Serializable service factory

gcloud-java-core/src/main/java/com/google/gcloud/BaseService.java

@@ -16,17 +16,26 @@
 
 package com.google.gcloud;
 
-public abstract class BaseService<OptionsT extends ServiceOptions<?, OptionsT>>
-    implements Service<OptionsT> {
+public abstract class BaseService<
+        OptionsT extends ServiceOptions<?, OptionsT>,
+        ServiceFactoryT extends ServiceFactory<?, OptionsT>>
+    implements Service<OptionsT, ServiceFactoryT> {
 
   private final OptionsT options;
+  private final ServiceFactoryT factory;
 
-  protected BaseService(OptionsT options) {
+  protected BaseService(OptionsT options, ServiceFactoryT factory) {
     this.options = options;
+    this.factory = factory;
   }
 
   @Override
   public OptionsT options() {
     return options;
   }
+
+  @Override
+  public ServiceFactoryT factory() {
+    return factory;
+  }
 }

gcloud-java-core/src/main/java/com/google/gcloud/Service.java

@@ -16,6 +16,9 @@
 
 package com.google.gcloud;
 
-public interface Service<OptionsT extends ServiceOptions<?, OptionsT>> {
+public interface Service<
+        OptionsT extends ServiceOptions<?, OptionsT>, 
+        ServiceFactoryT extends ServiceFactory<?, OptionsT>> {
   OptionsT options();
+  ServiceFactoryT factory();
 }

gcloud-java-core/src/main/java/com/google/gcloud/ServiceFactory.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2015 Google Inc. All Rights Reserved.
+ *
+ * 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.google.gcloud;
+
+import java.io.Serializable;
+
+public interface ServiceFactory<
+        ServiceT extends Service, 
+        OptionsT extends ServiceOptions<?, OptionsT>>
+    extends Serializable {
+
+  public ServiceT get(OptionsT options);
+
+}

gcloud-java-datastore/src/main/java/com/google/gcloud/datastore/Datastore.java

@@ -23,7 +23,8 @@
 /**
  * An interface for Google Cloud Datastore.
  */
-public interface Datastore extends Service<DatastoreOptions>, DatastoreReaderWriter {
+public interface Datastore extends Service<DatastoreOptions, DatastoreFactory>,
+    DatastoreReaderWriter {
 
   /**
    * Returns a new Datastore transaction.

gcloud-java-datastore/src/main/java/com/google/gcloud/datastore/DatastoreFactory.java

@@ -16,18 +16,29 @@
 
 package com.google.gcloud.datastore;
 
+import com.google.gcloud.ServiceFactory;
+import java.io.ObjectStreamException;
 
 /**
  * A base class for Datastore factories.
  */
-public abstract class DatastoreFactory {
+public abstract class DatastoreFactory implements ServiceFactory<Datastore, DatastoreOptions> {
+
+  private static final long serialVersionUID = 5037190305022535983L;
 
   private static final DatastoreFactory INSTANCE = new DatastoreFactory() {
-      @Override
-      public Datastore get(DatastoreOptions options) {
-        return new DatastoreImpl(options);
-      }
-    };
+
+    private static final long serialVersionUID = 5893914895344559491L;
+
+    @Override
+    public Datastore get(DatastoreOptions options) {
+      return new DatastoreImpl(options, this);
+    }
+
+    private Object readResolve() throws ObjectStreamException {
+      return INSTANCE;
+    }
+  };
 
   /**
    * Returns the default factory instance.
@@ -39,5 +50,6 @@ public static DatastoreFactory instance() {
   /**
    * Returns a {@code Datastore} service for the given options.
    */
+  @Override
   public abstract Datastore get(DatastoreOptions options);
 }

gcloud-java-datastore/src/main/java/com/google/gcloud/datastore/DatastoreImpl.java

@@ -43,7 +43,7 @@
 import java.util.concurrent.Callable;
 
 
-final class DatastoreImpl extends BaseService<DatastoreOptions>
+final class DatastoreImpl extends BaseService<DatastoreOptions, DatastoreFactory>
     implements Datastore {
 
   private static final Interceptor EXCEPTION_HANDLER_INTERCEPTOR =
@@ -72,8 +72,8 @@ public RetryResult beforeEval(Exception exception) {
   private final DatastoreRpc datastoreRpc;
   private final RetryParams retryParams;
 
-  DatastoreImpl(DatastoreOptions options) {
-    super(options);
+  DatastoreImpl(DatastoreOptions options, DatastoreFactory factory) {
+    super(options, factory);
     this.datastoreRpc = options.datastoreRpc();
     retryParams = MoreObjects.firstNonNull(options.retryParams(), RetryParams.noRetries());
   }

gcloud-java-datastore/src/test/java/com/google/gcloud/datastore/DatastoreTest.java

@@ -134,6 +134,11 @@ public void testGetOptions() {
     assertSame(options, datastore.options());
   }
 
