RedisCache#

class langchain_community.cache.RedisCache(redis_: Any, *, ttl: int | None = None)[source]#

Cache that uses Redis as a backend. Allows to use a sync redis.Redis client.

Initialize an instance of RedisCache.

This method initializes an object with Redis caching capabilities. It takes a redis_ parameter, which should be an instance of a Redis client class (redis.Redis), allowing the object to interact with a Redis server for caching purposes.

Parameters:

  • redis (Any) – An instance of a Redis client class (redis.Redis) to be used for caching. This allows the object to communicate with a Redis server for caching operations.

  • ttl (int, optional) – Time-to-live (TTL) for cached items in seconds. If provided, it sets the time duration for how long cached items will remain valid. If not provided, cached items will not have an automatic expiration.

  • redis_ (Any) –

Methods

__init__(redis_, *[, ttl])

Initialize an instance of RedisCache.

aclear(**kwargs)

Async clear cache that can take additional keyword arguments.

alookup(prompt, llm_string)

Async look up based on prompt and llm_string.

aupdate(prompt, llm_string, return_val)

Async update cache based on prompt and llm_string.

clear(**kwargs)

Clear cache.

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__(redis_: Any, *, ttl: int | None = None)[source]#

Initialize an instance of RedisCache.

This method initializes an object with Redis caching capabilities. It takes a redis_ parameter, which should be an instance of a Redis client class (redis.Redis), allowing the object to interact with a Redis server for caching purposes.

Parameters:

  • redis (Any) – An instance of a Redis client class (redis.Redis) to be used for caching. This allows the object to communicate with a Redis server for caching operations.

  • ttl (int, optional) – Time-to-live (TTL) for cached items in seconds. If provided, it sets the time duration for how long cached items will remain valid. If not provided, cached items will not have an automatic expiration.

  • redis_ (Any) –

async aclear(**kwargs: Any) → None#

Async clear cache that can take additional keyword arguments.

Parameters:

kwargs (Any) –

Return type:

None

async alookup(prompt: str, llm_string: str) → Sequence[Generation] | None#

Async look up based on prompt and llm_string.

A cache implementation is expected to generate a key from the 2-tuple of prompt and llm_string (e.g., by concatenating them with a delimiter).

Parameters:

  • prompt (str) – a string representation of the prompt. In the case of a Chat model, the prompt is a non-trivial serialization of the prompt into the language model.

  • llm_string (str) – A string representation of the LLM configuration. This is used to capture the invocation parameters of the LLM (e.g., model name, temperature, stop tokens, max tokens, etc.). These invocation parameters are serialized into a string representation.

Returns:

On a cache miss, return None. On a cache hit, return the cached value. The cached value is a list of Generations (or subclasses).

Return type:

Sequence[Generation] | None

async aupdate(prompt: str, llm_string: str, return_val: Sequence[Generation]) → None#

Async update cache based on prompt and llm_string.

The prompt and llm_string are used to generate a key for the cache. The key should match that of the look up method.

Parameters:

  • prompt (str) – a string representation of the prompt. In the case of a Chat model, the prompt is a non-trivial serialization of the prompt into the language model.

  • llm_string (str) – A string representation of the LLM configuration. This is used to capture the invocation parameters of the LLM (e.g., model name, temperature, stop tokens, max tokens, etc.). These invocation parameters are serialized into a string representation.

  • return_val (Sequence[Generation]) – The value to be cached. The value is a list of Generations (or subclasses).

Return type:

None

clear(**kwargs: Any) → None[source]#

Clear cache. If asynchronous is True, flush asynchronously.

Parameters:

kwargs (Any) –

Return type:

None

lookup(prompt: str, llm_string: str) → Sequence[Generation] | None[source]#

Look up based on prompt and llm_string.

Parameters:

  • prompt (str) –

  • llm_string (str) –

Return type:

Sequence[Generation] | None

update(prompt: str, llm_string: str, return_val: Sequence[Generation]) → None[source]#

Update cache based on prompt and llm_string.

Parameters:

  • prompt (str) –

  • llm_string (str) –

  • return_val (Sequence[Generation]) –

Return type:

None

Examples using RedisCache

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