aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/compiler/python_generator.cc
blob: 2982a89fad11b045717505b854f2e144d99b93b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <algorithm>
#include <cassert>
#include <cctype>
#include <cstring>
#include <map>
#include <memory>
#include <ostream>
#include <sstream>
#include <tuple>
#include <vector>

#include <grpc++/config.h>
#include "src/compiler/config.h"
#include "src/compiler/generator_helpers.h"
#include "src/compiler/python_generator.h"

using grpc_generator::StringReplace;
using grpc_generator::StripProto;
using grpc::protobuf::Descriptor;
using grpc::protobuf::FileDescriptor;
using grpc::protobuf::MethodDescriptor;
using grpc::protobuf::ServiceDescriptor;
using grpc::protobuf::compiler::GeneratorContext;
using grpc::protobuf::io::CodedOutputStream;
using grpc::protobuf::io::Printer;
using grpc::protobuf::io::StringOutputStream;
using grpc::protobuf::io::ZeroCopyOutputStream;
using std::initializer_list;
using std::make_pair;
using std::map;
using std::pair;
using std::replace;
using std::vector;

namespace grpc_python_generator {

PythonGrpcGenerator::PythonGrpcGenerator(const GeneratorConfiguration& config)
    : config_(config) {}

PythonGrpcGenerator::~PythonGrpcGenerator() {}

bool PythonGrpcGenerator::Generate(
    const FileDescriptor* file, const grpc::string& parameter,
    GeneratorContext* context, grpc::string* error) const {
  // Get output file name.
  grpc::string file_name;
  static const int proto_suffix_length = strlen(".proto");
  if (file->name().size() > static_cast<size_t>(proto_suffix_length) &&
      file->name().find_last_of(".proto") == file->name().size() - 1) {
    file_name = file->name().substr(
        0, file->name().size() - proto_suffix_length) + "_pb2.py";
  } else {
    *error = "Invalid proto file name. Proto file must end with .proto";
    return false;
  }

  std::unique_ptr<ZeroCopyOutputStream> output(
      context->OpenForInsert(file_name, "module_scope"));
  CodedOutputStream coded_out(output.get());
  bool success = false;
  grpc::string code = "";
  tie(success, code) = grpc_python_generator::GetServices(file, config_);
  if (success) {
    coded_out.WriteRaw(code.data(), code.size());
    return true;
  } else {
    return false;
  }
}

namespace {
//////////////////////////////////
// BEGIN FORMATTING BOILERPLATE //
//////////////////////////////////

// Converts an initializer list of the form { key0, value0, key1, value1, ... }
// into a map of key* to value*. Is merely a readability helper for later code.
map<grpc::string, grpc::string> ListToDict(
    const initializer_list<grpc::string>& values) {
  assert(values.size() % 2 == 0);
  map<grpc::string, grpc::string> value_map;
  auto value_iter = values.begin();
  for (unsigned i = 0; i < values.size()/2; ++i) {
    grpc::string key = *value_iter;
    ++value_iter;
    grpc::string value = *value_iter;
    value_map[key] = value;
    ++value_iter;
  }
  return value_map;
}

// Provides RAII indentation handling. Use as:
// {
//   IndentScope raii_my_indent_var_name_here(my_py_printer);
//   // constructor indented my_py_printer
//   ...
//   // destructor called at end of scope, un-indenting my_py_printer
// }
class IndentScope {
 public:
  explicit IndentScope(Printer* printer) : printer_(printer) {
    printer_->Indent();
  }

  ~IndentScope() {
    printer_->Outdent();
  }

 private:
  Printer* printer_;
};

