1/*
2 *
3 * Copyright 2015, Google Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 *
10 * * Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * * Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following disclaimer
14 * in the documentation AN/or other materials provided with the
15 * distribution.
16 * * Neither the name of Google Inc. nor the names of its
17 * contributors may be used to endorse or promote products derived from
18 * this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 *
32 */
33
34#include <map>
35#include <cctype>
36#include <sstream>
37
38#include "src/compiler/go_generator.h"
39
40template <class T>
41grpc::string as_string(T x) {
42 std::ostringstream out;
43 out << x;
44 return out.str();
45}
46
47inline bool ClientOnlyStreaming(const grpc_generator::Method *method) {
48 return method->ClientStreaming() && !method->ServerStreaming();
49}
50
51inline bool ServerOnlyStreaming(const grpc_generator::Method *method) {
52 return !method->ClientStreaming() && method->ServerStreaming();
53}
54
55namespace grpc_go_generator {
56
57// Returns string with first letter to lowerCase
58grpc::string unexportName(grpc::string s) {
59 if (s.empty())
60 return s;
61 s[0] = static_cast<char>(std::tolower(s[0]));
62 return s;
63}
64
65// Returns string with first letter to uppercase
66grpc::string exportName(grpc::string s) {
67 if (s.empty())
68 return s;
69 s[0] = static_cast<char>(std::toupper(s[0]));
70 return s;
71}
72
73// Generates imports for the service
74void GenerateImports(grpc_generator::File *file, grpc_generator::Printer *printer,
75 std::map<grpc::string, grpc::string> vars) {
76 vars["filename"] = file->filename();
77 printer->Print("//Generated by gRPC Go plugin\n");
78 printer->Print("//If you make any local changes, they will be lost\n");
79 printer->Print(vars, "//source: $filename$\n\n");
80 printer->Print(vars, "package $Package$\n\n");
81 if (file->additional_headers() != "") {
82 printer->Print(file->additional_headers().c_str());
83 printer->Print("\n\n");
84 }
85 printer->Print("import (\n");
86 printer->Indent();
87 printer->Print(vars, "$context$ \"context\"\n");
88 printer->Print(vars, "$grpc$ \"google.golang.org/grpc\"\n");
89 printer->Outdent();
90 printer->Print(")\n\n");
91}
92
93// Generates Server method signature source
94void GenerateServerMethodSignature(const grpc_generator::Method *method, grpc_generator::Printer *printer,
95 std::map<grpc::string, grpc::string> vars) {
96 vars["Method"] = exportName(method->name());
97 vars["Request"] = method->get_input_type_name();
98 vars["Response"] = (vars["CustomMethodIO"] == "") ? method->get_output_type_name() : vars["CustomMethodIO"];
99 if (method->NoStreaming()) {
100 printer->Print(vars, "$Method$($context$.Context, *$Request$) (*$Response$, error)");
101 } else if (ServerOnlyStreaming(method)) {
102 printer->Print(vars, "$Method$(*$Request$, $Service$_$Method$Server) error");
103 } else {
104 printer->Print(vars, "$Method$($Service$_$Method$Server) error");
105 }
106}
107
108void GenerateServerMethod(const grpc_generator::Method *method, grpc_generator::Printer *printer,
109 std::map<grpc::string, grpc::string> vars) {
110 vars["Method"] = exportName(method->name());
111 vars["Request"] = method->get_input_type_name();
112 vars["Response"] = (vars["CustomMethodIO"] == "") ? method->get_output_type_name() : vars["CustomMethodIO"];
113 vars["FullMethodName"] = "/" + vars["ServicePrefix"] + "." + vars["Service"] + "/" + vars["Method"];
114 vars["Handler"] = "_" + vars["Service"] + "_" + vars["Method"] + "_Handler";
115 if (method->NoStreaming()) {
116 printer->Print(vars, "func $Handler$(srv interface{}, ctx $context$.Context,\n\tdec func(interface{}) error, interceptor $grpc$.UnaryServerInterceptor) (interface{}, error) {\n");
117 printer->Indent();
118 printer->Print(vars, "in := new($Request$)\n");
119 printer->Print("if err := dec(in); err != nil { return nil, err }\n");
120 printer->Print(vars, "if interceptor == nil { return srv.($Service$Server).$Method$(ctx, in) }\n");
121 printer->Print(vars, "info := &$grpc$.UnaryServerInfo{\n");
122 printer->Indent();
123 printer->Print("Server: srv,\n");
124 printer->Print(vars, "FullMethod: \"$FullMethodName$\",\n");
125 printer->Outdent();
126 printer->Print("}\n\n");
127 printer->Print(vars, "handler := func(ctx $context$.Context, req interface{}) (interface{}, error) {\n");
128 printer->Indent();
129 printer->Print(vars, "return srv.($Service$Server).$Method$(ctx, req.(* $Request$))\n");
130 printer->Outdent();
131 printer->Print("}\n");
