Merge pull request #7 from optimizely/start_on_bucketing

Starts bucketing logic

Author: tjj5036

optimizely/bucket.go

@@ -0,0 +1,56 @@
+package optimizely
+
+import (
+	"fmt"
+	"hash/fnv"
+	"math"
+)
+
+var BUCKETING_ID_TEMPLATE = "{%v}{%v}"
+var MAX_HASH_VALUE = math.Exp2(32)
+
+// generate_bucket_value generates an unit32 value for a bucket
+func generate_bucket_value(bucketing_id string) uint32 {
+	h := fnv.New32a()
+	bucket_slice := []byte(bucketing_id)
+	h.Write(bucket_slice)
+	return h.Sum32()
+}
+
+// Given an experiment key, returns the traffic allocation within that experiment
+// experiment_key: key of experiment
+// experiments: array of ExperimentEntities
+// Returns: pointer to array of TrafficAllocationEntities
+func get_traffic_allocations(experiment_key string, experiments []ExperimentEntity) []TrafficAllocationEntity {
+	for i := 0; i < len(experiments); i++ {
+		if experiments[i].Key == experiment_key { // Id or Key?
+			return experiments[i].TrafficAllocation
+		}
+	}
+	return nil
+}
+
+// Bucket determines for a given experiment key and bucketing ID determines ID of variation to be shown to visitor.
+// experiment_key: Key representing experiment for which visitor is to be bucketed.
+// user_id: ID for user.
+// Returns: Variation ID for variation in which the visitor with ID user_id will be put in
+// If no variation, return empty string (TODO: move to error)
+func (client *OptimizelyClient) Bucket(experiment_key string, user_id string) string {
+	var experiment_id = ""
+	for j := 0; j < len(client.project_config.Experiments); j++ {
+		if client.project_config.Experiments[j].Key == experiment_id {
+			experiment_id = client.project_config.Experiments[j].Id
+		}
+	}
+	var bucketing_id = fmt.Sprintf(BUCKETING_ID_TEMPLATE, user_id, experiment_id)
+	var bucketing_number = generate_bucket_value(bucketing_id)
+	var traffic_allocations = get_traffic_allocations(experiment_key, client.project_config.Experiments)
+	for i := 0; i < len(traffic_allocations); i++ {
+		current_end_of_range := traffic_allocations[i].EndOfRange
+		if bucketing_number <= uint32(current_end_of_range) {
+			return traffic_allocations[i].EntityId
+		}
+	}
+	return ""
+
+}

optimizely/optimizely.go

@@ -60,7 +60,8 @@ func (client *OptimizelyClient) Track(
 	// Set event_value if set and also append the revenue goal ID
 	if len(event_value) != 0 {
 		parameters.Add(REVENUE, event_value)
-		//parameters.Add(GOAL_ID, fmt.Sprintf("{%v},{%v}", goal_id, GetRevenueGoalFromProjectConfig())
+		//parameters.Add(GOAL_ID, fmt.Sprintf(
+		//"{%v},{%v}", goal_id, GetRevenueGoalFromProjectConfig())
 	}
 
 	// Dispatch event
@@ -82,6 +83,8 @@ func (client *OptimizelyClient) Activate(experiment_key string, user_id string,
 // GetVariation gets the variation where the visitor will be bucketed
 // Experiment_key: experiment which needs to be activated
 // User_id: ID for user
+// Returns: variation key representing the variation the user will be
+// bucketed into
 func (client *OptimizelyClient) GetVariation(experient_key string, user_id string) {
 
 }