def encode_short_string(pieces, value):
    encoded_value = as_bytes(value)
    length = len(encoded_value)

    # 4.2.5.3
    # Short strings, stored as an 8-bit unsigned integer length followed by zero
    # or more octets of data. Short strings can carry up to 255 octets of UTF-8
    # data, but may not contain binary zero octets.
    # ...
    # 4.2.5.5
    # The server SHOULD validate field names and upon receiving an invalid field
    # name, it SHOULD signal a connection exception with reply code 503 (syntax
    # error).
    # -> validate length (avoid truncated utf-8 / corrupted data), but skip null
    # byte check.
    if length > 255:
        raise exceptions.ShortStringTooLong(encoded_value)

    pieces.append(struct.pack('B', length))
    pieces.append(encoded_value)
    return 1 + length
Encode a string value as short string and append it to pieces list
dataset/ETHPy150Open pika/pika/pika/data.py/encode_short_string