+  @Test
+  public void testGetFactory() {
+    assertSame(DatastoreFactory.instance(), datastore.factory());
+  }
+
   @Test
   public void testNewTransactionCommit() {
     Transaction transaction = datastore.newTransaction();

gcloud-java-datastore/src/test/java/com/google/gcloud/datastore/SerializationTest.java

@@ -40,6 +40,7 @@
 
 public class SerializationTest {
 
+  private static final DatastoreFactory DATASTORE_FACTORY = DatastoreFactory.instance();
   private static final IncompleteKey INCOMPLETE_KEY1 =
       IncompleteKey.builder("ds", "k").ancestors(PathElement.of("p", 1)).build();
   private static final Key KEY1 = Key.builder("ds", "k", "n").build();
@@ -131,6 +132,13 @@ public class SerializationTest {
       .put(ValueType.RAW_VALUE, RAW_VALUE)
       .build();
 
+  @Test
+  public void testStorageFactory() throws Exception {
+    DatastoreFactory serializedCopy = serializeAndDeserialize(DATASTORE_FACTORY);
+    assertEquals(DATASTORE_FACTORY, serializedCopy);
+    assertEquals(DATASTORE_FACTORY.hashCode(), serializedCopy.hashCode());
+  }
+
   @Test
   public void testServiceOptions() throws Exception {
     DatastoreOptions options = DatastoreOptions.builder()

gcloud-java-storage/src/main/java/com/google/gcloud/storage/Storage.java

@@ -38,7 +38,7 @@
  *
  * @see <a href="https://cloud.google.com/storage/docs">Google Cloud Storage</a>
  */
-public interface Storage extends Service<StorageOptions> {
+public interface Storage extends Service<StorageOptions, StorageFactory> {
 
   enum PredefinedAcl {
     AUTHENTICATED_READ("authenticatedRead"),

gcloud-java-storage/src/main/java/com/google/gcloud/storage/StorageFactory.java

@@ -16,16 +16,27 @@
 
 package com.google.gcloud.storage;
 
+import com.google.gcloud.ServiceFactory;
+import java.io.ObjectStreamException;
 
 /**
  * A base class for Storage factories.
  */
-public abstract class StorageFactory {
+public abstract class StorageFactory implements ServiceFactory<Storage, StorageOptions> {
+
+  private static final long serialVersionUID = 1866883249985063753L;
 
   private static final StorageFactory INSTANCE = new StorageFactory() {
+
+    private static final long serialVersionUID = -7985210081064222485L;
+
     @Override
     public Storage get(StorageOptions options) {
-      return new StorageImpl(options);
+      return new StorageImpl(options, this);
+    }
+
+    private Object readResolve() throws ObjectStreamException {
+      return INSTANCE;
     }
   };
 
@@ -39,5 +50,6 @@ public static StorageFactory instance() {
   /**
    * Returns a {@code Storage} service for the given options.
    */
+  @Override
   public abstract Storage get(StorageOptions options);
 }

gcloud-java-storage/src/main/java/com/google/gcloud/storage/StorageImpl.java

@@ -64,7 +64,7 @@
 import java.util.Set;
 import java.util.concurrent.Callable;
 
-final class StorageImpl extends BaseService<StorageOptions> implements Storage {
+final class StorageImpl extends BaseService<StorageOptions, StorageFactory> implements Storage {
 
   private static final Interceptor EXCEPTION_HANDLER_INTERCEPTOR = new Interceptor() {
 
@@ -90,8 +90,8 @@ public RetryResult beforeEval(Exception exception) {
 
   private final StorageRpc storageRpc;
 
-  StorageImpl(StorageOptions options) {
-    super(options);
+  StorageImpl(StorageOptions options, StorageFactory factory) {
+    super(options, factory);
     storageRpc = options.storageRpc();
     // todo: configure timeouts - https://developers.google.com/api-client-library/java/google-api-java-client/errors
     // todo: provide rewrite - https://cloud.google.com/storage/docs/json_api/v1/objects/rewrite

gcloud-java-storage/src/test/java/com/google/gcloud/storage/SerializationTest.java

@@ -35,6 +35,7 @@
 
 public class SerializationTest {
 
+  private static final StorageFactory STORAGE_FACTORY = StorageFactory.instance();
   private static final Acl.Domain ACL_DOMAIN = new Acl.Domain("domain");
   private static final Acl.Group ACL_GROUP = new Acl.Group("group");
   private static final Acl.Project ACL_PROJECT_ = new Acl.Project(ProjectRole.VIEWERS, "pid");
@@ -65,6 +66,13 @@ public class SerializationTest {
   private static final Storage.BucketTargetOption BUCKET_TARGET_OPTIONS =
       Storage.BucketTargetOption.metagenerationNotMatch();
 
+  @Test
+  public void testStorageFactory() throws Exception {
+    StorageFactory serializedCopy = serializeAndDeserialize(STORAGE_FACTORY);
+    assertEquals(STORAGE_FACTORY, serializedCopy);
+    assertEquals(STORAGE_FACTORY.hashCode(), serializedCopy.hashCode());
+  }
+
   @Test
   public void testServiceOptions() throws Exception {
     StorageOptions options = StorageOptions.builder()