text: # Copyright 2013-2016 DataStax, Inc.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from __future__ import absolute_import  # to enable import io from stdlib
  from collections import namedtuple
  import logging
  import socket
  from uuid import UUID
  
  import six
  from six.moves import range
  import io
  
  from cassandra import type_codes
  from cassandra import (Unavailable, WriteTimeout, ReadTimeout,
                         WriteFailure, ReadFailure, FunctionFailure,
                         AlreadyExists, InvalidRequest, Unauthorized,
                         UnsupportedOperation, UserFunctionDescriptor,
                         UserAggregateDescriptor, SchemaTargetType)
  from cassandra.marshal import (int32_pack, int32_unpack, uint16_pack, uint16_unpack,
                                 int8_pack, int8_unpack, uint64_pack, header_pack,
                                 v3_header_pack)
  from cassandra.cqltypes import (AsciiType, BytesType, BooleanType,
                                  CounterColumnType, DateType, DecimalType,
                                  DoubleType, FloatType, Int32Type,
                                  InetAddressType, IntegerType, ListType,
                                  LongType, MapType, SetType, TimeUUIDType,
                                  UTF8Type, VarcharType, UUIDType, UserType,
                                  TupleType, lookup_casstype, SimpleDateType,
                                  TimeType, ByteType, ShortType)
  from cassandra.policies import WriteType
  from cassandra.cython_deps import HAVE_CYTHON, HAVE_NUMPY
  from cassandra import util
  
  log = logging.getLogger(__name__)
  
  
  class NotSupportedError(Exception):
      pass
  
  
  class InternalError(Exception):
      pass
  
  ColumnMetadata = namedtuple("ColumnMetadata", ['keyspace_name', 'table_name', 'name', 'type'])
  
  MIN_SUPPORTED_VERSION = 1
  MAX_SUPPORTED_VERSION = 4
  
  HEADER_DIRECTION_TO_CLIENT = 0x80
  HEADER_DIRECTION_MASK = 0x80
  
  COMPRESSED_FLAG = 0x01
  TRACING_FLAG = 0x02
  CUSTOM_PAYLOAD_FLAG = 0x04
  WARNING_FLAG = 0x08
  
  _message_types_by_opcode = {}
  
  _UNSET_VALUE = object()
  
  
  def register_class(cls):
      _message_types_by_opcode[cls.opcode] = cls
  
  
  def get_registered_classes():
      return _message_types_by_opcode.copy()
  
  
  class _RegisterMessageType(type):
      def __init__(cls, name, bases, dct):
          if not name.startswith('_'):
              register_class(cls)
  
  
  @six.add_metaclass(_RegisterMessageType)
  class _MessageType(object):
  
      tracing = False
      custom_payload = None
      warnings = None
  
      def update_custom_payload(self, other):
          if other:
              if not self.custom_payload:
                  self.custom_payload = {}
              self.custom_payload.update(other)
              if len(self.custom_payload) > 65535:
                  raise ValueError("Custom payload map exceeds max count allowed by protocol (65535)")
  
      def __repr__(self):
          return '<%s(%s)>' % (self.__class__.__name__, ', '.join('%s=%r' % i for i in _get_params(self)))
  
  
  def _get_params(message_obj):
      base_attrs = dir(_MessageType)
      return (
          (n, a) for n, a in message_obj.__dict__.items()
          if n not in base_attrs and not n.startswith('_') and not callable(a)
      )
  
  
  error_classes = {}
  
  
  class ErrorMessage(_MessageType, Exception):
      opcode = 0x00
      name = 'ERROR'
      summary = 'Unknown'
  
      def __init__(self, code, message, info):
          self.code = code
          self.message = message
          self.info = info
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          code = read_int(f)
          msg = read_string(f)
          subcls = error_classes.get(code, cls)
          extra_info = subcls.recv_error_info(f)
          return subcls(code=code, message=msg, info=extra_info)
  
      def summary_msg(self):
          msg = 'code=%04x [%s] message="%s"' \
                % (self.code, self.summary, self.message)
          return msg
  
      def __str__(self):
          return '<ErrorMessage %s>' % self.summary_msg()
      __repr__ = __str__
  
      @staticmethod
      def recv_error_info(f):
          pass
  
      def to_exception(self):
          return self
  
  
  class ErrorMessageSubclass(_RegisterMessageType):
      def __init__(cls, name, bases, dct):
          if cls.error_code is not None:  # Server has an error code of 0.
              error_classes[cls.error_code] = cls
  
