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      1 // Protocol Buffers - Google's data interchange format
      2 // Copyright 2008 Google Inc.  All rights reserved.
      3 // http://code.google.com/p/protobuf/
      4 //
      5 // Redistribution and use in source and binary forms, with or without
      6 // modification, are permitted provided that the following conditions are
      7 // met:
      8 //
      9 //     * Redistributions of source code must retain the above copyright
     10 // notice, this list of conditions and the following disclaimer.
     11 //     * Redistributions in binary form must reproduce the above
     12 // copyright notice, this list of conditions and the following disclaimer
     13 // in the documentation and/or other materials provided with the
     14 // distribution.
     15 //     * Neither the name of Google Inc. nor the names of its
     16 // contributors may be used to endorse or promote products derived from
     17 // this software without specific prior written permission.
     18 //
     19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30 
     31 // Author: kenton (at) google.com (Kenton Varda)
     32 //  Based on original Protocol Buffers design by
     33 //  Sanjay Ghemawat, Jeff Dean, and others.
     34 
     35 #include <google/protobuf/compiler/cpp/cpp_service.h>
     36 #include <google/protobuf/compiler/cpp/cpp_helpers.h>
     37 #include <google/protobuf/io/printer.h>
     38 #include <google/protobuf/stubs/strutil.h>
     39 
     40 namespace google {
     41 namespace protobuf {
     42 namespace compiler {
     43 namespace cpp {
     44 
     45 ServiceGenerator::ServiceGenerator(const ServiceDescriptor* descriptor,
     46                                    const string& dllexport_decl)
     47   : descriptor_(descriptor) {
     48   vars_["classname"] = descriptor_->name();
     49   vars_["full_name"] = descriptor_->full_name();
     50   if (dllexport_decl.empty()) {
     51     vars_["dllexport"] = "";
     52   } else {
     53     vars_["dllexport"] = dllexport_decl + " ";
     54   }
     55 }
     56 
     57 ServiceGenerator::~ServiceGenerator() {}
     58 
     59 void ServiceGenerator::GenerateDeclarations(io::Printer* printer) {
     60   // Forward-declare the stub type.
     61   printer->Print(vars_,
     62     "class $classname$_Stub;\n"
     63     "\n");
     64 
     65   GenerateInterface(printer);
     66   GenerateStubDefinition(printer);
     67 }
     68 
     69 void ServiceGenerator::GenerateInterface(io::Printer* printer) {
     70   printer->Print(vars_,
     71     "class $dllexport$$classname$ : public ::google::protobuf::Service {\n"
     72     " protected:\n"
     73     "  // This class should be treated as an abstract interface.\n"
     74     "  inline $classname$() {};\n"
     75     " public:\n"
     76     "  virtual ~$classname$();\n");
     77   printer->Indent();
     78 
     79   printer->Print(vars_,
     80     "\n"
     81     "typedef $classname$_Stub Stub;\n"
     82     "\n"
     83     "static const ::google::protobuf::ServiceDescriptor* descriptor();\n"
     84     "\n");
     85 
     86   GenerateMethodSignatures(VIRTUAL, printer);
     87 
     88   printer->Print(
     89     "\n"
     90     "// implements Service ----------------------------------------------\n"
     91     "\n"
     92     "const ::google::protobuf::ServiceDescriptor* GetDescriptor();\n"
     93     "void CallMethod(const ::google::protobuf::MethodDescriptor* method,\n"
     94     "                ::google::protobuf::RpcController* controller,\n"
     95     "                const ::google::protobuf::Message* request,\n"
     96     "                ::google::protobuf::Message* response,\n"
     97     "                ::google::protobuf::Closure* done);\n"
     98     "const ::google::protobuf::Message& GetRequestPrototype(\n"
     99     "  const ::google::protobuf::MethodDescriptor* method) const;\n"
    100     "const ::google::protobuf::Message& GetResponsePrototype(\n"
    101     "  const ::google::protobuf::MethodDescriptor* method) const;\n");
    102 
    103   printer->Outdent();
    104   printer->Print(vars_,
    105     "\n"
    106     " private:\n"
    107     "  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS($classname$);\n"
    108     "};\n"
    109     "\n");
    110 }
    111 
    112 void ServiceGenerator::GenerateStubDefinition(io::Printer* printer) {
    113   printer->Print(vars_,
    114     "class $dllexport$$classname$_Stub : public $classname$ {\n"
    115     " public:\n");
    116 
    117   printer->Indent();
    118 
    119   printer->Print(vars_,
    120     "$classname$_Stub(::google::protobuf::RpcChannel* channel);\n"
    121     "$classname$_Stub(::google::protobuf::RpcChannel* channel,\n"
    122     "                 ::google::protobuf::Service::ChannelOwnership ownership);\n"
    123     "~$classname$_Stub();\n"
    124     "\n"
    125     "inline ::google::protobuf::RpcChannel* channel() { return channel_; }\n"
    126     "\n"
    127     "// implements $classname$ ------------------------------------------\n"
    128     "\n");
    129 
    130   GenerateMethodSignatures(NON_VIRTUAL, printer);
    131 
    132   printer->Outdent();
    133   printer->Print(vars_,
    134     " private:\n"
    135     "  ::google::protobuf::RpcChannel* channel_;\n"
    136     "  bool owns_channel_;\n"
    137     "  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS($classname$_Stub);\n"
