status-go/protocol/v1/decoder.go

71 lines
1.4 KiB
Go

package protocol
import (
"errors"
"fmt"
"io"
"github.com/russolsen/transit"
)
// NewMessageDecoder returns a new Transit decoder
// that can deserialize Message structs.
// More about Transit: https://github.com/cognitect/transit-format
func NewMessageDecoder(r io.Reader) *transit.Decoder {
decoder := transit.NewDecoder(r)
decoder.AddHandler(pairMessageTag, pairMessageHandler)
return decoder
}
const (
messageTag = "c4"
pairMessageTag = "p2"
)
func pairMessageHandler(d transit.Decoder, value interface{}) (interface{}, error) {
taggedValue, ok := value.(transit.TaggedValue)
if !ok {
return nil, errors.New("not a tagged value")
}
values, ok := taggedValue.Value.([]interface{})
if !ok {
return nil, errors.New("tagged value does not contain values")
}
pm := PairMessage{}
for idx, v := range values {
var ok bool
switch idx {
case 0:
pm.InstallationID, ok = v.(string)
case 1:
pm.DeviceType, ok = v.(string)
case 2:
pm.Name, ok = v.(string)
case 3:
pm.FCMToken, ok = v.(string)
default:
// skip any other values
ok = true
}
if !ok {
return nil, fmt.Errorf("invalid value for index: %d", idx)
}
}
return pm, nil
}
func setToString(set *transit.Set) ([]string, bool) {
result := make([]string, 0, len(set.Contents))
for _, item := range set.Contents {
val, ok := item.(string)
if !ok {
return nil, false
}
result = append(result, val)
}
return result, true
}