863 lines
25 KiB
Python
863 lines
25 KiB
Python
from copy import deepcopy, copy
|
|
from datetime import datetime
|
|
from datetime import date
|
|
import re
|
|
import six
|
|
import sys
|
|
|
|
from cassandra.cqltypes import DateType
|
|
from cassandra.encoder import cql_quote
|
|
from cassandra.cqlengine.exceptions import ValidationError
|
|
|
|
|
|
# move to central spot
|
|
class UnicodeMixin(object):
|
|
if sys.version_info > (3, 0):
|
|
__str__ = lambda x: x.__unicode__()
|
|
else:
|
|
__str__ = lambda x: six.text_type(x).encode('utf-8')
|
|
|
|
|
|
class BaseValueManager(object):
|
|
|
|
def __init__(self, instance, column, value):
|
|
self.instance = instance
|
|
self.column = column
|
|
self.previous_value = deepcopy(value)
|
|
self.value = value
|
|
self.explicit = False
|
|
|
|
@property
|
|
def deleted(self):
|
|
return self.value is None and self.previous_value is not None
|
|
|
|
@property
|
|
def changed(self):
|
|
"""
|
|
Indicates whether or not this value has changed.
|
|
|
|
:rtype: boolean
|
|
|
|
"""
|
|
return self.value != self.previous_value
|
|
|
|
def reset_previous_value(self):
|
|
self.previous_value = copy(self.value)
|
|
|
|
def getval(self):
|
|
return self.value
|
|
|
|
def setval(self, val):
|
|
self.value = val
|
|
|
|
def delval(self):
|
|
self.value = None
|
|
|
|
def get_property(self):
|
|
_get = lambda slf: self.getval()
|
|
_set = lambda slf, val: self.setval(val)
|
|
_del = lambda slf: self.delval()
|
|
|
|
if self.column.can_delete:
|
|
return property(_get, _set, _del)
|
|
else:
|
|
return property(_get, _set)
|
|
|
|
|
|
class ValueQuoter(object):
|
|
"""
|
|
contains a single value, which will quote itself for CQL insertion statements
|
|
"""
|
|
def __init__(self, value):
|
|
self.value = value
|
|
|
|
def __str__(self):
|
|
raise NotImplementedError
|
|
|
|
def __repr__(self):
|
|
return self.__str__()
|
|
|
|
def __eq__(self, other):
|
|
if isinstance(other, self.__class__):
|
|
return self.value == other.value
|
|
return False
|
|
|
|
|
|
class Column(object):
|
|
|
|
# the cassandra type this column maps to
|
|
db_type = None
|
|
value_manager = BaseValueManager
|
|
|
|
instance_counter = 0
|
|
|
|
primary_key = False
|
|
"""
|
|
bool flag, indicates this column is a primary key. The first primary key defined
|
|
on a model is the partition key (unless partition keys are set), all others are cluster keys
|
|
"""
|
|
|
|
partition_key = False
|
|
|
|
"""
|
|
indicates that this column should be the partition key, defining
|
|
more than one partition key column creates a compound partition key
|
|
"""
|
|
|
|
index = False
|
|
"""
|
|
bool flag, indicates an index should be created for this column
|
|
"""
|
|
|
|
db_field = False
|
|
"""
|
|
the fieldname this field will map to in the database
|
|
"""
|
|
|
|
default = False
|
|
"""
|
|
the default value, can be a value or a callable (no args)
|
|
"""
|
|
|
|
required = False
|
|
"""
|
|
boolean, is the field required? Model validation will raise and
|
|
exception if required is set to True and there is a None value assigned
|
|
"""
|
|
|
|
clustering_order = False
|
|
"""
|
|
only applicable on clustering keys (primary keys that are not partition keys)
|
|
determines the order that the clustering keys are sorted on disk
|
|
"""
|
|
|
|
polymorphic_key = False
|
|
"""
|
|
boolean, if set to True, this column will be used for saving and loading instances
|
|
of polymorphic tables
|
|
"""
|
|
|
|
static = False
|
|
"""
|
|
boolean, if set to True, this is a static column, with a single value per partition
|
|
"""
|
|
|
|
def __init__(self,
|
|
primary_key=False,
