accounts/abi/bind: refactored topics

accounts/abi/argument.go

@@ -292,7 +292,7 @@ func (arguments Arguments) UnpackValues(data []byte) ([]interface{}, error) {
 	retval := make([]interface{}, 0, arguments.LengthNonIndexed())
 	virtualArgs := 0
 	for index, arg := range arguments.NonIndexed() {
-		marshalledValue, err := toGoType((index+virtualArgs)*32, arg.Type, data)
+		marshalledValue, err := ToGoType((index+virtualArgs)*32, arg.Type, data)
 		if arg.Type.T == ArrayTy && !isDynamicType(arg.Type) {
 			// If we have a static array, like [3]uint256, these are coded as
 			// just like uint256,uint256,uint256.

accounts/abi/bind/topics.go

@@ -120,85 +120,16 @@ func parseTopics(out interface{}, fields abi.Arguments, topics []common.Hash) er
 		return errors.New("topic/field count mismatch")
 	}
 	// Iterate over all the fields and reconstruct them from topics
-	for _, arg := range fields {
+	for i, arg := range fields {
 		if !arg.Indexed {
 			return errors.New("non-indexed field in topic reconstruction")
 		}
 		field := reflect.ValueOf(out).Elem().FieldByName(capitalise(arg.Name))
-
+		reconstr, err := parseField(arg, topics[i])
-		// Try to parse the topic back into the fields based on primitive types
+		if err != nil {
-		switch field.Kind() {
+			return err
-		case reflect.Bool:
-			if topics[0][common.HashLength-1] == 1 {
-				field.Set(reflect.ValueOf(true))
-			}
-		case reflect.Int8:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(int8(num.Int64())))
-
-		case reflect.Int16:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(int16(num.Int64())))
-
-		case reflect.Int32:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(int32(num.Int64())))
-
-		case reflect.Int64:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(num.Int64()))
-
-		case reflect.Uint8:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(uint8(num.Uint64())))
-
-		case reflect.Uint16:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(uint16(num.Uint64())))
-
-		case reflect.Uint32:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(uint32(num.Uint64())))
-
-		case reflect.Uint64:
-			num := new(big.Int).SetBytes(topics[0][:])
-			field.Set(reflect.ValueOf(num.Uint64()))
-
-		default:
-			// Ran out of plain primitive types, try custom types
-
-			switch field.Type() {
-			case reflectHash: // Also covers all dynamic types
-				field.Set(reflect.ValueOf(topics[0]))
-
-			case reflectAddress:
-				var addr common.Address
-				copy(addr[:], topics[0][common.HashLength-common.AddressLength:])
-				field.Set(reflect.ValueOf(addr))
-
-			case reflectBigInt:
-				num := new(big.Int).SetBytes(topics[0][:])
-				if arg.Type.T == abi.IntTy {
-					if num.Cmp(abi.MaxInt256) > 0 {
-						num.Add(abi.MaxUint256, big.NewInt(0).Neg(num))
-						num.Add(num, big.NewInt(1))
-						num.Neg(num)
-					}
-				}
-				field.Set(reflect.ValueOf(num))
-
-			default:
-				// Ran out of custom types, try the crazies
-				switch {
-				// static byte array
-				case arg.Type.T == abi.FixedBytesTy:
-					reflect.Copy(field, reflect.ValueOf(topics[0][:arg.Type.Size]))
-				default:
-					return fmt.Errorf("unsupported indexed type: %v", arg.Type)
-				}
-			}
 		}
-		topics = topics[1:]
+		field.Set(reflect.ValueOf(reconstr))
 	}
 	return nil
 }
@@ -210,45 +141,38 @@ func parseTopicsIntoMap(out map[string]interface{}, fields abi.Arguments, topics
 		return errors.New("topic/field count mismatch")
 	}
 	// Iterate over all the fields and reconstruct them from topics
-	for _, arg := range fields {
+	for i, arg := range fields {
 		if !arg.Indexed {
 			return errors.New("non-indexed field in topic reconstruction")
 		}
-
+		reconstr, err := parseField(arg, topics[i])
-		switch arg.Type.T {
+		if err != nil {
-		case abi.BoolTy:
+			return err
-			out[arg.Name] = topics[0][common.HashLength-1] == 1
-		case abi.IntTy, abi.UintTy:
-			out[arg.Name] = abi.ReadInteger(arg.Type.T, arg.Type.Kind, topics[0].Bytes())
-		case abi.AddressTy:
-			var addr common.Address
-			copy(addr[:], topics[0][common.HashLength-common.AddressLength:])
-			out[arg.Name] = addr
-		case abi.HashTy:
-			out[arg.Name] = topics[0]
-		case abi.FixedBytesTy:
-			array, err := abi.ReadFixedBytes(arg.Type, topics[0].Bytes())
-			if err != nil {
-				return err
-			}
-			out[arg.Name] = array
-		case abi.StringTy, abi.BytesTy, abi.SliceTy, abi.ArrayTy:
-			// Array types (including strings and bytes) have their keccak256 hashes stored in the topic- not a hash
-			// whose bytes can be decoded to the actual value- so the best we can do is retrieve that hash
-			out[arg.Name] = topics[0]
-		case abi.FunctionTy:
-			if garbage := binary.BigEndian.Uint64(topics[0][0:8]); garbage != 0 {
-				return fmt.Errorf("bind: got improperly encoded function type, got %v", topics[0].Bytes())
-			}
-			var tmp [24]byte
-			copy(tmp[:], topics[0][8:32])
-			out[arg.Name] = tmp
-		default: // Not handling tuples
-			return fmt.Errorf("unsupported indexed type: %v", arg.Type)
 		}
-
+		out[arg.Name] = reconstr
-		topics = topics[1:]
 	}
 
