func readMessage(buf *streambuf.Buffer) (*message, error) {
if !buf.Avail(2) {
return nil, nil
}
version, _ := buf.ReadNetUint8At(0)
if version != '2' {
return nil, errors.New("version error")
}
code, _ := buf.ReadNetUint8At(1)
switch code {
case 'W':
if !buf.Avail(6) {
return nil, nil
}
size, _ := buf.ReadNetUint32At(2)
buf.Advance(6)
buf.Reset()
return &message{code: code, size: size}, buf.Err()
case 'C':
if !buf.Avail(6) {
return nil, nil
}
len, _ := buf.ReadNetUint32At(2)
if !buf.Avail(int(len) + 6) {
return nil, nil
}
buf.Advance(6)
tmp, _ := buf.Collect(int(len))
buf.Reset()
dataBuf := streambuf.New(nil)
// decompress data
decomp, err := zlib.NewReader(streambuf.NewFixed(tmp))
if err != nil {
return nil, err
}
// dataBuf.ReadFrom(streambuf.NewFixed(tmp))
dataBuf.ReadFrom(decomp)
decomp.Close()
// unpack data
dataBuf.Fix()
var events []*message
for dataBuf.Len() > 0 {
version, _ := dataBuf.ReadNetUint8()
if version != '2' {
return nil, errors.New("version error 2")
}
code, _ := dataBuf.ReadNetUint8()
if code != 'J' {
return nil, errors.New("expected json data frame")
}
seq, _ := dataBuf.ReadNetUint32()
payloadLen, _ := dataBuf.ReadNetUint32()
jsonRaw, _ := dataBuf.Collect(int(payloadLen))
var doc interface{}
err = json.Unmarshal(jsonRaw, &doc)
if err != nil {
return nil, err
}
events = append(events, &message{
code: code,
seq: seq,
doc: doc.(map[string]interface{}),
})
}
return &message{code: 'C', events: events}, nil
default:
return nil, errors.New("unknown code")
}
}