  
  @six.add_metaclass(ErrorMessageSubclass)
  class ErrorMessageSub(ErrorMessage):
      error_code = None
  
  
  class RequestExecutionException(ErrorMessageSub):
      pass
  
  
  class RequestValidationException(ErrorMessageSub):
      pass
  
  
  class ServerError(ErrorMessageSub):
      summary = 'Server error'
      error_code = 0x0000
  
  
  class ProtocolException(ErrorMessageSub):
      summary = 'Protocol error'
      error_code = 0x000A
  
  
  class BadCredentials(ErrorMessageSub):
      summary = 'Bad credentials'
      error_code = 0x0100
  
  
  class UnavailableErrorMessage(RequestExecutionException):
      summary = 'Unavailable exception'
      error_code = 0x1000
  
      @staticmethod
      def recv_error_info(f):
          return {
              'consistency': read_consistency_level(f),
              'required_replicas': read_int(f),
              'alive_replicas': read_int(f),
          }
  
      def to_exception(self):
          return Unavailable(self.summary_msg(), **self.info)
  
  
  class OverloadedErrorMessage(RequestExecutionException):
      summary = 'Coordinator node overloaded'
      error_code = 0x1001
  
  
  class IsBootstrappingErrorMessage(RequestExecutionException):
      summary = 'Coordinator node is bootstrapping'
      error_code = 0x1002
  
  
  class TruncateError(RequestExecutionException):
      summary = 'Error during truncate'
      error_code = 0x1003
  
  
  class WriteTimeoutErrorMessage(RequestExecutionException):
      summary = "Coordinator node timed out waiting for replica nodes' responses"
      error_code = 0x1100
  
      @staticmethod
      def recv_error_info(f):
          return {
              'consistency': read_consistency_level(f),
              'received_responses': read_int(f),
              'required_responses': read_int(f),
              'write_type': WriteType.name_to_value[read_string(f)],
          }
  
      def to_exception(self):
          return WriteTimeout(self.summary_msg(), **self.info)
  
  
  class ReadTimeoutErrorMessage(RequestExecutionException):
      summary = "Coordinator node timed out waiting for replica nodes' responses"
      error_code = 0x1200
  
      @staticmethod
      def recv_error_info(f):
          return {
              'consistency': read_consistency_level(f),
              'received_responses': read_int(f),
              'required_responses': read_int(f),
              'data_retrieved': bool(read_byte(f)),
          }
  
      def to_exception(self):
          return ReadTimeout(self.summary_msg(), **self.info)
  
  
  class ReadFailureMessage(RequestExecutionException):
      summary = "Replica(s) failed to execute read"
      error_code = 0x1300
  
      @staticmethod
      def recv_error_info(f):
          return {
              'consistency': read_consistency_level(f),
              'received_responses': read_int(f),
              'required_responses': read_int(f),
              'failures': read_int(f),
              'data_retrieved': bool(read_byte(f)),
          }
  
      def to_exception(self):
          return ReadFailure(self.summary_msg(), **self.info)
  
  
  class FunctionFailureMessage(RequestExecutionException):
      summary = "User Defined Function failure"
      error_code = 0x1400
  
      @staticmethod
      def recv_error_info(f):
          return {
              'keyspace': read_string(f),
              'function': read_string(f),
              'arg_types': [read_string(f) for _ in range(read_short(f))],
          }
  
      def to_exception(self):
          return FunctionFailure(self.summary_msg(), **self.info)
  
  
  class WriteFailureMessage(RequestExecutionException):
      summary = "Replica(s) failed to execute write"
      error_code = 0x1500
  
      @staticmethod
      def recv_error_info(f):
          return {
              'consistency': read_consistency_level(f),
              'received_responses': read_int(f),
              'required_responses': read_int(f),
              'failures': read_int(f),
              'write_type': WriteType.name_to_value[read_string(f)],
          }
  
      def to_exception(self):
          return WriteFailure(self.summary_msg(), **self.info)
  
  
  class SyntaxException(RequestValidationException):
      summary = 'Syntax error in CQL query'
      error_code = 0x2000
  
  
  class UnauthorizedErrorMessage(RequestValidationException):
      summary = 'Unauthorized'
      error_code = 0x2100
  
      def to_exception(self):
          return Unauthorized(self.summary_msg())
  
  
  class InvalidRequestException(RequestValidationException):
      summary = 'Invalid query'
      error_code = 0x2200
  
      def to_exception(self):
          return InvalidRequest(self.summary_msg())
  
  
  class ConfigurationException(RequestValidationException):
      summary = 'Query invalid because of configuration issue'
      error_code = 0x2300
  
  
  class PreparedQueryNotFound(RequestValidationException):
      summary = 'Matching prepared statement not found on this node'
      error_code = 0x2500
  
      @staticmethod
      def recv_error_info(f):
          # return the query ID
          return read_binary_string(f)
  
  
  class AlreadyExistsException(ConfigurationException):
      summary = 'Item already exists'
      error_code = 0x2400
  
