Support for Golang GRPC (Experimental) (#4082)
* support for grpc golang
* refactored grpc go generator
* added grpc-go test and refactored
* refactored idl_gen_grpc.cpp
* fixed grpc generate method name
* refactored flatc and fixed line length issue
* added codec to go lib and fixed formatting issues
* fixed spacing issues
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 835aa3e..7a6b370 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -50,6 +50,8 @@
grpc/src/compiler/schema_interface.h
grpc/src/compiler/cpp_generator.h
grpc/src/compiler/cpp_generator.cc
+ grpc/src/compiler/go_generator.h
+ grpc/src/compiler/go_generator.cc
)
set(FlatHash_SRCS
diff --git a/go/grpc.go b/go/grpc.go
new file mode 100644
index 0000000..07d374b
--- /dev/null
+++ b/go/grpc.go
@@ -0,0 +1,23 @@
+package flatbuffers
+
+// FlatbuffersCodec implements gRPC-go Codec which is used to encode and decode messages.
+var Codec string = "flatbuffers"
+
+type FlatbuffersCodec struct{}
+
+func (FlatbuffersCodec) Marshal(v interface{}) ([]byte, error) {
+ return v.(*Builder).FinishedBytes(), nil
+}
+
+func (FlatbuffersCodec) Unmarshal(data []byte, v interface{}) error {
+ v.(flatbuffersInit).Init(data, GetUOffsetT(data))
+ return nil
+}
+
+func (FlatbuffersCodec) String() string {
+ return Codec
+}
+
+type flatbuffersInit interface {
+ Init(data []byte, i UOffsetT)
+}
diff --git a/grpc/src/compiler/go_generator.cc b/grpc/src/compiler/go_generator.cc
new file mode 100644
index 0000000..a35e572
--- /dev/null
+++ b/grpc/src/compiler/go_generator.cc
@@ -0,0 +1,437 @@
+/*
+ *
+ * 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 AN/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 <map>
+#include <cctype>
+#include <sstream>
+
+#include "src/compiler/go_generator.h"
+
+template <class T>
+grpc::string as_string(T x) {
+ std::ostringstream out;
+ out << x;
+ return out.str();
+}
+
+namespace grpc_go_generator {
+
+// Returns string with first letter to lowerCase
+grpc::string unexportName(grpc::string s) {
+ if (s.size() <= 0)
+ return s;
+ s[0] = std::tolower(s[0]);
+ return s;
+}
+
+// Returns string with first letter to uppercase
+grpc::string exportName(grpc::string s) {
+ if (s.size() <= 0)
+ return s;
+ s[0] = std::toupper(s[0]);
+ return s;
+}
+
+// Generates imports for the service
+void GenerateImports(grpc_generator::File *file, grpc_generator::Printer *printer,
+ std::map<grpc::string, grpc::string> vars) {
+ vars["filename"] = file->filename();
+ printer->Print("//Generated by gRPC Go plugin\n");
+ printer->Print("//If you make any local changes, they will be lost\n");
+ printer->Print(vars, "//source: $filename$\n\n");
+ printer->Print(vars, "package $Package$\n\n");
+ if (file->additional_imports() != "") {
+ printer->Print(file->additional_imports().c_str());
+ printer->Print("\n\n");
+ }
+ printer->Print("import (\n");
+ printer->Indent();
+ printer->Print(vars, "$context$ \"golang.org/x/net/context\"\n");
+ printer->Print(vars, "$grpc$ \"google.golang.org/grpc\"\n");
+ printer->Outdent();
+ printer->Print(")\n\n");
+}
+
+// Generates Server method signature source
+void GenerateServerMethodSignature(const grpc_generator::Method *method, grpc_generator::Printer *printer,
+ std::map<grpc::string, grpc::string> vars) {
+ vars["Method"] = exportName(method->name());
+ vars["Request"] = method->input_name();
+ vars["Response"] = (vars["CustomMethodIO"] == "") ? method->output_name() : vars["CustomMethodIO"];
+ if (method->NoStreaming()) {
+ printer->Print(vars, "$Method$($context$.Context, *$Request$) (*$Response$, error)");
+ } else if (method->ServerOnlyStreaming()) {
+ printer->Print(vars, "$Method$(*$Request$, $Service$_$Method$Server) error");
+ } else {
+ printer->Print(vars, "$Method$($Service$_$Method$Server) error");
+ }
+}
+
+void GenerateServerMethod(const grpc_generator::Method *method, grpc_generator::Printer *printer,
+ std::map<grpc::string, grpc::string> vars) {
+ vars["Method"] = exportName(method->name());
+ vars["Request"] = method->input_name();
+ vars["Response"] = (vars["CustomMethodIO"] == "") ? method->output_name() : vars["CustomMethodIO"];
+ vars["FullMethodName"] = "/" + vars["Package"] + "." + vars["Service"] + "/" + vars["Method"];
+ vars["Handler"] = "_" + vars["Service"] + "_" + vars["Method"] + "_Handler";
+ if (method->NoStreaming()) {
