Merge pull request googleapis#1 from michaelbausor/generator-initial-commit

Generator initial commit

Author: michaelbausor

.gitignore

@@ -0,0 +1,16 @@
+# Common build output directory names
+.build/
+_build/
+build-output/
+
+# Common bazel output directories
+bazel-*
+
+# Common editor files
+*~
+*.swp
+
+# Ignore IDEA / IntelliJ files
+.idea/
+cmake-build-*/
+

BUILD.bazel

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+# Copyright 2019 Google Inc.  All rights reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])  # Apache 2.0
+
+exports_files([
+    "LICENSE",
+])
+

WORKSPACE

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+# Copyright 2019 Google Inc.  All rights reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+workspace(name = "com_google_gapic_generator_cpp")
+
+load(
+    "//:repositories.bzl",
+    "com_google_gapic_generator_cpp_repositories",
+)
+
+com_google_gapic_generator_cpp_repositories()
+
+bind(
+    name = "zlib",
+    actual = "@net_zlib//:zlib",
+)
+

generator/BUILD.bazel

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+# Copyright 2019 Google Inc.  All rights reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])  # Apache 2.0
+
+cc_library(
+    name = "cpp_gapic_generator",
+    srcs = [
+        "gapic_generator.cc",
+        "internal/gapic_utils.h",
+    ],
+    hdrs = [
+        "gapic_generator.h",
+    ],
+    deps = [
+        "@absl//absl/base",
+        "@absl//absl/strings",
+        "@com_google_protobuf//:protoc_lib",
+        "@api_common_protos//google/api:client_cc_proto",
+    ],
+)
+
+cc_binary(
+    name = "cpp_gapic_generator_plugin",
+    srcs = ["plugin.cc"],
+    deps = [
+        ":cpp_gapic_generator",
+    ],
+)
+
+cc_test(
+    name = "gapic_generator_unittest",
+    srcs = ["gapic_generator_unittest.cc"],
+    deps = [
+        "//generator:cpp_gapic_generator",
+        "@gtest//:gtest_main",
+    ],
+    data = glob(
+        ["testdata/**"],
+    ) + [
+        "@api_common_protos//google/api:client_proto",
+    ],
+)
+
+generator_unit_tests = [
+    "internal/gapic_utils_unittest.cc"
+]
+
+[cc_test(
+    name = "generator_" + test.replace("/", "_").replace(".cc", ""),
+    srcs = [test],
+    deps = [
+        "@absl//absl/base",
+        "@absl//absl/strings",
+        "//generator:cpp_gapic_generator",
+        "@gtest//:gtest_main",
+    ],
+) for test in generator_unit_tests]

generator/README.md

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+# API Client Generator for C++
+
+A generator for protocol buffer described APIs for and in C++.
+
+This is a generator for API client libraries for APIs specified by protocol buffers, such as those inside Google.
+It takes a protocol buffer (with particular annotations) and uses it to generate a client library.
+