|
|
partition_key=False,
|
|
index=False,
|
|
db_field=None,
|
|
default=None,
|
|
required=False,
|
|
clustering_order=None,
|
|
polymorphic_key=False,
|
|
static=False):
|
|
self.partition_key = partition_key
|
|
self.primary_key = partition_key or primary_key
|
|
self.index = index
|
|
self.db_field = db_field
|
|
self.default = default
|
|
self.required = required
|
|
self.clustering_order = clustering_order
|
|
self.polymorphic_key = polymorphic_key
|
|
# the column name in the model definition
|
|
self.column_name = None
|
|
self.static = static
|
|
|
|
self.value = None
|
|
|
|
# keep track of instantiation order
|
|
self.position = Column.instance_counter
|
|
Column.instance_counter += 1
|
|
|
|
def validate(self, value):
|
|
"""
|
|
Returns a cleaned and validated value. Raises a ValidationError
|
|
if there's a problem
|
|
"""
|
|
if value is None:
|
|
if self.required:
|
|
raise ValidationError('{} - None values are not allowed'.format(self.column_name or self.db_field))
|
|
return value
|
|
|
|
def to_python(self, value):
|
|
"""
|
|
Converts data from the database into python values
|
|
raises a ValidationError if the value can't be converted
|
|
"""
|
|
return value
|
|
|
|
def to_database(self, value):
|
|
"""
|
|
Converts python value into database value
|
|
"""
|
|
if value is None and self.has_default:
|
|
return self.get_default()
|
|
return value
|
|
|
|
@property
|
|
def has_default(self):
|
|
return self.default is not None
|
|
|
|
@property
|
|
def is_primary_key(self):
|
|
return self.primary_key
|
|
|
|
@property
|
|
def can_delete(self):
|
|
return not self.primary_key
|
|
|
|
def get_default(self):
|
|
if self.has_default:
|
|
if callable(self.default):
|
|
return self.default()
|
|
else:
|
|
return self.default
|
|
|
|
def get_column_def(self):
|
|
"""
|
|
Returns a column definition for CQL table definition
|
|
"""
|
|
static = "static" if self.static else ""
|
|
return '{} {} {}'.format(self.cql, self.db_type, static)
|
|
|
|
def set_column_name(self, name):
|
|
"""
|
|
Sets the column name during document class construction
|
|
This value will be ignored if db_field is set in __init__
|
|
"""
|
|
self.column_name = name
|
|
|
|
@property
|
|
def db_field_name(self):
|
|
""" Returns the name of the cql name of this column """
|
|
return self.db_field or self.column_name
|
|
|
|
@property
|
|
def db_index_name(self):
|
|
""" Returns the name of the cql index """
|
|
return 'index_{}'.format(self.db_field_name)
|
|
|
|
@property
|
|
def cql(self):
|
|
return self.get_cql()
|
|
|
|
def get_cql(self):
|
|
return '"{}"'.format(self.db_field_name)
|
|
|
|
def _val_is_null(self, val):
|
|
""" determines if the given value equates to a null value for the given column type """
|
|
return val is None
|
|
|
|
|
|
class Blob(Column):
|
|
"""
|
|
Stores a raw binary value
|
|
"""
|
|
db_type = 'blob'
|
|
|
|
def to_database(self, value):
|
|
|
|
if not isinstance(value, (six.binary_type, bytearray)):
|
|
raise Exception("expecting a binary, got a %s" % type(value))
|
|
|
|
val = super(Bytes, self).to_database(value)
|
|
return bytearray(val)
|
|
|
|
def to_python(self, value):
|
|
return value
|
|
|
|
Bytes = Blob
|
|
|
|
|
|
class Ascii(Column):
|
|
"""
|
|
Stores a US-ASCII character string
|
|
"""
|
|
db_type = 'ascii'
|
|
|
|
|
|
class Inet(Column):
|
|
"""
|
|
Stores an IP address in IPv4 or IPv6 format
|
|
"""
|
|
db_type = 'inet'
|
|
|
|
|
|
class Text(Column):
|
|
"""
|
|
Stores a UTF-8 encoded string
|
|
"""
|
|
|
|
db_type = 'text'
|
|
|
|
min_length = None
|
|
"""
|
|
Sets the minimum length of this string, for validation purposes.