+ printer->Print(vars, "func $Handler$(srv interface{}, ctx $context$.Context,\n\tdec func(interface{}) error, interceptor $grpc$.UnaryServerInterceptor) (interface{}, error) {\n");
+ printer->Indent();
+ printer->Print(vars, "in := new($Request$)\n");
+ printer->Print("if err := dec(in); err != nil { return nil, err }\n");
+ printer->Print(vars, "if interceptor == nil { return srv.($Service$Server).$Method$(ctx, in) }\n");
+ printer->Print(vars, "info := &$grpc$.UnaryServerInfo{\n");
+ printer->Indent();
+ printer->Print("Server: srv,\n");
+ printer->Print(vars, "FullMethod: \"$FullMethodName$\",\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ printer->Print(vars, "handler := func(ctx $context$.Context, req interface{}) (interface{}, error) {\n");
+ printer->Indent();
+ printer->Print(vars, "return srv.($Service$Server).$Method$(ctx, req.(* $Request$))\n");
+ printer->Outdent();
+ printer->Print("}\n");
+ printer->Print("return interceptor(ctx, in, info, handler)\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ return;
+ }
+ vars["StreamType"] = vars["ServiceUnexported"] + vars["Method"] + "Server";
+ printer->Print(vars, "func $Handler$(srv interface{}, stream $grpc$.ServerStream) error {\n");
+ printer->Indent();
+ if (method->ServerOnlyStreaming()) {
+ printer->Print(vars, "m := new($Request$)\n");
+ printer->Print(vars, "if err := stream.RecvMsg(m); err != nil { return err }\n");
+ printer->Print(vars, "return srv.($Service$Server).$Method$(m, &$StreamType${stream})\n");
+ } else {
+ printer->Print(vars, "return srv.($Service$Server).$Method$(&$StreamType${stream})\n");
+ }
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ bool genSend = method->BidiStreaming() || method->ServerOnlyStreaming();
+ bool genRecv = method->BidiStreaming() || method->ClientOnlyStreaming();
+ bool genSendAndClose = method->ClientOnlyStreaming();
+
+ printer->Print(vars, "type $Service$_$Method$Server interface { \n");
+ printer->Indent();
+ if (genSend) {
+ printer->Print(vars, "Send(* $Response$) error\n");
+ }
+ if (genRecv) {
+ printer->Print(vars, "Recv() (* $Request$, error)\n");
+ }
+ if (genSendAndClose) {
+ printer->Print(vars, "SendAndClose(* $Response$) error\n");
+ }
+ printer->Print(vars, "$grpc$.ServerStream\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ printer->Print(vars, "type $StreamType$ struct {\n");
+ printer->Indent();
+ printer->Print(vars, "$grpc$.ServerStream\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ if (genSend) {
+ printer->Print(vars, "func (x *$StreamType$) Send(m *$Response$) error {\n");
+ printer->Indent();
+ printer->Print("return x.ServerStream.SendMsg(m)\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ }
+ if (genRecv) {
+ printer->Print(vars, "func (x *$StreamType$) Recv() (*$Request$, error) {\n");
+ printer->Indent();
+ printer->Print(vars, "m := new($Request$)\n");
+ printer->Print("if err := x.ServerStream.RecvMsg(m); err != nil { return nil, err }\n");
+ printer->Print("return m, nil\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ }
+ if (genSendAndClose) {
+ printer->Print(vars, "func (x *$StreamType$) SendAndClose(m *$Response$) error {\n");
+ printer->Indent();
+ printer->Print("return x.ServerStream.SendMsg(m)\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ }
+
+}
+
+// Generates Client method signature source
+void GenerateClientMethodSignature(const grpc_generator::Method *method, grpc_generator::Printer *printer,
+ std::map<grpc::string, grpc::string> vars) {
+ vars["Method"] = exportName(method->name());
+ vars["Request"] = ", in *" + ((vars["CustomMethodIO"] == "") ? method->input_name() : vars["CustomMethodIO"]);
+ if (method->ClientOnlyStreaming() || method->BidiStreaming()) {
+ vars["Request"] = "";
+ }
+ vars["Response"] = "* " + method->output_name();
+ if (method->ClientOnlyStreaming() || method->BidiStreaming() || method->ServerOnlyStreaming()) {
+ vars["Response"] = vars["Service"] + "_" + vars["Method"] + "Client" ;
+ }
+ printer->Print(vars, "$Method$(ctx $context$.Context$Request$, \n\topts... $grpc$.CallOption) ($Response$, error)");
+}
+
+// Generates Client method source
+void GenerateClientMethod(const grpc_generator::Method *method, grpc_generator::Printer *printer,
+ std::map<grpc::string, grpc::string> vars) {
+ printer->Print(vars, "func (c *$ServiceUnexported$Client) ");
+ GenerateClientMethodSignature(method, printer, vars);
+ printer->Print(" {\n");
+ printer->Indent();
+ vars["Method"] = exportName(method->name());