////////////////////////////////
// END FORMATTING BOILERPLATE //
////////////////////////////////

bool PrintServicer(const ServiceDescriptor* service,
                   Printer* out) {
  grpc::string doc = "<fill me in later!>";
  map<grpc::string, grpc::string> dict = ListToDict({
        "Service", service->name(),
        "Documentation", doc,
      });
  out->Print(dict, "class EarlyAdopter$Service$Servicer(object):\n");
  {
    IndentScope raii_class_indent(out);
    out->Print(dict, "\"\"\"$Documentation$\"\"\"\n");
    out->Print("__metaclass__ = abc.ABCMeta\n");
    for (int i = 0; i < service->method_count(); ++i) {
      auto meth = service->method(i);
      grpc::string arg_name = meth->client_streaming() ?
          "request_iterator" : "request";
      out->Print("@abc.abstractmethod\n");
      out->Print("def $Method$(self, $ArgName$, context):\n",
                 "Method", meth->name(), "ArgName", arg_name);
      {
        IndentScope raii_method_indent(out);
        out->Print("raise NotImplementedError()\n");
      }
    }
  }
  return true;
}

bool PrintServer(const ServiceDescriptor* service, Printer* out) {
  grpc::string doc = "<fill me in later!>";
  map<grpc::string, grpc::string> dict = ListToDict({
        "Service", service->name(),
        "Documentation", doc,
      });
  out->Print(dict, "class EarlyAdopter$Service$Server(object):\n");
  {
    IndentScope raii_class_indent(out);
    out->Print(dict, "\"\"\"$Documentation$\"\"\"\n");
    out->Print("__metaclass__ = abc.ABCMeta\n");
    out->Print("@abc.abstractmethod\n");
    out->Print("def start(self):\n");
    {
      IndentScope raii_method_indent(out);
      out->Print("raise NotImplementedError()\n");
    }

    out->Print("@abc.abstractmethod\n");
    out->Print("def stop(self):\n");
    {
      IndentScope raii_method_indent(out);
      out->Print("raise NotImplementedError()\n");
    }
  }
  return true;
}

bool PrintStub(const ServiceDescriptor* service,
               Printer* out) {
  grpc::string doc = "<fill me in later!>";
  map<grpc::string, grpc::string> dict = ListToDict({
        "Service", service->name(),
        "Documentation", doc,
      });
  out->Print(dict, "class EarlyAdopter$Service$Stub(object):\n");
  {
    IndentScope raii_class_indent(out);
    out->Print(dict, "\"\"\"$Documentation$\"\"\"\n");
    out->Print("__metaclass__ = abc.ABCMeta\n");
    for (int i = 0; i < service->method_count(); ++i) {
      const MethodDescriptor* meth = service->method(i);
      grpc::string arg_name = meth->client_streaming() ?
          "request_iterator" : "request";
      auto methdict = ListToDict({"Method", meth->name(), "ArgName", arg_name});
      out->Print("@abc.abstractmethod\n");
      out->Print(methdict, "def $Method$(self, $ArgName$):\n");
      {
        IndentScope raii_method_indent(out);
        out->Print("raise NotImplementedError()\n");
      }
      out->Print(methdict, "$Method$.async = None\n");
    }
  }
  return true;
}

// TODO(protobuf team): Export `ModuleName` from protobuf's
// `src/google/protobuf/compiler/python/python_generator.cc` file.
grpc::string ModuleName(const grpc::string& filename) {
  grpc::string basename = StripProto(filename);
  basename = StringReplace(basename, "-", "_");
  basename = StringReplace(basename, "/", ".");
  return basename + "_pb2";
}

bool GetModuleAndMessagePath(const Descriptor* type,
                             pair<grpc::string, grpc::string>* out) {
  const Descriptor* path_elem_type = type;
  vector<const Descriptor*> message_path;
  do {
    message_path.push_back(path_elem_type);
    path_elem_type = path_elem_type->containing_type();
  } while (path_elem_type); // implicit nullptr comparison; don't be explicit
  grpc::string file_name = type->file()->name();
  static const int proto_suffix_length = strlen(".proto");
  if (!(file_name.size() > static_cast<size_t>(proto_suffix_length) &&
        file_name.find_last_of(".proto") == file_name.size() - 1)) {
    return false;
  }
  grpc::string module = ModuleName(file_name);
  grpc::string message_type;
  for (auto path_iter = message_path.rbegin();
       path_iter != message_path.rend(); ++path_iter) {
    message_type += (*path_iter)->name() + ".";
  }
  // no pop_back prior to C++11
  message_type.resize(message_type.size() - 1);
  *out = make_pair(module, message_type);
  return true;
}

