feature (multi-rollout): Added support for multiple rollouts. (#247)

feature (multi-rollout): Added support for multiple rollouts

Author: yasirfolio3

pkg/decision/helpers_test.go

@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2019, Optimizely, Inc. and contributors                        *
+ * Copyright 2019-2020, Optimizely, Inc. and contributors                   *
  *                                                                          *
  * Licensed under the Apache License, Version 2.0 (the "License");          *
  * you may not use this file except in compliance with the License.         *
@@ -150,6 +150,48 @@ var testExp1112 = entities.Experiment{
 		entities.Range{EntityID: "2222", EndOfRange: 10000},
 	},
 }
+var testExp1117Var2223 = entities.Variation{ID: "2223", Key: "2223"}
+var testAudience5556 = entities.Audience{ID: "5556"}
+var testExp1117 = entities.Experiment{
+	AudienceConditionTree: &entities.TreeNode{
+		Operator: "and",
+		Nodes: []*entities.TreeNode{
+			&entities.TreeNode{Item: "test_audience_5556"},
+		},
+	},
+	ID:  "1117",
+	Key: testExp1111Key,
+	Variations: map[string]entities.Variation{
+		"2223": testExp1117Var2223,
+	},
+	VariationKeyToIDMap: map[string]string{
+		"2223": "2223",
+	},
+	TrafficAllocation: []entities.Range{
+		entities.Range{EntityID: "2223", EndOfRange: 10000},
+	},
+}
+var testExp1118Var2224 = entities.Variation{ID: "2224", Key: "2224"}
+var testAudience5557 = entities.Audience{ID: "5557"}
+var testExp1118 = entities.Experiment{
+	AudienceConditionTree: &entities.TreeNode{
+		Operator: "and",
+		Nodes: []*entities.TreeNode{
+			&entities.TreeNode{Item: "test_audience_5557"},
+		},
+	},
+	ID:  "1118",
+	Key: testExp1111Key,
+	Variations: map[string]entities.Variation{
+		"2224": testExp1118Var2224,
+	},
+	VariationKeyToIDMap: map[string]string{
+		"2224": "2224",
+	},
+	TrafficAllocation: []entities.Range{
+		entities.Range{EntityID: "2224", EndOfRange: 10000},
+	},
+}
 
 const testFeatRollout3334Key = "test_feature_rollout_3334_key"
 
@@ -158,7 +200,7 @@ var testFeatRollout3334 = entities.Feature{
 	Key: testFeatRollout3334Key,
 	Rollout: entities.Rollout{
 		ID:          "4444",
-		Experiments: []entities.Experiment{testExp1112},
+		Experiments: []entities.Experiment{testExp1112, testExp1117, testExp1118},
 	},
 }
 

pkg/decision/rollout_service.go

@@ -30,25 +30,61 @@ import (
 type RolloutService struct {
 	audienceTreeEvaluator     evaluator.TreeEvaluator
 	experimentBucketerService ExperimentService
-	logger logging.OptimizelyLogProducer
+	logger                    logging.OptimizelyLogProducer
 }
 
 // NewRolloutService returns a new instance of the Rollout service
 func NewRolloutService(sdkKey string) *RolloutService {
 	return &RolloutService{
-		logger:logging.GetLogger(sdkKey, "RolloutService"),
+		logger:                    logging.GetLogger(sdkKey, "RolloutService"),
 		audienceTreeEvaluator:     evaluator.NewMixedTreeEvaluator(),
 		experimentBucketerService: NewExperimentBucketerService(logging.GetLogger(sdkKey, "ExperimentBucketerService")),
 	}
 }
 