+ vars["Request"] = (vars["CustomMethodIO"] == "") ? method->input_name() : vars["CustomMethodIO"];
+ vars["Response"] = method->output_name();
+ vars["FullMethodName"] = "/" + vars["Package"] + "." + vars["Service"] + "/" + vars["Method"];
+ if (method->NoStreaming()) {
+ printer->Print(vars, "out := new($Response$)\n");
+ printer->Print(vars, "err := $grpc$.Invoke(ctx, \"$FullMethodName$\", in, out, c.cc, opts...)\n");
+ printer->Print("if err != nil { return nil, err }\n");
+ printer->Print("return out, nil\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ return;
+ }
+ vars["StreamType"] = vars["ServiceUnexported"] + vars["Method"] + "Client";
+ printer->Print(vars, "stream, err := $grpc$.NewClientStream(ctx, &$MethodDesc$, c.cc, \"$FullMethodName$\", opts...)\n");
+ printer->Print("if err != nil { return nil, err }\n");
+
+ printer->Print(vars, "x := &$StreamType${stream}\n");
+ if (method->ServerOnlyStreaming()) {
+ printer->Print("if err := x.ClientStream.SendMsg(in); err != nil { return nil, err }\n");
+ printer->Print("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }\n");
+ }
+ printer->Print("return x,nil\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ bool genSend = method->BidiStreaming() || method->ClientOnlyStreaming();
+ bool genRecv = method->BidiStreaming() || method->ServerOnlyStreaming();
+ bool genCloseAndRecv = method->ClientOnlyStreaming();
+
+ //Stream interface
+ printer->Print(vars, "type $Service$_$Method$Client interface {\n");
+ printer->Indent();
+ if (genSend) {
+ printer->Print(vars, "Send(*$Request$) error\n");
+ }
+ if (genRecv) {
+ printer->Print(vars, "Recv() (*$Response$, error)\n");
+ }
+ if (genCloseAndRecv) {
+ printer->Print(vars, "CloseAndRecv() (*$Response$, error)\n");
+ }
+ printer->Print(vars, "$grpc$.ClientStream\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ //Stream Client
+ printer->Print(vars, "type $StreamType$ struct{\n");
+ printer->Indent();
+ printer->Print(vars, "$grpc$.ClientStream\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ if (genSend) {
+ printer->Print(vars, "func (x *$StreamType$) Send(m *$Request$) error {\n");
+ printer->Indent();
+ printer->Print("return x.ClientStream.SendMsg(m)\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ }
+
+ if (genRecv) {
+ printer->Print(vars, "func (x *$StreamType$) Recv() (*$Response$, error) {\n");
+ printer->Indent();
+ printer->Print(vars, "m := new($Response$)\n");
+ printer->Print("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }\n");
+ printer->Print("return m, nil\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ }
+
+ if (genCloseAndRecv) {
+ printer->Print(vars, "func (x *$StreamType$) CloseAndRecv() (*$Response$, error) {\n");
+ printer->Indent();
+ printer->Print("if err := x.ClientStream.CloseSend(); err != nil { return nil, err }\n");
+ printer->Print(vars, "m := new ($Response$)\n");
+ printer->Print("if err := x.ClientStream.RecvMsg(m); err != nil { return nil, err }\n");
+ printer->Print("return m, nil\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+ }
+}
+
+// Generates client API for the service
+void GenerateService(const grpc_generator::Service *service, grpc_generator::Printer* printer,
+ std::map<grpc::string, grpc::string> vars) {
+ vars["Service"] = exportName(service->name());
+ // Client Interface
+ printer->Print(vars, "// Client API for $Service$ service\n");
+ printer->Print(vars, "type $Service$Client interface{\n");
+ printer->Indent();
+ for (int i = 0; i < service->method_count(); i++) {
+ GenerateClientMethodSignature(service->method(i).get(), printer, vars);
+ printer->Print("\n");
+ }
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ // Client structure
+ vars["ServiceUnexported"] = unexportName(vars["Service"]);
+ printer->Print(vars, "type $ServiceUnexported$Client struct {\n");
+ printer->Indent();
+ printer->Print(vars, "cc *$grpc$.ClientConn\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ // NewClient
+ printer->Print(vars, "func New$Service$Client(cc *$grpc$.ClientConn) $Service$Client {\n");
+ printer->Indent();
+ printer->Print(vars, "return &$ServiceUnexported$Client{cc}");
+ printer->Outdent();
+ printer->Print("\n}\n\n");
+
+ int unary_methods = 0, streaming_methods = 0;
+ vars["ServiceDesc"] = "_" + vars["Service"] + "_serviceDesc";
+ for (int i = 0; i < service->method_count(); i++) {
+ auto method = service->method(i);
