Migrate Java SDK to use V2 Randomization Endpoint (#8)

* Migrate SDK to RAC version 2

* bump version of pom

* don't log subject attributes

* remove matchesAnyRule function

Author: ploomiz

.gitignore

@@ -2,4 +2,4 @@
 target/
 out/
 src/test/resources/assignment-v2
-src/test/resources/rac-experiments.json
+src/test/resources/rac-experiments-v2.json

Makefile

@@ -34,7 +34,7 @@ testDataDir := src/test/resources/
 test-data: 
 	rm -rf $(testDataDir)
 	mkdir -p $(testDataDir)
-	gsutil cp gs://sdk-test-data/rac-experiments.json $(testDataDir)
+	gsutil cp gs://sdk-test-data/rac-experiments-v2.json $(testDataDir)
 	gsutil cp -r gs://sdk-test-data/assignment-v2 $(testDataDir)
 
 .PHONY: test

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>cloud.eppo</groupId>
     <artifactId>eppo-server-sdk</artifactId>
-    <version>1.0.2</version>
+    <version>1.1.0</version>
 
     <name>${project.groupId}:${project.artifactId}</name>
     <description>Eppo Server-Side SDK for Java</description>

src/main/java/com/eppo/sdk/EppoClient.java

@@ -1,12 +1,28 @@
 package com.eppo.sdk;
 
 import com.eppo.sdk.constants.Constants;
-import com.eppo.sdk.dto.*;
-import com.eppo.sdk.helpers.*;
+import com.eppo.sdk.dto.Allocation;
+import com.eppo.sdk.dto.AssignmentLogData;
+import com.eppo.sdk.dto.EppoClientConfig;
+import com.eppo.sdk.dto.EppoValue;
+import com.eppo.sdk.dto.ExperimentConfiguration;
+import com.eppo.sdk.dto.Rule;
+import com.eppo.sdk.dto.SubjectAttributes;
+import com.eppo.sdk.dto.Variation;
+import com.eppo.sdk.exception.EppoClientIsNotInitializedException;
+import com.eppo.sdk.exception.InvalidInputException;
+import com.eppo.sdk.helpers.AppDetails;
+import com.eppo.sdk.helpers.CacheHelper;
+import com.eppo.sdk.helpers.ConfigurationStore;
+import com.eppo.sdk.helpers.EppoHttpClient;
+import com.eppo.sdk.helpers.ExperimentConfigurationRequestor;
+import com.eppo.sdk.helpers.FetchConfigurationsTask;
+import com.eppo.sdk.helpers.InputValidator;
+import com.eppo.sdk.helpers.RuleValidator;
+import com.eppo.sdk.helpers.Shard;
 
 import lombok.extern.slf4j.Slf4j;
 
-import com.eppo.sdk.exception.*;
 import org.ehcache.Cache;
 
 import java.util.List;
@@ -35,55 +51,67 @@ private EppoClient(ConfigurationStore configurationStore, Timer poller, EppoClie
      * This function is used to get assignment Value
      *
      * @param subjectKey
-     * @param experimentKey
+     * @param flagKey
      * @param subjectAttributes
      * @return
      */
     public Optional<String> getAssignment(
             String subjectKey,
-            String experimentKey,
+            String flagKey,
             SubjectAttributes subjectAttributes
     ) {
         // Validate Input Values
         InputValidator.validateNotBlank(subjectKey, "Invalid argument: subjectKey cannot be blank");
-        InputValidator.validateNotBlank(experimentKey, "Invalid argument: experimentKey cannot be blank");
+        InputValidator.validateNotBlank(flagKey, "Invalid argument: flagKey cannot be blank");
 
         // Fetch Experiment Configuration
-        ExperimentConfiguration configuration = this.configurationStore.getExperimentConfiguration(experimentKey);
+        ExperimentConfiguration configuration = this.configurationStore.getExperimentConfiguration(flagKey);
         if (configuration == null) {
-            log.warn("No configuration found for experiment key: " + experimentKey);
+            log.warn("[Eppo SDK] No configuration found for key: " + flagKey);
             return Optional.empty();
         }
 
