Dropping Support for App Engine Java 7 Runtime (#153)

* Dropping support for GAE 7

* Removed GaeThreadFactory, GaeExecutorService and RevivingScheduledExecutor

* Removed the deprecated FirebaseCredential API

* Removing GAE java7 related APIs (GaeThreadFactory, RevivingScheduledExecutor)

* Removed GaePlatform implementation

* Added FirebaseScheduledExecutor

* Updated documentation

* Some minor nits from code reviews

* Calling super method in DefaultRunLoop executor

Author: hiranya911

CHANGELOG.md

@@ -2,6 +2,15 @@
 
 - [fixed] Improved error handling in FCM by mapping more server-side
   errors to client-side error codes.
+- [added] `FirebaseAuth`, `'FirebaseMessaging` and `FirebaseInstanceId`
+  interfaces now expose a set of blocking methods. Each operation has
+  blocking an asynchronous versions.
+- [changed] Removed the deprecated `FirebaseCredential` interface.
+- [changed] Removed the deprecated `Task` interface along with the
+  `com.google.firebase.tasks` package.
+- [changed] Dropped support for App Engine's Java 7 runtime. Developers
+  are advised to use the Admin SDK with Java 8 when deploying to App
+  Engine.
 
 # v5.9.0
 

src/main/java/com/google/firebase/FirebaseApp.java

@@ -19,7 +19,6 @@
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
-import static java.nio.charset.StandardCharsets.UTF_8;
 
 import com.google.api.client.googleapis.util.Utils;
 import com.google.api.client.json.JsonFactory;
@@ -35,14 +34,12 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
-import com.google.common.io.BaseEncoding;
 import com.google.firebase.internal.FirebaseAppStore;
+import com.google.firebase.internal.FirebaseScheduledExecutor;
 import com.google.firebase.internal.FirebaseService;
-import com.google.firebase.internal.GaeThreadFactory;
 import com.google.firebase.internal.ListenableFuture2ApiFuture;
 import com.google.firebase.internal.NonNull;
 import com.google.firebase.internal.Nullable;
-import com.google.firebase.internal.RevivingScheduledExecutor;
 
 import java.io.FileReader;
 import java.io.IOException;
@@ -252,19 +249,6 @@ static void clearInstancesForTest() {
     }
   }
 
-  /**
-   * Returns persistence key. Exists to support getting {@link FirebaseApp} persistence key after
-   * the app has been deleted.
-   */
-  static String getPersistenceKey(String name, FirebaseOptions options) {
-    return BaseEncoding.base64Url().omitPadding().encode(name.getBytes(UTF_8));
-  }
-
-  /** Use this key to store data per FirebaseApp. */
-  String getPersistenceKey() {
-    return FirebaseApp.getPersistenceKey(getName(), getOptions());
-  }
-
   private static List<String> getAllAppNames() {
     Set<String> allAppNames = new HashSet<>();
     synchronized (appsLock) {
@@ -328,10 +312,7 @@ String getProjectId() {
 
   @Override
   public boolean equals(Object o) {
-    if (!(o instanceof FirebaseApp)) {
-      return false;
-    }
-    return name.equals(((FirebaseApp) o).getName());
+    return o instanceof FirebaseApp && name.equals(((FirebaseApp) o).getName());
   }
 
   @Override
@@ -394,8 +375,8 @@ private ScheduledExecutorService ensureScheduledExecutorService() {
       synchronized (lock) {
         checkNotDeleted();
         if (scheduledExecutor == null) {
-          scheduledExecutor = new RevivingScheduledExecutor(threadManager.getThreadFactory(),
-              "firebase-scheduled-worker", GaeThreadFactory.isAvailable());
+          scheduledExecutor = new FirebaseScheduledExecutor(getThreadFactory(),
+              "firebase-scheduled-worker");
         }
       }
     }
@@ -472,7 +453,7 @@ static class TokenRefresher implements CredentialsChangedListener {
     }
 
     @Override
-    public final synchronized void onChanged(OAuth2Credentials credentials) throws IOException {
+    public final synchronized void onChanged(OAuth2Credentials credentials) {
       if (state.get() != State.STARTED) {
         return;
       }

src/main/java/com/google/firebase/ImplFirebaseTrampolines.java

@@ -47,14 +47,6 @@ public static boolean isDefaultApp(@NonNull FirebaseApp app) {
     return app.isDefaultApp();
   }
 
