Simplified the internals. Removed DnsBatch.Request.

Author: mderka

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

@@ -17,13 +17,13 @@
 package com.google.gcloud;
 
 /**
- * The class that holds a single result of a batch call.
+ * this class holds a single result of a batch call.
  */
-public interface BatchResult<T, E extends Throwable> {
+public interface BatchResult<T, E extends BaseServiceException> {
 
   /**
    * Returns {@code true} if the batch has been submitted and the result is available, and {@code
-   * false} otherwise
+   * false} otherwise.
    */
   boolean submitted();
 
@@ -34,4 +34,24 @@ public interface BatchResult<T, E extends Throwable> {
    * @throws E if an error occured when processing this request
    */
   T get() throws E;
+
+  /**
+   * Registers a callback for the batch operation.
+   */
+  void notify(Callback<T,E> callback);
+
+  /**
+   * An interface for the batch callbacks.
+   */
+  interface Callback<T,E> {
+    /**
+     * The method to be called when the batched operation succeeds.
+     */
+    void success(T result);
+
+    /**
+     * The method to be called when the batched operation fails.
+     */
+    void error(E exception);
+  }
 }

gcloud-java-dns/src/main/java/com/google/gcloud/dns/Dns.java

@@ -535,10 +535,7 @@ ChangeRequest getChangeRequest(String zoneName, String changeRequestId,
   Page<ChangeRequest> listChangeRequests(String zoneName, ChangeRequestListOption... options);
 
   /**
-   * Initiates a new empty batch ready to be populated with service calls, which will use this
-   * {@code Dns} instance when submitted for processing to Google Cloud DNS.
+   * Initiates a new empty batch ready to be populated with service calls.
    */
   DnsBatch batch();
-
-  void submitBatch(DnsBatch batch);
 }

gcloud-java-dns/src/main/java/com/google/gcloud/dns/DnsBatch.java

@@ -16,190 +16,92 @@
 
 package com.google.gcloud.dns;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.api.client.googleapis.batch.BatchRequest;
+import com.google.api.client.googleapis.batch.json.JsonBatchCallback;
+import com.google.api.client.googleapis.json.GoogleJsonError;
+import com.google.api.client.http.HttpHeaders;
+import com.google.api.services.dns.model.ManagedZone;
+import com.google.api.services.dns.model.ManagedZonesListResponse;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Maps;
 import com.google.gcloud.Page;
+import com.google.gcloud.PageImpl;
+import com.google.gcloud.dns.spi.DnsRpc;
 
-import java.util.LinkedList;
+import java.io.IOException;
 import java.util.List;
+import java.util.Map;
 
 /**
  * A batch of operations to be submitted to Google Cloud DNS using a single HTTP request.
  */
 public class DnsBatch {
 
-  private List<Request> requests = new LinkedList<>();
-  private Dns dns;
+  private final BatchRequest batch;
+  private transient DnsRpc dnsRpc;
+  private final DnsOptions options;
 
-  /**
-   * An operation to be submitted to Google Cloud DNS within this batch. Only an subset of the class
-   * attributes appropriate for the represented operation is initialized. Refer to the class method
-   * and attribute documentation for the specific fields.
-   */
-  public static class Request {
-
-    private final String zoneName;
-    private final String changeId;
-    private final ChangeRequest changeRequest;
-    private final ZoneInfo zoneInfo;
-    private final Operation operation;
-    private final AbstractOption[] options;
-    private final DnsBatchResult result;
-
-    private Request(RequestBuilder builder) {
-      this.zoneName = builder.zoneName;
-      this.changeId = builder.changeId;
-      this.changeRequest = builder.changeRequest;
-      this.zoneInfo = builder.zoneInfo;
-      this.operation = builder.operation;
-      this.options = builder.options;
-      this.result = builder.result;
-    }
-
-    private static RequestBuilder builder(Operation operation, DnsBatchResult result,
-        AbstractOption... options) {
-      return new RequestBuilder(operation, result, options);
-    }
-
-    /**
-     * Returns the name of the zone to which the operation is applied. This field is initialized for
-     * zone create, get and delete operation, and listing DNS records and changes within a zone.
-     * Returns {@code null} in other cases.
-     */
-    public String zoneName() {
-      return zoneName;
-    }
-
-    /**
-     * Returns the id of the change request which is being retrieved. Getting a change request is
-     * the only operation when this attribute is initialized. The method returns {@code null} in the
-     * remaining cases.
-     */
-    public String changeId() {
-      return changeId;
-    }
-
-    /**
-     * Returns the change request which is being created. Creating a change request is the only
-     * operation when this attribute is initialized. The method returns {@code null} in the
-     * remaining cases.
-     */
-    public ChangeRequest changeRequest() {
-      return changeRequest;
-    }
-
-    /**
-     * Returns the zone which is being created. Creating a zone is the only operation when this
-     * attribute is initialized. The method returns {@code null} in the remaining cases.
-     */
-    public ZoneInfo zoneInfo() {
-      return zoneInfo;
-    }
-
-    /**
-     * Returns the type of the operation represented by this {@link DnsBatch.Request}. This field is
-     * always initialized.
-     */
-    public Operation operation() {
-      return operation;
-    }
-
-    /**
-     * Returns options provided to the operation. Returns an empty array if no options were
-     * provided.
-     */
-    public AbstractOption[] options() {
-      return options == null ? new AbstractOption[0] : options;
-    }
-
-    DnsBatchResult result() {
-      return result;
-    }
-  }
-
-  static class RequestBuilder {
-    private final AbstractOption[] options;
-    private String zoneName;
-    private String changeId;
-    private ChangeRequest changeRequest;
-    private ZoneInfo zoneInfo;
-    private final Operation operation;
-    private final DnsBatchResult result;
-
-    RequestBuilder(Operation operation, DnsBatchResult result, AbstractOption... options) {
-      this.operation = operation;
-      this.options = options;
-      this.result = result;
-    }
-
-    RequestBuilder zoneName(String zoneName) {
-      this.zoneName = zoneName;
-      return this;
-    }
-
-    RequestBuilder changeId(String changeId) {
-      this.changeId = changeId;
-      return this;
-    }
-
-    RequestBuilder changeRequest(ChangeRequest changeRequest) {
-      this.changeRequest = changeRequest;
-      return this;
-    }
-
-    RequestBuilder zoneInfo(ZoneInfo zoneInfo) {
-      this.zoneInfo = zoneInfo;
-      return this;
-    }
-
-    Request build() {
-      return new Request(this);
-    }
+  DnsBatch(DnsOptions options) {
+    this.options = options;
+    this.dnsRpc = options.rpc();
+    this.batch = dnsRpc.createBatch();
   }
 
