gob: delete some unused bits from the GobEncoder/GobDecoder code.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4631076

src/pkg/gob/decode.go

@@ -741,7 +741,7 @@ func (dec *Decoder) ignoreInterface(state *decoderState) {
 
 // decodeGobDecoder decodes something implementing the GobDecoder interface.
 // The data is encoded as a byte slice.
-func (dec *Decoder) decodeGobDecoder(state *decoderState, v reflect.Value, index int) {
+func (dec *Decoder) decodeGobDecoder(state *decoderState, v reflect.Value) {
 	// Read the bytes for the value.
 	b := make([]byte, state.decodeUint())
 	_, err := state.b.Read(b)
@@ -969,7 +969,7 @@ func (dec *Decoder) gobDecodeOpFor(ut *userTypeInfo) (*decOp, int) {
 		} else {
 			v = reflect.ValueOf(unsafe.Unreflect(rcvrType, p))
 		}
-		state.dec.decodeGobDecoder(state, v, methodIndex(rcvrType, gobDecodeMethodName))
+		state.dec.decodeGobDecoder(state, v)
 	}
 	return &op, int(ut.indir)
 

src/pkg/gob/encode.go

@@ -468,7 +468,7 @@ func (enc *Encoder) encodeInterface(b *bytes.Buffer, iv reflect.Value) {
 
 // encGobEncoder encodes a value that implements the GobEncoder interface.
 // The data is sent as a byte array.
-func (enc *Encoder) encodeGobEncoder(b *bytes.Buffer, v reflect.Value, index int) {
+func (enc *Encoder) encodeGobEncoder(b *bytes.Buffer, v reflect.Value) {
 	// TODO: should we catch panics from the called method?
 	// We know it's a GobEncoder, so just call the method directly.
 	data, err := v.Interface().(GobEncoder).GobEncode()
@@ -592,17 +592,6 @@ func (enc *Encoder) encOpFor(rt reflect.Type, inProgress map[reflect.Type]*encOp
 	return &op, indir
 }
 
-// methodIndex returns which method of rt implements the method.
-func methodIndex(rt reflect.Type, method string) int {
-	for i := 0; i < rt.NumMethod(); i++ {
-		if rt.Method(i).Name == method {
-			return i
-		}
-	}
-	errorf("internal error: can't find method %s", method)
-	return 0
-}
-
 // gobEncodeOpFor returns the op for a type that is known to implement
 // GobEncoder.
 func (enc *Encoder) gobEncodeOpFor(ut *userTypeInfo) (*encOp, int) {
@@ -624,7 +613,7 @@ func (enc *Encoder) gobEncodeOpFor(ut *userTypeInfo) (*encOp, int) {
 			v = reflect.ValueOf(unsafe.Unreflect(rt, p))
 		}
 		state.update(i)
-		state.enc.encodeGobEncoder(state.b, v, methodIndex(rt, gobEncodeMethodName))
+		state.enc.encodeGobEncoder(state.b, v)
 	}
 	return &op, int(ut.encIndir) // encIndir: op will get called with p == address of receiver.
 }

src/pkg/gob/type.go

@@ -80,11 +80,6 @@ func validUserType(rt reflect.Type) (ut *userTypeInfo, err os.Error) {
 	return
 }
 
-const (
-	gobEncodeMethodName = "GobEncode"
-	gobDecodeMethodName = "GobDecode"
-)
-
 var (
 	gobEncoderInterfaceType = reflect.TypeOf(new(GobEncoder)).Elem()
 	gobDecoderInterfaceType = reflect.TypeOf(new(GobDecoder)).Elem()