Marshal/Unmarshal arguments and return values separately to allow struct tags to take effect for each codec

This commit is contained in:
Arsen Musayelyan 2022-08-06 22:48:42 -07:00
parent 5e61e89ac1
commit e02c8bc5ff
5 changed files with 114 additions and 85 deletions

View File

@ -26,7 +26,6 @@ import (
"sync"
"go.arsenm.dev/lrpc/codec"
"go.arsenm.dev/lrpc/internal/reflectutil"
"go.arsenm.dev/lrpc/internal/types"
"github.com/gofrs/uuid"
@ -81,12 +80,17 @@ func (c *Client) Call(ctx context.Context, rcvr, method string, arg interface{},
c.chs[idStr] = make(chan *types.Response, 1)
c.chMtx.Unlock()
argData, err := c.codec.Marshal(arg)
if err != nil {
return err
}
// Encode request using codec
err = c.codec.Encode(types.Request{
ID: idStr,
Receiver: rcvr,
Method: method,
Arg: arg,
Arg: argData,
})
if err != nil {
return err
@ -124,7 +128,11 @@ func (c *Client) Call(ctx context.Context, rcvr, method string, arg interface{},
return ErrReturnNotChannel
}
// Get channel ID returned in response
chID := resp.Return.(string)
var chID string
err = c.codec.Unmarshal(resp.Return, &chID)
if resp.Return == nil {
return nil
}
// Create new channel using channel ID
c.chMtx.Lock()
@ -149,21 +157,16 @@ func (c *Client) Call(ctx context.Context, rcvr, method string, arg interface{},
retVal.Close()
break
}
// Get reflect value from channel response
rVal := reflect.ValueOf(val.Return)
// If return value is not the same as the channel
if rVal.Type() != chElemType {
// Attempt to convert value, skip if impossible
newVal, err := reflectutil.Convert(rVal, chElemType)
if err != nil {
continue
}
rVal = newVal
outVal := reflect.New(chElemType)
err = c.codec.Unmarshal(val.Return, outVal.Interface())
if err != nil {
continue
}
outVal = outVal.Elem()
chosen, _, _ := reflect.Select([]reflect.SelectCase{
{Dir: reflect.SelectSend, Chan: retVal, Send: rVal},
{Dir: reflect.SelectSend, Chan: retVal, Send: outVal},
{Dir: reflect.SelectRecv, Chan: ctxDoneVal, Send: reflect.Value{}},
})
if chosen == 1 {
@ -179,28 +182,10 @@ func (c *Client) Call(ctx context.Context, rcvr, method string, arg interface{},
}
}()
} else if resp.Type == types.ResponseTypeNormal {
// IF return value is not a pointer, return error
if retVal.Kind() != reflect.Ptr {
return ErrReturnNotPointer
err = c.codec.Unmarshal(resp.Return, ret)
if err != nil {
return err
}
// Get return type
retType := retVal.Type().Elem()
// Get refkect value from response
rVal := reflect.ValueOf(resp.Return)
// If types do not match
if rVal.Type() != retType {
// Attempt to convert types, return error if not possible
newVal, err := reflectutil.Convert(rVal, retType)
if err != nil {
return err
}
rVal = newVal
}
// Set return value to received value
retVal.Elem().Set(rVal)
}
return nil

View File

@ -19,6 +19,7 @@
package codec
import (
"bytes"
"encoding/gob"
"encoding/json"
"io"
@ -38,42 +39,76 @@ type CodecFunc func(io.ReadWriter) Codec
type Codec interface {
Encode(val any) error
Decode(val any) error
Unmarshal(data []byte, v any) error
Marshal(v any) ([]byte, error)
}
// Default is the default CodecFunc
var Default = Msgpack
type JsonCodec struct {
*json.Encoder
*json.Decoder
}
func (JsonCodec) Unmarshal(data []byte, v any) error {
return json.Unmarshal(data, v)
}
func (JsonCodec) Marshal(v any) ([]byte, error) {
return json.Marshal(v)
}
// JSON is a CodecFunc that creates a JSON Codec
func JSON(rw io.ReadWriter) Codec {
type jsonCodec struct {
*json.Encoder
*json.Decoder
}
return jsonCodec{
return JsonCodec{
Encoder: json.NewEncoder(rw),
Decoder: json.NewDecoder(rw),
}
}
type MsgpackCodec struct {
*msgpack.Encoder
*msgpack.Decoder
}
func (MsgpackCodec) Unmarshal(data []byte, v any) error {
return msgpack.Unmarshal(data, v)
}
func (MsgpackCodec) Marshal(v any) ([]byte, error) {
return msgpack.Marshal(v)
}
// Msgpack is a CodecFunc that creates a Msgpack Codec
func Msgpack(rw io.ReadWriter) Codec {
type msgpackCodec struct {
*msgpack.Encoder
*msgpack.Decoder
}
return msgpackCodec{
return MsgpackCodec{
Encoder: msgpack.NewEncoder(rw),
Decoder: msgpack.NewDecoder(rw),
}
}
type GobCodec struct {
*gob.Encoder
*gob.Decoder
}
func (GobCodec) Unmarshal(data []byte, v any) error {
return gob.NewDecoder(bytes.NewReader(data)).Decode(v)
}
func (GobCodec) Marshal(v any) ([]byte, error) {
buf := &bytes.Buffer{}
err := gob.NewEncoder(buf).Encode(v)
if err != nil {
return nil, err
}
return buf.Bytes(), nil
}
// Gob is a CodecFunc that creates a Gob Codec
func Gob(rw io.ReadWriter) Codec {
type gobCodec struct {
*gob.Encoder
*gob.Decoder
}
return gobCodec{
return GobCodec{
Encoder: gob.NewEncoder(rw),
Decoder: gob.NewDecoder(rw),
}

