Add data governance related functionality

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2018 ConfigCat
+Copyright (c) 2020 ConfigCat
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -18,7 +18,7 @@ ConfigCat is a <a href="https://configcat.com" target="_blank">hosted feature fl
 ### 1. Install the package
 *Gradle:*
 ```groovy
-implementation 'com.configcat:configcat-android-client:5.+'
+implementation 'com.configcat:configcat-android-client:6.+'
 ```
 
 ### 2. Go to <a href="https://app.configcat.com/sdkkey" target="_blank">Connect your application</a> tab to get your *SDK Key*:

gradle.properties

@@ -1 +1 @@
-version=5.1.1
+version=6.0.0

samples/android/app/build.gradle

@@ -32,7 +32,7 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation 'com.android.support:appcompat-v7:26.1.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
-    implementation group: "com.configcat", name: "configcat-android-client", version:"5.+"
+    implementation group: "com.configcat", name: "configcat-android-client", version:"6.+"
     implementation 'org.slf4j:slf4j-android:1.+'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'

src/main/java/com/configcat/AutoPollingMode.java

@@ -4,8 +4,8 @@
  * The auto polling mode configuration.
  */
 public class AutoPollingMode extends PollingMode {
-    private int autoPollRateInSeconds;
-    private ConfigurationChangeListener listener;
+    private final int autoPollRateInSeconds;
+    private final ConfigurationChangeListener listener;
 
     AutoPollingMode(int autoPollRateInSeconds, ConfigurationChangeListener listener) {
         if(autoPollRateInSeconds < 2)

src/main/java/com/configcat/AutoPollingPolicy.java

@@ -41,10 +41,10 @@ class AutoPollingPolicy extends RefreshPolicy {
         this.scheduler.scheduleAtFixedRate(() -> {
             try {
                 FetchResponse response = super.fetcher().getConfigurationJsonStringAsync().get();
-                String cached = super.cache().get();
+                String cached = super.readConfigCache();
                 String config = response.config();
                 if (response.isFetched() && !config.equals(cached)) {
-                    super.cache().set(config);
+                    super.writeConfigCache(config);
                     this.broadcastConfigurationChanged();
                 }
 
@@ -60,9 +60,9 @@ class AutoPollingPolicy extends RefreshPolicy {
     @Override
     public CompletableFuture<String> getConfigurationJsonAsync() {
         if(this.initFuture.isDone())
-            return CompletableFuture.completedFuture(super.cache().get());
+            return CompletableFuture.completedFuture(super.readConfigCache());
 
-        return this.initFuture.thenApplyAsync(v -> super.cache().get());
+        return this.initFuture.thenApplyAsync(v -> super.readConfigCache());
     }
 
     @Override

src/main/java/com/configcat/ConfigAttributes.java

@@ -1,5 +1,15 @@
 package com.configcat;
 
+class Config {
+    static final String Preferences = "p";
+    static final String Entries = "f";
+}
+
+class Preferences {
+    static final String BaseUrl = "u";
+    static final String Redirect = "r";
+}
+
 class Setting {
     static final String Value = "v";
     static final String Type = "t";

src/main/java/com/configcat/ConfigCache.java

@@ -1,61 +1,27 @@
 package com.configcat;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.io.Closeable;
-import java.io.IOException;
-
 /**
  * A cache API used to make custom cache implementations for {@link ConfigCatClient}.
  */
 public abstract class ConfigCache {
-    private static final Logger LOGGER = LoggerFactory.getLogger(ConfigCache.class);
-    private String inMemoryValue;
-
-    public String get() {
-        try {
-            return this.read();
-        } catch (Exception e) {
-            LOGGER.error("An error occurred during the cache read", e);
-            return this.inMemoryValue;
-        }
-    }
-
-    public void set(String value) {
-        try {
-            this.inMemoryValue = value;
-            this.write(value);
-        } catch (Exception e) {
-            LOGGER.error("An error occurred during the cache write", e);
-        }
-    }
-
-    /**
-     * Through this getter, the in-memory representation of the cached value can be accessed.
-     * When the underlying cache implementations is not able to load or store its value,
-     * this will represent the latest cached configuration.
-     *
-     * @return the cached value in memory.
-     */
-    public String inMemoryValue() { return this.inMemoryValue; }
-
     /**
      * Child classes has to implement this method, the {@link ConfigCatClient}
      * uses it to get the actual value from the cache.
      *
+     * @param key the key of the cache entry.
      * @return the cached configuration.
      * @throws Exception if unable to read the cache.
      */
-    protected abstract String read() throws Exception;
+    protected abstract String read(String key) throws Exception;
 
     /**
      * * Child classes has to implement this method, the {@link ConfigCatClient}
      * uses it to set the actual cached value.
      *
+     * @param key the key of the cache entry.
      * @param value the new value to cache.
      * @throws Exception if unable to save the value.
      */
-    protected abstract void write(String value) throws Exception;
+    protected abstract void write(String key, String value) throws Exception;
 }
 

src/main/java/com/configcat/ConfigCatClient.java

@@ -18,6 +18,9 @@
 public final class ConfigCatClient implements ConfigurationProvider {
     private static final Logger LOGGER = LoggerFactory.getLogger(ConfigCatClient.class);
     private static final ConfigurationParser parser = new ConfigurationParser();
+    private static final String BASE_URL_GLOBAL = "https://cdn-global.configcat.com";
+    private static final String BASE_URL_EU = "https://cdn-eu.configcat.com";
+
     private final RefreshPolicy refreshPolicy;
     private final int maxWaitTimeForSyncCallsInSeconds;
 