|
|
Defaults to 1 if this is a ``required`` column. Otherwise, None.
|
|
"""
|
|
|
|
max_length = None
|
|
"""
|
|
Sets the maximum length of this string, for validation purposes.
|
|
"""
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
self.min_length = kwargs.pop('min_length', 1 if kwargs.get('required', False) else None)
|
|
self.max_length = kwargs.pop('max_length', None)
|
|
super(Text, self).__init__(*args, **kwargs)
|
|
|
|
def validate(self, value):
|
|
value = super(Text, self).validate(value)
|
|
if value is None:
|
|
return
|
|
if not isinstance(value, (six.string_types, bytearray)) and value is not None:
|
|
raise ValidationError('{} {} is not a string'.format(self.column_name, type(value)))
|
|
if self.max_length:
|
|
if len(value) > self.max_length:
|
|
raise ValidationError('{} is longer than {} characters'.format(self.column_name, self.max_length))
|
|
if self.min_length:
|
|
if len(value) < self.min_length:
|
|
raise ValidationError('{} is shorter than {} characters'.format(self.column_name, self.min_length))
|
|
return value
|
|
|
|
|
|
class Integer(Column):
|
|
"""
|
|
Stores a 32-bit signed integer value
|
|
"""
|
|
|
|
db_type = 'int'
|
|
|
|
def validate(self, value):
|
|
val = super(Integer, self).validate(value)
|
|
if val is None:
|
|
return
|
|
try:
|
|
return int(val)
|
|
except (TypeError, ValueError):
|
|
raise ValidationError("{} {} can't be converted to integral value".format(self.column_name, value))
|
|
|
|
def to_python(self, value):
|
|
return self.validate(value)
|
|
|
|
def to_database(self, value):
|
|
return self.validate(value)
|
|
|
|
|
|
class BigInt(Integer):
|
|
"""
|
|
Stores a 64-bit signed long value
|
|
"""
|
|
db_type = 'bigint'
|
|
|
|
|
|
class VarInt(Column):
|
|
"""
|
|
Stores an arbitrary-precision integer
|
|
"""
|
|
db_type = 'varint'
|
|
|
|
def validate(self, value):
|
|
val = super(VarInt, self).validate(value)
|
|
if val is None:
|
|
return
|
|
try:
|
|
return int(val)
|
|
except (TypeError, ValueError):
|
|
raise ValidationError(
|
|
"{} {} can't be converted to integral value".format(self.column_name, value))
|
|
|
|
def to_python(self, value):
|
|
return self.validate(value)
|
|
|
|
def to_database(self, value):
|
|
return self.validate(value)
|
|
|
|
|
|
class CounterValueManager(BaseValueManager):
|
|
def __init__(self, instance, column, value):
|
|
super(CounterValueManager, self).__init__(instance, column, value)
|
|
self.value = self.value or 0
|
|
self.previous_value = self.previous_value or 0
|
|
|
|
|
|
class Counter(Integer):
|
|
"""
|
|
Stores a counter that can be inremented and decremented
|
|
"""
|
|
db_type = 'counter'
|
|
|
|
value_manager = CounterValueManager
|
|
|
|
def __init__(self,
|
|
index=False,
|
|
db_field=None,
|
|
required=False):
|
|
super(Counter, self).__init__(
|
|
primary_key=False,
|
|
partition_key=False,
|
|
index=index,
|
|
db_field=db_field,
|
|
default=0,
|
|
required=required,
|
|
)
|
|
|
|
|
|
class DateTime(Column):
|
|
"""
|
|
Stores a datetime value
|
|
"""
|
|
db_type = 'timestamp'
|
|
|
|
def to_python(self, value):
|
|
if value is None:
|
|
return
|
|
if isinstance(value, datetime):
|
|
return value
|
|
elif isinstance(value, date):
|
|