      @staticmethod
      def recv_error_info(f):
          return {
              'keyspace': read_string(f),
              'table': read_string(f),
          }
  
      def to_exception(self):
          return AlreadyExists(**self.info)
  
  
  class StartupMessage(_MessageType):
      opcode = 0x01
      name = 'STARTUP'
  
      KNOWN_OPTION_KEYS = set((
          'CQL_VERSION',
          'COMPRESSION',
      ))
  
      def __init__(self, cqlversion, options):
          self.cqlversion = cqlversion
          self.options = options
  
      def send_body(self, f, protocol_version):
          optmap = self.options.copy()
          optmap['CQL_VERSION'] = self.cqlversion
          write_stringmap(f, optmap)
  
  
  class ReadyMessage(_MessageType):
      opcode = 0x02
      name = 'READY'
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          return cls()
  
  
  class AuthenticateMessage(_MessageType):
      opcode = 0x03
      name = 'AUTHENTICATE'
  
      def __init__(self, authenticator):
          self.authenticator = authenticator
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          authname = read_string(f)
          return cls(authenticator=authname)
  
  
  class CredentialsMessage(_MessageType):
      opcode = 0x04
      name = 'CREDENTIALS'
  
      def __init__(self, creds):
          self.creds = creds
  
      def send_body(self, f, protocol_version):
          if protocol_version > 1:
              raise UnsupportedOperation(
                  "Credentials-based authentication is not supported with "
                  "protocol version 2 or higher.  Use the SASL authentication "
                  "mechanism instead.")
          write_short(f, len(self.creds))
          for credkey, credval in self.creds.items():
              write_string(f, credkey)
              write_string(f, credval)
  
  
  class AuthChallengeMessage(_MessageType):
      opcode = 0x0E
      name = 'AUTH_CHALLENGE'
  
      def __init__(self, challenge):
          self.challenge = challenge
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          return cls(read_binary_longstring(f))
  
  
  class AuthResponseMessage(_MessageType):
      opcode = 0x0F
      name = 'AUTH_RESPONSE'
  
      def __init__(self, response):
          self.response = response
  
      def send_body(self, f, protocol_version):
          write_longstring(f, self.response)
  
  
  class AuthSuccessMessage(_MessageType):
      opcode = 0x10
      name = 'AUTH_SUCCESS'
  
      def __init__(self, token):
          self.token = token
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          return cls(read_longstring(f))
  
  
  class OptionsMessage(_MessageType):
      opcode = 0x05
      name = 'OPTIONS'
  
      def send_body(self, f, protocol_version):
          pass
  
  
  class SupportedMessage(_MessageType):
      opcode = 0x06
      name = 'SUPPORTED'
  
      def __init__(self, cql_versions, options):
          self.cql_versions = cql_versions
          self.options = options
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          options = read_stringmultimap(f)
          cql_versions = options.pop('CQL_VERSION')
          return cls(cql_versions=cql_versions, options=options)
  
  
  # used for QueryMessage and ExecuteMessage
  _VALUES_FLAG = 0x01
  _SKIP_METADATA_FLAG = 0x01
  _PAGE_SIZE_FLAG = 0x04
  _WITH_PAGING_STATE_FLAG = 0x08
  _WITH_SERIAL_CONSISTENCY_FLAG = 0x10
  _PROTOCOL_TIMESTAMP = 0x20
  
  
  class QueryMessage(_MessageType):
      opcode = 0x07
      name = 'QUERY'
  
      def __init__(self, query, consistency_level, serial_consistency_level=None,
                   fetch_size=None, paging_state=None, timestamp=None):
          self.query = query
          self.consistency_level = consistency_level
          self.serial_consistency_level = serial_consistency_level
          self.fetch_size = fetch_size
          self.paging_state = paging_state
          self.timestamp = timestamp
          self._query_params = None  # only used internally. May be set to a list of native-encoded values to have them sent with the request.
  
      def send_body(self, f, protocol_version):
          write_longstring(f, self.query)
          write_consistency_level(f, self.consistency_level)
          flags = 0x00
          if self._query_params is not None:
              flags |= _VALUES_FLAG  # also v2+, but we're only setting params internally right now
  
          if self.serial_consistency_level:
              if protocol_version >= 2:
                  flags |= _WITH_SERIAL_CONSISTENCY_FLAG
              else:
                  raise UnsupportedOperation(
                      "Serial consistency levels require the use of protocol version "
                      "2 or higher. Consider setting Cluster.protocol_version to 2 "
                      "to support serial consistency levels.")
  
          if self.fetch_size:
              if protocol_version >= 2:
                  flags |= _PAGE_SIZE_FLAG
              else:
                  raise UnsupportedOperation(
                      "Automatic query paging may only be used with protocol version "
                      "2 or higher. Consider setting Cluster.protocol_version to 2.")
  