+ if (method->NoStreaming()) {
+ vars["MethodDesc"] = vars["ServiceDesc"] + ".Method[" + as_string(unary_methods) + "]";
+ unary_methods++;
+ } else {
+ vars["MethodDesc"] = vars["ServiceDesc"] + ".Streams[" + as_string(streaming_methods) + "]";
+ streaming_methods++;
+ }
+ GenerateClientMethod(method.get(), printer, vars);
+ }
+
+ //Server Interface
+ printer->Print(vars, "// Server API for $Service$ service\n");
+ printer->Print(vars, "type $Service$Server interface {\n");
+ printer->Indent();
+ for (int i = 0; i < service->method_count(); i++) {
+ GenerateServerMethodSignature(service->method(i).get(), printer, vars);
+ printer->Print("\n");
+ }
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ // Server registration.
+ printer->Print(vars, "func Register$Service$Server(s *$grpc$.Server, srv $Service$Server) {\n");
+ printer->Indent();
+ printer->Print(vars, "s.RegisterService(&$ServiceDesc$, srv)\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+ for (int i = 0; i < service->method_count(); i++) {
+ GenerateServerMethod(service->method(i).get(), printer, vars);
+ printer->Print("\n");
+ }
+
+
+ //Service Descriptor
+ printer->Print(vars, "var $ServiceDesc$ = $grpc$.ServiceDesc{\n");
+ printer->Indent();
+ printer->Print(vars, "ServiceName: \"$Package$.$Service$\",\n");
+ printer->Print(vars, "HandlerType: (*$Service$Server)(nil),\n");
+ printer->Print(vars, "Methods: []$grpc$.MethodDesc{\n");
+ printer->Indent();
+ for (int i = 0; i < service->method_count(); i++) {
+ auto method = service->method(i);
+ vars["Method"] = method->name();
+ vars["Handler"] = "_" + vars["Service"] + "_" + vars["Method"] + "_Handler";
+ if (method->NoStreaming()) {
+ printer->Print("{\n");
+ printer->Indent();
+ printer->Print(vars, "MethodName: \"$Method$\",\n");
+ printer->Print(vars, "Handler: $Handler$, \n");
+ printer->Outdent();
+ printer->Print("},\n");
+ }
+ }
+ printer->Outdent();
+ printer->Print("},\n");
+ printer->Print(vars, "Streams: []$grpc$.StreamDesc{\n");
+ printer->Indent();
+ for (int i = 0; i < service->method_count(); i++) {
+ auto method = service->method(i);
+ vars["Method"] = method->name();
+ vars["Handler"] = "_" + vars["Service"] + "_" + vars["Method"] + "_Handler";
+ if (!method->NoStreaming()) {
+ printer->Print("{\n");
+ printer->Indent();
+ printer->Print(vars, "StreamName: \"$Method$\",\n");
+ printer->Print(vars, "Handler: $Handler$, \n");
+ if (method->ClientOnlyStreaming()) {
+ printer->Print("ClientStreams: true,\n");
+ } else if (method->ServerOnlyStreaming()) {
+ printer->Print("ServerStreams: true,\n");
+ } else {
+ printer->Print("ServerStreams: true,\n");
+ printer->Print("ClientStreams: true,\n");
+ }
+ printer->Outdent();
+ printer->Print("},\n");
+ }
+ }
+ printer->Outdent();
+ printer->Print("},\n");
+ printer->Outdent();
+ printer->Print("}\n\n");
+
+}
+
+
+// Returns source for the service
+grpc::string GenerateServiceSource(grpc_generator::File *file,
+ const grpc_generator::Service *service,
+ grpc_go_generator::Parameters *parameters) {
+ grpc::string out;
+ auto p = file->CreatePrinter(&out);
+ auto printer = p.get();
+ std::map<grpc::string, grpc::string> vars;
+ vars["Package"] = parameters->package_name;
+ vars["grpc"] = "grpc";
+ vars["context"] = "context";
+ GenerateImports(file, printer, vars);
+ if (parameters->custom_method_io_type != "") {
+ vars["CustomMethodIO"] = parameters->custom_method_io_type;
+ }
+ GenerateService(service, printer, vars);
+ return out;
+}
+}// Namespace grpc_go_generator
\ No newline at end of file
diff --git a/grpc/src/compiler/go_generator.h b/grpc/src/compiler/go_generator.h
new file mode 100644
index 0000000..a8f7a3d
--- /dev/null
+++ b/grpc/src/compiler/go_generator.h
@@ -0,0 +1,61 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_COMPILER_GO_GENERATOR_H
+#define GRPC_INTERNAL_COMPILER_GO_GENERATOR_H
+
+//go generator is used to generate GRPC code for serialization system, such as flatbuffers
+#include <memory>
+#include <vector>
+
+#include "src/compiler/schema_interface.h"
+
+namespace grpc_go_generator {
+
+struct Parameters {
+ //Defines the custom parameter types for methods
+ //eg: flatbuffers uses flatbuffers.Builder as input for the client and output for the server
+ grpc::string custom_method_io_type;
+
+ //Package name for the service
+ grpc::string package_name;
+};
+
+// Return the source of the generated service file.
