"`
 	ExperimentIds     []string                    `json:"experiment_ids"`
+	Domain            *Domain                     `json:"domain"`
+	ParentDomains     []Domain                    `json:"parent_domains"`
+}
+
+// HitDomain 方法用于检查给定的 decisionID 是否命中当前层及其所有父域
+func (l Layer) HitDomain(decisionID string) bool {
+	// 层不属于互斥域，直接返回
+	if l.Domain == nil || l.Domain.ID == "0" {
+		return true
+	}
+	hit := l.Domain.Hit(decisionID)
+	if !hit {
+		return false
+	}
+	for _, d := range l.ParentDomains {
+		hit = d.Hit(decisionID)
+		if !hit {
+			return false
+		}
+	}
+	return true
 }