bool PrintServerFactory(const grpc::string& package_qualified_service_name,
                        const ServiceDescriptor* service, Printer* out) {
  out->Print("def early_adopter_create_$Service$_server(servicer, port, "
             "private_key=None, certificate_chain=None):\n",
             "Service", service->name());
  {
    IndentScope raii_create_server_indent(out);
    map<grpc::string, grpc::string> method_description_constructors;
    map<grpc::string, pair<grpc::string, grpc::string>>
        input_message_modules_and_classes;
    map<grpc::string, pair<grpc::string, grpc::string>>
        output_message_modules_and_classes;
    for (int i = 0; i < service->method_count(); ++i) {
      const MethodDescriptor* method = service->method(i);
      const grpc::string method_description_constructor =
          grpc::string(method->client_streaming() ? "stream_" : "unary_") +
          grpc::string(method->server_streaming() ? "stream_" : "unary_") +
          "service_description";
      pair<grpc::string, grpc::string> input_message_module_and_class;
      if (!GetModuleAndMessagePath(method->input_type(),
                                   &input_message_module_and_class)) {
        return false;
      }
      pair<grpc::string, grpc::string> output_message_module_and_class;
      if (!GetModuleAndMessagePath(method->output_type(),
                                   &output_message_module_and_class)) {
        return false;
      }
      // Import the modules that define the messages used in RPCs.
      out->Print("import $Module$\n", "Module",
                 input_message_module_and_class.first);
      out->Print("import $Module$\n", "Module",
                 output_message_module_and_class.first);
      method_description_constructors.insert(
          make_pair(method->name(), method_description_constructor));
      input_message_modules_and_classes.insert(
          make_pair(method->name(), input_message_module_and_class));
      output_message_modules_and_classes.insert(
          make_pair(method->name(), output_message_module_and_class));
    }
    out->Print("method_service_descriptions = {\n");
    for (auto name_and_description_constructor =
	   method_description_constructors.begin();
	 name_and_description_constructor !=
	   method_description_constructors.end();
	 name_and_description_constructor++) {
      IndentScope raii_descriptions_indent(out);
      const grpc::string method_name = name_and_description_constructor->first;
      auto input_message_module_and_class =
          input_message_modules_and_classes.find(method_name);
      auto output_message_module_and_class =
          output_message_modules_and_classes.find(method_name);
      out->Print("\"$Method$\": utilities.$Constructor$(\n", "Method",
                 method_name, "Constructor",
                 name_and_description_constructor->second);
      {
        IndentScope raii_description_arguments_indent(out);
        out->Print("servicer.$Method$,\n", "Method", method_name);
        out->Print(
            "$InputTypeModule$.$InputTypeClass$.FromString,\n",
            "InputTypeModule", input_message_module_and_class->second.first,
            "InputTypeClass", input_message_module_and_class->second.second);
        out->Print(
            "$OutputTypeModule$.$OutputTypeClass$.SerializeToString,\n",
            "OutputTypeModule", output_message_module_and_class->second.first,
            "OutputTypeClass", output_message_module_and_class->second.second);
      }
      out->Print("),\n");
    }
    out->Print("}\n");
    out->Print(
        "return implementations.server("
        "\"$PackageQualifiedServiceName$\","
        " method_service_descriptions, port, private_key=private_key,"
        " certificate_chain=certificate_chain)\n",
        "PackageQualifiedServiceName", package_qualified_service_name);
  }
  return true;
}