          if self.paging_state:
              if protocol_version >= 2:
                  flags |= _WITH_PAGING_STATE_FLAG
              else:
                  raise UnsupportedOperation(
                      "Automatic query paging may only be used with protocol version "
                      "2 or higher. Consider setting Cluster.protocol_version to 2.")
  
          if self.timestamp is not None:
              flags |= _PROTOCOL_TIMESTAMP
  
          write_byte(f, flags)
  
          if self._query_params is not None:
              write_short(f, len(self._query_params))
              for param in self._query_params:
                  write_value(f, param)
  
          if self.fetch_size:
              write_int(f, self.fetch_size)
          if self.paging_state:
              write_longstring(f, self.paging_state)
          if self.serial_consistency_level:
              write_consistency_level(f, self.serial_consistency_level)
          if self.timestamp is not None:
              write_long(f, self.timestamp)
  
  CUSTOM_TYPE = object()
  
  RESULT_KIND_VOID = 0x0001
  RESULT_KIND_ROWS = 0x0002
  RESULT_KIND_SET_KEYSPACE = 0x0003
  RESULT_KIND_PREPARED = 0x0004
  RESULT_KIND_SCHEMA_CHANGE = 0x0005
  
  class ResultMessage(_MessageType):
      opcode = 0x08
      name = 'RESULT'
  
      kind = None
      results = None
      paging_state = None
  
      # Names match type name in module scope. Most are imported from cassandra.cqltypes (except CUSTOM_TYPE)
      type_codes = _cqltypes_by_code = dict((v, globals()[k]) for k, v in type_codes.__dict__.items() if not k.startswith('_'))
  
      _FLAGS_GLOBAL_TABLES_SPEC = 0x0001
      _HAS_MORE_PAGES_FLAG = 0x0002
      _NO_METADATA_FLAG = 0x0004
  
      def __init__(self, kind, results, paging_state=None):
          self.kind = kind
          self.results = results
          self.paging_state = paging_state
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          kind = read_int(f)
          paging_state = None
          if kind == RESULT_KIND_VOID:
              results = None
          elif kind == RESULT_KIND_ROWS:
              paging_state, results = cls.recv_results_rows(
                  f, protocol_version, user_type_map)
          elif kind == RESULT_KIND_SET_KEYSPACE:
              ksname = read_string(f)
              results = ksname
          elif kind == RESULT_KIND_PREPARED:
              results = cls.recv_results_prepared(f, protocol_version, user_type_map)
          elif kind == RESULT_KIND_SCHEMA_CHANGE:
              results = cls.recv_results_schema_change(f, protocol_version)
          else:
              raise Exception("Unknown RESULT kind: %d" % kind)
          return cls(kind, results, paging_state)
  
      @classmethod
      def recv_results_rows(cls, f, protocol_version, user_type_map):
          paging_state, column_metadata = cls.recv_results_metadata(f, user_type_map)
          rowcount = read_int(f)
          rows = [cls.recv_row(f, len(column_metadata)) for _ in range(rowcount)]
          colnames = [c[2] for c in column_metadata]
          coltypes = [c[3] for c in column_metadata]
          parsed_rows = [
              tuple(ctype.from_binary(val, protocol_version)
                    for ctype, val in zip(coltypes, row))
              for row in rows]
          return (paging_state, (colnames, parsed_rows))
  
      @classmethod
      def recv_results_prepared(cls, f, protocol_version, user_type_map):
          query_id = read_binary_string(f)
          column_metadata, pk_indexes = cls.recv_prepared_metadata(f, protocol_version, user_type_map)
          return (query_id, column_metadata, pk_indexes)
  
      @classmethod
      def recv_results_metadata(cls, f, user_type_map):
          flags = read_int(f)
          glob_tblspec = bool(flags & cls._FLAGS_GLOBAL_TABLES_SPEC)
          colcount = read_int(f)
  
          if flags & cls._HAS_MORE_PAGES_FLAG:
              paging_state = read_binary_longstring(f)
          else:
              paging_state = None
          if glob_tblspec:
              ksname = read_string(f)
              cfname = read_string(f)
          column_metadata = []
          for _ in range(colcount):
              if glob_tblspec:
                  colksname = ksname
                  colcfname = cfname
              else:
                  colksname = read_string(f)
                  colcfname = read_string(f)
              colname = read_string(f)
              coltype = cls.read_type(f, user_type_map)
              column_metadata.append((colksname, colcfname, colname, coltype))
          return paging_state, column_metadata
  