return datetime(*(value.timetuple()[:6]))
|
|
try:
|
|
return datetime.utcfromtimestamp(value)
|
|
except TypeError:
|
|
return datetime.utcfromtimestamp(DateType.deserialize(value))
|
|
|
|
def to_database(self, value):
|
|
value = super(DateTime, self).to_database(value)
|
|
if value is None:
|
|
return
|
|
if not isinstance(value, datetime):
|
|
if isinstance(value, date):
|
|
value = datetime(value.year, value.month, value.day)
|
|
else:
|
|
raise ValidationError("{} '{}' is not a datetime object".format(self.column_name, value))
|
|
epoch = datetime(1970, 1, 1, tzinfo=value.tzinfo)
|
|
offset = epoch.tzinfo.utcoffset(epoch).total_seconds() if epoch.tzinfo else 0
|
|
|
|
return int(((value - epoch).total_seconds() - offset) * 1000)
|
|
|
|
|
|
class Date(Column):
|
|
"""
|
|
*Note: this type is overloaded, and will likely be changed or removed to accommodate distinct date type
|
|
in a future version*
|
|
|
|
Stores a date value, with no time-of-day
|
|
"""
|
|
db_type = 'timestamp'
|
|
|
|
def to_python(self, value):
|
|
if value is None:
|
|
return
|
|
if isinstance(value, datetime):
|
|
return value.date()
|
|
elif isinstance(value, date):
|
|
return value
|
|
try:
|
|
return datetime.utcfromtimestamp(value).date()
|
|
except TypeError:
|
|
return datetime.utcfromtimestamp(DateType.deserialize(value)).date()
|
|
|
|
def to_database(self, value):
|
|
value = super(Date, self).to_database(value)
|
|
if value is None:
|
|
return
|
|
if isinstance(value, datetime):
|
|
value = value.date()
|
|
if not isinstance(value, date):
|
|
raise ValidationError("{} '{}' is not a date object".format(self.column_name, repr(value)))
|
|
|
|
return int((value - date(1970, 1, 1)).total_seconds() * 1000)
|
|
|
|
|
|
class UUID(Column):
|
|
"""
|
|
Stores a type 1 or 4 UUID
|
|
"""
|
|
db_type = 'uuid'
|
|
|
|
re_uuid = re.compile(r'[0-9a-f]{8}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{4}-?[0-9a-f]{12}')
|
|
|
|
def validate(self, value):
|
|
val = super(UUID, self).validate(value)
|
|
if val is None:
|
|
return
|
|
from uuid import UUID as _UUID
|
|
if isinstance(val, _UUID):
|
|
return val
|
|
if isinstance(val, six.string_types) and self.re_uuid.match(val):
|
|
return _UUID(val)
|
|
raise ValidationError("{} {} is not a valid uuid".format(self.column_name, value))
|
|
|
|
def to_python(self, value):
|
|
return self.validate(value)
|
|
|
|
def to_database(self, value):
|
|
return self.validate(value)
|
|
|
|
from uuid import UUID as pyUUID, getnode
|
|
|
|
|
|
class TimeUUID(UUID):
|
|
"""
|
|
UUID containing timestamp
|
|
"""
|
|
|
|
db_type = 'timeuuid'
|
|
|
|
@classmethod
|
|
def from_datetime(self, dt):
|
|
"""
|
|
generates a UUID for a given datetime
|
|
|
|
:param dt: datetime
|
|
:type dt: datetime
|
|
:return:
|
|
"""
|
|
global _last_timestamp
|
|
|
|
epoch = datetime(1970, 1, 1, tzinfo=dt.tzinfo)
|
|
offset = epoch.tzinfo.utcoffset(epoch).total_seconds() if epoch.tzinfo else 0
|
|
timestamp = (dt - epoch).total_seconds() - offset
|
|
|
|
node = None
|
|
clock_seq = None
|
|
|
|
nanoseconds = int(timestamp * 1e9)
|
|
timestamp = int(nanoseconds // 100) + 0x01b21dd213814000
|
|
|
|
if clock_seq is None:
|
|
import random
|
|
clock_seq = random.randrange(1 << 14) # instead of stable storage