 // GetDecision returns a decision for the given feature and user context
 func (r RolloutService) GetDecision(decisionContext FeatureDecisionContext, userContext entities.UserContext) (FeatureDecision, error) {
+
 	featureDecision := FeatureDecision{
 		Source: Rollout,
 	}
 	feature := decisionContext.Feature
 	rollout := feature.Rollout
+
+	evaluateConditionTree := func(experiment *entities.Experiment) bool {
+		condTreeParams := entities.NewTreeParameters(&userContext, decisionContext.ProjectConfig.GetAudienceMap())
+		evalResult, _ := r.audienceTreeEvaluator.Evaluate(experiment.AudienceConditionTree, condTreeParams)
+		if !evalResult {
+			featureDecision.Reason = reasons.FailedRolloutTargeting
+			r.logger.Debug(fmt.Sprintf(`User "%s" failed targeting for feature rollout with key "%s".`, userContext.ID, feature.Key))
+		}
+		return evalResult
+	}
+
+	getFeatureDecision := func(experiment *entities.Experiment, decision *ExperimentDecision) (FeatureDecision, error) {
+		// translate the experiment reason into a more rollouts-appropriate reason
+		switch decision.Reason {
+		case reasons.NotBucketedIntoVariation:
+			featureDecision.Decision = Decision{Reason: reasons.FailedRolloutBucketing}
+		case reasons.BucketedIntoVariation:
+			featureDecision.Decision = Decision{Reason: reasons.BucketedIntoRollout}
+		default:
+			featureDecision.Decision = decision.Decision
+		}
+
+		featureDecision.Experiment = *experiment
+		featureDecision.Variation = decision.Variation
+		r.logger.Debug(fmt.Sprintf(`Decision made for user "%s" for feature rollout with key "%s": %s.`, userContext.ID, feature.Key, featureDecision.Reason))
+		return featureDecision, nil
+	}
+
+	getExperimentDecisionContext := func(experiment *entities.Experiment) ExperimentDecisionContext {
+		return ExperimentDecisionContext{
+			Experiment:    experiment,
+			ProjectConfig: decisionContext.ProjectConfig,
+		}
+	}
+
 	if rollout.ID == "" {
 		featureDecision.Reason = reasons.NoRolloutForFeature
 		return featureDecision, nil
@@ -60,38 +96,30 @@ func (r RolloutService) GetDecision(decisionContext FeatureDecisionContext, user
 		return featureDecision, nil
 	}
 
-	// For now, Rollouts is just a single experiment layer
-	experiment := rollout.Experiments[0]
-	experimentDecisionContext := ExperimentDecisionContext{
-		Experiment:    &experiment,
-		ProjectConfig: decisionContext.ProjectConfig,
-	}
-
-	// if user fails rollout targeting rule we return out of it
-	if experiment.AudienceConditionTree != nil {
-		condTreeParams := entities.NewTreeParameters(&userContext, decisionContext.ProjectConfig.GetAudienceMap())
-		evalResult, _ := r.audienceTreeEvaluator.Evaluate(experiment.AudienceConditionTree, condTreeParams)
-		if !evalResult {
-			featureDecision.Reason = reasons.FailedRolloutTargeting
-			r.logger.Debug(fmt.Sprintf(`User "%s" failed targeting for feature rollout with key "%s".`, userContext.ID, feature.Key))
-			return featureDecision, nil
+	for index := 0; index < numberOfExperiments-1; index++ {
+		experiment := &rollout.Experiments[index]
+		experimentDecisionContext := getExperimentDecisionContext(experiment)
+		// Move to next evaluation if condition tree is available and evaluation fails
+		if experiment.AudienceConditionTree != nil && !evaluateConditionTree(experiment) {
+			// Evaluate this user for the next rule
+			continue
+		}
+		decision, _ := r.experimentBucketerService.GetDecision(experimentDecisionContext, userContext)
+		if decision.Variation == nil {
+			// Evaluate fall back rule / last rule now
+			break
 		}
+		return getFeatureDecision(experiment, &decision)
 	}
 
-	decision, _ := r.experimentBucketerService.GetDecision(experimentDecisionContext, userContext)
-	// translate the experiment reason into a more rollouts-appropriate reason
-	switch decision.Reason {
-	case reasons.NotBucketedIntoVariation:
-		featureDecision.Decision = Decision{Reason: reasons.FailedRolloutBucketing}
-	case reasons.BucketedIntoVariation:
-		featureDecision.Decision = Decision{Reason: reasons.BucketedIntoRollout}
-	default:
-		featureDecision.Decision = decision.Decision
+	// fall back rule / last rule
+	experiment := &rollout.Experiments[numberOfExperiments-1]
+	experimentDecisionContext := getExperimentDecisionContext(experiment)
+	// Move to bucketing if conditionTree is unavailable or evaluation passes
+	if experiment.AudienceConditionTree == nil || evaluateConditionTree(experiment) {
+		decision, _ := r.experimentBucketerService.GetDecision(experimentDecisionContext, userContext)
+		return getFeatureDecision(experiment, &decision)
 	}
 
-	featureDecision.Experiment = experiment
-	featureDecision.Variation = decision.Variation
-	r.logger.Debug(fmt.Sprintf(`Decision made for user "%s" for feature rollout with key "%s": %s.`, userContext.ID, feature.Key, featureDecision.Reason))
-
 	return featureDecision, nil
 }