      @classmethod
      def recv_prepared_metadata(cls, f, protocol_version, user_type_map):
          flags = read_int(f)
          glob_tblspec = bool(flags & cls._FLAGS_GLOBAL_TABLES_SPEC)
          colcount = read_int(f)
          pk_indexes = None
          if protocol_version >= 4:
              num_pk_indexes = read_int(f)
              pk_indexes = [read_short(f) for _ in range(num_pk_indexes)]
  
          if glob_tblspec:
              ksname = read_string(f)
              cfname = read_string(f)
          column_metadata = []
          for _ in range(colcount):
              if glob_tblspec:
                  colksname = ksname
                  colcfname = cfname
              else:
                  colksname = read_string(f)
                  colcfname = read_string(f)
              colname = read_string(f)
              coltype = cls.read_type(f, user_type_map)
              column_metadata.append(ColumnMetadata(colksname, colcfname, colname, coltype))
          return column_metadata, pk_indexes
  
      @classmethod
      def recv_results_schema_change(cls, f, protocol_version):
          return EventMessage.recv_schema_change(f, protocol_version)
  
      @classmethod
      def read_type(cls, f, user_type_map):
          optid = read_short(f)
          try:
              typeclass = cls.type_codes[optid]
          except KeyError:
              raise NotSupportedError("Unknown data type code 0x%04x. Have to skip"
                                      " entire result set." % (optid,))
          if typeclass in (ListType, SetType):
              subtype = cls.read_type(f, user_type_map)
              typeclass = typeclass.apply_parameters((subtype,))
          elif typeclass == MapType:
              keysubtype = cls.read_type(f, user_type_map)
              valsubtype = cls.read_type(f, user_type_map)
              typeclass = typeclass.apply_parameters((keysubtype, valsubtype))
          elif typeclass == TupleType:
              num_items = read_short(f)
              types = tuple(cls.read_type(f, user_type_map) for _ in range(num_items))
              typeclass = typeclass.apply_parameters(types)
          elif typeclass == UserType:
              ks = read_string(f)
              udt_name = read_string(f)
              num_fields = read_short(f)
              names, types = zip(*((read_string(f), cls.read_type(f, user_type_map))
                                   for _ in range(num_fields)))
              specialized_type = typeclass.make_udt_class(ks, udt_name, names, types)
              specialized_type.mapped_class = user_type_map.get(ks, {}).get(udt_name)
              typeclass = specialized_type
          elif typeclass == CUSTOM_TYPE:
              classname = read_string(f)
              typeclass = lookup_casstype(classname)
  
          return typeclass
  
      @staticmethod
      def recv_row(f, colcount):
          return [read_value(f) for _ in range(colcount)]
  
  
  class PrepareMessage(_MessageType):
      opcode = 0x09
      name = 'PREPARE'
  
      def __init__(self, query):
          self.query = query
  
      def send_body(self, f, protocol_version):
          write_longstring(f, self.query)
  
  
  class ExecuteMessage(_MessageType):
      opcode = 0x0A
      name = 'EXECUTE'
  
      def __init__(self, query_id, query_params, consistency_level,
                   serial_consistency_level=None, fetch_size=None,
                   paging_state=None, timestamp=None):
          self.query_id = query_id
          self.query_params = query_params
          self.consistency_level = consistency_level
          self.serial_consistency_level = serial_consistency_level
          self.fetch_size = fetch_size
          self.paging_state = paging_state
          self.timestamp = timestamp
  
      def send_body(self, f, protocol_version):
          write_string(f, self.query_id)
          if protocol_version == 1:
              if self.serial_consistency_level:
                  raise UnsupportedOperation(
                      "Serial consistency levels require the use of protocol version "
                      "2 or higher. Consider setting Cluster.protocol_version to 2 "
                      "to support serial consistency levels.")
              if self.fetch_size or self.paging_state:
                  raise UnsupportedOperation(
                      "Automatic query paging may only be used with protocol version "
                      "2 or higher. Consider setting Cluster.protocol_version to 2.")
              write_short(f, len(self.query_params))
              for param in self.query_params:
                  write_value(f, param)
              write_consistency_level(f, self.consistency_level)
          else:
              write_consistency_level(f, self.consistency_level)
              flags = _VALUES_FLAG
              if self.serial_consistency_level:
                  flags |= _WITH_SERIAL_CONSISTENCY_FLAG
              if self.fetch_size:
                  flags |= _PAGE_SIZE_FLAG
              if self.paging_state:
                  flags |= _WITH_PAGING_STATE_FLAG
              if self.timestamp is not None:
                  if protocol_version >= 3:
                      flags |= _PROTOCOL_TIMESTAMP
                  else:
                      raise UnsupportedOperation(
                          "Protocol-level timestamps may only be used with protocol version "
                          "3 or higher. Consider setting Cluster.protocol_version to 3.")
              write_byte(f, flags)
              write_short(f, len(self.query_params))
              for param in self.query_params:
                  write_value(f, param)
              if self.fetch_size:
                  write_int(f, self.fetch_size)
              if self.paging_state:
                  write_longstring(f, self.paging_state)
              if self.serial_consistency_level:
                  write_consistency_level(f, self.serial_consistency_level)
              if self.timestamp is not None:
                  write_long(f, self.timestamp)
  
