Files
deb-python-cassandra-driver/cassandra/decoder.py
2013-05-06 14:42:03 -05:00

642 lines
18 KiB
Python

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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.
import socket
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO # ignore flake8 warning: # NOQA
from cassandra import ConsistencyLevel
from cassandra.marshal import (int32_pack, int32_unpack, uint16_pack, uint16_unpack,
int8_pack, int8_unpack)
from cassandra.types import lookup_cqltype
class NotSupportedError(Exception):
pass
class InternalError(Exception):
pass
PROTOCOL_VERSION = 0x01
PROTOCOL_VERSION_MASK = 0x7f
HEADER_DIRECTION_FROM_CLIENT = 0x00
HEADER_DIRECTION_TO_CLIENT = 0x80
HEADER_DIRECTION_MASK = 0x80
def warn(msg):
print msg
class PreparedResult:
def __init__(self, queryid, param_metadata):
self.queryid = queryid
self.param_metadata = param_metadata
def __str__(self):
return '<PreparedResult: queryid=%r, column_metadata=%r>' \
% (self.queryid, self.column_metadata)
__repr__ = __str__
_message_types_by_name = {}
_message_types_by_opcode = {}
class _register_msg_type(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
class _MessageType(object):
__metaclass__ = _register_msg_type
params = ()
def __init__(self, **kwargs):
for pname in self.params:
try:
pval = kwargs[pname]
except KeyError:
raise ValueError("%s instances need the %s keyword parameter"
% (self.__class__.__name__, pname))
setattr(self, pname, pval)
def to_string(self, stream_id, compression=None):
body = StringIO()
self.send_body(body)
body = body.getvalue()
version = PROTOCOL_VERSION | HEADER_DIRECTION_FROM_CLIENT
flags = 0
if compression is not None and len(body) > 0:
body = compression(body)
flags |= 0x1
msglen = int32_pack(len(body))
msg_parts = map(int8_pack, (version, flags, stream_id, self.opcode)) + [msglen, body]
return ''.join(msg_parts)
def send(self, f, streamid, compression=None):
body = StringIO()
self.send_body(body)
body = body.getvalue()
version = PROTOCOL_VERSION | HEADER_DIRECTION_FROM_CLIENT
flags = 0
if compression is not None and len(body) > 0:
body = compression(body)
flags |= 0x1
msglen = int32_pack(len(body))
header = ''.join(map(int8_pack, (version, flags, streamid, self.opcode))) \
+ msglen
f.write(header)
if len(body) > 0:
f.write(body)
def __str__(self):
paramstrs = ['%s=%r' % (pname, getattr(self, pname)) for pname in self.params]
return '<%s(%s)>' % (self.__class__.__name__, ', '.join(paramstrs))
__repr__ = __str__
def decode_response(stream_id, flags, opcode, body, decompressor=None):
if flags & 0x1:
if decompressor is None:
raise Exception("No decompressor available for compressed frame!")
