2017-03-31 18:01:58 +02:00

145 lines
3.5 KiB
Go

package main
import (
"flag"
"fmt"
"io"
"io/ioutil"
"os"
"strings"
"github.com/golang/glog"
"github.com/golang/protobuf/proto"
plugin "github.com/golang/protobuf/protoc-gen-go/plugin"
"github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway/descriptor"
"github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger/genswagger"
)
var (
importPrefix = flag.String("import_prefix", "", "prefix to be added to go package paths for imported proto files")
file = flag.String("file", "stdin", "where to load data from")
allowDeleteBody = flag.Bool("allow_delete_body", false, "unless set, HTTP DELETE methods may not have a body")
)
func parseReq(r io.Reader) (*plugin.CodeGeneratorRequest, error) {
glog.V(1).Info("Parsing code generator request")
input, err := ioutil.ReadAll(r)
if err != nil {
glog.Errorf("Failed to read code generator request: %v", err)
return nil, err
}
req := new(plugin.CodeGeneratorRequest)
if err = proto.Unmarshal(input, req); err != nil {
glog.Errorf("Failed to unmarshal code generator request: %v", err)
return nil, err
}
glog.V(1).Info("Parsed code generator request")
return req, nil
}
func main() {
flag.Parse()
defer glog.Flush()
reg := descriptor.NewRegistry()
glog.V(1).Info("Processing code generator request")
f := os.Stdin
if *file != "stdin" {
f, _ = os.Open("input.txt")
}
req, err := parseReq(f)
if err != nil {
glog.Fatal(err)
}
pkgMap := make(map[string]string)
if req.Parameter != nil {
err := parseReqParam(req.GetParameter(), flag.CommandLine, pkgMap)
if err != nil {
glog.Fatalf("Error parsing flags: %v", err)
}
}
reg.SetPrefix(*importPrefix)
reg.SetAllowDeleteBody(*allowDeleteBody)
for k, v := range pkgMap {
reg.AddPkgMap(k, v)
}
g := genswagger.New(reg)
if err := reg.Load(req); err != nil {
emitError(err)
return
}
var targets []*descriptor.File
for _, target := range req.FileToGenerate {
f, err := reg.LookupFile(target)
if err != nil {
glog.Fatal(err)
}
targets = append(targets, f)
}
out, err := g.Generate(targets)
glog.V(1).Info("Processed code generator request")
if err != nil {
emitError(err)
return
}
emitFiles(out)
}
func emitFiles(out []*plugin.CodeGeneratorResponse_File) {
emitResp(&plugin.CodeGeneratorResponse{File: out})
}
func emitError(err error) {
emitResp(&plugin.CodeGeneratorResponse{Error: proto.String(err.Error())})
}
func emitResp(resp *plugin.CodeGeneratorResponse) {
buf, err := proto.Marshal(resp)
if err != nil {
glog.Fatal(err)
}
if _, err := os.Stdout.Write(buf); err != nil {
glog.Fatal(err)
}
}
// parseReqParam parses a CodeGeneratorRequest parameter and adds the
// extracted values to the given FlagSet and pkgMap. Returns a non-nil
// error if setting a flag failed.
func parseReqParam(param string, f *flag.FlagSet, pkgMap map[string]string) error {
if param == "" {
return nil
}
for _, p := range strings.Split(param, ",") {
spec := strings.SplitN(p, "=", 2)
if len(spec) == 1 {
if spec[0] == "allow_delete_body" {
err := f.Set(spec[0], "true")
if err != nil {
return fmt.Errorf("Cannot set flag %s: %v", p, err)
}
continue
}
err := f.Set(spec[0], "")
if err != nil {
return fmt.Errorf("Cannot set flag %s: %v", p, err)
}
continue
}
name, value := spec[0], spec[1]
if strings.HasPrefix(name, "M") {
pkgMap[name[1:]] = value
continue
}
if err := f.Set(name, value); err != nil {
return fmt.Errorf("Cannot set flag %s: %v", p, err)
}
}
return nil
}