-  public static String getPersistenceKey(@NonNull FirebaseApp app) {
-    return app.getPersistenceKey();
-  }
-  
-  public static String getPersistenceKey(String name, FirebaseOptions options) {
-    return FirebaseApp.getPersistenceKey(name, options);
-  }
-
   public static <T extends FirebaseService> T getService(
       @NonNull FirebaseApp app, @NonNull String id, @NonNull Class<T> type) {
     return type.cast(app.getService(id));

src/main/java/com/google/firebase/database/connection/NettyWebSocketClient.java

@@ -5,8 +5,7 @@
 import static com.google.common.base.Preconditions.checkState;
 
 import com.google.common.base.Strings;
-import com.google.firebase.internal.GaeThreadFactory;
-import com.google.firebase.internal.RevivingScheduledExecutor;
+import com.google.firebase.internal.FirebaseScheduledExecutor;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
@@ -66,8 +65,8 @@ class NettyWebSocketClient implements WebsocketConnection.WSClient {
     this.uri = checkNotNull(uri, "uri must not be null");
     this.eventHandler = checkNotNull(eventHandler, "event handler must not be null");
     this.channelHandler = new WebSocketClientHandler(uri, userAgent, eventHandler);
-    this.executorService = new RevivingScheduledExecutor(
-        threadFactory, "firebase-websocket-worker", GaeThreadFactory.isAvailable());
+    this.executorService = new FirebaseScheduledExecutor(threadFactory,
+        "firebase-websocket-worker");
     this.group = new NioEventLoopGroup(1, this.executorService);
   }
 
@@ -103,7 +102,7 @@ protected void initChannel(SocketChannel ch) {
       channelFuture.addListener(
           new ChannelFutureListener() {
             @Override
-            public void operationComplete(ChannelFuture future) throws Exception {
+            public void operationComplete(ChannelFuture future) {
               if (!future.isSuccess()) {
                 eventHandler.onError(future.cause());
               }
@@ -169,7 +168,7 @@ public void channelInactive(ChannelHandlerContext context) {
     }
 
     @Override
-    public void channelRead0(ChannelHandlerContext context, Object message) throws Exception {
+    public void channelRead0(ChannelHandlerContext context, Object message) {
       Channel channel = context.channel();
       if (message instanceof FullHttpResponse) {
         checkState(!handshaker.isHandshakeComplete());

src/main/java/com/google/firebase/database/core/Context.java

@@ -38,17 +38,18 @@ public class Context {
   private static final long DEFAULT_CACHE_SIZE = 10 * 1024 * 1024;
 
   protected Logger logger;
-  protected EventTarget eventTarget;
-  protected AuthTokenProvider authTokenProvider;
-  protected RunLoop runLoop;
-  protected String persistenceKey;
-  protected List<String> loggedComponents;
-  protected String userAgent;
-  protected Logger.Level logLevel = Logger.Level.INFO;
-  protected boolean persistenceEnabled;
-  protected long cacheSize = DEFAULT_CACHE_SIZE;
-  protected FirebaseApp firebaseApp;
-  private PersistenceManager forcedPersistenceManager;
+  FirebaseApp firebaseApp;
+
+  EventTarget eventTarget;
+  AuthTokenProvider authTokenProvider;
+  RunLoop runLoop;
+  String persistenceKey;
+  List<String> loggedComponents;
+  Logger.Level logLevel = Logger.Level.INFO;
+  boolean persistenceEnabled;
+  long cacheSize = DEFAULT_CACHE_SIZE;
+
+  private String userAgent;
   private boolean frozen = false;
   private boolean stopped = false;
 
@@ -78,19 +79,11 @@ public void onError(String error) {
 
   private Platform getPlatform() {
     if (platform == null) {
-      if (GaePlatform.isActive()) {
-        platform = new GaePlatform(firebaseApp);
-      } else {
-        platform = new JvmPlatform(firebaseApp);
-      }
+      platform = new JvmPlatform(firebaseApp);
     }
     return platform;
   }
 
-  public boolean isFrozen() {
-    return frozen;
-  }
-
   public boolean isStopped() {
     return stopped;
   }
@@ -137,8 +130,8 @@ void stop() {
     }
   }
 
-  protected void assertUnfrozen() {
-    if (isFrozen()) {
+  void assertUnfrozen() {
+    if (frozen) {
       throw new DatabaseException(
           "Modifications to DatabaseConfig objects must occur before they are in use");
     }
@@ -168,10 +161,6 @@ public ConnectionContext getConnectionContext() {
   }
 
   PersistenceManager getPersistenceManager(String firebaseId) {
-    // TODO[persistence]: Create this once and store it.
-    if (forcedPersistenceManager != null) {
-      return forcedPersistenceManager;
-    }
     if (this.persistenceEnabled) {
       PersistenceManager cache = platform.createPersistenceManager(this, firebaseId);
       if (cache == null) {
@@ -193,11 +182,6 @@ public long getPersistenceCacheSizeBytes() {
     return this.cacheSize;
   }
 
-  // For testing
-  void forcePersistenceManager(PersistenceManager persistenceManager) {
-    this.forcedPersistenceManager = persistenceManager;
-  }
-
   public EventTarget getEventTarget() {
     return eventTarget;
   }
@@ -210,14 +194,6 @@ public String getUserAgent() {
     return userAgent;
   }
 
-  public String getPlatformVersion() {
-    return getPlatform().getPlatformVersion();
-  }
-
-  public String getSessionPersistenceKey() {
-    return this.persistenceKey;
-  }
-
   public AuthTokenProvider getAuthTokenProvider() {
     return this.authTokenProvider;
   }