+grpc::string GenerateServiceSource(grpc_generator::File *file,
+ const grpc_generator::Service *service,
+ grpc_go_generator::Parameters *parameters);
+
+}
+
+#endif // GRPC_INTERNAL_COMPILER_GO_GENERATOR_H
diff --git a/grpc/src/compiler/schema_interface.h b/grpc/src/compiler/schema_interface.h
index e511ff5..c9b7f46 100644
--- a/grpc/src/compiler/schema_interface.h
+++ b/grpc/src/compiler/schema_interface.h
@@ -59,6 +59,8 @@
virtual grpc::string input_type_name() const = 0;
virtual grpc::string output_type_name() const = 0;
+ virtual grpc::string input_name() const = 0;
+ virtual grpc::string output_name() const = 0;
virtual bool NoStreaming() const = 0;
virtual bool ClientOnlyStreaming() const = 0;
@@ -98,6 +100,7 @@
virtual grpc::string package() const = 0;
virtual std::vector<grpc::string> package_parts() const = 0;
virtual grpc::string additional_headers() const = 0;
+ virtual grpc::string additional_imports() const = 0;
virtual int service_count() const = 0;
virtual std::unique_ptr<const Service> service(int i) const = 0;
diff --git a/grpc/tests/go_test.go b/grpc/tests/go_test.go
new file mode 100644
index 0000000..f133692
--- /dev/null
+++ b/grpc/tests/go_test.go
@@ -0,0 +1,94 @@
+package testing
+
+import (
+ "../../tests/MyGame/Example"
+
+ "net"
+ "testing"
+
+ "github.com/google/flatbuffers/go"
+ "golang.org/x/net/context"
+ "google.golang.org/grpc"
+)
+
+type server struct{}
+
+// test used to send and receive in grpc methods
+var test string = "Flatbuffers"
+var addr string = "0.0.0.0:50051"
+
+// gRPC server store method
+func (s *server) Store(context context.Context, in *Example.Monster) (*flatbuffers.Builder, error) {
+ b := flatbuffers.NewBuilder(0)
+ i := b.CreateString(test)
+ Example.StatStart(b)
+ Example.StatAddId(b, i)
+ b.Finish(Example.StatEnd(b))
+ return b, nil
+
+}
+
+// gRPC server retrieve method
+func (s *server) Retrieve(context context.Context, in *Example.Stat) (*flatbuffers.Builder, error) {
+ b := flatbuffers.NewBuilder(0)
+ i := b.CreateString(test)
+ Example.MonsterStart(b)
+ Example.MonsterAddName(b, i)
+ b.Finish(Example.MonsterEnd(b))
+ return b, nil
+}
+
+func StoreClient(c Example.MonsterStorageClient, t *testing.T) {
+ b := flatbuffers.NewBuilder(0)
+ i := b.CreateString(test)
+ Example.MonsterStart(b)
+ Example.MonsterAddName(b, i)
+ b.Finish(Example.MonsterEnd(b))
+ out, err := c.Store(context.Background(), b)
+ if err != nil {
+ t.Fatal("Store client failed: %v", err)
+ }
+ if string(out.Id()) != test {
+ t.Errorf("StoreClient failed: expected=%s, got=%s\n", test, out.Id())
+ t.Fail()
+ }
+}
+
+func RetrieveClient(c Example.MonsterStorageClient, t *testing.T) {
+ b := flatbuffers.NewBuilder(0)
+ i := b.CreateString(test)
+ Example.StatStart(b)
+ Example.StatAddId(b, i)
+ b.Finish(Example.StatEnd(b))
+ out, err := c.Retrieve(context.Background(), b)
+ if err != nil {
+ t.Fatal("Retrieve client failed: %v", err)
+ }
+ if string(out.Name()) != test {
+ t.Errorf("RetrieveClient failed: expected=%s, got=%s\n", test, out.Name())
+ t.Fail()
+ }
+}
+
+func TestGRPC(t *testing.T) {
+ lis, err := net.Listen("tcp", addr)
+ if err != nil {
+ t.Fatalf("Failed to listen: %v", err)
+ }
+ ser := grpc.NewServer(grpc.CustomCodec(flatbuffers.FlatbuffersCodec{}))
+ Example.RegisterMonsterStorageServer(ser, &server{})
+ go func() {
+ if err := ser.Serve(lis); err != nil {
+ t.Fatalf("Failed to serve: %v", err)
+ t.FailNow()
+ }
+ }()
+ conn, err := grpc.Dial(addr, grpc.WithInsecure(), grpc.WithCodec(flatbuffers.FlatbuffersCodec{}))