    138     "};\n"
    139     "\n");
    140 }
    141 
    142 void ServiceGenerator::GenerateMethodSignatures(
    143     VirtualOrNon virtual_or_non, io::Printer* printer) {
    144   for (int i = 0; i < descriptor_->method_count(); i++) {
    145     const MethodDescriptor* method = descriptor_->method(i);
    146     map<string, string> sub_vars;
    147     sub_vars["name"] = method->name();
    148     sub_vars["input_type"] = ClassName(method->input_type(), true);
    149     sub_vars["output_type"] = ClassName(method->output_type(), true);
    150     sub_vars["virtual"] = virtual_or_non == VIRTUAL ? "virtual " : "";
    151 
    152     printer->Print(sub_vars,
    153       "$virtual$void $name$(::google::protobuf::RpcController* controller,\n"
    154       "                     const $input_type$* request,\n"
    155       "                     $output_type$* response,\n"
    156       "                     ::google::protobuf::Closure* done);\n");
    157   }
    158 }
    159 
    160 // ===================================================================
    161 
    162 void ServiceGenerator::GenerateDescriptorInitializer(
    163     io::Printer* printer, int index) {
    164   map<string, string> vars;
    165   vars["classname"] = descriptor_->name();
    166   vars["index"] = SimpleItoa(index);
    167 
    168   printer->Print(vars,
    169     "$classname$_descriptor_ = file->service($index$);\n");
    170 }
    171 
    172 // ===================================================================
    173 
    174 void ServiceGenerator::GenerateImplementation(io::Printer* printer) {
    175   printer->Print(vars_,
    176     "$classname$::~$classname$() {}\n"
    177     "\n"
    178     "const ::google::protobuf::ServiceDescriptor* $classname$::descriptor() {\n"
    179     "  protobuf_AssignDescriptorsOnce();\n"
    180     "  return $classname$_descriptor_;\n"
    181     "}\n"
    182     "\n"
    183     "const ::google::protobuf::ServiceDescriptor* $classname$::GetDescriptor() {\n"
    184     "  protobuf_AssignDescriptorsOnce();\n"
    185     "  return $classname$_descriptor_;\n"
    186     "}\n"
    187     "\n");
    188 
    189   // Generate methods of the interface.
    190   GenerateNotImplementedMethods(printer);
    191   GenerateCallMethod(printer);
    192   GenerateGetPrototype(REQUEST, printer);
    193   GenerateGetPrototype(RESPONSE, printer);
    194 
    195   // Generate stub implementation.
    196   printer->Print(vars_,
    197     "$classname$_Stub::$classname$_Stub(::google::protobuf::RpcChannel* channel)\n"
    198     "  : channel_(channel), owns_channel_(false) {}\n"
    199     "$classname$_Stub::$classname$_Stub(\n"
    200     "    ::google::protobuf::RpcChannel* channel,\n"
    201     "    ::google::protobuf::Service::ChannelOwnership ownership)\n"
    202     "  : channel_(channel),\n"
    203     "    owns_channel_(ownership == ::google::protobuf::Service::STUB_OWNS_CHANNEL) {}\n"
    204     "$classname$_Stub::~$classname$_Stub() {\n"
    205     "  if (owns_channel_) delete channel_;\n"
    206     "}\n"
    207     "\n");
    208 
    209   GenerateStubMethods(printer);
    210 }
    211 
    212 void ServiceGenerator::GenerateNotImplementedMethods(io::Printer* printer) {
    213   for (int i = 0; i < descriptor_->method_count(); i++) {
    214     const MethodDescriptor* method = descriptor_->method(i);
    215     map<string, string> sub_vars;
    216     sub_vars["classname"] = descriptor_->name();
    217     sub_vars["name"] = method->name();
    218     sub_vars["index"] = SimpleItoa(i);
    219     sub_vars["input_type"] = ClassName(method->input_type(), true);
    220     sub_vars["output_type"] = ClassName(method->output_type(), true);
    221 
    222     printer->Print(sub_vars,
    223       "void $classname$::$name$(::google::protobuf::RpcController* controller,\n"
    224       "                         const $input_type$*,\n"
    225       "                         $output_type$*,\n"
    226       "                         ::google::protobuf::Closure* done) {\n"
    227       "  controller->SetFailed(\"Method $name$() not implemented.\");\n"
    228       "  done->Run();\n"
    229       "}\n"
    230       "\n");
    231   }
    232 }
    233 
    234 void ServiceGenerator::GenerateCallMethod(io::Printer* printer) {
    235   printer->Print(vars_,
    236     "void $classname$::CallMethod(const ::google::protobuf::MethodDescriptor* method,\n"
    237     "                             ::google::protobuf::RpcController* controller,\n"
    238     "                             const ::google::protobuf::Message* request,\n"
    239     "                             ::google::protobuf::Message* response,\n"
    240     "                             ::google::protobuf::Closure* done) {\n"
    241     "  GOOGLE_DCHECK_EQ(method->service(), $classname$_descriptor_);\n"
    242     "  switch(method->index()) {\n");
    243 
    244   for (int i = 0; i < descriptor_->method_count(); i++) {
    245     const MethodDescriptor* method = descriptor_->method(i);
    246     map<string, string> sub_vars;
    247     sub_vars["name"] = method->name();
    248     sub_vars["index"] = SimpleItoa(i);
    249     sub_vars["input_type"] = ClassName(method->input_type(), true);
    250     sub_vars["output_type"] = ClassName(method->output_type(), true);
    251 
    252     // Note:  down_cast does not work here because it only works on pointers,
    253     //   not references.
