45 lines
1.8 KiB
Python
45 lines
1.8 KiB
Python
from typing import Generic, TypeVar
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from rainbowadn.data.collection.collection_interface.querycollectioninterface import QueryCollectionInterface
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from rainbowadn.data.collection.keyvalue import KeyValue
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from rainbowadn.hashing.hashpoint import HashPoint
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from rainbowadn.hashing.hashresolver import HashResolver
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from rainbowadn.hashing.nullability.notnull import NotNull
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from rainbowadn.hashing.nullability.null import Null
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from rainbowadn.hashing.nullability.nullable import Nullable
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__all__ = ('QueryMapping',)
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KVKeyType = TypeVar('KVKeyType')
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KVValueType = TypeVar('KVValueType')
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class QueryMapping(Generic[KVKeyType, KVValueType]):
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def __init__(
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self,
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collection: QueryCollectionInterface[KeyValue[KVKeyType, KVValueType]],
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empty_value: HashPoint[KVValueType],
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resoler: HashResolver
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):
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assert isinstance(collection, QueryCollectionInterface)
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assert isinstance(empty_value, HashPoint)
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assert isinstance(resoler, HashResolver)
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self.collection = collection
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self.empty_value = empty_value
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self.resolver = resoler
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def query(self, key: HashPoint[KVKeyType]) -> Nullable[HashPoint[KVValueType]]:
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assert isinstance(key, HashPoint)
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query_result: Nullable[
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HashPoint[KeyValue[KVKeyType, KVValueType]]
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] = self.collection.query(HashPoint.of(KeyValue(key, self.empty_value)))
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assert isinstance(query_result, Nullable)
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if isinstance(query_result, Null):
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return Null()
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elif isinstance(query_result, NotNull):
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key_value: KeyValue[KVKeyType, KVValueType] = self.resolver.resolve(query_result.value)
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assert isinstance(key_value, KeyValue)
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return NotNull(key_value.value)
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else:
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raise TypeError
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