(feat): Implement default ProjectConfigManager. (#287)

* Extract ProjectConfig interface and create DatafileProjectConfig.
* Create ProjectConfigManager and refactor for dynamic ProjectConfig updates.
* Add PollingProjectConfigManager implementation.
* Add Apache HttpClient implementation of ProjectConfigManager.
* Move forced variations mapping into DecisionService.
* Add ability to block execution until ProjectConfig resolves.

Author: Mike Davis

core-api/src/jmh/java/com/optimizely/ab/config/parser/JacksonConfigParserBenchmark.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2018, Optimizely and contributors
+ *    Copyright 2018-2019 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.
@@ -17,7 +17,7 @@
 package com.optimizely.ab.config.parser;
 
 import com.optimizely.ab.config.ProjectConfig;
-import com.optimizely.ab.config.ProjectConfigTestUtils;
+import com.optimizely.ab.config.DatafileProjectConfigTestUtils;
 import org.openjdk.jmh.annotations.*;
 
 import java.io.IOException;
@@ -38,9 +38,9 @@ public class JacksonConfigParserBenchmark {
     @Setup
     public void setUp() throws IOException {
         parser = new JacksonConfigParser();
-        jsonV2 = ProjectConfigTestUtils.validConfigJsonV2();
-        jsonV3 = ProjectConfigTestUtils.validConfigJsonV3();
-        jsonV4 = ProjectConfigTestUtils.validConfigJsonV4();
+        jsonV2 = DatafileProjectConfigTestUtils.validConfigJsonV2();
+        jsonV3 = DatafileProjectConfigTestUtils.validConfigJsonV3();
+        jsonV4 = DatafileProjectConfigTestUtils.validConfigJsonV4();
     }
 
     @Benchmark

core-api/src/main/java/com/optimizely/ab/Optimizely.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2017, 2019 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.
@@ -16,8 +16,8 @@
  */
 package com.optimizely.ab;
 
-import com.optimizely.ab.config.EventType;
 import com.optimizely.ab.config.ProjectConfig;
+import com.optimizely.ab.config.EventType;
 
 /**
  * Exception thrown when attempting to use/refer to an {@link EventType} that isn't present in the current

core-api/src/main/java/com/optimizely/ab/UnknownEventTypeException.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2016-2017, Optimizely and contributors
+ *    Copyright 2016-2017, 2019 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.
@@ -16,8 +16,8 @@
  */
 package com.optimizely.ab;
 
-import com.optimizely.ab.config.Experiment;
 import com.optimizely.ab.config.ProjectConfig;
+import com.optimizely.ab.config.Experiment;
 
 /**
  * Exception thrown when attempting to use/refer to an {@link Experiment} that isn't present in the current

core-api/src/main/java/com/optimizely/ab/UnknownExperimentException.java

@@ -36,15 +36,13 @@
  * identifier.
  * <p>
  * The user identifier <i>must</i> be provided in the first data argument passed to
- * {@link #bucket(Experiment, String)} and <i>must</i> be non-null and non-empty.
+ * {@link #bucket(Experiment, String, ProjectConfig)} and <i>must</i> be non-null and non-empty.
  *
  * @see <a href="https://en.wikipedia.org/wiki/MurmurHash">MurmurHash</a>
  */
 @Immutable
 public class Bucketer {
 
-    private final ProjectConfig projectConfig;
-
     private static final Logger logger = LoggerFactory.getLogger(Bucketer.class);
 
     private static final int MURMUR_HASH_SEED = 1;
@@ -55,10 +53,6 @@ public class Bucketer {
     @VisibleForTesting
     static final int MAX_TRAFFIC_VALUE = 10000;
 
-    public Bucketer(ProjectConfig projectConfig) {
-        this.projectConfig = projectConfig;
-    }
-
     private String bucketToEntity(int bucketValue, List<TrafficAllocation> trafficAllocations) {
         int currentEndOfRange;
         for (TrafficAllocation currAllocation : trafficAllocations) {
@@ -76,7 +70,8 @@ private String bucketToEntity(int bucketValue, List<TrafficAllocation> trafficAl
     }
 
     private Experiment bucketToExperiment(@Nonnull Group group,
-                                          @Nonnull String bucketingId) {
+                                          @Nonnull String bucketingId,
+                                          @Nonnull ProjectConfig projectConfig) {
         // "salt" the bucket id using the group id
         String bucketKey = bucketingId + group.getId();
 
@@ -132,15 +127,16 @@ private Variation bucketToVariation(@Nonnull Experiment experiment,
      */
     @Nullable
     public Variation bucket(@Nonnull Experiment experiment,
-                            @Nonnull String bucketingId) {
+                            @Nonnull String bucketingId,
+                            @Nonnull ProjectConfig projectConfig) {
         // ---------- Bucket User ----------
         String groupId = experiment.getGroupId();
         // check whether the experiment belongs to a group
         if (!groupId.isEmpty()) {
             Group experimentGroup = projectConfig.getGroupIdMapping().get(groupId);
             // bucket to an experiment only if group entities are to be mutually exclusive
             if (experimentGroup.getPolicy().equals(Group.RANDOM_POLICY)) {
-                Experiment bucketedExperiment = bucketToExperiment(experimentGroup, bucketingId);
+                Experiment bucketedExperiment = bucketToExperiment(experimentGroup, bucketingId, projectConfig);
                 if (bucketedExperiment == null) {
                     logger.info("User with bucketingId \"{}\" is not in any experiment of group {}.", bucketingId, experimentGroup.getId());
                     return null;