解析msgpack编码的单个切片的msgpack编码的切片时为空片

Question

I am trying to decode a gzip response from server which an msgpack array or msgpack array which is finally gzipped.

so to illustrate this my response looks something like:

gzip(msgpack([msgpack([]), msgpack([]), msgpack([]) ....]))

this is what I have done so far, but I am getting msgpack error

msgpack: invalid code=3f decoding array length and hence all I get is empty slices.

this getBytes function I have taken from this SO answer

func getBytes(key interface{}) ([]byte, error) {
    var buf bytes.Buffer
    enc := gob.NewEncoder(&buf)
    err := enc.Encode(key)
    if err != nil {
        return nil, err
    }
    return buf.Bytes(), nil
}

var unZipped io.Reader
unZipped, err = gzip.NewReader(resp.Body)
var dataBytes bytes.Buffer
_, err = dataBytes.ReadFrom(unZipped)
if err != nil {
    logger.Println("error un gzipping", err)
}
var packedSlices []interface{}
bytesSlice := dataBytes.Bytes()
err = msgpack.Unmarshal(bytesSlice, &packedSlices)
for _, c := range packedSlices {
    var packedSlice []interface{}
    byts, _ := getBytes(c)
    err = msgpack.Unmarshal(byts, &packedSlice)
    logger.Println(err, packedSlice)
}

When I do the same thing in python 3.7 it is working fine:

resp = requests.post(url, headers=headers, json=payload, stream=True)
datas = msgpack.loads(gzip.decompress(resp.raw.data))
datas = [msgpack.loads(k) for k in datas]

Is there something I am missing here ??

Answer 1

Instead of using []interface{} type as unpacked type use [][]byte. Unmarshal root msg to [][]byte then iterate over slice of slices of bytes and unmarshal every child byte slice. You do not need getBytes func.

Here some example:

var root [][]byte
if err :=  msgpack.Unmarshal(bytesSlice, &root); err != nil {
    panic(err)
}

for _, childBytes := range root {
    var child []interface{}
    if err := msgpack.Unmarshal(childBytes, &child); err != nil {
        panic(err)
    }

    _ = child
}