cpp_service.cc revision fbaaef999ba563838ebd00874ed8a1c01fbf286d 
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30
31// Author: kenton@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
40namespace google {
41namespace protobuf {
42namespace compiler {
43namespace cpp {
44
45ServiceGenerator::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
57ServiceGenerator::~ServiceGenerator() {}
58
59void 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
69void ServiceGenerator::GenerateInterface(io::Printer* printer) {
70  printer->Print(vars_,
71    "class $dllexport$$classname$ : public ::google::protobuf::Service {\n"
72    " protected:\n"
73    "  // This class should be treated as an abstract interface.\n"
74    "  inline $classname$() {};\n"
75    " public:\n"
76    "  virtual ~$classname$();\n");
77  printer->Indent();
78
79  printer->Print(vars_,
80    "\n"
81    "typedef $classname$_Stub Stub;\n"
82    "\n"
83    "static const ::google::protobuf::ServiceDescriptor* descriptor();\n"
84    "\n");
85
86  GenerateMethodSignatures(VIRTUAL, printer);
87
88  printer->Print(
89    "\n"
90    "// implements Service ----------------------------------------------\n"
91    "\n"
92    "const ::google::protobuf::ServiceDescriptor* GetDescriptor();\n"
93    "void CallMethod(const ::google::protobuf::MethodDescriptor* method,\n"
94    "                ::google::protobuf::RpcController* controller,\n"
95    "                const ::google::protobuf::Message* request,\n"
96    "                ::google::protobuf::Message* response,\n"
97    "                ::google::protobuf::Closure* done);\n"
98    "const ::google::protobuf::Message& GetRequestPrototype(\n"
99    "  const ::google::protobuf::MethodDescriptor* method) const;\n"
100    "const ::google::protobuf::Message& GetResponsePrototype(\n"
101    "  const ::google::protobuf::MethodDescriptor* method) const;\n");
102
103  printer->Outdent();
104  printer->Print(vars_,
105    "\n"
106    " private:\n"
107    "  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS($classname$);\n"
108    "};\n"
109    "\n");
110}
111
112void ServiceGenerator::GenerateStubDefinition(io::Printer* printer) {
113  printer->Print(vars_,
114    "class $dllexport$$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
142void 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
162void 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
174void 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
212void 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
234void 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
272void 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
310void 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