feature flag parsing (#130)

* add variableIdToLiveVariableUsageInstanceMap to Varaitions.
* Add equality methods to LiveVariable and FeatureFlag models to improve ProjectConfigParsing evaluation.
*Update the v4 datafile with an empty top level "variables" array
* Added empty array passed in to ProjectConfig constructor in ValidProjectConfigV4.java
* ProjectConfigTestUtils now compare feature flags more effectively
* Add GsonParser for FeatureFlags
* Add org.Json FeatureFlag parsing
* Add JsonSimple FeatureFlag parsing
* add variableKeyToLiveVariableMap to FeatureFlag

Author: wangjoshuah

core-api/src/main/java/com/optimizely/ab/config/FeatureFlag.java

@@ -21,6 +21,7 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import java.util.List;
+import java.util.Map;
 
 /**
  * Represents a FeatureFlag definition at the project level
@@ -33,6 +34,7 @@ public class FeatureFlag implements IdKeyMapped{
     private final String layerId;
     private final List<String> experimentIds;
     private final List<LiveVariable> variables;
+    private final Map<String, LiveVariable> variableKeyToLiveVariableMap;
 
     @JsonCreator
     public FeatureFlag(@JsonProperty("id") String id,
@@ -45,6 +47,7 @@ public FeatureFlag(@JsonProperty("id") String id,
         this.layerId = layerId;
         this.experimentIds = experimentIds;
         this.variables = variables;
+        this.variableKeyToLiveVariableMap = ProjectConfigUtils.generateNameMapping(variables);
     }
 
     public String getId() {
@@ -67,6 +70,10 @@ public List<LiveVariable> getVariables() {
         return variables;
     }
 
+    public Map<String, LiveVariable> getVariableKeyToLiveVariableMap() {
+        return variableKeyToLiveVariableMap;
+    }
+
     @Override
     public String toString() {
         return "FeatureFlag{" +
@@ -75,6 +82,33 @@ public String toString() {
                 ", layerId='" + layerId + '\'' +
                 ", experimentIds=" + experimentIds +
                 ", variables=" + variables +
+                ", variableKeyToLiveVariableMap=" + variableKeyToLiveVariableMap +
                 '}';
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        FeatureFlag that = (FeatureFlag) o;
+
+        if (!id.equals(that.id)) return false;
+        if (!key.equals(that.key)) return false;
+        if (!layerId.equals(that.layerId)) return false;
+        if (!experimentIds.equals(that.experimentIds)) return false;
+        if (!variables.equals(that.variables)) return false;
+        return variableKeyToLiveVariableMap.equals(that.variableKeyToLiveVariableMap);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = id.hashCode();
+        result = 31 * result + key.hashCode();
+        result = 31 * result + layerId.hashCode();
+        result = 31 * result + experimentIds.hashCode();
+        result = 31 * result + variables.hashCode();
+        result = 31 * result + variableKeyToLiveVariableMap.hashCode();
+        return result;
+    }
 }

core-api/src/main/java/com/optimizely/ab/config/LiveVariable.java

@@ -22,6 +22,8 @@
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.google.gson.annotations.SerializedName;
 
+import javax.annotation.Nullable;
+
 /**
  * Represents a live variable definition at the project level
  */
@@ -100,7 +102,7 @@ public static VariableType fromString(String variableTypeString) {
     private final String key;
     private final String defaultValue;
     private final VariableType type;
-    private final VariableStatus status;
+    @Nullable private final VariableStatus status;
 
     @JsonCreator
     public LiveVariable(@JsonProperty("id") String id,
@@ -111,16 +113,11 @@ public LiveVariable(@JsonProperty("id") String id,
         this.id = id;
         this.key = key;
         this.defaultValue = defaultValue;
-        if (status == null) {
-            this.status = VariableStatus.ACTIVE;
-        }
-        else {
-            this.status = status;
-        }
+        this.status = status;
         this.type = type;
     }
 
-    public VariableStatus getStatus() {
+    public @Nullable VariableStatus getStatus() {
         return status;
     }
 
