1    :  // Copyright 2012 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // Helper functions to wrap RPC invocations.
  16    :  
  17    :  #ifndef SYZYGY_TRACE_RPC_RPC_HELPERS_H_
  18    :  #define SYZYGY_TRACE_RPC_RPC_HELPERS_H_
  19    :  
  20    :  #include <rpc.h>
  21    :  #include <wtypes.h>
  22    :  
  23    :  #include "base/string_piece.h"
  24    :  
  25    :  // TODO(rogerm): Is there directly usable stuff in base/callback.h that
  26    :  //     might make this simpler/cleaner?
  27    :  
  28    :  namespace trace {
  29    :  namespace client {
  30    :  
  31    :  // Create an RPC binding.
  32    :  //
  33    :  // @param protocol The RPC protocol to bind.
  34    :  // @param endpoint The endpoint/address to bind.
  35    :  // @param out_handle A handle to the rpc binding will be returned here.
  36    :  //
  37    :  // @return true on success.
  38    :  bool CreateRpcBinding(const base::StringPiece16& protocol,
  39    :                        const base::StringPiece16& endpoint,
  40    :                        handle_t* out_handle);
  41    :  
  42    :  // Structure returned by RPC calls
  43    :  struct RpcStatus {
  44    :    boolean exception_occurred;
  45    :    boolean result;
  46    :  
  47  E :    bool succeeded() const {
  48  E :      return exception_occurred == FALSE && result == TRUE;
  49  E :    }
  50    :  };
  51    :  
  52    :  // Helper to invoke an RPC function taking one parameter.
  53    :  template<typename Func, typename T1>
  54  i :  RpcStatus InvokeRpc(const Func& func, const T1& p1) {
  55  i :    RpcStatus status = { FALSE, FALSE };
  56  i :    RpcTryExcept {
  57  i :      status.result = func(p1);
  58  i :    } RpcExcept(1) {
  59  i :      status.exception_occurred = TRUE;
  60  i :    } RpcEndExcept;
  61  i :    return status;
  62  i :  }
  63    :  
  64    :  // Helper to invoke an RPC function taking two parameters.
  65    :  template<typename Func, typename T1, typename T2>
  66  i :  RpcStatus InvokeRpc(const Func& func, const T1& p1, const T2& p2) {
  67  i :    RpcStatus status = { FALSE, FALSE };
  68  i :    RpcTryExcept {
  69  i :      status.result = func(p1, p2);
  70  i :    } RpcExcept(1) {
  71  i :      status.exception_occurred = TRUE;
  72  i :    } RpcEndExcept;
  73  i :    return status;
  74  i :  }
  75    :  
  76    :  // Helper to invoke an RPC function taking three parameters.
  77    :  template<typename Func, typename T1, typename T2, typename T3>
  78    :  RpcStatus InvokeRpc(const Func& func,
  79  i :                      const T1& p1, const T2& p2, const T3& p3) {
  80  i :    RpcStatus status = { FALSE, FALSE };
  81  i :    RpcTryExcept {
  82  i :      status.result = func(p1, p2, p3);
  83  i :    } RpcExcept(1) {
  84  i :      status.exception_occurred = TRUE;
  85  i :    } RpcEndExcept;
  86  i :    return status;
  87  i :  }
  88    :  
  89    :  // Helper to invoke an RPC function taking four parameters.
  90    :  template<typename Func, typename T1, typename T2, typename T3, typename T4>
  91    :  RpcStatus InvokeRpc(const Func& func,
  92  i :                      const T1& p1, const T2& p2, const T3& p3, const T4& p4) {
  93  i :    RpcStatus status = { FALSE, FALSE };
  94  i :    RpcTryExcept {
  95  i :      status.result = func(p1, p2, p3, p4);
  96  i :    } RpcExcept(1) {
  97  i :      status.exception_occurred = TRUE;
  98  i :    } RpcEndExcept;
  99  i :    return status;
 100  i :  }
 101    :  
 102    :  // Helper to invoke an RPC function taking five parameters.
 103    :  template<typename Func,
 104    :           typename T1, typename T2, typename T3, typename T4, typename T5>
 105    :  RpcStatus InvokeRpc(const Func& func,
 106    :                      const T1& p1, const T2& p2, const T3& p3, const T4& p4,
 107    :                      const T5& p5) {
 108    :    RpcStatus status = { FALSE, FALSE };
 109    :    RpcTryExcept {
 110    :      status.result = func(p1, p2, p3, p4, p5);
 111    :    } RpcExcept(1) {
 112    :      status.exception_occurred = TRUE;
 113    :    } RpcEndExcept;
 114    :    return status;
 115    :  }
 116    :  
 117    :  // A helper function to get an @p instance_id specialized version of the
 118    :  // given @p root string.
 119    :  std::wstring GetInstanceString(const base::StringPiece16& root,
 120    :                                 const base::StringPiece16& instance_id);
 121    :  
 122    :  // A helper class to manage an RPC binding handle.
 123    :  class ScopedRpcBinding {
 124    :   public:
 125    :    ScopedRpcBinding();
 126    :    ~ScopedRpcBinding();
 127    :  
 128    :    // @returns the underlying RPC handle.
 129  E :    handle_t Get() const { return rpc_binding_; }
 130    :  
 131    :    // Opens an RPC connection to @p endpoint using @p protocol.
 132    :    bool Open(const base::StringPiece16& protocol,
 133    :              const base::StringPiece16& endpoint);
 134    :  
 135    :    // Closes this RPC connection.
 136    :    bool Close();
 137    :  
 138    :   protected:
 139    :    // The OS level binding to the RPC layer.
 140    :    handle_t rpc_binding_;
 141    :  
 142    :   private:
 143    :    DISALLOW_COPY_AND_ASSIGN(ScopedRpcBinding);
 144    :  };
 145    :  
 146    :  }  // namespace client
 147    :  }  // namespace trace
 148    :  
 149    :  #endif  // SYZYGY_TRACE_RPC_RPC_HELPERS_H_