generator/gapic_generator.cc

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+// Copyright 2019 Google Inc.  All rights reserved
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string>
+#include <map>
+#include <vector>
+
+#include "absl/strings/str_cat.h"
+#include "absl/strings/string_view.h"
+#include "absl/strings/str_replace.h"
+#include "generator/gapic_generator.h"
+#include "internal/gapic_utils.h"
+
+#include "google/api/client.pb.h"
+
+namespace pb = google::protobuf;
+
+namespace google {
+namespace api {
+namespace codegen {
+
+using Vars = std::map<std::string, std::string>;
+
+void SetServiceVars(
+    pb::ServiceDescriptor const* service,
+    std::map<std::string, std::string>& vars) {
+  vars["class_name"] = service->name();
+  vars["proto_file_name"] = service->file()->name();
+  vars["header_include_guard_const"] = absl::StrCat(service->name(), "_H_");
+  vars["class_comment_block"] = "// TODO: pull in comments";
+  vars["grpc_stub_fqn"] = internal::ProtoNameToCppName(service->full_name());
+  vars["service_endpoint"] = service->options().GetExtension(google::api::default_host);
+}
+
+void SetMethodVars(
+    pb::MethodDescriptor const* method,
+    std::map<std::string, std::string>& vars) {
+  vars["method_name"] = method->name();
+  vars["request_object"] = internal::ProtoNameToCppName(method->input_type()->full_name());
+  vars["response_object"] = internal::ProtoNameToCppName(method->output_type()->full_name());
+}
+
+std::vector<std::string> BuildHeaderIncludes(
+    pb::ServiceDescriptor const* /* service */) {
+  return std::vector<std::string>();
+}
+
+std::vector<std::string> BuildCCIncludes(
+    pb::ServiceDescriptor const* /* service */) {
+  return std::vector<std::string>();
+}
+
+std::vector<std::string> BuildNamespaces(
+    pb::ServiceDescriptor const* /* service */) {
+  return std::vector<std::string>();
+}
+
+void PrintMethods(
+    pb::ServiceDescriptor const* service,
+    std::map<std::string, std::string> vars,
+    pb::io::Printer* p,
+    char const* tmplt) {
+  for (int i = 0; i < service->method_count(); i++) {
+    const pb::MethodDescriptor* method = service->method(i);
+    SetMethodVars(method, vars);
+    p->Print(vars, tmplt);
+  }
+}
+
+bool GenerateClientHeaderFile(
+    pb::ServiceDescriptor const* service,
+    std::map<std::string, std::string> const& vars,
+    pb::io::Printer* p,
+    std::string * /* error */) {
+  auto includes = BuildHeaderIncludes(service);
+  auto namespaces = BuildNamespaces(service);
+
+  p->Print(vars,
+    "// Generated by the GAPIC C++ plugin.\n"
+    "// If you make any local changes, they will be lost.\n"
+    "// source: $proto_file_name$\n"
+    "#ifndef $header_include_guard_const$\n"
+    "#define $header_include_guard_const$");
+
+  for (auto include : includes) {
+    p->Print("\n#include $include$", "include", include);
+  }
+  for (auto nspace : namespaces) {
+    p->Print("\nnamespace $namespace$ {", "namespace", nspace);
+  }
+
+  p->Print(vars, "\n"
+    "$class_comment_block$\n"
+    "class $class_name$ {");
+
+  PrintMethods(service, vars, p, "");
+
+  p->Print(vars, "\n}; // $class_name$");
+
+  for (auto nspace : namespaces) {
+    p->Print("\n} // namespace $namespace$", "namespace", nspace);
+  }
+
+  p->Print(vars, "\n"
+    "#endif // $header_include_guard_const$\n");
+
+  return true;
+}
+
+bool GenerateClientCCFile(
+    pb::ServiceDescriptor const* service,
+    std::map<std::string, std::string> const& vars,
+    pb::io::Printer* p,
+    std::string * /* error */) {
+  auto includes = BuildCCIncludes(service);
+  auto namespaces = BuildNamespaces(service);
+
+  p->Print(vars,
+    "// Generated by the GAPIC C++ plugin.\n"
+    "// If you make any local changes, they will be lost.\n"
+    "// source: $proto_file_name$");
+
+  for (auto include : includes) {
+    p->Print("\n#include $include$", "include", include);
+  }
+  for (auto nspace : namespaces) {
+    p->Print("\nnamespace $namespace$ {", "namespace", nspace);
+  }
+
+  p->Print(vars, "\n"
+    "// TODO: add content");
+
+  for (auto nspace : namespaces) {
+    p->Print("\n} // namespace $namespace$", "namespace", nspace);
+  }
+
+  p->Print("\n");
+
+  return true;
+}
+
+bool GapicGenerator::Generate(pb::FileDescriptor const* file,
+                                 std::string const& /* parameter */,
+                                 pb::compiler::GeneratorContext* generator_context,
+                                 std::string* error) const {
+  if (file->options().cc_generic_services()) {
+    *error =
+        "cpp gapic proto compiler plugin does not work with generic "
+        "services. To generate cpp grpc APIs, please set \""
+        "cc_generic_service = false\".";
+    return false;
+  }
+
+  for (int i = 0; i < file->service_count(); i++) {
+    pb::ServiceDescriptor const* service = file->service(i);
+
+    // TODO(michaelbausor): initialize Vars with cross-file-descriptor
+    // configuration, e.g. metadata annotation.
+    std::map<std::string, std::string> vars;
+    SetServiceVars(service, vars);
+
+    std::string service_file_path = internal::ServiceNameToFilePath(
+        service->full_name());
+
+    std::string header_file_path = absl::StrCat(service_file_path, ".gapic.h");
+    std::unique_ptr<pb::io::ZeroCopyOutputStream> header_output(
+        generator_context->Open(header_file_path));
+    pb::io::Printer header_printer(header_output.get(), '$', NULL);
+    if (!GenerateClientHeaderFile(service, vars, &header_printer, error)) {
+      return false;
+    }
+
+    std::string cc_file_path = absl::StrCat(service_file_path, ".gapic.cc");
+    std::unique_ptr<pb::io::ZeroCopyOutputStream> cc_output(
+        generator_context->Open(cc_file_path));
+    pb::io::Printer cc_printer(cc_output.get(), '$', NULL);
+    if (!GenerateClientCCFile(service, vars, &cc_printer, error)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+} // namespace codegen
+} // namespace api
+} // namespace google

generator/gapic_generator.h

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+// Copyright 2019 Google Inc.  All rights reserved
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef GOOGLE_API_CODEGEN_GAPIC_GENERATOR_H_
+#define GOOGLE_API_CODEGEN_GAPIC_GENERATOR_H_
+
+#include <memory>
+#include <sstream>
+#include <string>
+
+#include "src/google/protobuf/compiler/code_generator.h"
+#include "src/google/protobuf/io/printer.h"
+#include "src/google/protobuf/io/zero_copy_stream.h"
+#include "src/google/protobuf/descriptor.h"
+#include "src/google/protobuf/descriptor.pb.h"
+#include "absl/strings/string_view.h"
+
+namespace google {
+namespace api {
+namespace codegen {
+
+/**
+ * Code generator that outputs a C++ GAPIC client from proto descriptors.
+ */
+class GapicGenerator : public google::protobuf::compiler::CodeGenerator {
+ public:
+  bool Generate(google::protobuf::FileDescriptor const* file,
+                std::string const& parameter,
+                google::protobuf::compiler::GeneratorContext* generator_context,
+                std::string* error) const override;
+};
+
+} // namespace codegen
+} // namespace api
+} // namespace google
+
+#endif // GOOGLE_API_CODEGEN_GAPIC_GENERATOR_H_