func (t *Transformer) toMsg(incoming interface{}, msg *message.Msg) error {
switch newMsg := incoming.(type) {
case map[string]interface{}: // we're a proper message.Msg, so copy the data over
msg.Op = message.OpTypeFromString(newMsg["op"].(string))
msg.Timestamp = newMsg["ts"].(int64)
msg.Namespace = newMsg["ns"].(string)
switch data := newMsg["data"].(type) {
case otto.Value:
exported, err := data.Export()
if err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return nil
}
d, err := mejson.Unmarshal(exported.(map[string]interface{}))
if err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return nil
}
msg.Data = map[string]interface{}(d)
case map[string]interface{}:
d, err := mejson.Unmarshal(data)
if err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return nil
}
msg.Data = map[string]interface{}(d)
default:
msg.Data = data
}
case bool: // skip this doc if we're a bool and we're false
if !newMsg {
msg.Op = message.Noop
return nil
}
default: // something went wrong
return fmt.Errorf("returned doc was not a map[string]interface{}")
}
return nil
}
func (t *Transformer) transformOne(msg *message.Msg) (*message.Msg, error) {
var (
doc interface{}
value otto.Value
outDoc otto.Value
result interface{}
err error
)
// short circuit for deletes and commands
if msg.Op == message.Command {
return msg, nil
}
now := time.Now().Nanosecond()
fullDoc := map[string]interface{}{
"data": msg.Data,
"ts": msg.Timestamp,
"op": msg.Op.String(),
}
if msg.IsMap() {
if doc, err = mejson.Marshal(msg.Data); err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return msg, nil
}
fullDoc["data"] = doc
}
if value, err = t.vm.ToValue(fullDoc); err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return msg, nil
}
// now that we have finished casting our map to a bunch of different types,
// lets run our transformer on the document
beforeVM := time.Now().Nanosecond()
if outDoc, err = t.vm.Call(`module.exports`, nil, value); err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return msg, nil
}
if result, err = outDoc.Export(); err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return msg, nil
}
afterVM := time.Now().Nanosecond()
fullDoc, ok := result.(map[string]interface{})
if !ok {
t.pipe.Err <- t.transformerError(ERROR, fmt.Errorf("returned doc was not a map[string]interface{}"), msg)
return msg, fmt.Errorf("returned doc was not a map[string]interface{}")
}
msg.Op = message.OpTypeFromString(fullDoc["op"].(string))
msg.Timestamp = fullDoc["ts"].(int64)
switch data := fullDoc["data"].(type) {
case otto.Value:
exported, err := data.Export()
if err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return msg, nil
}
d, err := mejson.Unmarshal(exported.(map[string]interface{}))
if err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return msg, nil
}
msg.Data = map[string]interface{}(d)
case map[string]interface{}:
d, err := mejson.Unmarshal(data)
if err != nil {
t.pipe.Err <- t.transformerError(ERROR, err, msg)
return msg, nil
}
msg.Data = map[string]interface{}(d)
default:
msg.Data = data
}
if t.debug {
then := time.Now().Nanosecond()
fmt.Printf("document transformed in %dus. %d to marshal, %d in the vm, %d to unmarshal\n", (then-now)/1000, (beforeVM-now)/1000, (afterVM-beforeVM)/1000, (then-afterVM)/1000)
}
return msg, nil
}