|
|
time_low = timestamp & 0xffffffff
|
|
time_mid = (timestamp >> 32) & 0xffff
|
|
time_hi_version = (timestamp >> 48) & 0x0fff
|
|
clock_seq_low = clock_seq & 0xff
|
|
clock_seq_hi_variant = (clock_seq >> 8) & 0x3f
|
|
if node is None:
|
|
node = getnode()
|
|
return pyUUID(fields=(time_low, time_mid, time_hi_version,
|
|
clock_seq_hi_variant, clock_seq_low, node), version=1)
|
|
|
|
|
|
class Boolean(Column):
|
|
"""
|
|
Stores a boolean True or False value
|
|
"""
|
|
db_type = 'boolean'
|
|
|
|
def validate(self, value):
|
|
""" Always returns a Python boolean. """
|
|
value = super(Boolean, self).validate(value)
|
|
|
|
if value is not None:
|
|
value = bool(value)
|
|
|
|
return value
|
|
|
|
def to_python(self, value):
|
|
return self.validate(value)
|
|
|
|
|
|
class Float(Column):
|
|
"""
|
|
Stores a 32-bit floating point value
|
|
"""
|
|
db_type = 'double'
|
|
|
|
def __init__(self, double_precision=True, **kwargs):
|
|
self.db_type = 'double' if double_precision else 'float'
|
|
super(Float, self).__init__(**kwargs)
|
|
|
|
def validate(self, value):
|
|
value = super(Float, self).validate(value)
|
|
if value is None:
|
|
return
|
|
try:
|
|
return float(value)
|
|
except (TypeError, ValueError):
|
|
raise ValidationError("{} {} is not a valid float".format(self.column_name, value))
|
|
|
|
def to_python(self, value):
|
|
return self.validate(value)
|
|
|
|
def to_database(self, value):
|
|
return self.validate(value)
|
|
|
|
|
|
class Decimal(Column):
|
|
"""
|
|
Stores a variable precision decimal value
|
|
"""
|
|
db_type = 'decimal'
|
|
|
|
def validate(self, value):
|
|
from decimal import Decimal as _Decimal
|
|
from decimal import InvalidOperation
|
|
val = super(Decimal, self).validate(value)
|
|
if val is None:
|
|
return
|
|
try:
|
|
return _Decimal(val)
|
|
except InvalidOperation:
|
|
raise ValidationError("{} '{}' can't be coerced to decimal".format(self.column_name, val))
|
|
|
|
def to_python(self, value):
|
|
return self.validate(value)
|
|
|
|
def to_database(self, value):
|
|
return self.validate(value)
|
|
|
|
|
|
class BaseContainerColumn(Column):
|
|
"""
|
|
Base Container type for collection-like columns.
|
|
|
|
https://cassandra.apache.org/doc/cql3/CQL.html#collections
|
|
"""
|
|
|
|
def __init__(self, value_type, **kwargs):
|
|
"""
|
|
:param value_type: a column class indicating the types of the value
|
|
"""
|
|
inheritance_comparator = issubclass if isinstance(value_type, type) else isinstance
|
|
if not inheritance_comparator(value_type, Column):
|
|
raise ValidationError('value_type must be a column class')
|
|
if inheritance_comparator(value_type, BaseContainerColumn):
|
|
raise ValidationError('container types cannot be nested')
|
|
if value_type.db_type is None:
|
|
raise ValidationError('value_type cannot be an abstract column type')
|
|
|
|
if isinstance(value_type, type):
|
|
self.value_type = value_type
|
|
self.value_col = self.value_type()
|
|
else:
|
|
self.value_col = value_type
|
|
self.value_type = self.value_col.__class__
|
|
|
|
super(BaseContainerColumn, self).__init__(**kwargs)
|
|
|
|
def validate(self, value):
|
|
value = super(BaseContainerColumn, self).validate(value)