body = decompressor(body)
flags ^= 0x1
if flags:
warn("Unknown protocol flags set: %02x. May cause problems." % flags)
msg_class = _message_types_by_opcode[opcode]
msg = msg_class.recv_body(StringIO(body))
msg.stream_id = stream_id
return msg
error_classes = {}
class ErrorMessage(_MessageType, Exception):
opcode = 0x00
name = 'ERROR'
params = ('code', 'message', 'info')
summary = 'Unknown'
@classmethod
def recv_body(cls, f):
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=' + str(self.info))
return msg
def __str__(self):
return '<ErrorMessage %s>' % self.summary_msg()
__repr__ = __str__
@staticmethod
def recv_error_info(f):
pass
class ErrorMessageSubclass(_register_msg_type):
def __init__(cls, name, bases, dct):
if cls.error_code is not None:
error_classes[cls.error_code] = cls
class ErrorMessageSub(ErrorMessage):
__metaclass__ = ErrorMessageSubclass
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 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),
}
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 RequestTimeoutException(RequestExecutionException):
pass
class WriteTimeoutErrorMessage(RequestTimeoutException):
summary = 'Timeout during write request'
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': read_string(f),
}
class ReadTimeoutErrorMessage(RequestTimeoutException):
summary = 'Timeout during read request'
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)),
}
class SyntaxException(RequestValidationException):
summary = 'Syntax error in CQL query'
error_code = 0x2000
class UnauthorizedErrorMessage(RequestValidationException):
summary = 'Unauthorized'
error_code = 0x2100
class InvalidRequestException(RequestValidationException):
summary = 'Invalid query'
error_code = 0x2200
class ConfigurationException(RequestValidationException):
summary = 'Query invalid because of configuration issue'
error_code = 0x2300
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),
}
class StartupMessage(_MessageType):
opcode = 0x01
name = 'STARTUP'
params = ('cqlversion', 'options')
KNOWN_OPTION_KEYS = set((
'CQL_VERSION',
'COMPRESSION',
))
def send_body(self, f):
optmap = self.options.copy()
optmap['CQL_VERSION'] = self.cqlversion
write_stringmap(f, optmap)
class ReadyMessage(_MessageType):
opcode = 0x02
name = 'READY'
params = ()
@classmethod
def recv_body(cls, f):
return cls()
class AuthenticateMessage(_MessageType):
opcode = 0x03
name = 'AUTHENTICATE'
params = ('authenticator',)
@classmethod
def recv_body(cls, f):
authname = read_string(f)
return cls(authenticator=authname)
class CredentialsMessage(_MessageType):
opcode = 0x04
name = 'CREDENTIALS'
params = ('creds',)
def send_body(self, f):
write_short(f, len(self.creds))
for credkey, credval in self.creds:
write_string(f, credkey)
write_string(f, credval)
class OptionsMessage(_MessageType):
opcode = 0x05
name = 'OPTIONS'
params = ()
def send_body(self, f):
pass
class SupportedMessage(_MessageType):
opcode = 0x06
name = 'SUPPORTED'
params = ('cql_versions', 'options',)
@classmethod
def recv_body(cls, f):
options = read_stringmultimap(f)
cql_versions = options.pop('CQL_VERSION')
return cls(cql_versions=cql_versions, options=options)
class QueryMessage(_MessageType):
opcode = 0x07
name = 'QUERY'
params = ('query', 'consistency_level',)
def send_body(self, f):
write_longstring(f, self.query)
write_consistency_level(f, self.consistency_level)
class ResultMessage(_MessageType):
opcode = 0x08
name = 'RESULT'
params = ('kind', 'results',)
KIND_VOID = 0x0001
KIND_ROWS = 0x0002
KIND_SET_KEYSPACE = 0x0003
KIND_PREPARED = 0x0004
KIND_SCHEMA_CHANGE = 0x0005
type_codes = {
0x0001: 'ascii',
0x0002: 'bigint',
0x0003: 'blob',
0x0004: 'boolean',
0x0005: 'counter',
0x0006: 'decimal',
0x0007: 'double',
0x0008: 'float',
0x0009: 'int',
0x000A: 'text',
0x000B: 'timestamp',
0x000C: 'uuid',
0x000D: 'varchar',
0x000E: 'varint',
0x000F: 'timeuuid',
0x0010: 'inet',
0x0020: 'list',
0x0021: 'map',
0x0022: 'set',
}
FLAGS_GLOBAL_TABLES_SPEC = 0x0001
@classmethod
def recv_body(cls, f):
kind = read_int(f)
