EncoderBackedStore#

class langchain.storage.encoder_backed.EncoderBackedStore(store: BaseStore[str, Any], key_encoder: Callable[[K], str], value_serializer: Callable[[V], bytes], value_deserializer: Callable[[Any], V])[source]#

Wraps a store with key and value encoders/decoders.

Examples that uses JSON for encoding/decoding:

import json

def key_encoder(key: int) -> str:
    return json.dumps(key)

def value_serializer(value: float) -> str:
    return json.dumps(value)

def value_deserializer(serialized_value: str) -> float:
    return json.loads(serialized_value)

# Create an instance of the abstract store
abstract_store = MyCustomStore()

# Create an instance of the encoder-backed store
store = EncoderBackedStore(
    store=abstract_store,
    key_encoder=key_encoder,
    value_serializer=value_serializer,
    value_deserializer=value_deserializer
)

# Use the encoder-backed store methods
store.mset([(1, 3.14), (2, 2.718)])
values = store.mget([1, 2])  # Retrieves [3.14, 2.718]
store.mdelete([1, 2])  # Deletes the keys 1 and 2

Initialize an EncodedStore.

Methods

`__init__`(store, key_encoder, ...)	Initialize an EncodedStore.
`amdelete`(keys)	Delete the given keys and their associated values.
`amget`(keys)	Get the values associated with the given keys.
`amset`(key_value_pairs)	Set the values for the given keys.
`ayield_keys`(*[, prefix])	Get an iterator over keys that match the given prefix.
`mdelete`(keys)	Delete the given keys and their associated values.
`mget`(keys)	Get the values associated with the given keys.
`mset`(key_value_pairs)	Set the values for the given keys.
`yield_keys`(*[, prefix])	Get an iterator over keys that match the given prefix.

Parameters:

store (BaseStore[str, Any])
key_encoder (Callable[[K], str])
value_serializer (Callable[[V], bytes])
value_deserializer (Callable[[Any], V])

__init__(store: BaseStore[str, Any], key_encoder: Callable[[K], str], value_serializer: Callable[[V], bytes], value_deserializer: Callable[[Any], V]) → None[source]#

Initialize an EncodedStore.

Parameters:

store (BaseStore[str, Any])
key_encoder (Callable[[K], str])
value_serializer (Callable[[V], bytes])
value_deserializer (Callable[[Any], V])

Return type:

None

async amdelete(keys: Sequence[K]) → None[source]#

Delete the given keys and their associated values.

Parameters:: keys (Sequence[K])
Return type:: None

async amget(keys: Sequence[K]) → List[V | None][source]#

Get the values associated with the given keys.

Parameters:: keys (Sequence[K])
Return type:: List[V | None]

async amset(key_value_pairs: Sequence[Tuple[K, V]]) → None[source]#

Set the values for the given keys.

Parameters:: key_value_pairs (Sequence[Tuple[K, V]])
Return type:: None

async ayield_keys(*, prefix: str | None = None) → AsyncIterator[K] | AsyncIterator[str][source]#

Get an iterator over keys that match the given prefix.

Parameters:: prefix (str | None)
Return type:: AsyncIterator[K] | AsyncIterator[str]

mdelete(keys: Sequence[K]) → None[source]#

Delete the given keys and their associated values.

Parameters:: keys (Sequence[K])
Return type:: None

mget(keys: Sequence[K]) → List[V | None][source]#

Get the values associated with the given keys.

Parameters:: keys (Sequence[K])
Return type:: List[V | None]

mset(key_value_pairs: Sequence[Tuple[K, V]]) → None[source]#

Set the values for the given keys.

Parameters:: key_value_pairs (Sequence[Tuple[K, V]])
Return type:: None

yield_keys(*, prefix: str | None = None) → Iterator[K] | Iterator[str][source]#

Get an iterator over keys that match the given prefix.

Parameters:: prefix (str | None)
Return type:: Iterator[K] | Iterator[str]