@@ -31,15 +34,21 @@ private ConfigCatClient(String sdkKey, Builder builder) throws IllegalArgumentEx
                 ? PollingModes.AutoPoll(60)
                 : builder.pollingMode;
 
+        boolean hasCustomBaseUrl = builder.baseUrl != null && !builder.baseUrl.isEmpty();
         ConfigFetcher fetcher = new ConfigFetcher(builder.httpClient == null
                 ? new OkHttpClient
                     .Builder()
                     .retryOnConnectionFailure(true)
                     .build()
                 : builder.httpClient,
                 sdkKey,
-                builder.baseUrl,
-                pollingMode);
+                !hasCustomBaseUrl
+                        ? builder.dataGovernance == DataGovernance.GLOBAL
+                        ? BASE_URL_GLOBAL
+                        : BASE_URL_EU
+                        : builder.baseUrl,
+                hasCustomBaseUrl,
+                pollingMode.getPollingIdentifier());
 
         ConfigCache cache = builder.cache == null
                 ? new InMemoryConfigCache()
@@ -300,6 +309,7 @@ public static class Builder {
         private int maxWaitTimeForSyncCallsInSeconds;
         private String baseUrl;
         private PollingMode pollingMode;
+        private DataGovernance dataGovernance = DataGovernance.GLOBAL;
 
         /**
          * Sets the underlying http client which will be used to fetch the latest configuration.
@@ -345,6 +355,17 @@ public Builder mode(PollingMode pollingMode) {
             return this;
         }
 
+        /**
+         * Sets the preferred data governance.
+         *
+         * @param dataGovernance the {@link DataGovernance} parameter.
+         * @return the builder.
+         */
+        public Builder dataGovernance(DataGovernance dataGovernance) {
+            this.dataGovernance = dataGovernance;
+            return this;
+        }
+
         /**
          * Sets the maximum time in seconds at most how long the synchronous calls
          * e.g. {@code client.getConfiguration(...)} have to be blocked.

src/main/java/com/configcat/ConfigFetcher.java

@@ -1,5 +1,7 @@
 package com.configcat;
 
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
 import okhttp3.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -10,25 +12,85 @@
 
 class ConfigFetcher implements Closeable {
     private static final Logger LOGGER = LoggerFactory.getLogger(ConfigFetcher.class);
+    private static final String CONFIG_JSON_NAME = "config_v5.json";
+
+    private final JsonParser parser = new JsonParser();
     private final OkHttpClient httpClient;
-    private final String url;
     private final String mode;
     private final String version;
+    private final String apiKey;
+    private final boolean urlIsCustom;
+    private String url;
     private String eTag;
 
-    ConfigFetcher(OkHttpClient httpClient, String sdkKey, PollingMode mode) {
-        this(httpClient, sdkKey, null, mode);
-    }
-
-    ConfigFetcher(OkHttpClient httpClient, String sdkKey, String baseUrl, PollingMode mode) {
-        baseUrl = baseUrl == null || baseUrl.isEmpty() ? "https://cdn.configcat.com" : baseUrl;
+    ConfigFetcher(OkHttpClient httpClient,
+                  String apiKey,
+                  String url,
+                  boolean urlIsCustom,
+                  String pollingIdentifier) {
+        this.apiKey = apiKey;
+        this.urlIsCustom = urlIsCustom;
+        this.url = url;
         this.httpClient = httpClient;
-        this.url = baseUrl + "/configuration-files/" + sdkKey + "/config_v4.json";
         this.version = this.getClass().getPackage().getImplementationVersion();
-        this.mode = mode.getPollingIdentifier();
+        this.mode = pollingIdentifier;
     }
 
