langchain_community.cache
.CassandraCache¶
- class langchain_community.cache.CassandraCache(session: Optional[CassandraSession] = None, keyspace: Optional[str] = None, table_name: str = 'langchain_llm_cache', ttl_seconds: Optional[int] = None, skip_provisioning: bool = False)[source]¶
Cache that uses Cassandra / Astra DB as a backend.
It uses a single Cassandra table. The lookup keys (which get to form the primary key) are:
prompt, a string
llm_string, a deterministic str representation of the model parameters. (needed to prevent collisions same-prompt-different-model collisions)
Initialize with a ready session and a keyspace name. :param session: an open Cassandra session :type session: cassandra.cluster.Session :param keyspace: the keyspace to use for storing the cache :type keyspace: str :param table_name: name of the Cassandra table to use as cache :type table_name: str :param ttl_seconds: time-to-live for cache entries
(default: None, i.e. forever)
Methods
__init__
([session, keyspace, table_name, ...])Initialize with a ready session and a keyspace name. :param session: an open Cassandra session :type session: cassandra.cluster.Session :param keyspace: the keyspace to use for storing the cache :type keyspace: str :param table_name: name of the Cassandra table to use as cache :type table_name: str :param ttl_seconds: time-to-live for cache entries (default: None, i.e. forever) :type ttl_seconds: optional int.
clear
(**kwargs)Clear cache.
delete
(prompt, llm_string)Evict from cache if there's an entry.
delete_through_llm
(prompt, llm[, stop])A wrapper around delete with the LLM being passed.
lookup
(prompt, llm_string)Look up based on prompt and llm_string.
update
(prompt, llm_string, return_val)Update cache based on prompt and llm_string.
- __init__(session: Optional[CassandraSession] = None, keyspace: Optional[str] = None, table_name: str = 'langchain_llm_cache', ttl_seconds: Optional[int] = None, skip_provisioning: bool = False)[source]¶
Initialize with a ready session and a keyspace name. :param session: an open Cassandra session :type session: cassandra.cluster.Session :param keyspace: the keyspace to use for storing the cache :type keyspace: str :param table_name: name of the Cassandra table to use as cache :type table_name: str :param ttl_seconds: time-to-live for cache entries
(default: None, i.e. forever)
- delete_through_llm(prompt: str, llm: LLM, stop: Optional[List[str]] = None) None [source]¶
A wrapper around delete with the LLM being passed. In case the llm(prompt) calls have a stop param, you should pass it here
- lookup(prompt: str, llm_string: str) Optional[Sequence[Generation]] [source]¶
Look up based on prompt and llm_string.
- update(prompt: str, llm_string: str, return_val: Sequence[Generation]) None [source]¶
Update cache based on prompt and llm_string.