  
  class BatchMessage(_MessageType):
      opcode = 0x0D
      name = 'BATCH'
  
      def __init__(self, batch_type, queries, consistency_level,
                   serial_consistency_level=None, timestamp=None):
          self.batch_type = batch_type
          self.queries = queries
          self.consistency_level = consistency_level
          self.serial_consistency_level = serial_consistency_level
          self.timestamp = timestamp
  
      def send_body(self, f, protocol_version):
          write_byte(f, self.batch_type.value)
          write_short(f, len(self.queries))
          for prepared, string_or_query_id, params in self.queries:
              if not prepared:
                  write_byte(f, 0)
                  write_longstring(f, string_or_query_id)
              else:
                  write_byte(f, 1)
                  write_short(f, len(string_or_query_id))
                  f.write(string_or_query_id)
              write_short(f, len(params))
              for param in params:
                  write_value(f, param)
  
          write_consistency_level(f, self.consistency_level)
          if protocol_version >= 3:
              flags = 0
              if self.serial_consistency_level:
                  flags |= _WITH_SERIAL_CONSISTENCY_FLAG
              if self.timestamp is not None:
                  flags |= _PROTOCOL_TIMESTAMP
              write_byte(f, flags)
  
              if self.serial_consistency_level:
                  write_consistency_level(f, self.serial_consistency_level)
              if self.timestamp is not None:
                  write_long(f, self.timestamp)
  
  
  known_event_types = frozenset((
      'TOPOLOGY_CHANGE',
      'STATUS_CHANGE',
      'SCHEMA_CHANGE'
  ))
  
  
  class RegisterMessage(_MessageType):
      opcode = 0x0B
      name = 'REGISTER'
  
      def __init__(self, event_list):
          self.event_list = event_list
  
      def send_body(self, f, protocol_version):
          write_stringlist(f, self.event_list)
  
  
  class EventMessage(_MessageType):
      opcode = 0x0C
      name = 'EVENT'
  
      def __init__(self, event_type, event_args):
          self.event_type = event_type
          self.event_args = event_args
  
      @classmethod
      def recv_body(cls, f, protocol_version, user_type_map):
          event_type = read_string(f).upper()
          if event_type in known_event_types:
              read_method = getattr(cls, 'recv_' + event_type.lower())
              return cls(event_type=event_type, event_args=read_method(f, protocol_version))
          raise NotSupportedError('Unknown event type %r' % event_type)
  
      @classmethod
      def recv_topology_change(cls, f, protocol_version):
          # "NEW_NODE" or "REMOVED_NODE"
          change_type = read_string(f)
          address = read_inet(f)
          return dict(change_type=change_type, address=address)
  
      @classmethod
      def recv_status_change(cls, f, protocol_version):
          # "UP" or "DOWN"
          change_type = read_string(f)
          address = read_inet(f)
          return dict(change_type=change_type, address=address)
  
      @classmethod
      def recv_schema_change(cls, f, protocol_version):
          # "CREATED", "DROPPED", or "UPDATED"
          change_type = read_string(f)
          if protocol_version >= 3:
              target = read_string(f)
              keyspace = read_string(f)
              event = {'target_type': target, 'change_type': change_type, 'keyspace': keyspace}
              if target != SchemaTargetType.KEYSPACE:
                  target_name = read_string(f)
                  if target == SchemaTargetType.FUNCTION:
                      event['function'] = UserFunctionDescriptor(target_name, [read_string(f) for _ in range(read_short(f))])
                  elif target == SchemaTargetType.AGGREGATE:
                      event['aggregate'] = UserAggregateDescriptor(target_name, [read_string(f) for _ in range(read_short(f))])
                  else:
                      event[target.lower()] = target_name
          else:
              keyspace = read_string(f)
              table = read_string(f)
              if table:
                  event = {'target_type': SchemaTargetType.TABLE, 'change_type': change_type, 'keyspace': keyspace, 'table': table}
              else:
                  event = {'target_type': SchemaTargetType.KEYSPACE, 'change_type': change_type, 'keyspace': keyspace}
          return event
  
  
  class _ProtocolHandler(object):
      """
      _ProtocolHander handles encoding and decoding messages.
  
      This class can be specialized to compose Handlers which implement alternative
      result decoding or type deserialization. Class definitions are passed to :class:`cassandra.cluster.Cluster`
      on initialization.
  