bool PrintStubFactory(const grpc::string& package_qualified_service_name,
                      const ServiceDescriptor* service, Printer* out) {
  map<grpc::string, grpc::string> dict = ListToDict({
        "Service", service->name(),
      });
  out->Print(dict, "def early_adopter_create_$Service$_stub(host, port,"
             " metadata_transformer=None,"
             " secure=False, root_certificates=None, private_key=None,"
             " certificate_chain=None, server_host_override=None):\n");
  {
    IndentScope raii_create_server_indent(out);
    map<grpc::string, grpc::string> method_description_constructors;
    map<grpc::string, pair<grpc::string, grpc::string>>
        input_message_modules_and_classes;
    map<grpc::string, pair<grpc::string, grpc::string>>
        output_message_modules_and_classes;
    for (int i = 0; i < service->method_count(); ++i) {
      const MethodDescriptor* method = service->method(i);
      const grpc::string method_description_constructor =
          grpc::string(method->client_streaming() ? "stream_" : "unary_") +
          grpc::string(method->server_streaming() ? "stream_" : "unary_") +
          "invocation_description";
      pair<grpc::string, grpc::string> input_message_module_and_class;
      if (!GetModuleAndMessagePath(method->input_type(),
                                   &input_message_module_and_class)) {
        return false;
      }
      pair<grpc::string, grpc::string> output_message_module_and_class;
      if (!GetModuleAndMessagePath(method->output_type(),
                                   &output_message_module_and_class)) {
        return false;
      }
      // Import the modules that define the messages used in RPCs.
      out->Print("import $Module$\n", "Module",
                 input_message_module_and_class.first);
      out->Print("import $Module$\n", "Module",
                 output_message_module_and_class.first);
      method_description_constructors.insert(
          make_pair(method->name(), method_description_constructor));
      input_message_modules_and_classes.insert(
          make_pair(method->name(), input_message_module_and_class));
      output_message_modules_and_classes.insert(
          make_pair(method->name(), output_message_module_and_class));
    }
    out->Print("method_invocation_descriptions = {\n");
    for (auto name_and_description_constructor =
	   method_description_constructors.begin();
	 name_and_description_constructor !=
	   method_description_constructors.end();
	 name_and_description_constructor++) {
      IndentScope raii_descriptions_indent(out);
      const grpc::string method_name = name_and_description_constructor->first;
      auto input_message_module_and_class =
          input_message_modules_and_classes.find(method_name);
      auto output_message_module_and_class =
          output_message_modules_and_classes.find(method_name);
      out->Print("\"$Method$\": utilities.$Constructor$(\n", "Method",
                 method_name, "Constructor",
                 name_and_description_constructor->second);
      {
        IndentScope raii_description_arguments_indent(out);
        out->Print(
            "$InputTypeModule$.$InputTypeClass$.SerializeToString,\n",
            "InputTypeModule", input_message_module_and_class->second.first,
            "InputTypeClass", input_message_module_and_class->second.second);
        out->Print(
            "$OutputTypeModule$.$OutputTypeClass$.FromString,\n",
            "OutputTypeModule", output_message_module_and_class->second.first,
            "OutputTypeClass", output_message_module_and_class->second.second);
      }
      out->Print("),\n");
    }
    out->Print("}\n");
    out->Print(
        "return implementations.stub("
        "\"$PackageQualifiedServiceName$\","
        " method_invocation_descriptions, host, port,"
        " metadata_transformer=metadata_transformer, secure=secure,"
        " root_certificates=root_certificates, private_key=private_key,"
        " certificate_chain=certificate_chain,"
        " server_host_override=server_host_override)\n",
        "PackageQualifiedServiceName", package_qualified_service_name);
  }
  return true;
}

bool PrintPreamble(const FileDescriptor* file,
                   const GeneratorConfiguration& config, Printer* out) {
  out->Print("import abc\n");
  out->Print("from $Package$ import implementations\n",
             "Package", config.implementations_package_root);
  out->Print("from grpc.framework.alpha import utilities\n");
  return true;
}

}  // namespace

pair<bool, grpc::string> GetServices(const FileDescriptor* file,
                                    const GeneratorConfiguration& config) {
  grpc::string output;
  {
    // Scope the output stream so it closes and finalizes output to the string.
    StringOutputStream output_stream(&output);
    Printer out(&output_stream, '$');
    if (!PrintPreamble(file, config, &out)) {
      return make_pair(false, "");
    }
    auto package = file->package();
    if (!package.empty()) {
      package = package.append(".");
    }
    for (int i = 0; i < file->service_count(); ++i) {
      auto service = file->service(i);
      auto package_qualified_service_name = package + service->name();
      if (!(PrintServicer(service, &out) &&
            PrintServer(service, &out) &&
            PrintStub(service, &out) &&
            PrintServerFactory(package_qualified_service_name, service, &out) &&
            PrintStubFactory(package_qualified_service_name, service, &out))) {
        return make_pair(false, "");
      }
    }
  }
  return make_pair(true, std::move(output));
}

}  // namespace grpc_python_generator