+ if err != nil {
+ t.Fatal("Failed to connect: %v", err)
+ }
+ defer conn.Close()
+ client := Example.NewMonsterStorageClient(conn)
+ StoreClient(client, t)
+ RetrieveClient(client, t)
+}
diff --git a/include/flatbuffers/idl.h b/include/flatbuffers/idl.h
index 1261031..6ae8dd2 100644
--- a/include/flatbuffers/idl.h
+++ b/include/flatbuffers/idl.h
@@ -649,8 +649,8 @@
// Generate Php code from the definitions in the Parser object.
// See idl_gen_php.
extern bool GeneratePhp(const Parser &parser,
- const std::string &path,
- const std::string &file_name);
+ const std::string &path,
+ const std::string &file_name);
// Generate Python files from the definitions in the Parser object.
// See idl_gen_python.cpp.
@@ -708,11 +708,17 @@
const std::string &path,
const std::string &file_name);
-// Generate GRPC interfaces.
+// Generate GRPC Cpp interfaces.
// See idl_gen_grpc.cpp.
-bool GenerateGRPC(const Parser &parser,
- const std::string &path,
- const std::string &file_name);
+bool GenerateCppGRPC(const Parser &parser,
+ const std::string &path,
+ const std::string &file_name);
+
+// Generate GRPC Go interfaces.
+// See idl_gen_grpc.cpp.
+bool GenerateGoGRPC(const Parser &parser,
+ const std::string &path,
+ const std::string &file_name);
} // namespace flatbuffers
diff --git a/src/flatc.cpp b/src/flatc.cpp
index 5f8340e..fae00de 100644
--- a/src/flatc.cpp
+++ b/src/flatc.cpp
@@ -33,6 +33,9 @@
const char *generator_opt_short;
const char *generator_opt_long;
const char *lang_name;
+ bool (*generateGRPC)(const flatbuffers::Parser &parser,
+ const std::string &path,
+ const std::string &file_name);
flatbuffers::IDLOptions::Language lang;
const char *generator_help;
@@ -43,45 +46,50 @@
const Generator generators[] = {
{ flatbuffers::GenerateBinary, "-b", "--binary", "binary",
+ nullptr,
flatbuffers::IDLOptions::kMAX,
"Generate wire format binaries for any data definitions",
flatbuffers::BinaryMakeRule },
{ flatbuffers::GenerateTextFile, "-t", "--json", "text",
+ nullptr,
flatbuffers::IDLOptions::kMAX,
"Generate text output for any data definitions",
flatbuffers::TextMakeRule },
{ flatbuffers::GenerateCPP, "-c", "--cpp", "C++",
+ flatbuffers::GenerateCppGRPC,
flatbuffers::IDLOptions::kMAX,
"Generate C++ headers for tables/structs",
flatbuffers::CPPMakeRule },
{ flatbuffers::GenerateGo, "-g", "--go", "Go",
+ flatbuffers::GenerateGoGRPC,
flatbuffers::IDLOptions::kGo,
"Generate Go files for tables/structs",
flatbuffers::GeneralMakeRule },
{ flatbuffers::GenerateGeneral, "-j", "--java", "Java",
+ nullptr,
flatbuffers::IDLOptions::kJava,
"Generate Java classes for tables/structs",
flatbuffers::GeneralMakeRule },
{ flatbuffers::GenerateJS, "-s", "--js", "JavaScript",
+ nullptr,
flatbuffers::IDLOptions::kMAX,
"Generate JavaScript code for tables/structs",
flatbuffers::JSMakeRule },
{ flatbuffers::GenerateGeneral, "-n", "--csharp", "C#",
+ nullptr,
flatbuffers::IDLOptions::kCSharp,
"Generate C# classes for tables/structs",
flatbuffers::GeneralMakeRule },
{ flatbuffers::GeneratePython, "-p", "--python", "Python",
+ nullptr,
flatbuffers::IDLOptions::kMAX,
"Generate Python files for tables/structs",
flatbuffers::GeneralMakeRule },
{ flatbuffers::GeneratePhp, nullptr, "--php", "PHP",
+ nullptr,
flatbuffers::IDLOptions::kMAX,
"Generate PHP files for tables/structs",
flatbuffers::GeneralMakeRule },
- { flatbuffers::GenerateGRPC, nullptr, "--grpc", "GRPC",
- flatbuffers::IDLOptions::kMAX,
- "Generate GRPC interfaces",
- flatbuffers::CPPMakeRule },
};