|
|
# It is dangerous to let collections have more than 65535.
|
|
# See: https://issues.apache.org/jira/browse/CASSANDRA-5428
|
|
if value is not None and len(value) > 65535:
|
|
raise ValidationError("{} Collection can't have more than 65535 elements.".format(self.column_name))
|
|
return value
|
|
|
|
def get_column_def(self):
|
|
"""
|
|
Returns a column definition for CQL table definition
|
|
"""
|
|
static = "static" if self.static else ""
|
|
db_type = self.db_type.format(self.value_type.db_type)
|
|
return '{} {} {}'.format(self.cql, db_type, static)
|
|
|
|
def _val_is_null(self, val):
|
|
return not val
|
|
|
|
|
|
class BaseContainerQuoter(ValueQuoter):
|
|
|
|
def __nonzero__(self):
|
|
return bool(self.value)
|
|
|
|
|
|
class Set(BaseContainerColumn):
|
|
"""
|
|
Stores a set of unordered, unique values
|
|
|
|
http://www.datastax.com/documentation/cql/3.1/cql/cql_using/use_set_t.html
|
|
"""
|
|
db_type = 'set<{}>'
|
|
|
|
class Quoter(BaseContainerQuoter):
|
|
|
|
def __str__(self):
|
|
cq = cql_quote
|
|
return '{' + ', '.join([cq(v) for v in self.value]) + '}'
|
|
|
|
def __init__(self, value_type, strict=True, default=set, **kwargs):
|
|
"""
|
|
:param value_type: a column class indicating the types of the value
|
|
:param strict: sets whether non set values will be coerced to set
|
|
type on validation, or raise a validation error, defaults to True
|
|
"""
|
|
self.strict = strict
|
|
|
|
super(Set, self).__init__(value_type, default=default, **kwargs)
|
|
|
|
def validate(self, value):
|
|
val = super(Set, self).validate(value)
|
|
if val is None:
|
|
return
|
|
types = (set,) if self.strict else (set, list, tuple)
|
|
if not isinstance(val, types):
|
|
if self.strict:
|
|
raise ValidationError('{} {} is not a set object'.format(self.column_name, val))
|
|
else:
|
|
raise ValidationError('{} {} cannot be coerced to a set object'.format(self.column_name, val))
|
|
|
|
if None in val:
|
|
raise ValidationError("{} None not allowed in a set".format(self.column_name))
|
|
|
|
return {self.value_col.validate(v) for v in val}
|
|
|
|
def to_python(self, value):
|
|
if value is None:
|
|
return set()
|
|
return {self.value_col.to_python(v) for v in value}
|
|
|
|
def to_database(self, value):
|
|
if value is None:
|
|
return None
|
|
|
|
if isinstance(value, self.Quoter):
|
|
return value
|
|
return self.Quoter({self.value_col.to_database(v) for v in value})
|
|
|
|
|
|
class List(BaseContainerColumn):
|
|
"""
|
|
Stores a list of ordered values
|
|
|
|
http://www.datastax.com/documentation/cql/3.1/cql/cql_using/use_list_t.html
|
|
"""
|
|
db_type = 'list<{}>'
|
|
|
|
class Quoter(BaseContainerQuoter):
|
|
|
|
def __str__(self):
|
|
cq = cql_quote
|
|
return '[' + ', '.join([cq(v) for v in self.value]) + ']'
|
|
|
|
def __nonzero__(self):
|
|
return bool(self.value)
|
|
|
|
def __init__(self, value_type, default=list, **kwargs):
|
|
return super(List, self).__init__(value_type=value_type, default=default, **kwargs)
|
|
|
|
def validate(self, value):
|
|
val = super(List, self).validate(value)
|
|
if val is None:
|
|
return
|
|
if not isinstance(val, (set, list, tuple)):
|
|
raise ValidationError('{} {} is not a list object'.format(self.column_name, val))
|
|
if None in val:
|
|
raise ValidationError("{} None is not allowed in a list".format(self.column_name))
|
|
return [self.value_col.validate(v) for v in val]
|
|
|
|
def to_python(self, value):
|
|
if value is None:
|
|
return []
|
|
return [self.value_col.to_python(v) for v in value]