View File

@ -26,7 +26,7 @@ type Request struct {
ID string
Receiver string
Method string
Arg any
Arg []byte
}
type ResponseType uint8
@ -43,5 +43,5 @@ type Response struct {
Type ResponseType
ID string
Error string
Return any
Return []byte
}

View File

@ -122,7 +122,7 @@ func TestCodecs(t *testing.T) {
if err != nil {
t.Errorf("codec/%s: %v", name, err)
}
if add != 4 {
t.Errorf("codec/%s: add: expected 4, got %d", name, add)
}

View File

@ -28,7 +28,6 @@ import (
"sync"
"go.arsenm.dev/lrpc/codec"
"go.arsenm.dev/lrpc/internal/reflectutil"
"go.arsenm.dev/lrpc/internal/types"
"golang.org/x/net/websocket"
)
@ -37,12 +36,11 @@ import (
type any = interface{}
var (
ErrInvalidType = errors.New("type must be struct or pointer to struct")
ErrNoSuchReceiver = errors.New("no such receiver registered")
ErrNoSuchMethod = errors.New("no such method was found")
ErrInvalidMethod = errors.New("method invalid for lrpc call")
ErrUnexpectedArgument = errors.New("argument provided but the function does not accept any arguments")
ErrArgNotProvided = errors.New("method expected an argument, but none was provided")
ErrInvalidType = errors.New("type must be struct or pointer to struct")
ErrNoSuchReceiver = errors.New("no such receiver registered")
ErrNoSuchMethod = errors.New("no such method was found")
ErrInvalidMethod = errors.New("method invalid for lrpc call")
ErrArgNotProvided = errors.New("method expected an argument, but none was provided")
)
// Server is an lrpc server
@ -101,7 +99,7 @@ func (s *Server) Register(v any) error {
}
// execute runs a method of a registered value
func (s *Server) execute(pCtx context.Context, typ string, name string, arg any, c codec.Codec) (a any, ctx *Context, err error) {
func (s *Server) execute(pCtx context.Context, typ string, name string, data []byte, c codec.Codec) (a any, ctx *Context, err error) {
// Try to get value from receivers map
val, ok := s.rcvrs[typ]
if !ok {
@ -122,29 +120,19 @@ func (s *Server) execute(pCtx context.Context, typ string, name string, arg any,
// Get method type
mtdType := mtd.Type()
// Return error if argument provided but isn't expected
if mtdType.NumIn() == 1 && arg != nil {
return nil, nil, ErrUnexpectedArgument
}
//TODO: if arg not nil but fn has no arg, err
// IF argument is []any
anySlice, ok := arg.([]any)
if ok {
// Convert slice to the method's arg type and
// set arg to the newly-converted slice
arg = reflectutil.ConvertSlice(anySlice, mtdType.In(1))
}
argType := mtdType.In(1)
argVal := reflect.New(argType)
arg := argVal.Interface()
// Get argument value
argVal := reflect.ValueOf(arg)
// If argument's type does not match method's argument type
if arg != nil && argVal.Type() != mtdType.In(1) {
val, err = reflectutil.Convert(argVal, mtdType.In(1))
if err != nil {
return nil, nil, err
}
arg = val.Interface()
err = c.Unmarshal(data, arg)
if err != nil {
return nil, nil, err
}
arg = argVal.Elem().Interface()
ctx = newContext(pCtx, c)
// Get reflect value of context
@ -327,18 +315,30 @@ func (s *Server) handleConn(pCtx context.Context, c codec.Codec) {
if err != nil {
s.sendErr(c, call, val, err)
} else {
valData, err := c.Marshal(val)
if err != nil {
s.sendErr(c, call, val, err)
continue
}
// Create response
res := types.Response{
ID: call.ID,
Return: val,
Return: valData,
}
// If function has created a channel
if ctx.isChannel {
idData, err := c.Marshal(ctx.channelID)
if err != nil {
s.sendErr(c, call, val, err)
continue
}
// Set IsChannel to true
res.Type = types.ResponseTypeChannel
// Overwrite return value with channel ID
res.Return = ctx.channelID
res.Return = idData
// Store context in map for future use
s.contextsMtx.Lock()
@ -349,11 +349,18 @@ func (s *Server) handleConn(pCtx context.Context, c codec.Codec) {
// For every value received from channel
for val := range ctx.channel {
codecMtx.Lock()
valData, err := c.Marshal(val)
if err != nil {
continue
}
// Encode response using codec
c.Encode(types.Response{
ID: ctx.channelID,
Return: val,
Return: valData,
})
codecMtx.Unlock()
}
@ -383,12 +390,14 @@ func (s *Server) handleConn(pCtx context.Context, c codec.Codec) {
// sendErr sends an error response
func (s *Server) sendErr(c codec.Codec, req types.Request, val any, err error) {
valData, _ := c.Marshal(val)
// Encode error response using codec
c.Encode(types.Response{
Type: types.ResponseTypeError,
ID: req.ID,
Error: err.Error(),
Return: val,
Return: valData,
})
}