132 printer->Print("return interceptor(ctx, in, info, handler)\n");
133 printer->Outdent();
134 printer->Print("}\n\n");
135 return;
136 }
137 vars["StreamType"] = vars["ServiceUnexported"] + vars["Method"] + "Server";
138 printer->Print(vars, "func $Handler$(srv interface{}, stream $grpc$.ServerStream) error {\n");
139 printer->Indent();
140 if (ServerOnlyStreaming(method)) {
141 printer->Print(vars, "m := new($Request$)\n");
142 printer->Print(vars, "if err := stream.RecvMsg(m); err != nil { return err }\n");
143 printer->Print(vars, "return srv.($Service$Server).$Method$(m, &$StreamType${stream})\n");
144 } else {
145 printer->Print(vars, "return srv.($Service$Server).$Method$(&$StreamType${stream})\n");
146 }
147 printer->Outdent();
148 printer->Print("}\n\n");
149
150 bool genSend = method->BidiStreaming() || ServerOnlyStreaming(method);
151 bool genRecv = method->BidiStreaming() || ClientOnlyStreaming(method);
152 bool genSendAndClose = ClientOnlyStreaming(method);
153
154 printer->Print(vars, "type $Service$_$Method$Server interface { \n");
155 printer->Indent();
156 if (genSend) {
157 printer->Print(vars, "Send(* $Response$) error\n");
158 }
159 if (genRecv) {
160 printer->Print(vars, "Recv() (* $Request$, error)\n");
161 }
162 if (genSendAndClose) {
163 printer->Print(vars, "SendAndClose(* $Response$) error\n");
164 }
165 printer->Print(vars, "$grpc$.ServerStream\n");
166 printer->Outdent();
167 printer->Print("}\n\n");
168
169 printer->Print(vars, "type $StreamType$ struct {\n");
170 printer->Indent();
171 printer->Print(vars, "$grpc$.ServerStream\n");
172 printer->Outdent();
173 printer->Print("}\n\n");
174
175 if (genSend) {
176 printer->Print(vars, "func (x *$StreamType$) Send(m *$Response$) error {\n");
177 printer->Indent();
178 printer->Print("return x.ServerStream.SendMsg(m)\n");
179 printer->Outdent();
180 printer->Print("}\n\n");
181 }
182 if (genRecv) {
183 printer->Print(vars, "func (x *$StreamType$) Recv() (*$Request$, error) {\n");
184 printer->Indent();
185 printer->Print(vars, "m := new($Request$)\n");
186 printer->Print("if err := x.ServerStream.RecvMsg(m); err != nil { return nil, err }\n");
187 printer->Print("return m, nil\n");
188 printer->Outdent();
189 printer->Print("}\n\n");
190 }
191 if (genSendAndClose) {
192 printer->Print(vars, "func (x *$StreamType$) SendAndClose(m *$Response$) error {\n");
193 printer->Indent();
194 printer->Print("return x.ServerStream.SendMsg(m)\n");
195 printer->Outdent();
196 printer->Print("}\n\n");
197 }
198
199}
200
201// Generates Client method signature source
202void GenerateClientMethodSignature(const grpc_generator::Method *method, grpc_generator::Printer *printer,
203 std::map<grpc::string, grpc::string> vars) {
204 vars["Method"] = exportName(method->name());
205 vars["Request"] = ", in *" + ((vars["CustomMethodIO"] == "") ? method->get_input_type_name() : vars["CustomMethodIO"]);
206 if (ClientOnlyStreaming(method) || method->BidiStreaming()) {
207 vars["Request"] = "";
208 }
209 vars["Response"] = "* " + method->get_output_type_name();
210 if (ClientOnlyStreaming(method) || method->BidiStreaming() || ServerOnlyStreaming(method)) {
211 vars["Response"] = vars["Service"] + "_" + vars["Method"] + "Client" ;
212 }
213 printer->Print(vars, "$Method$(ctx $context$.Context$Request$, \n\topts... $grpc$.CallOption) ($Response$, error)");
214}
215
216// Generates Client method source
217void GenerateClientMethod(const grpc_generator::Method *method, grpc_generator::Printer *printer,
218 std::map<grpc::string, grpc::string> vars) {
219 printer->Print(vars, "func (c *$ServiceUnexported$Client) ");
220 GenerateClientMethodSignature(method, printer, vars);
221 printer->Print(" {\n");
222 printer->Indent();
223 vars["Method"] = exportName(method->name());
224 vars["Request"] = (vars["CustomMethodIO"] == "") ? method->get_input_type_name() : vars["CustomMethodIO"];
225 vars["Response"] = method->get_output_type_name();
226 vars["FullMethodName"] = "/" + vars["ServicePrefix"] + "." + vars["Service"] + "/" + vars["Method"];
227 if (method->NoStreaming()) {
228 printer->Print(vars, "out := new($Response$)\n");
229 printer->Print(vars, "err := $grpc$.Invoke(ctx, \"$FullMethodName$\", in, out, c.cc, opts...)\n");
230 printer->Print("if err != nil { return nil, err }\n");
231 printer->Print("return out, nil\n");
232 printer->Outdent();
233 printer->Print("}\n\n");
234 return;
235 }
236 vars["StreamType"] = vars["ServiceUnexported"] + vars["Method"] + "Client";
237 printer->Print(vars, "stream, err := $grpc$.NewClientStream(ctx, &$MethodDesc$, c.cc, \"$FullMethodName$\", opts...)\n");