if kind == cls.KIND_VOID:
results = None
elif kind == cls.KIND_ROWS:
results = cls.recv_results_rows(f)
elif kind == cls.KIND_SET_KEYSPACE:
ksname = read_string(f)
results = ksname
elif kind == cls.KIND_PREPARED:
results = cls.recv_results_prepared(f)
elif kind == cls.KIND_SCHEMA_CHANGE:
results = cls.recv_results_schema_change(f)
return cls(kind=kind, results=results)
@classmethod
def recv_results_rows(cls, f):
colspecs = cls.recv_results_metadata(f)
rowcount = read_int(f)
rows = [cls.recv_row(f, len(colspecs)) for x in xrange(rowcount)]
colnames = [c[2] for c in colspecs]
coltypes = [c[3] for c in colspecs]
return [dict(zip(colnames, [ctype.from_binary(val) for ctype, val in zip(coltypes, row)]))
for row in rows]
@classmethod
def recv_results_prepared(cls, f):
queryid = read_int(f)
colspecs = cls.recv_results_metadata(f)
return (queryid, colspecs)
@classmethod
def recv_results_metadata(cls, f):
flags = read_int(f)
glob_tblspec = bool(flags & cls.FLAGS_GLOBAL_TABLES_SPEC)
colcount = read_int(f)
if glob_tblspec:
ksname = read_string(f)
cfname = read_string(f)
colspecs = []
for x in xrange(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)
colspecs.append((colksname, colcfname, colname, coltype))
return colspecs
@classmethod
def recv_results_schema_change(cls, f):
change_type = read_string(f)
keyspace = read_string(f)
table = read_string(f)
return dict(change_type=change_type, keyspace=keyspace, table=table)
@classmethod
def read_type(cls, f):
optid = read_short(f)
try:
cqltype = lookup_cqltype(cls.type_codes[optid])
except KeyError:
raise NotSupportedError("Unknown data type code 0x%x. Have to skip"
" entire result set." % optid)
if cqltype.typename in ('list', 'set'):
subtype = cls.read_type(f)
cqltype = cqltype.apply_parameters(subtype)
elif cqltype.typename == 'map':
keysubtype = cls.read_type(f)
valsubtype = cls.read_type(f)
cqltype = cqltype.apply_parameters(keysubtype, valsubtype)
return cqltype
@staticmethod
def recv_row(f, colcount):
return [read_value(f) for x in xrange(colcount)]
class PrepareMessage(_MessageType):
opcode = 0x09
name = 'PREPARE'
params = ('query',)
def send_body(self, f):
write_longstring(f, self.query)
class ExecuteMessage(_MessageType):
opcode = 0x0A
name = 'EXECUTE'
params = ('queryid', 'query_params', 'consistency_level',)
def send_body(self, f):
write_int(f, self.queryid)
write_short(f, len(self.query_params))
for param in self.query_params:
write_value(f, param)
write_consistency_level(f, self.consistency_level)
known_event_types = frozenset((
'TOPOLOGY_CHANGE',
'STATUS_CHANGE',
'SCHEMA_CHANGE'
))
class RegisterMessage(_MessageType):
opcode = 0x0B
name = 'REGISTER'
params = ('event_list',)
def send_body(self, f):
write_stringlist(f, self.event_list)
class EventMessage(_MessageType):
opcode = 0x0C
name = 'EVENT'
params = ('event_type', 'event_args')
@classmethod
def recv_body(cls, f):
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))
raise NotSupportedError('Unknown event type %r' % event_type)
@classmethod
def recv_topology_change(cls, f):
# "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):
# "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):
# "CREATED", "DROPPED", or "UPDATED"
change_type = read_string(f)
keyspace = read_string(f)
table = read_string(f)
return dict(change_type=change_type, keyspace=keyspace, table=table)
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 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 ConsistencyLevel.value_to_name[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 write_string(f, s):
if isinstance(s, unicode):
s = s.encode('utf8')
write_short(f, len(s))
f.write(s)
def read_longstring(f):
size = read_int(f)
contents = f.read(size)
return contents.decode('utf8')
def write_longstring(f, s):
if isinstance(s, unicode):
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 x in xrange(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 x in xrange(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 x in xrange(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)