- PARSE_ERROR_TRY_OTHERS: current protocol is not matched, the framework would try next protocol. The data in source cannot be comsumed.
- PARSE_ERROR_NOT_ENOUGH_DATA: the input data hasn't violated the current protocol yet, but the whole message cannot be detected as well. When there is new data from connection, new data will be appended to source and parse function is called again. If we can determine that data fits current protocol, the content of source can also be transferred to the internal state of protocol. For example, if source doesn't contain a whole http message, it will be consumed by http parser to avoid repeated parsing.
- PARSE_ERROR_TOO_BIG_DATA: message size is too big, the connection will be closed to protect server.