238 printer->Print("if err != nil { return nil, err }\n");
239
240 printer->Print(vars, "x := &$StreamType${stream}\n");
241 if (ServerOnlyStreaming(method)) {
242 printer->Print("if err := x.ClientStream.SendMsg(in); err != nil { return nil, err }\n");
243 printer->Print("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }\n");
244 }
245 printer->Print("return x,nil\n");
246 printer->Outdent();
247 printer->Print("}\n\n");
248
249 bool genSend = method->BidiStreaming() || ClientOnlyStreaming(method);
250 bool genRecv = method->BidiStreaming() || ServerOnlyStreaming(method);
251 bool genCloseAndRecv = ClientOnlyStreaming(method);
252
253 //Stream interface
254 printer->Print(vars, "type $Service$_$Method$Client interface {\n");
255 printer->Indent();
256 if (genSend) {
257 printer->Print(vars, "Send(*$Request$) error\n");
258 }
259 if (genRecv) {
260 printer->Print(vars, "Recv() (*$Response$, error)\n");
261 }
262 if (genCloseAndRecv) {
263 printer->Print(vars, "CloseAndRecv() (*$Response$, error)\n");
264 }
265 printer->Print(vars, "$grpc$.ClientStream\n");
266 printer->Outdent();
267 printer->Print("}\n\n");
268
269 //Stream Client
270 printer->Print(vars, "type $StreamType$ struct{\n");
271 printer->Indent();
272 printer->Print(vars, "$grpc$.ClientStream\n");
273 printer->Outdent();
274 printer->Print("}\n\n");
275
276 if (genSend) {
277 printer->Print(vars, "func (x *$StreamType$) Send(m *$Request$) error {\n");
278 printer->Indent();
279 printer->Print("return x.ClientStream.SendMsg(m)\n");
280 printer->Outdent();
281 printer->Print("}\n\n");
282 }
283
284 if (genRecv) {
285 printer->Print(vars, "func (x *$StreamType$) Recv() (*$Response$, error) {\n");
286 printer->Indent();
287 printer->Print(vars, "m := new($Response$)\n");
288 printer->Print("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }\n");
289 printer->Print("return m, nil\n");
290 printer->Outdent();
291 printer->Print("}\n\n");
292 }
293
294 if (genCloseAndRecv) {
295 printer->Print(vars, "func (x *$StreamType$) CloseAndRecv() (*$Response$, error) {\n");
296 printer->Indent();
297 printer->Print("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }\n");
298 printer->Print(vars, "m := new ($Response$)\n");
299 printer->Print("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }\n");
300 printer->Print("return m, nil\n");
301 printer->Outdent();
302 printer->Print("}\n\n");
303 }
304}
305
306// Generates client API for the service
307void GenerateService(const grpc_generator::Service *service, grpc_generator::Printer* printer,
308 std::map<grpc::string, grpc::string> vars) {
309 vars["Service"] = exportName(service->name());
310 // Client Interface
311 printer->Print(vars, "// Client API for $Service$ service\n");
312 printer->Print(vars, "type $Service$Client interface{\n");
313 printer->Indent();
314 for (int i = 0; i < service->method_count(); i++) {
315 GenerateClientMethodSignature(service->method(i).get(), printer, vars);
316 printer->Print("\n");
317 }
318 printer->Outdent();
319 printer->Print("}\n\n");
320
321 // Client structure
322 vars["ServiceUnexported"] = unexportName(vars["Service"]);
323 printer->Print(vars, "type $ServiceUnexported$Client struct {\n");
324 printer->Indent();
325 printer->Print(vars, "cc *$grpc$.ClientConn\n");
326 printer->Outdent();
327 printer->Print("}\n\n");
328
329 // NewClient
330 printer->Print(vars, "func New$Service$Client(cc *$grpc$.ClientConn) $Service$Client {\n");
331 printer->Indent();
332 printer->Print(vars, "return &$ServiceUnexported$Client{cc}");
333 printer->Outdent();
334 printer->Print("\n}\n\n");
335
336 int unary_methods = 0, streaming_methods = 0;
337 vars["ServiceDesc"] = "_" + vars["Service"] + "_serviceDesc";
338 for (int i = 0; i < service->method_count(); i++) {
339 auto method = service->method(i);
340 if (method->NoStreaming()) {
341 vars["MethodDesc"] = vars["ServiceDesc"] + ".Method[" + as_string(unary_methods) + "]";
342 unary_methods++;
343 } else {
344 vars["MethodDesc"] = vars["ServiceDesc"] + ".Streams[" + as_string(streaming_methods) + "]";
345 streaming_methods++;
346 }
347 GenerateClientMethod(method.get(), printer, vars);
348 }
349
350 //Server Interface
351 printer->Print(vars, "// Server API for $Service$ service\n");
352 printer->Print(vars, "type $Service$Server interface {\n");
353 printer->Indent();
354 for (int i = 0; i < service->method_count(); i++) {
355 GenerateServerMethodSignature(service->method(i).get(), printer, vars);
356 printer->Print("\n");
357 }
358 printer->Outdent();
359 printer->Print("}\n\n");
360
361 // Server registration.
