moment/src/python/models/model_store.py
2019-08-15 09:57:58 -04:00

62 lines
1.6 KiB
Python

from typing import Dict, Iterator, MutableMapping, Set, Tuple, Type, Union
from dataclasses import dataclass, field
from . import SyncId
from .model_item import ModelItem
from .model import Model
KeyType = Union[Type[ModelItem], Tuple[Type, ...]]
@dataclass(frozen=True)
class ModelStore(MutableMapping):
allowed_key_types: Set[KeyType] = field()
data: Dict[SyncId, Model] = field(init=False, default_factory=dict)
def __getitem__(self, key: SyncId) -> Model:
try:
return self.data[key]
except KeyError:
if isinstance(key, tuple):
for i in key:
if not i:
raise ValueError(f"Empty string in key: {key!r}")
key_type = (key[0],) + \
tuple(type(el) for el in key[1:]) # type: ignore
else:
key_type = key # type: ignore
if key_type not in self.allowed_key_types:
raise TypeError(f"{key_type!r} not in allowed key types: "
f"{self.allowed_key_types!r}")
model = Model(key)
self.data[key] = model
return model
def __setitem__(self, key, item) -> None:
raise NotImplementedError()
def __delitem__(self, key: SyncId) -> None:
del self.data[key]
def __iter__(self) -> Iterator[SyncId]:
return iter(self.data)
def __len__(self) -> int:
return len(self.data)
def __str__(self) -> str:
return "%s(\n %s\n)" % (
type(self).__name__,
"\n ".join(sorted(str(v) for v in self.values())),
)