      Contracted class methods are :meth:`_ProtocolHandler.encode_message` and :meth:`_ProtocolHandler.decode_message`.
      """
  
      message_types_by_opcode = _message_types_by_opcode.copy()
      """
      Default mapping of opcode to Message implementation. The default ``decode_message`` implementation uses
      this to instantiate a message and populate using ``recv_body``. This mapping can be updated to inject specialized
      result decoding implementations.
      """
  
      @classmethod
      def encode_message(cls, msg, stream_id, protocol_version, compressor):
          """
          Encodes a message using the specified frame parameters, and compressor
  
          :param msg: the message, typically of cassandra.protocol._MessageType, generated by the driver
          :param stream_id: protocol stream id for the frame header
          :param protocol_version: version for the frame header, and used encoding contents
          :param compressor: optional compression function to be used on the body
          """
          flags = 0
          body = io.BytesIO()
          if msg.custom_payload:
              if protocol_version < 4:
                  raise UnsupportedOperation("Custom key/value payloads can only be used with protocol version 4 or higher")
              flags |= CUSTOM_PAYLOAD_FLAG
              write_bytesmap(body, msg.custom_payload)
          msg.send_body(body, protocol_version)
          body = body.getvalue()
  
          if compressor and len(body) > 0:
              body = compressor(body)
              flags |= COMPRESSED_FLAG
  
          if msg.tracing:
              flags |= TRACING_FLAG
  
          buff = io.BytesIO()
          cls._write_header(buff, protocol_version, flags, stream_id, msg.opcode, len(body))
          buff.write(body)
  
          return buff.getvalue()
  
      @staticmethod
      def _write_header(f, version, flags, stream_id, opcode, length):
          """
          Write a CQL protocol frame header.
          """
          pack = v3_header_pack if version >= 3 else header_pack
          f.write(pack(version, flags, stream_id, opcode))
          write_int(f, length)
  
      @classmethod
      def decode_message(cls, protocol_version, user_type_map, stream_id, flags, opcode, body,
                         decompressor):
          """
          Decodes a native protocol message body
  
          :param protocol_version: version to use decoding contents
          :param user_type_map: map[keyspace name] = map[type name] = custom type to instantiate when deserializing this type
          :param stream_id: native protocol stream id from the frame header
          :param flags: native protocol flags bitmap from the header
          :param opcode: native protocol opcode from the header
          :param body: frame body
          :param decompressor: optional decompression function to inflate the body
          :return: a message decoded from the body and frame attributes
          """
          if flags & COMPRESSED_FLAG:
              if decompressor is None:
                  raise Exception("No de-compressor available for compressed frame!")
              body = decompressor(body)
              flags ^= COMPRESSED_FLAG
  
          body = io.BytesIO(body)
          if flags & TRACING_FLAG:
              trace_id = UUID(bytes=body.read(16))
              flags ^= TRACING_FLAG
          else:
              trace_id = None
  
          if flags & WARNING_FLAG:
              warnings = read_stringlist(body)
              flags ^= WARNING_FLAG
          else:
              warnings = None
  
          if flags & CUSTOM_PAYLOAD_FLAG:
              custom_payload = read_bytesmap(body)
              flags ^= CUSTOM_PAYLOAD_FLAG
          else:
              custom_payload = None
  
          if flags:
              log.warning("Unknown protocol flags set: %02x. May cause problems.", flags)
  
          msg_class = cls.message_types_by_opcode[opcode]
          msg = msg_class.recv_body(body, protocol_version, user_type_map)
          msg.stream_id = stream_id
          msg.trace_id = trace_id
          msg.custom_payload = custom_payload
          msg.warnings = warnings
  
          if msg.warnings:
              for w in msg.warnings:
                  log.warning("Server warning: %s", w)
  
          return msg
  
  def cython_protocol_handler(colparser):
      """
      Given a column parser to deserialize ResultMessages, return a suitable
      Cython-based protocol handler.
  
      There are three Cython-based protocol handlers:
  
          - obj_parser.ListParser
              decodes result messages into a list of tuples
  
          - obj_parser.LazyParser
              decodes result messages lazily by returning an iterator
  
          - numpy_parser.NumPyParser
              decodes result messages into NumPy arrays
  
