| // Protocol Buffers - Google's data interchange format |
| // Copyright 2008 Google Inc. All rights reserved. |
| // https://developers.google.com/protocol-buffers/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| 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>Starting with version 2.3.0, RPC implementations should not try to build |
| * on this, but should instead provide code generator plugins which generate |
| * code specific to the particular RPC implementation. This way the generated |
| * code can be more appropriate for the implementation in use and can avoid |
| * unnecessary layers of indirection. |
| * |
| * <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); |
| } |