const char *g_program_name = nullptr;
@@ -170,6 +178,7 @@
bool print_make_rules = false;
bool raw_binary = false;
bool schema_binary = false;
+ bool grpc_enabled = false;
std::vector<std::string> filenames;
std::vector<const char *> include_directories;
std::vector<const char *> conform_include_directories;
@@ -243,6 +252,8 @@
} else if(arg == "--version") {
printf("flatc version %s\n", FLATC_VERSION);
exit(0);
+ } else if(arg == "--grpc") {
+ grpc_enabled = true;
} else {
for (size_t i = 0; i < num_generators; ++i) {
if (arg == generators[i].generator_opt_long ||
@@ -360,6 +371,17 @@
printf("%s\n", flatbuffers::WordWrap(
make_rule, 80, " ", " \\").c_str());
}
+ if (grpc_enabled) {
+ if (generators[i].generateGRPC != nullptr) {
+ if (!generators[i].generateGRPC(*g_parser, output_path, filebase)) {
+ Error(std::string("Unable to generate GRPC interface for") +
+ generators[i].lang_name);
+ }
+ } else {
+ Error(std::string("GRPC interface generator not implemented for ") +
+ generators[i].lang_name);
+ }
+ }
}
}
diff --git a/src/idl_gen_grpc.cpp b/src/idl_gen_grpc.cpp
index 9bcd5bc..a540b8b 100644
--- a/src/idl_gen_grpc.cpp
+++ b/src/idl_gen_grpc.cpp
@@ -19,8 +19,10 @@
#include "flatbuffers/flatbuffers.h"
#include "flatbuffers/idl.h"
#include "flatbuffers/util.h"
+#include "flatbuffers/code_generators.h"
#include "src/compiler/cpp_generator.h"
+#include "src/compiler/go_generator.h"
namespace flatbuffers {
@@ -52,6 +54,14 @@
return GRPCType(*method_->response);
}
+ std::string input_name() const {
+ return (*method_->request).name;
+ }
+
+ std::string output_name() const {
+ return (*method_->response).name;
+ }
+
bool NoStreaming() const { return streaming_ == kNone; }
bool ClientOnlyStreaming() const { return streaming_ == kClient; }
bool ServerOnlyStreaming() const { return streaming_ == kServer; }
@@ -159,6 +169,10 @@
return "#include \"flatbuffers/grpc.h\"\n";
}
+ std::string additional_imports() const {
+ return "import \"github.com/google/flatbuffers/go\"";
+ }
+
int service_count() const {
return static_cast<int>(parser_.services_.vec.size());
};
@@ -178,7 +192,47 @@
const std::string &file_name_;
};
-bool GenerateGRPC(const Parser &parser,
+class GoGRPCGenerator : public flatbuffers::BaseGenerator {
+ public:
+ GoGRPCGenerator(const Parser &parser, const std::string &path,
+ const std::string &file_name)
+ : BaseGenerator(parser, path, file_name, "", "" /*Unused*/),
+ parser_(parser), path_(path), file_name_(file_name) {}
+
+ bool generate() {
+ FlatBufFile file(parser_, file_name_);
+ grpc_go_generator::Parameters p;
+ p.custom_method_io_type = "flatbuffers.Builder";
+ for (int i = 0; i < file.service_count(); i++) {
+ auto service = file.service(i);
+ const Definition *def = parser_.services_.vec[i];
+ p.package_name = LastNamespacePart(*(def->defined_namespace));
+ std::string output = grpc_go_generator::GenerateServiceSource(&file, service.get(), &p);
+ std::string filename = NamespaceDir(*def->defined_namespace) + def->name + "_grpc.go";
+ if (!flatbuffers::SaveFile(filename.c_str(), output, false))
+ return false;
+ }
+ return true;
+ }
+
+ protected:
+ const Parser &parser_;
+ const std::string &path_, &file_name_;
+};
+
+bool GenerateGoGRPC(const Parser &parser,
+ const std::string &path,
+ const std::string &file_name) {
+ int nservices = 0;
+ for (auto it = parser.services_.vec.begin();
+ it != parser.services_.vec.end(); ++it) {
+ if (!(*it)->generated) nservices++;
+ }
+ if (!nservices) return true;
+ return GoGRPCGenerator(parser, path, file_name).generate();