         // Check if subject has override variations
-        String subjectVariationOverride = this.getSubjectVariationOverride(subjectKey, configuration);
-        if (subjectVariationOverride != null) {
-            return Optional.of(subjectVariationOverride);
+        EppoValue subjectVariationOverride = this.getSubjectVariationOverride(subjectKey, configuration);
+        if (!subjectVariationOverride.isNull()) {
+            return Optional.of(subjectVariationOverride.stringValue());
+        }
+
+        // Check if disabled
+        if (!configuration.isEnabled()) {
+            log.info("[Eppo SDK] No assigned variation because the experiment or feature flag {} is disabled", flagKey);
+            return Optional.empty();
         }
 
-        // If disabled or not in Experiment Sampler or Rules not satisfied return empty string
-        if (!configuration.enabled ||
-                !this.isInExperimentSample(subjectKey, experimentKey, configuration) ||
-                !this.subjectAttributesSatisfyRules(subjectAttributes, configuration.rules)
-        ) {
+        // Find matched rule
+        Optional<Rule> rule = RuleValidator.findMatchingRule(subjectAttributes, configuration.getRules());
+        if (rule.isEmpty()) {
+            log.info("[Eppo SDK] No assigned variation. The subject attributes did not match any targeting rules");
+            return Optional.empty();
+        }
+
+        // Check if in experiment sample
+        Allocation allocation = configuration.getAllocation(rule.get().getAllocationKey());
+        if (!this.isInExperimentSample(subjectKey, flagKey, configuration.getSubjectShards(), allocation.getPercentExposure())) {
+            log.info("[Eppo SDK] No assigned variation. The subject is not part of the sample population");
             return Optional.empty();
         }
 
         // Get assigned variation
-        Variation assignedVariation = this.getAssignedVariation(subjectKey, experimentKey, configuration);
+        Variation assignedVariation = this.getAssignedVariation(subjectKey, flagKey, configuration.getSubjectShards(), allocation.getVariations());
 
         try {
             this.eppoClientConfig.getAssignmentLogger()
                 .logAssignment(new AssignmentLogData(
-                        experimentKey,
-                        assignedVariation.name,
+                        flagKey,
+                        assignedVariation.getValue().stringValue(),
                         subjectKey,
                         subjectAttributes
                 ));
         } catch (Exception e){
             // Ignore Exception
         }
-        return Optional.of(assignedVariation.name);
+        return Optional.of(assignedVariation.getValue().stringValue());
     }
 
     /**
@@ -108,11 +136,9 @@ public Optional<String> getAssignment(String subjectKey, String experimentKey) {
     private boolean isInExperimentSample(
             String subjectKey,
             String experimentKey,
-            ExperimentConfiguration experimentConfiguration
+            int subjectShards,
+            float percentageExposure
     ) {
-        int subjectShards = experimentConfiguration.subjectShards;
-        float percentageExposure = experimentConfiguration.percentExposure;
-
         int shard = Shard.getShard("exposure-" + subjectKey + "-" + experimentKey, subjectShards);
         return shard <= percentageExposure * subjectShards;
     }
@@ -128,13 +154,13 @@ private boolean isInExperimentSample(
     private Variation getAssignedVariation(
             String subjectKey,
             String experimentKey,
-            ExperimentConfiguration experimentConfiguration
+            int subjectShards,
+            List<Variation> variations
     ) {
-        int subjectShards = experimentConfiguration.subjectShards;
         int shard = Shard.getShard("assignment-" + subjectKey + "-" + experimentKey, subjectShards);
 
-        Optional<Variation> variation = experimentConfiguration.variations.stream()
-                .filter(config -> Shard.isShardInRange(shard, config.shardRange))
+        Optional<Variation> variation = variations.stream()
+                .filter(config -> Shard.isShardInRange(shard, config.getShardRange()))
                 .findFirst();
 
