1 files changed, 98 insertions, 0 deletions
diff --git a/java/src/main/java/com/google/protobuf/RpcController.java b/java/src/main/java/com/google/protobuf/RpcController.java
new file mode 100644
index 00000000..7495bb8a
--- /dev/null
+++ b/java/src/main/java/com/google/protobuf/RpcController.java
@@ -0,0 +1,98 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.
+// http://code.google.com/p/protobuf/
+//
+// 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.protobuf;
+
+/**
+ * <p>An {@code RpcController} mediates a single method call.  The primary
+ * purpose of the controller is to provide a way to manipulate settings
+ * specific to the RPC implementation and to find out about RPC-level errors.
+ *
+ * <p>The methods provided by the {@code RpcController} interface are intended
+ * to be a "least common denominator" set of features which we expect all
+ * implementations to support.  Specific implementations may provide more
+ * advanced features (e.g. deadline propagation).
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public interface RpcController {
+  // -----------------------------------------------------------------
+  // These calls may be made from the client side only.  Their results
+  // are undefined on the server side (may throw RuntimeExceptions).
+
+  /**
+   * Resets the RpcController to its initial state so that it may be reused in
+   * a new call.  This can be called from the client side only.  It must not
+   * be called while an RPC is in progress.
+   */
+  void reset();
+
+  /**
+   * After a call has finished, returns true if the call failed.  The possible
+   * reasons for failure depend on the RPC implementation.  {@code failed()}
+   * most only be called on the client side, and must not be called before a
+   * call has finished.
+   */
+  boolean failed();
+
+  /**
+   * If {@code failed()} is {@code true}, returns a human-readable description
+   * of the error.
+   */
+  String errorText();
+
+  /**
+   * Advises the RPC system that the caller desires that the RPC call be
+   * canceled.  The RPC system may cancel it immediately, may wait awhile and
+   * then cancel it, or may not even cancel the call at all.  If the call is
+   * canceled, the "done" callback will still be called and the RpcController
+   * will indicate that the call failed at that time.
+   */
+  void startCancel();
+
+  // -----------------------------------------------------------------
+  // These calls may be made from the server side only.  Their results
+  // are undefined on the client side (may throw RuntimeExceptions).
+
+  /**
+   * Causes {@code failed()} to return true on the client side.  {@code reason}
+   * will be incorporated into the message returned by {@code errorText()}.
+   * If you find you need to return machine-readable information about
+   * failures, you should incorporate it into your response protocol buffer
+   * and should NOT call {@code setFailed()}.
+   */
+  void setFailed(String reason);
+
+  /**
+   * If {@code true}, indicates that the client canceled the RPC, so the server
+   * may as well give up on replying to it.  This method must be called on the
+   * server side only.  The server should still call the final "done" callback.
+   */
+  boolean isCanceled();
+
+  /**
+   * Asks that the given callback be called when the RPC is canceled.  The
+   * parameter passed to the callback will always be {@code null}.  The
+   * callback will always be called exactly once.  If the RPC completes without
+   * being canceled, the callback will be called after completion.  If the RPC
+   * has already been canceled when NotifyOnCancel() is called, the callback
+   * will be called immediately.
+   *
+   * <p>{@code notifyOnCancel()} must be called no more than once per request.
+   * It must be called on the server side only.
+   */
+  void notifyOnCancel(RpcCallback<Object> callback);
+}