362 printer->Print(vars, "func Register$Service$Server(s *$grpc$.Server, srv $Service$Server) {\n");
363 printer->Indent();
364 printer->Print(vars, "s.RegisterService(&$ServiceDesc$, srv)\n");
365 printer->Outdent();
366 printer->Print("}\n\n");
367
368 for (int i = 0; i < service->method_count(); i++) {
369 GenerateServerMethod(service->method(i).get(), printer, vars);
370 printer->Print("\n");
371 }
372
373
374 //Service Descriptor
375 printer->Print(vars, "var $ServiceDesc$ = $grpc$.ServiceDesc{\n");
376 printer->Indent();
377 printer->Print(vars, "ServiceName: \"$ServicePrefix$.$Service$\",\n");
378 printer->Print(vars, "HandlerType: (*$Service$Server)(nil),\n");
379 printer->Print(vars, "Methods: []$grpc$.MethodDesc{\n");
380 printer->Indent();
381 for (int i = 0; i < service->method_count(); i++) {
382 auto method = service->method(i);
383 vars["Method"] = method->name();
384 vars["Handler"] = "_" + vars["Service"] + "_" + vars["Method"] + "_Handler";
385 if (method->NoStreaming()) {
386 printer->Print("{\n");
387 printer->Indent();
388 printer->Print(vars, "MethodName: \"$Method$\",\n");
389 printer->Print(vars, "Handler: $Handler$, \n");
390 printer->Outdent();
391 printer->Print("},\n");
392 }
393 }
394 printer->Outdent();
395 printer->Print("},\n");
396 printer->Print(vars, "Streams: []$grpc$.StreamDesc{\n");
397 printer->Indent();
398 for (int i = 0; i < service->method_count(); i++) {
399 auto method = service->method(i);
400 vars["Method"] = method->name();
401 vars["Handler"] = "_" + vars["Service"] + "_" + vars["Method"] + "_Handler";
402 if (!method->NoStreaming()) {
403 printer->Print("{\n");
404 printer->Indent();
405 printer->Print(vars, "StreamName: \"$Method$\",\n");
406 printer->Print(vars, "Handler: $Handler$, \n");
407 if (ClientOnlyStreaming(method.get())) {
408 printer->Print("ClientStreams: true,\n");
409 } else if (ServerOnlyStreaming(method.get())) {
410 printer->Print("ServerStreams: true,\n");
411 } else {
412 printer->Print("ServerStreams: true,\n");
413 printer->Print("ClientStreams: true,\n");
414 }
415 printer->Outdent();
416 printer->Print("},\n");
417 }
418 }
419 printer->Outdent();
420 printer->Print("},\n");
421 printer->Outdent();
422 printer->Print("}\n\n");
423
424}
425
426
427// Returns source for the service
428grpc::string GenerateServiceSource(grpc_generator::File *file,
429 const grpc_generator::Service *service,
430 grpc_go_generator::Parameters *parameters) {
431 grpc::string out;
432 auto p = file->CreatePrinter(&out);
433 auto printer = p.get();
434 std::map<grpc::string, grpc::string> vars;
435 vars["Package"] = parameters->package_name;
436 vars["ServicePrefix"] = parameters->service_prefix;
437 vars["grpc"] = "grpc";
438 vars["context"] = "context";
439 GenerateImports(file, printer, vars);
440 if (parameters->custom_method_io_type != "") {
441 vars["CustomMethodIO"] = parameters->custom_method_io_type;
442 }
443 GenerateService(service, printer, vars);
444 return out;
445}
446}// Namespace grpc_go_generator
447