    254     printer->Print(sub_vars,
    255       "    case $index$:\n"
    256       "      $name$(controller,\n"
    257       "             ::google::protobuf::down_cast<const $input_type$*>(request),\n"
    258       "             ::google::protobuf::down_cast< $output_type$*>(response),\n"
    259       "             done);\n"
    260       "      break;\n");
    261   }
    262 
    263   printer->Print(vars_,
    264     "    default:\n"
    265     "      GOOGLE_LOG(FATAL) << \"Bad method index; this should never happen.\";\n"
    266     "      break;\n"
    267     "  }\n"
    268     "}\n"
    269     "\n");
    270 }
    271 
    272 void ServiceGenerator::GenerateGetPrototype(RequestOrResponse which,
    273                                             io::Printer* printer) {
    274   if (which == REQUEST) {
    275     printer->Print(vars_,
    276       "const ::google::protobuf::Message& $classname$::GetRequestPrototype(\n");
    277   } else {
    278     printer->Print(vars_,
    279       "const ::google::protobuf::Message& $classname$::GetResponsePrototype(\n");
    280   }
    281 
    282   printer->Print(vars_,
    283     "    const ::google::protobuf::MethodDescriptor* method) const {\n"
    284     "  GOOGLE_DCHECK_EQ(method->service(), descriptor());\n"
    285     "  switch(method->index()) {\n");
    286 
    287   for (int i = 0; i < descriptor_->method_count(); i++) {
    288     const MethodDescriptor* method = descriptor_->method(i);
    289     const Descriptor* type =
    290       (which == REQUEST) ? method->input_type() : method->output_type();
    291 
    292     map<string, string> sub_vars;
    293     sub_vars["index"] = SimpleItoa(i);
    294     sub_vars["type"] = ClassName(type, true);
    295 
    296     printer->Print(sub_vars,
    297       "    case $index$:\n"
    298       "      return $type$::default_instance();\n");
    299   }
    300 
    301   printer->Print(vars_,
    302     "    default:\n"
    303     "      GOOGLE_LOG(FATAL) << \"Bad method index; this should never happen.\";\n"
    304     "      return *reinterpret_cast< ::google::protobuf::Message*>(NULL);\n"
    305     "  }\n"
    306     "}\n"
    307     "\n");
    308 }
    309 
    310 void ServiceGenerator::GenerateStubMethods(io::Printer* printer) {
    311   for (int i = 0; i < descriptor_->method_count(); i++) {
    312     const MethodDescriptor* method = descriptor_->method(i);
    313     map<string, string> sub_vars;
    314     sub_vars["classname"] = descriptor_->name();
    315     sub_vars["name"] = method->name();
    316     sub_vars["index"] = SimpleItoa(i);
    317     sub_vars["input_type"] = ClassName(method->input_type(), true);
    318     sub_vars["output_type"] = ClassName(method->output_type(), true);
    319 
    320     printer->Print(sub_vars,
    321       "void $classname$_Stub::$name$(::google::protobuf::RpcController* controller,\n"
    322       "                              const $input_type$* request,\n"
    323       "                              $output_type$* response,\n"
    324       "                              ::google::protobuf::Closure* done) {\n"
    325       "  channel_->CallMethod(descriptor()->method($index$),\n"
    326       "                       controller, request, response, done);\n"
    327       "}\n");
    328   }
    329 }
    330 
    331 }  // namespace cpp
    332 }  // namespace compiler
    333 }  // namespace protobuf
    334 }  // namespace google
    335