@@ -150,4 +147,28 @@ public String toString() {
                 ", status=" + status +
                 '}';
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        LiveVariable variable = (LiveVariable) o;
+
+        if (!id.equals(variable.id)) return false;
+        if (!key.equals(variable.key)) return false;
+        if (!defaultValue.equals(variable.defaultValue)) return false;
+        if (type != variable.type) return false;
+        return status == variable.status;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = id.hashCode();
+        result = 31 * result + key.hashCode();
+        result = 31 * result + defaultValue.hashCode();
+        result = 31 * result + type.hashCode();
+        result = 31 * result + status.hashCode();
+        return result;
+    }
 }

core-api/src/main/java/com/optimizely/ab/config/LiveVariableUsageInstance.java

@@ -24,7 +24,7 @@
  * Represents the value of a live variable for a variation
  */
 @JsonIgnoreProperties(ignoreUnknown = true)
-public class LiveVariableUsageInstance {
+public class LiveVariableUsageInstance implements IdMapped {
 
     private final String id;
     private final String value;

core-api/src/main/java/com/optimizely/ab/config/ProjectConfig.java

@@ -224,6 +224,10 @@ public List<Experiment> getExperimentsForEventKey(String eventKey) {
         return Collections.emptyList();
     }
 
+    public List<FeatureFlag> getFeatureFlags() {
+        return featureFlags;
+    }
+
     public List<Attribute> getAttributes() {
         return attributes;
     }

core-api/src/main/java/com/optimizely/ab/config/Variation.java

@@ -23,7 +23,9 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Represents the Optimizely Variation configuration.
@@ -36,6 +38,7 @@ public class Variation implements IdKeyMapped {
     private final String id;
     private final String key;
     private final List<LiveVariableUsageInstance> liveVariableUsageInstances;
+    private final Map<String, LiveVariableUsageInstance> variableIdToLiveVariableUsageInstanceMap;
 
     public Variation(String id, String key) {
         this(id, key, null);
@@ -47,7 +50,13 @@ public Variation(@JsonProperty("id") String id,
                      @JsonProperty("variables") List<LiveVariableUsageInstance> liveVariableUsageInstances) {
         this.id = id;
         this.key = key;
-        this.liveVariableUsageInstances = liveVariableUsageInstances;
+        if (liveVariableUsageInstances == null) {
+            this.liveVariableUsageInstances = Collections.emptyList();
+        }
+        else {
+            this.liveVariableUsageInstances = liveVariableUsageInstances;
+        }
+        this.variableIdToLiveVariableUsageInstanceMap = ProjectConfigUtils.generateIdMapping(this.liveVariableUsageInstances);
     }
 
     public @Nonnull String getId() {
@@ -62,6 +71,10 @@ public Variation(@JsonProperty("id") String id,
         return liveVariableUsageInstances;
     }
 
+    public Map<String, LiveVariableUsageInstance> getVariableIdToLiveVariableUsageInstanceMap() {
+        return variableIdToLiveVariableUsageInstanceMap;
+    }
+
     public boolean is(String otherKey) {
         return key.equals(otherKey);
     }

core-api/src/main/java/com/optimizely/ab/config/parser/FeatureFlagGsonDeserializer.java

@@ -0,0 +1,36 @@
+/**
+ *
+ *    Copyright 2017, Optimizely and contributors
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+package com.optimizely.ab.config.parser;
+
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import com.optimizely.ab.config.FeatureFlag;
+
+import java.lang.reflect.Type;
+
+public class FeatureFlagGsonDeserializer implements JsonDeserializer<FeatureFlag> {
+    @Override
+    public FeatureFlag deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
+            throws JsonParseException {
+
+        JsonObject jsonObject = json.getAsJsonObject();
+        return GsonHelpers.parseFeatureFlag(jsonObject, context);
+    }
+}

core-api/src/main/java/com/optimizely/ab/config/parser/GsonConfigParser.java

@@ -18,11 +18,11 @@
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
-
 import com.optimizely.ab.config.Experiment;
+import com.optimizely.ab.config.FeatureFlag;
 import com.optimizely.ab.config.Group;
-import com.optimizely.ab.config.audience.Audience;
 import com.optimizely.ab.config.ProjectConfig;
+import com.optimizely.ab.config.audience.Audience;
 
 import javax.annotation.Nonnull;
 