|
|
|
|
def to_database(self, value):
|
|
if value is None:
|
|
return None
|
|
if isinstance(value, self.Quoter):
|
|
return value
|
|
return self.Quoter([self.value_col.to_database(v) for v in value])
|
|
|
|
|
|
class Map(BaseContainerColumn):
|
|
"""
|
|
Stores a key -> value map (dictionary)
|
|
|
|
http://www.datastax.com/documentation/cql/3.1/cql/cql_using/use_map_t.html
|
|
"""
|
|
|
|
db_type = 'map<{}, {}>'
|
|
|
|
class Quoter(BaseContainerQuoter):
|
|
|
|
def __str__(self):
|
|
cq = cql_quote
|
|
return '{' + ', '.join([cq(k) + ':' + cq(v) for k, v in self.value.items()]) + '}'
|
|
|
|
def get(self, key):
|
|
return self.value.get(key)
|
|
|
|
def keys(self):
|
|
return self.value.keys()
|
|
|
|
def items(self):
|
|
return self.value.items()
|
|
|
|
def __init__(self, key_type, value_type, default=dict, **kwargs):
|
|
"""
|
|
:param key_type: a column class indicating the types of the key
|
|
:param value_type: a column class indicating the types of the value
|
|
"""
|
|
inheritance_comparator = issubclass if isinstance(key_type, type) else isinstance
|
|
if not inheritance_comparator(key_type, Column):
|
|
raise ValidationError('key_type must be a column class')
|
|
if inheritance_comparator(key_type, BaseContainerColumn):
|
|
raise ValidationError('container types cannot be nested')
|
|
if key_type.db_type is None:
|
|
raise ValidationError('key_type cannot be an abstract column type')
|
|
|
|
if isinstance(key_type, type):
|
|
self.key_type = key_type
|
|
self.key_col = self.key_type()
|
|
else:
|
|
self.key_col = key_type
|
|
self.key_type = self.key_col.__class__
|
|
super(Map, self).__init__(value_type, default=default, **kwargs)
|
|
|
|
def get_column_def(self):
|
|
"""
|
|
Returns a column definition for CQL table definition
|
|
"""
|
|
db_type = self.db_type.format(
|
|
self.key_type.db_type,
|
|
self.value_type.db_type
|
|
)
|
|
static = "static" if self.static else ""
|
|
return '{} {} {}'.format(self.cql, db_type, static)
|
|
|
|
def validate(self, value):
|
|
val = super(Map, self).validate(value)
|
|
if val is None:
|
|
return
|
|
if not isinstance(val, dict):
|
|
raise ValidationError('{} {} is not a dict object'.format(self.column_name, val))
|
|
return {self.key_col.validate(k): self.value_col.validate(v) for k, v in val.items()}
|
|
|
|
def to_python(self, value):
|
|
if value is None:
|
|
return {}
|
|
if value is not None:
|
|
return {self.key_col.to_python(k): self.value_col.to_python(v) for k, v in value.items()}
|
|
|
|
def to_database(self, value):
|
|
if value is None:
|
|
return None
|
|
if isinstance(value, self.Quoter):
|
|
return value
|
|
return self.Quoter({self.key_col.to_database(k): self.value_col.to_database(v) for k, v in value.items()})
|
|
|
|
|
|
class _PartitionKeysToken(Column):
|
|
"""
|
|
virtual column representing token of partition columns.
|
|
Used by filter(pk__token=Token(...)) filters
|
|
"""
|
|
|
|
def __init__(self, model):
|
|
self.partition_columns = model._partition_keys.values()
|
|
super(_PartitionKeysToken, self).__init__(partition_key=True)
|
|
|
|
@property
|
|
def db_field_name(self):
|
|
return 'token({})'.format(', '.join(['"{}"'.format(c.db_field_name) for c in self.partition_columns]))
|
|
|
|
def to_database(self, value):
|
|
from cqlengine.functions import Token
|
|
assert isinstance(value, Token)
|
|
value.set_columns(self.partition_columns)
|
|
return value
|
|
|
|
def get_cql(self):
|
|
return "token({})".format(", ".join(c.cql for c in self.partition_columns))
|