     public CompletableFuture<FetchResponse> getConfigurationJsonStringAsync() {
+        return this.executeFetchAsync(2);
+    }
+
+    private CompletableFuture<FetchResponse> executeFetchAsync(int executionCount) {
+        return this.getResponseAsync().thenComposeAsync(fetchResponse -> {
+            if(!fetchResponse.isFetched()) {
+                return CompletableFuture.completedFuture(fetchResponse);
+            }
+            try {
+                JsonObject json = parser.parse(fetchResponse.config()).getAsJsonObject();
+                JsonObject preferences = json.getAsJsonObject(Config.Preferences);
+                if(preferences == null) {
+                    return CompletableFuture.completedFuture(fetchResponse);
+                }
+
+                String newUrl = preferences.get(Preferences.BaseUrl).getAsString();
+                if(newUrl == null || newUrl.isEmpty() || newUrl.equals(this.url)) {
+                    return CompletableFuture.completedFuture(fetchResponse);
+                }
+
+                int redirect = preferences.get(Preferences.Redirect).getAsInt();
+
+                // we have a custom url set and we didn't get a forced redirect
+                if(this.urlIsCustom && redirect != 2) {
+                    return CompletableFuture.completedFuture(fetchResponse);
+                }
+
+                this.url = newUrl;
+
+                if(redirect == 0) { // no redirect
+                    return CompletableFuture.completedFuture(fetchResponse);
+                } else { // redirect
+                    if (redirect == 1) {
+                        LOGGER.warn("Please check the data_governance parameter in the ConfigCatClient initialization. " +
+                                "It should match the settings provided in " +
+                                "https://app.configcat.com/organization/data-governance. " +
+                                "If you are not allowed to view this page, ask your Organization's Admins " +
+                                "for the correct setting.");
+                    }
+
+                    if(executionCount > 0) {
+                        return this.executeFetchAsync(executionCount - 1);
+                    }
+                }
+
+            } catch (Exception exception) {
+                LOGGER.error("Exception in ConfigFetcher.executeFetchAsync", exception);
+            }
+
+            return CompletableFuture.completedFuture(fetchResponse);
+        });
+    }
+
+    private CompletableFuture<FetchResponse> getResponseAsync() {
         Request request = this.getRequest();
 
         CompletableFuture<FetchResponse> future = new CompletableFuture<>();
@@ -54,7 +116,7 @@ public void onResponse(Call call, Response response) {
                         future.complete(new FetchResponse(FetchResponse.Status.FAILED, null));
                     }
                 } catch (Exception e) {
-                    LOGGER.error("Exception in ConfigFetcher.getConfigurationJsonStringAsync", e);
+                    LOGGER.error("Exception in ConfigFetcher.getResponseAsync", e);
                     future.complete(new FetchResponse(FetchResponse.Status.FAILED, null));
                 }
             }
@@ -79,13 +141,14 @@ public void close() throws IOException {
     }
 
     Request getRequest() {
+        String url = this.url + "/configuration-files/" + this.apiKey + "/" + CONFIG_JSON_NAME;
         Request.Builder builder =  new Request.Builder()
                 .addHeader("X-ConfigCat-UserAgent", "ConfigCat-Java/"+ this.mode + "-" + this.version);
 
         if(this.eTag != null)
             builder.addHeader("If-None-Match", this.eTag);
 
-        return builder.url(this.url).build();
+        return builder.url(url).build();
     }
 }
 

src/main/java/com/configcat/ConfigurationParser.java

@@ -44,7 +44,7 @@ public <T> T parseValue(Class<T> classOfT, String config, String key, User user)
     public String parseVariationId(String config, String key, User user) throws ParsingFailedException {
         try {
             LOGGER.info("Evaluating getVariationId("+key+").");
-            JsonObject root = this.parser.parse(config).getAsJsonObject();
+            JsonObject root = this.parseConfigSection(config);
 
             JsonObject node = root.getAsJsonObject(key);
             if(node == null) {
@@ -61,7 +61,7 @@ public String parseVariationId(String config, String key, User user) throws Pars
 
     public <T> Map.Entry<String, T> parseKeyValue(Class<T> classOfT, String config, String variationId) throws ParsingFailedException {
         try {
-            Set<Map.Entry<String, JsonElement>> root = this.parser.parse(config).getAsJsonObject().entrySet();
+            Set<Map.Entry<String, JsonElement>> root = this.parseConfigSection(config).entrySet();
             for (Map.Entry<String, JsonElement> node: root) {
                 String settingKey = node.getKey();
                 JsonObject setting = node.getValue().getAsJsonObject();
@@ -94,7 +94,7 @@ public <T> Map.Entry<String, T> parseKeyValue(Class<T> classOfT, String config,
 
     public Collection<String> getAllKeys(String config) throws ParsingFailedException {
         try {
-            JsonObject root = this.parser.parse(config).getAsJsonObject();
+            JsonObject root = this.parseConfigSection(config);
             return root.keySet();
 
         } catch (Exception e) {
@@ -105,7 +105,7 @@ public Collection<String> getAllKeys(String config) throws ParsingFailedExceptio
     private Object parseValueInternal(Class<?> classOfT, String config, String key, User user) throws ParsingFailedException, IllegalArgumentException {
         try {
             LOGGER.info("Evaluating getValue("+key+").");
-            JsonObject root = this.parser.parse(config).getAsJsonObject();
+            JsonObject root = this.parseConfigSection(config);
 
             JsonObject node = root.getAsJsonObject(key);
             if(node == null) {
@@ -130,4 +130,9 @@ else if (classOfT == Double.class || classOfT == double.class)
         else
             return element.getAsBoolean();
     }
+
+    private JsonObject parseConfigSection(String json) {
+        JsonObject root = this.parser.parse(json).getAsJsonObject();
+        return root.getAsJsonObject(Config.Entries);
+    }
 }

src/main/java/com/configcat/DataGovernance.java

@@ -0,0 +1,9 @@
+package com.configcat;
+
+/**
+ * The available values for data governance.
+ */
+public enum DataGovernance {
+    GLOBAL,
+    EU_ONLY
+}