returning a lost file TDispatchProcessor.h (#4622)

Author: dorooleg

contrib/restricted/thrift/thrift/TDispatchProcessor.h

@@ -0,0 +1,141 @@
+/*
+ * 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.
+ */
+#ifndef _THRIFT_TDISPATCHPROCESSOR_H_
+#define _THRIFT_TDISPATCHPROCESSOR_H_ 1
+
+#include <thrift/TProcessor.h>
+
+namespace apache {
+namespace thrift {
+
+/**
+ * TDispatchProcessor is a helper class to parse the message header then call
+ * another function to dispatch based on the function name.
+ *
+ * Subclasses must implement dispatchCall() to dispatch on the function name.
+ */
+template <class Protocol_>
+class TDispatchProcessorT : public TProcessor {
+public:
+  virtual bool process(stdcxx::shared_ptr<protocol::TProtocol> in,
+                       stdcxx::shared_ptr<protocol::TProtocol> out,
+                       void* connectionContext) {
+    protocol::TProtocol* inRaw = in.get();
+    protocol::TProtocol* outRaw = out.get();
+
+    // Try to dynamic cast to the template protocol type
+    Protocol_* specificIn = dynamic_cast<Protocol_*>(inRaw);
+    Protocol_* specificOut = dynamic_cast<Protocol_*>(outRaw);
+    if (specificIn && specificOut) {
+      return processFast(specificIn, specificOut, connectionContext);
+    }
+
+    // Log the fact that we have to use the slow path
+    T_GENERIC_PROTOCOL(this, inRaw, specificIn);
+    T_GENERIC_PROTOCOL(this, outRaw, specificOut);
+
+    std::string fname;
+    protocol::TMessageType mtype;
+    int32_t seqid;
+    inRaw->readMessageBegin(fname, mtype, seqid);
+
+    // If this doesn't look like a valid call, log an error and return false so
+    // that the server will close the connection.
+    //
+    // (The old generated processor code used to try to skip a T_STRUCT and
+    // continue.  However, that seems unsafe.)
+    if (mtype != protocol::T_CALL && mtype != protocol::T_ONEWAY) {
+      GlobalOutput.printf("received invalid message type %d from client", mtype);
+      return false;
+    }
+
+    return this->dispatchCall(inRaw, outRaw, fname, seqid, connectionContext);
+  }
+
+protected:
+  bool processFast(Protocol_* in, Protocol_* out, void* connectionContext) {
+    std::string fname;
+    protocol::TMessageType mtype;
+    int32_t seqid;
+    in->readMessageBegin(fname, mtype, seqid);
+
+    if (mtype != protocol::T_CALL && mtype != protocol::T_ONEWAY) {
+      GlobalOutput.printf("received invalid message type %d from client", mtype);
+      return false;
+    }
+
+    return this->dispatchCallTemplated(in, out, fname, seqid, connectionContext);
+  }
+
+  /**
+   * dispatchCall() methods must be implemented by subclasses
+   */
+  virtual bool dispatchCall(apache::thrift::protocol::TProtocol* in,
+                            apache::thrift::protocol::TProtocol* out,
+                            const std::string& fname,
+                            int32_t seqid,
+                            void* callContext) = 0;
+
+  virtual bool dispatchCallTemplated(Protocol_* in,
+                                     Protocol_* out,
+                                     const std::string& fname,
+                                     int32_t seqid,
+                                     void* callContext) = 0;
+};
+
+/**
+ * Non-templatized version of TDispatchProcessor, that doesn't bother trying to
+ * perform a dynamic_cast.
+ */
+class TDispatchProcessor : public TProcessor {
+public:
+  virtual bool process(stdcxx::shared_ptr<protocol::TProtocol> in,
+                       stdcxx::shared_ptr<protocol::TProtocol> out,
+                       void* connectionContext) {
+    std::string fname;
+    protocol::TMessageType mtype;
+    int32_t seqid;
+    in->readMessageBegin(fname, mtype, seqid);
+
+    if (mtype != protocol::T_CALL && mtype != protocol::T_ONEWAY) {
+      GlobalOutput.printf("received invalid message type %d from client", mtype);
+      return false;
+    }
+
+    return dispatchCall(in.get(), out.get(), fname, seqid, connectionContext);
+  }
+
+protected:
+  virtual bool dispatchCall(apache::thrift::protocol::TProtocol* in,
+                            apache::thrift::protocol::TProtocol* out,
+                            const std::string& fname,
+                            int32_t seqid,
+                            void* callContext) = 0;
+};
+
+// Specialize TDispatchProcessorT for TProtocol and TDummyProtocol just to use
+// the generic TDispatchProcessor.
+template <>
+class TDispatchProcessorT<protocol::TDummyProtocol> : public TDispatchProcessor {};
+template <>
+class TDispatchProcessorT<protocol::TProtocol> : public TDispatchProcessor {};
+}
+} // apache::thrift
+
+#endif // _THRIFT_TDISPATCHPROCESSOR_H_