      The default is to use obj_parser.ListParser
      """
      from cassandra.row_parser import make_recv_results_rows
  
      class FastResultMessage(ResultMessage):
          """
          Cython version of Result Message that has a faster implementation of
          recv_results_row.
          """
          # type_codes = ResultMessage.type_codes.copy()
          code_to_type = dict((v, k) for k, v in ResultMessage.type_codes.items())
          recv_results_rows = classmethod(make_recv_results_rows(colparser))
  
      class CythonProtocolHandler(_ProtocolHandler):
          """
          Use FastResultMessage to decode query result message messages.
          """
  
          my_opcodes = _ProtocolHandler.message_types_by_opcode.copy()
          my_opcodes[FastResultMessage.opcode] = FastResultMessage
          message_types_by_opcode = my_opcodes
  
          col_parser = colparser
  
      return CythonProtocolHandler
  
  
  if HAVE_CYTHON:
      from cassandra.obj_parser import ListParser, LazyParser
      ProtocolHandler = cython_protocol_handler(ListParser())
      LazyProtocolHandler = cython_protocol_handler(LazyParser())
  else:
      # Use Python-based ProtocolHandler
      ProtocolHandler = _ProtocolHandler
      LazyProtocolHandler = None
  
  
  if HAVE_CYTHON and HAVE_NUMPY:
      from cassandra.numpy_parser import NumpyParser
      NumpyProtocolHandler = cython_protocol_handler(NumpyParser())
  else:
      NumpyProtocolHandler = None
  
  
  def read_byte(f):
      return int8_unpack(f.read(1))
  
  
  def write_byte(f, b):
      f.write(int8_pack(b))
  
  
  def read_int(f):
      return int32_unpack(f.read(4))
  
  
  def write_int(f, i):
      f.write(int32_pack(i))
  
  
  def write_long(f, i):
      f.write(uint64_pack(i))
  
  
  def read_short(f):
      return uint16_unpack(f.read(2))
  
  
  def write_short(f, s):
      f.write(uint16_pack(s))
  
  
  def read_consistency_level(f):
      return read_short(f)
  
  
  def write_consistency_level(f, cl):
      write_short(f, cl)
  
  
  def read_string(f):
      size = read_short(f)
      contents = f.read(size)
      return contents.decode('utf8')
  
  
  def read_binary_string(f):
      size = read_short(f)
      contents = f.read(size)
      return contents
  
  
  def write_string(f, s):
      if isinstance(s, six.text_type):
          s = s.encode('utf8')
      write_short(f, len(s))
      f.write(s)
  
  
  def read_binary_longstring(f):
      size = read_int(f)
      contents = f.read(size)
      return contents
  
  
  def read_longstring(f):
      return read_binary_longstring(f).decode('utf8')
  
  
  def write_longstring(f, s):
      if isinstance(s, six.text_type):
          s = s.encode('utf8')
      write_int(f, len(s))
      f.write(s)
  
  
  def read_stringlist(f):
      numstrs = read_short(f)
      return [read_string(f) for _ in range(numstrs)]
  
  
  def write_stringlist(f, stringlist):
      write_short(f, len(stringlist))
      for s in stringlist:
          write_string(f, s)
  
  
  def read_stringmap(f):
      numpairs = read_short(f)
      strmap = {}
      for _ in range(numpairs):
          k = read_string(f)
          strmap[k] = read_string(f)
      return strmap
  
  
  def write_stringmap(f, strmap):
      write_short(f, len(strmap))
      for k, v in strmap.items():
          write_string(f, k)
          write_string(f, v)
  
  
  def read_bytesmap(f):
      numpairs = read_short(f)
      bytesmap = {}
      for _ in range(numpairs):
          k = read_string(f)
          bytesmap[k] = read_value(f)
      return bytesmap
  
  
  def write_bytesmap(f, bytesmap):
      write_short(f, len(bytesmap))
      for k, v in bytesmap.items():
          write_string(f, k)
          write_value(f, v)
  
  
  def read_stringmultimap(f):
      numkeys = read_short(f)
      strmmap = {}
      for _ in range(numkeys):
          k = read_string(f)
          strmmap[k] = read_stringlist(f)
      return strmmap
  
  
  def write_stringmultimap(f, strmmap):
      write_short(f, len(strmmap))
      for k, v in strmmap.items():
          write_string(f, k)
          write_stringlist(f, v)
  
  
  def read_value(f):
      size = read_int(f)
      if size < 0:
          return None
      return f.read(size)
  
  
  def write_value(f, v):
      if v is None:
          write_int(f, -1)
      elif v is _UNSET_VALUE:
          write_int(f, -2)
      else:
          write_int(f, len(v))
          f.write(v)
  
  
  def read_inet(f):
      size = read_byte(f)
      addrbytes = f.read(size)
      port = read_int(f)
      if size == 4:
          addrfam = socket.AF_INET
      elif size == 16:
          addrfam = socket.AF_INET6
      else:
          raise InternalError("bad inet address: %r" % (addrbytes,))
      return (util.inet_ntop(addrfam, addrbytes), port)
  
  
  def write_inet(f, addrtuple):
      addr, port = addrtuple
      if ':' in addr:
          addrfam = socket.AF_INET6
      else:
          addrfam = socket.AF_INET
      addrbytes = util.inet_pton(addrfam, addr)
      write_byte(f, len(addrbytes))
      f.write(addrbytes)
      write_int(f, port)
  