Files
deb-python-cassandra-driver/cassandra/protocol.py
2014-06-24 18:25:35 -05:00

998 lines
29 KiB
Python

# Copyright 2013-2014 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
import logging
import socket
from uuid import UUID
import six
from six.moves import range
import io
from cassandra import (Unavailable, WriteTimeout, ReadTimeout,
AlreadyExists, InvalidRequest, Unauthorized,
UnsupportedOperation)
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, UUIDType, UserDefinedType,
TupleType, lookup_casstype)
from cassandra.policies import WriteType
log = logging.getLogger(__name__)
class NotSupportedError(Exception):
pass
class InternalError(Exception):
pass
HEADER_DIRECTION_FROM_CLIENT = 0x00
HEADER_DIRECTION_TO_CLIENT = 0x80
HEADER_DIRECTION_MASK = 0x80
COMPRESSED_FLAG = 0x01
TRACING_FLAG = 0x02
_message_types_by_name = {}
_message_types_by_opcode = {}
class _RegisterMessageType(type):
def __init__(cls, name, bases, dct):
if not name.startswith('_'):
_message_types_by_name[cls.name] = cls
_message_types_by_opcode[cls.opcode] = cls
@six.add_metaclass(_RegisterMessageType)
class _MessageType(object):
tracing = False
def to_binary(self, stream_id, protocol_version, compression=None):
body = io.BytesIO()
self.send_body(body, protocol_version)
body = body.getvalue()
flags = 0
if compression and len(body) > 0:
body = compression(body)
flags |= COMPRESSED_FLAG
if self.tracing:
flags |= TRACING_FLAG
msg = io.BytesIO()
write_header(msg, protocol_version, flags, stream_id, self.opcode, len(body))
msg.write(body)
return msg.getvalue()
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)
)
def decode_response(protocol_version, user_type_map, stream_id, flags, opcode, body,
decompressor=None):
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:
log.warning("Unknown protocol flags set: %02x. May cause problems.", flags)
msg_class = _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
return msg
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)
if self.info is not None:
msg += (' info=' + repr(self.info))
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 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_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
def send_body(self, f, protocol_version):
write_longstring(f, self.query)
write_consistency_level(f, self.consistency_level)
flags = 0x00
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.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
_type_codes = {
0x0000: CUSTOM_TYPE,
0x0001: AsciiType,
0x0002: LongType,
0x0003: BytesType,
0x0004: BooleanType,
0x0005: CounterColumnType,
0x0006: DecimalType,
0x0007: DoubleType,
0x0008: FloatType,
0x0009: Int32Type,
0x000A: UTF8Type,
0x000B: DateType,
0x000C: UUIDType,
0x000D: UTF8Type,
0x000E: IntegerType,
0x000F: TimeUUIDType,
0x0010: InetAddressType,
0x0020: ListType,
0x0021: MapType,
0x0022: SetType,
0x0030: UserDefinedType,
0x0031: TupleType,
}
_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, user_type_map)
elif kind == RESULT_KIND_SCHEMA_CHANGE:
results = cls.recv_results_schema_change(f, protocol_version)
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, user_type_map):
query_id = read_binary_string(f)
_, column_metadata = cls.recv_results_metadata(f, user_type_map)
return (query_id, column_metadata)
@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_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 xrange(num_items))
typeclass = typeclass.apply_parameters(types)
elif typeclass == UserDefinedType:
ks = read_string(f)
udt_name = read_string(f)
num_fields = read_short(f)
names_and_types = tuple((read_string(f), cls.read_type(f, user_type_map))
for _ in xrange(num_fields))
mapped_class = user_type_map.get(ks, {}).get(udt_name)
typeclass = typeclass.apply_parameters(
ks, udt_name, names_and_types, mapped_class)
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)
if target != "KEYSPACE":
table_or_type = read_string(f)
return {'change_type': change_type, 'keyspace': keyspace, target.lower(): table_or_type}
else:
return {'change_type': change_type, 'keyspace': keyspace}
else:
keyspace = read_string(f)
table = read_string(f)
return {'change_type': change_type, 'keyspace': keyspace, 'table': table}
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 | HEADER_DIRECTION_FROM_CLIENT, flags, stream_id, opcode))
write_int(f, length)
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_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)
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 (socket.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 = socket.inet_pton(addrfam, addr)
write_byte(f, len(addrbytes))
f.write(addrbytes)
write_int(f, port)