+}
+
+bool GenerateCppGRPC(const Parser &parser,
const std::string &/*path*/,
const std::string &file_name) {
diff --git a/tests/MyGame/Example/MonsterStorage_grpc.go b/tests/MyGame/Example/MonsterStorage_grpc.go
new file mode 100644
index 0000000..8aac5c2
--- /dev/null
+++ b/tests/MyGame/Example/MonsterStorage_grpc.go
@@ -0,0 +1,106 @@
+//Generated by gRPC Go plugin
+//If you make any local changes, they will be lost
+//source: monster_test
+
+package Example
+
+import "github.com/google/flatbuffers/go"
+
+import (
+ context "golang.org/x/net/context"
+ grpc "google.golang.org/grpc"
+)
+
+// Client API for MonsterStorage service
+type MonsterStorageClient interface{
+ Store(ctx context.Context, in *flatbuffers.Builder,
+ opts... grpc.CallOption) (* Stat, error)
+ Retrieve(ctx context.Context, in *flatbuffers.Builder,
+ opts... grpc.CallOption) (* Monster, error)
+}
+
+type monsterStorageClient struct {
+ cc *grpc.ClientConn
+}
+
+func NewMonsterStorageClient(cc *grpc.ClientConn) MonsterStorageClient {
+ return &monsterStorageClient{cc}
+}
+
+func (c *monsterStorageClient) Store(ctx context.Context, in *flatbuffers.Builder,
+ opts... grpc.CallOption) (* Stat, error) {
+ out := new(Stat)
+ err := grpc.Invoke(ctx, "/Example.MonsterStorage/Store", in, out, c.cc, opts...)
+ if err != nil { return nil, err }
+ return out, nil
+}
+
+func (c *monsterStorageClient) Retrieve(ctx context.Context, in *flatbuffers.Builder,
+ opts... grpc.CallOption) (* Monster, error) {
+ out := new(Monster)
+ err := grpc.Invoke(ctx, "/Example.MonsterStorage/Retrieve", in, out, c.cc, opts...)
+ if err != nil { return nil, err }
+ return out, nil
+}
+
+// Server API for MonsterStorage service
+type MonsterStorageServer interface {
+ Store(context.Context, *Monster) (*flatbuffers.Builder, error)
+ Retrieve(context.Context, *Stat) (*flatbuffers.Builder, error)
+}
+
+func RegisterMonsterStorageServer(s *grpc.Server, srv MonsterStorageServer) {
+ s.RegisterService(&_MonsterStorage_serviceDesc, srv)
+}
+
+func _MonsterStorage_Store_Handler(srv interface{}, ctx context.Context,
+ dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+ in := new(Monster)
+ if err := dec(in); err != nil { return nil, err }
+ if interceptor == nil { return srv.(MonsterStorageServer).Store(ctx, in) }
+ info := &grpc.UnaryServerInfo{
+ Server: srv,
+ FullMethod: "/Example.MonsterStorage/Store",
+ }
+
+ handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+ return srv.(MonsterStorageServer).Store(ctx, req.(* Monster))
+ }
+ return interceptor(ctx, in, info, handler)
+}
+
+
+func _MonsterStorage_Retrieve_Handler(srv interface{}, ctx context.Context,
+ dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+ in := new(Stat)
+ if err := dec(in); err != nil { return nil, err }
+ if interceptor == nil { return srv.(MonsterStorageServer).Retrieve(ctx, in) }
+ info := &grpc.UnaryServerInfo{
+ Server: srv,
+ FullMethod: "/Example.MonsterStorage/Retrieve",
+ }
+
+ handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+ return srv.(MonsterStorageServer).Retrieve(ctx, req.(* Stat))
+ }
+ return interceptor(ctx, in, info, handler)
+}
+
+
+var _MonsterStorage_serviceDesc = grpc.ServiceDesc{
+ ServiceName: "Example.MonsterStorage",
+ HandlerType: (*MonsterStorageServer)(nil),
+ Methods: []grpc.MethodDesc{
+ {
+ MethodName: "Store",
+ Handler: _MonsterStorage_Store_Handler,
+ },
+ {
+ MethodName: "Retrieve",
+ Handler: _MonsterStorage_Retrieve_Handler,
+ },
+ },
+ Streams: []grpc.StreamDesc{
+ },
+}
+