         return variation.get();
@@ -147,30 +173,12 @@ private Variation getAssignedVariation(
      * @param experimentConfiguration
      * @return
      */
-    private String getSubjectVariationOverride(
+    private EppoValue getSubjectVariationOverride(
             String subjectKey,
             ExperimentConfiguration experimentConfiguration
     ) {
         String hexedSubjectKey = Shard.getHex(subjectKey);
-        return experimentConfiguration.overrides.getOrDefault(hexedSubjectKey, null);
-    }
-
-    /**
-     * This function is used to test if subject attributes are satisfying rules or not
-     *
-     * @param subjectAttributes
-     * @param rules
-     * @return
-     * @throws Exception
-     */
-    private boolean subjectAttributesSatisfyRules(
-            SubjectAttributes subjectAttributes,
-            List<Rule> rules
-    ) {
-        if (rules.size() == 0) {
-            return true;
-        }
-        return RuleValidator.matchesAnyRule(subjectAttributes, rules);
+        return experimentConfiguration.getOverrides().getOrDefault(hexedSubjectKey, new EppoValue());
     }
 
     /***

src/main/java/com/eppo/sdk/constants/Constants.java

@@ -31,7 +31,7 @@ public class Constants {
     /**
      * RAC settings
      */
-    public static final String RAC_ENDPOINT = "/randomized_assignment/config";
+    public static final String RAC_ENDPOINT = "/randomized_assignment/v2/config";
 
 
     /**

src/main/java/com/eppo/sdk/dto/Allocation.java

@@ -0,0 +1,11 @@
+package com.eppo.sdk.dto;
+
+import java.util.List;
+
+import lombok.Data;
+
+@Data
+public class Allocation {
+  private float percentExposure;
+  private List<Variation> variations;
+}

src/main/java/com/eppo/sdk/dto/ExperimentConfiguration.java

@@ -3,22 +3,21 @@
 import java.util.List;
 import java.util.Map;
 
+import lombok.Data;
+
 /**
  * Experiment Configuration Class
  */
+@Data
 public class ExperimentConfiguration {
-    public String name;
-    public boolean enabled;
-    public int subjectShards;
-    public float percentExposure;
-    public List<Variation> variations;
-    public Map<String, String> overrides;
-    public List<Rule> rules;
+    private String name;
+    private boolean enabled;
+    private int subjectShards;
+    private Map<String, EppoValue> overrides;
+    private Map<String, Allocation> allocations;
+    private List<Rule> rules;
 
-    @Override
-    public String toString() {
-        return "[Name: " + name + " | Enabled: " + enabled + " | SubjectShards: " +
-                subjectShards + " | PercentExposure: " + percentExposure + " | Variations: " +
-                variations.toString() + " | Overrides: " + overrides.toString() + " | Rules: " + rules.toString() +  "]";
+    public Allocation getAllocation(String allocationKey) {
+        return getAllocations().get(allocationKey);
     }
 }

src/main/java/com/eppo/sdk/dto/ExperimentConfigurationResponse.java

@@ -2,14 +2,12 @@
 
 import java.util.Map;
 
+import lombok.Data;
+
 /**
  * Experiment Configuration Response Class
  */
+@Data
 public class ExperimentConfigurationResponse {
-    public Map<String, ExperimentConfiguration> experiments;
-
-    @Override
-    public String toString() {
-       return "[Experiments: " + experiments.toString() + "]";
-    }
+    private Map<String, ExperimentConfiguration> flags;
 }

src/main/java/com/eppo/sdk/dto/Rule.java

@@ -2,14 +2,13 @@
 
 import java.util.List;
 
+import lombok.Data;
+
 /**
  * Rule Class
  */
+@Data
 public class Rule {
-    public List<Condition> conditions;
-
-    @Override
-    public String toString() {
-        return "[Conditions: " + conditions + "]";
-    }
+    private String allocationKey;
+    private List<Condition> conditions;
 }

src/main/java/com/eppo/sdk/dto/Variation.java

@@ -1,14 +1,12 @@
 package com.eppo.sdk.dto;
 
+import lombok.Data;
+
 /**
  * Experiment's Variation Class
  */
+@Data
 public class Variation {
-    public String name;
-    public ShardRange shardRange;
-
-    @Override
-    public String toString() {
-        return "[Name: " + name + "| ShareRange: " + shardRange.toString() + "]";
-    }
+    private EppoValue value;
+    private ShardRange shardRange;
 }