Source code for langchain_community.storage.redis

from typing import Any, Iterator, List, Optional, Sequence, Tuple, cast

from langchain_core.stores import ByteStore

from langchain_community.utilities.redis import get_client


[docs] class RedisStore(ByteStore): """BaseStore implementation using Redis as the underlying store. Examples: Create a RedisStore instance and perform operations on it: .. code-block:: python # Instantiate the RedisStore with a Redis connection from langchain_community.storage import RedisStore from langchain_community.utilities.redis import get_client client = get_client('redis://localhost:6379') redis_store = RedisStore(client=client) # Set values for keys redis_store.mset([("key1", b"value1"), ("key2", b"value2")]) # Get values for keys values = redis_store.mget(["key1", "key2"]) # [b"value1", b"value2"] # Delete keys redis_store.mdelete(["key1"]) # Iterate over keys for key in redis_store.yield_keys(): print(key) # noqa: T201 """
[docs] def __init__( self, *, client: Any = None, redis_url: Optional[str] = None, client_kwargs: Optional[dict] = None, ttl: Optional[int] = None, namespace: Optional[str] = None, ) -> None: """Initialize the RedisStore with a Redis connection. Must provide either a Redis client or a redis_url with optional client_kwargs. Args: client: A Redis connection instance redis_url: redis url client_kwargs: Keyword arguments to pass to the Redis client ttl: time to expire keys in seconds if provided, if None keys will never expire namespace: if provided, all keys will be prefixed with this namespace """ try: from redis import Redis except ImportError as e: raise ImportError( "The RedisStore requires the redis library to be installed. " "pip install redis" ) from e if client and (redis_url or client_kwargs): raise ValueError( "Either a Redis client or a redis_url with optional client_kwargs " "must be provided, but not both." ) if not client and not redis_url: raise ValueError("Either a Redis client or a redis_url must be provided.") if client: if not isinstance(client, Redis): raise TypeError( f"Expected Redis client, got {type(client).__name__} instead." ) _client = client else: if not redis_url: raise ValueError( "Either a Redis client or a redis_url must be provided." ) _client = get_client(redis_url, **(client_kwargs or {})) self.client = _client if not isinstance(ttl, int) and ttl is not None: raise TypeError(f"Expected int or None, got {type(ttl)=} instead.") self.ttl = ttl self.namespace = namespace
def _get_prefixed_key(self, key: str) -> str: """Get the key with the namespace prefix. Args: key (str): The original key. Returns: str: The key with the namespace prefix. """ delimiter = "/" if self.namespace: return f"{self.namespace}{delimiter}{key}" return key
[docs] def mget(self, keys: Sequence[str]) -> List[Optional[bytes]]: """Get the values associated with the given keys.""" return cast( List[Optional[bytes]], self.client.mget([self._get_prefixed_key(key) for key in keys]), )
[docs] def mset(self, key_value_pairs: Sequence[Tuple[str, bytes]]) -> None: """Set the given key-value pairs.""" pipe = self.client.pipeline() for key, value in key_value_pairs: pipe.set(self._get_prefixed_key(key), value, ex=self.ttl) pipe.execute()
[docs] def mdelete(self, keys: Sequence[str]) -> None: """Delete the given keys.""" _keys = [self._get_prefixed_key(key) for key in keys] self.client.delete(*_keys)
[docs] def yield_keys(self, *, prefix: Optional[str] = None) -> Iterator[str]: """Yield keys in the store.""" if prefix: pattern = self._get_prefixed_key(prefix) else: pattern = self._get_prefixed_key("*") scan_iter = cast(Iterator[bytes], self.client.scan_iter(match=pattern)) for key in scan_iter: decoded_key = key.decode("utf-8") if self.namespace: relative_key = decoded_key[len(self.namespace) + 1 :] yield relative_key else: yield decoded_key