   /**
-   * Represents the type of the batch operation.
-   */
-  public enum Operation {
-    CREATE_ZONE,
-    DELETE_ZONE,
-    GET_ZONE,
-    LIST_ZONES,
-    APPLY_CHANGE_REQUEST,
-    GET_CHANGE_REQUEST,
-    LIST_CHANGES_REQUESTS,
-    LIST_DNS_RECORDS
-  }
-
-  DnsBatch(Dns dns) {
-    this.dns = dns;
-  }
-
-  public Dns service() {
-    return dns;
-  }
-
-  List<Request> requests() {
-    return requests;
-  }
-
-  /**
-   * Adds a {@code DnsBatch.Request} representing the list zones operation to this batch. The
+   * Adds a request representing the list zones operation to this batch. The
    * request will not have initialized any fields except for the operation type and options (if
    * provided). The {@code options} can be used to restrict the fields returned or provide page size
    * limits in the same way as for {@link Dns#listZones(Dns.ZoneListOption...)}.
    */
   public DnsBatchResult<Page<Zone>> listZones(Dns.ZoneListOption... options) {
     DnsBatchResult<Page<Zone>> result = new DnsBatchResult<>();
-    Request request = Request.builder(Operation.LIST_ZONES, result, options).build();
-    requests.add(request);
+    final Map<DnsRpc.Option, ?> optionMap = optionMap(options);
+    JsonBatchCallback callback = listZonesCallback(this.options, result, optionMap);
+    dnsRpc.prepareListZones(this.batch, callback, optionMap);
     return result;
   }
 
-  // todo(mderka) add the rest of the operations
-
   /**
    * Submits this batch for processing using a single HTTP request.
    */
   public void submit() {
-    dns.submitBatch(this);
+    dnsRpc.submitBatch(batch);
+  }
+
+  // todo(mderka) make methods to prepare other callbacks
+  private JsonBatchCallback listZonesCallback(final DnsOptions serviceOptions,
+      final DnsBatchResult result, final Map<DnsRpc.Option, ?> optionMap) {
+    JsonBatchCallback callback = new JsonBatchCallback<ManagedZonesListResponse>() {
+      @Override
+      public void onSuccess(ManagedZonesListResponse response, HttpHeaders httpHeaders)
+          throws IOException {
+        List<ManagedZone> zones = response.getManagedZones();
+        Page<Zone> zonePage = new PageImpl<>(
+            new DnsImpl.ZonePageFetcher(options, response.getNextPageToken(), optionMap),
+            response.getNextPageToken(), zones == null ? ImmutableList.<Zone>of()
+            : Iterables.transform(zones, DnsImpl.pbToZoneFunction(serviceOptions)));
+        result.success(zonePage);
+      }
+
+      @Override
+      public void onFailure(GoogleJsonError googleJsonError, HttpHeaders httpHeaders)
+          throws IOException {
+        result.error(new DnsException(googleJsonError));
+      }
+    };
+    return callback;
+  }
+
+  private Map<DnsRpc.Option, ?> optionMap(AbstractOption... options) {
+    Map<DnsRpc.Option, Object> temp = Maps.newEnumMap(DnsRpc.Option.class);
+    for (AbstractOption option : options) {
+      Object prev = temp.put(option.rpcOption(), option.value());
+      checkArgument(prev == null, "Duplicate option %s", option);
+    }
+    return ImmutableMap.copyOf(temp);
   }
-}
+}

gcloud-java-dns/src/main/java/com/google/gcloud/dns/DnsBatchResult.java

@@ -30,15 +30,19 @@ public T get() throws DnsException {
     return result;
   }
 
-  void result(T result) {
-    this.result = result;
+  @Override
+  public void notify(Callback<T, DnsException> callback) {
+    // todo(mderka) implement
+    throw new UnsupportedOperationException("Not implemented yet");
   }
 
   void error(DnsException error) {
     this.error = error;
+    this.submitted = true;
   }
 
-  void submit() {
+  void success(T result) {
+    this.result = result;
     this.submitted = true;
   }
 }