autogenpb/marshal.go

package main

import (
	"fmt"
	"io"
	"os"

	"go.wit.com/log"
)

// makes Marshal and Unmarshal functions for protoWIRE protoTEXT and protoJSON
func (pb *Files) marshal(f *File) {
	if argv.DryRun {
		return
	}

	w, _ := os.OpenFile(f.Filebase+".marshal.pb.go", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)

	headerComment(w)
	fmt.Fprintf(w, "package %s\n", f.Package)
	fmt.Fprintln(w, "import (")
	fmt.Fprintln(w, "	\"google.golang.org/protobuf/encoding/protojson\"")
	fmt.Fprintln(w, "	\"google.golang.org/protobuf/encoding/prototext\"")
	fmt.Fprintln(w, "	\"google.golang.org/protobuf/proto\"")
	fmt.Fprintln(w, ")")
	fmt.Fprintln(w, "")

	for _, msg := range f.MsgNames {
		if msg.DoMarshal {
			marshalThing(w, msg.Name)
		} else {
			log.Info("Skipping. DoMarshal = false for", msg.Name)
		}
	}
}

func marshalThing(w io.Writer, thing string) {
	fmt.Fprintln(w, "// human readable JSON")
	fmt.Fprintln(w, "func (v *"+thing+") FormatJSON() string {")
	fmt.Fprintln(w, "	return protojson.Format(v)")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// marshal json")
	fmt.Fprintln(w, "func (v *"+thing+") MarshalJSON() ([]byte, error) {")
	fmt.Fprintln(w, "	return protojson.Marshal(v)")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// unmarshal json")
	fmt.Fprintln(w, "func (v *"+thing+") UnmarshalJSON(data []byte) error {")
	fmt.Fprintln(w, "	return protojson.Unmarshal(data, v)")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// apparently this isn't stable, but it's awesomely better")
	fmt.Fprintln(w, "// https://protobuf.dev/reference/go/faq/#unstable-text")
	fmt.Fprintln(w, "// it's brilliant for config files!")
	fmt.Fprintln(w, "func (v *"+thing+") FormatTEXT() string {")
	fmt.Fprintln(w, "	return prototext.Format(v)")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// unmarshalTEXT. This reads the .text config file back in after the user edits it")
	fmt.Fprintln(w, "func (v *"+thing+") UnmarshalTEXT(data []byte) error {")
	fmt.Fprintln(w, "	return prototext.Unmarshal(data, v)")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// marshal to wire. This is called winning.")
	fmt.Fprintln(w, "func (v *"+thing+") Marshal() ([]byte, error) {")
	fmt.Fprintln(w, "	return proto.Marshal(v)")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
	fmt.Fprintln(w, "// unmarshal from wire. You have won.")
	fmt.Fprintln(w, "func (v *"+thing+") Unmarshal(data []byte) error {")
	fmt.Fprintln(w, "	return proto.Unmarshal(data, v)")
	fmt.Fprintln(w, "}")
	fmt.Fprintln(w, "")
}