@@ -40,11 +40,12 @@ public ProjectConfig parseProjectConfig(@Nonnull String json) throws ConfigParse
             throw new ConfigParseException("Unable to parse empty json.");
         }
         Gson gson = new GsonBuilder()
-            .registerTypeAdapter(ProjectConfig.class, new ProjectConfigGsonDeserializer())
-            .registerTypeAdapter(Audience.class, new AudienceGsonDeserializer())
-            .registerTypeAdapter(Group.class, new GroupGsonDeserializer())
-            .registerTypeAdapter(Experiment.class, new ExperimentGsonDeserializer())
-            .create();
+                .registerTypeAdapter(Audience.class, new AudienceGsonDeserializer())
+                .registerTypeAdapter(Experiment.class, new ExperimentGsonDeserializer())
+                .registerTypeAdapter(FeatureFlag.class, new FeatureFlagGsonDeserializer())
+                .registerTypeAdapter(Group.class, new GroupGsonDeserializer())
+                .registerTypeAdapter(ProjectConfig.class, new ProjectConfigGsonDeserializer())
+                .create();
 
         try {
             return gson.fromJson(json, ProjectConfig.class);

core-api/src/main/java/com/optimizely/ab/config/parser/GsonHelpers.java

@@ -20,23 +20,30 @@
 import com.google.gson.JsonDeserializationContext;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
 import com.google.gson.reflect.TypeToken;
-
+import com.optimizely.ab.bucketing.DecisionService;
 import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.Experiment.ExperimentStatus;
+import com.optimizely.ab.config.FeatureFlag;
+import com.optimizely.ab.config.LiveVariable;
 import com.optimizely.ab.config.LiveVariableUsageInstance;
 import com.optimizely.ab.config.TrafficAllocation;
 import com.optimizely.ab.config.Variation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.lang.reflect.Type;
 import java.util.ArrayList;
-import java.util.List;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
 final class GsonHelpers {
 
+    private static final Logger logger = LoggerFactory.getLogger(DecisionService.class);
+
     private static List<Variation> parseVariations(JsonArray variationJson, JsonDeserializationContext context) {
         List<Variation> variations = new ArrayList<Variation>(variationJson.size());
         for (Object obj : variationJson) {
@@ -114,4 +121,35 @@ static Experiment parseExperiment(JsonObject experimentJson, String groupId, Jso
     static Experiment parseExperiment(JsonObject experimentJson, JsonDeserializationContext context) {
         return parseExperiment(experimentJson, "", context);
     }
+
+    static FeatureFlag parseFeatureFlag(JsonObject featureFlagJson, JsonDeserializationContext context) {
+        String id = featureFlagJson.get("id").getAsString();
+        String key = featureFlagJson.get("key").getAsString();
+        String layerId = featureFlagJson.get("layerId").getAsString();
+
+        JsonArray experimentIdsJson = featureFlagJson.getAsJsonArray("experimentIds");
+        List<String> experimentIds = new ArrayList<String>();
+        for (JsonElement experimentIdObj : experimentIdsJson) {
+            experimentIds.add(experimentIdObj.getAsString());
+        }
+
+        List<LiveVariable> liveVariables = new ArrayList<LiveVariable>();
+        try {
+            Type liveVariableType = new TypeToken<List<LiveVariable>>() {}.getType();
+            liveVariables = context.deserialize(featureFlagJson.getAsJsonArray("variables"),
+                    liveVariableType);
+        }
+        catch (JsonParseException exception) {
+            logger.warn("Unable to parse variables for feature \"" + key
+                    + "\". JsonParseException: " + exception);
+        }
+
+        return new FeatureFlag(
+                id,
+                key,
+                layerId,
+                experimentIds,
+                liveVariables
+        );
+    }
 }