 	return nil
 }
+
+func parseField(arg abi.Argument, topic common.Hash) (interface{}, error) {
+	if !arg.Indexed {
+		return nil, errors.New("non-indexed field in topic reconstruction")
+	}
+
+	switch arg.Type.T {
+	case abi.StringTy, abi.BytesTy, abi.SliceTy, abi.ArrayTy:
+		// Array types (including strings and bytes) have their keccak256 hashes stored in the topic- not a hash
+		// whose bytes can be decoded to the actual value- so the best we can do is retrieve that hash
+		return topic, nil
+	case abi.FunctionTy:
+		if garbage := binary.BigEndian.Uint64(topic[0:8]); garbage != 0 {
+			return nil, fmt.Errorf("bind: got improperly encoded function type, got %v", topic.Bytes())
+		}
+		var tmp [24]byte
+		copy(tmp[:], topic[8:32])
+		return tmp, nil
+	default:
+		return abi.ToGoType(0, arg.Type, topic.Bytes())
+	}
+}

accounts/abi/unpack.go

@@ -144,7 +144,7 @@ func forEachUnpack(t Type, output []byte, start, size int) (interface{}, error)
 	elemSize := getTypeSize(*t.Elem)
 
 	for i, j := start, 0; j < size; i, j = i+elemSize, j+1 {
-		inter, err := toGoType(i, *t.Elem, output)
+		inter, err := ToGoType(i, *t.Elem, output)
 		if err != nil {
 			return nil, err
 		}
@@ -161,7 +161,7 @@ func forTupleUnpack(t Type, output []byte) (interface{}, error) {
 	retval := reflect.New(t.Type).Elem()
 	virtualArgs := 0
 	for index, elem := range t.TupleElems {
-		marshalledValue, err := toGoType((index+virtualArgs)*32, *elem, output)
+		marshalledValue, err := ToGoType((index+virtualArgs)*32, *elem, output)
 		if elem.T == ArrayTy && !isDynamicType(*elem) {
 			// If we have a static array, like [3]uint256, these are coded as
 			// just like uint256,uint256,uint256.
@@ -187,9 +187,9 @@ func forTupleUnpack(t Type, output []byte) (interface{}, error) {
 	return retval.Interface(), nil
 }
 
-// toGoType parses the output bytes and recursively assigns the value of these bytes
+// ToGoType parses the output bytes and recursively assigns the value of these bytes
 // into a go type with accordance with the ABI spec.
-func toGoType(index int, t Type, output []byte) (interface{}, error) {
+func ToGoType(index int, t Type, output []byte) (interface{}, error) {
 	if index+32 > len(output) {
 		return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), index+32)
 	}