| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| module thrift.protocol.processor; |
| |
| // Use selective import once DMD @@BUG314@@ is fixed. |
| import std.variant /+ : Variant +/; |
| import thrift.protocol.base; |
| import thrift.transport.base; |
| |
| /** |
| * A processor is a generic object which operates upon an input stream and |
| * writes to some output stream. |
| * |
| * The definition of this object is loose, though the typical case is for some |
| * sort of server that either generates responses to an input stream or |
| * forwards data from one pipe onto another. |
| * |
| * An implementation can optionally allow one or more TProcessorEventHandlers |
| * to be attached, providing an interface to hook custom code into the |
| * handling process, which can be used e.g. for gathering statistics. |
| */ |
| interface TProcessor { |
| /// |
| bool process(TProtocol iprot, TProtocol oprot, |
| Variant connectionContext = Variant() |
| ) in { |
| assert(iprot); |
| assert(oprot); |
| } |
| |
| /// |
| final bool process(TProtocol prot, Variant connectionContext = Variant()) { |
| return process(prot, prot, connectionContext); |
| } |
| } |
| |
| /** |
| * Handles events from a processor. |
| */ |
| interface TProcessorEventHandler { |
| /** |
| * Called before calling other callback methods. |
| * |
| * Expected to return some sort of »call context«, which is passed to all |
| * other callbacks for that function invocation. |
| */ |
| Variant createContext(string methodName, Variant connectionContext); |
| |
| /** |
| * Called when handling the method associated with a context has been |
| * finished – can be used to perform clean up work. |
| */ |
| void deleteContext(Variant callContext, string methodName); |
| |
| /** |
| * Called before reading arguments. |
| */ |
| void preRead(Variant callContext, string methodName); |
| |
| /** |
| * Called between reading arguments and calling the handler. |
| */ |
| void postRead(Variant callContext, string methodName); |
| |
| /** |
| * Called between calling the handler and writing the response. |
| */ |
| void preWrite(Variant callContext, string methodName); |
| |
| /** |
| * Called after writing the response. |
| */ |
| void postWrite(Variant callContext, string methodName); |
| |
| /** |
| * Called when handling a one-way function call is completed successfully. |
| */ |
| void onewayComplete(Variant callContext, string methodName); |
| |
| /** |
| * Called if the handler throws an undeclared exception. |
| */ |
| void handlerError(Variant callContext, string methodName, Exception e); |
| } |
| |
| struct TConnectionInfo { |
| /// The input and output protocols. |
| TProtocol input; |
| TProtocol output; /// Ditto. |
| |
| /// The underlying transport used for the connection |
| /// This is the transport that was returned by TServerTransport.accept(), |
| /// and it may be different than the transport pointed to by the input and |
| /// output protocols. |
| TTransport transport; |
| } |
| |
| interface TProcessorFactory { |
| /** |
| * Get the TProcessor to use for a particular connection. |
| * |
| * This method is always invoked in the same thread that the connection was |
| * accepted on, which is always the same thread for all current server |
| * implementations. |
| */ |
| TProcessor getProcessor(ref const(TConnectionInfo) connInfo); |
| } |
| |
| /** |
| * The default processor factory which always returns the same instance. |
| */ |
| class TSingletonProcessorFactory : TProcessorFactory { |
| /** |
| * Creates a new instance. |
| * |
| * Params: |
| * processor = The processor object to return from getProcessor(). |
| */ |
| this(TProcessor processor) { |
| processor_ = processor; |
| } |
| |
| override TProcessor getProcessor(ref const(TConnectionInfo) connInfo) { |
| return processor_; |
| } |
| |
| private: |
| TProcessor processor_; |
| } |