langchain[minor], community[minor], core[minor]: Async Cache support and AsyncRedisCache

docker/docker-compose.yml

@@ -0,0 +1,17 @@
+# docker-compose to make it easier to spin up integration tests.
+# Services should use NON standard ports to avoid collision with
+version: "3"
+name: langchain-tests
+
+services:
+  redis:
+    image: redis/redis-stack-server:latest
+    # We use non standard ports since 
+    # these instances are used for testing
+    # and users may already have existing
+    # redis instances set up locally
+    # for other projects
+    ports:
+      - "6020:6379"
+    volumes:
+      - ./redis-volume:/data

libs/community/langchain_community/cache.py

@@ -27,6 +27,7 @@
 import logging
 import uuid
 import warnings
+from abc import ABC
 from datetime import timedelta
 from functools import lru_cache
 from typing import (
@@ -351,21 +352,73 @@ def clear(self, **kwargs: Any) -> None:
         self.redis.flushdb(flush_type=asynchronous)
 
 
-class RedisCache(BaseCache):
-    """Cache that uses Redis as a backend."""
+class _RedisCacheBase(BaseCache, ABC):
+    @staticmethod
+    def _key(prompt: str, llm_string: str) -> str:
+        """Compute key from prompt and llm_string"""
+        return _hash(prompt + llm_string)
+
+    @staticmethod
+    def _ensure_generation_type(return_val: RETURN_VAL_TYPE) -> None:
+        for gen in return_val:
+            if not isinstance(gen, Generation):
+                raise ValueError(
+                    "RedisCache only supports caching of normal LLM generations, "
+                    f"got {type(gen)}"
+                )
+
+    @staticmethod
+    def _get_generations(
+        results: dict[str | bytes, str | bytes],
+    ) -> Optional[List[Generation]]:
+        generations = []
+        if results:
+            for _, text in results.items():
+                try:
+                    generations.append(loads(text))
+                except Exception:
+                    logger.warning(
+                        "Retrieving a cache value that could not be deserialized "
+                        "properly. This is likely due to the cache being in an "
+                        "older format. Please recreate your cache to avoid this "
+                        "error."
+                    )
+                    # In a previous life we stored the raw text directly
+                    # in the table, so assume it's in that format.
+                    generations.append(Generation(text=text))
+        return generations if generations else None
+
+    @staticmethod
+    def _configure_pipeline_for_update(
+        key: str, pipe: Any, return_val: RETURN_VAL_TYPE, ttl: Optional[int] = None
+    ) -> None:
+        pipe.hset(
+            key,
+            mapping={
+                str(idx): dumps(generation) for idx, generation in enumerate(return_val)
+            },
+        )
+        if ttl is not None:
+            pipe.expire(key, ttl)
+
+
+class RedisCache(_RedisCacheBase):
+    """
+    Cache that uses Redis as a backend. Allows to use a sync `redis.Redis` client.
+    """
 
     def __init__(self, redis_: Any, *, ttl: Optional[int] = None):
         """
         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, allowing the object to interact with a Redis
-        server for caching purposes.
+        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
-                (e.g., redis.Redis) used for caching.
+                (`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.
@@ -377,61 +430,27 @@ def __init__(self, redis_: Any, *, ttl: Optional[int] = None):
             from redis import Redis
         except ImportError:
             raise ValueError(
-                "Could not import redis python package. "
+                "Could not import `redis` python package. "
                 "Please install it with `pip install redis`."
             )
         if not isinstance(redis_, Redis):
-            raise ValueError("Please pass in Redis object.")
+            raise ValueError("Please pass a valid `redis.Redis` client.")
         self.redis = redis_
         self.ttl = ttl
 
-    def _key(self, prompt: str, llm_string: str) -> str:
-        """Compute key from prompt and llm_string"""
-        return _hash(prompt + llm_string)
-
     def lookup(self, prompt: str, llm_string: str) -> Optional[RETURN_VAL_TYPE]:
         """Look up based on prompt and llm_string."""
-        generations = []
         # Read from a Redis HASH
         results = self.redis.hgetall(self._key(prompt, llm_string))
-        if results:
-            for _, text in results.items():
-                try:
-                    generations.append(loads(text))
-                except Exception:
-                    logger.warning(
-                        "Retrieving a cache value that could not be deserialized "
-                        "properly. This is likely due to the cache being in an "
-                        "older format. Please recreate your cache to avoid this "
-                        "error."
-                    )
-                    # In a previous life we stored the raw text directly
-                    # in the table, so assume it's in that format.
-                    generations.append(Generation(text=text))
-        return generations if generations else None
+        return self._get_generations(results)  # type: ignore[arg-type]
 
     def update(self, prompt: str, llm_string: str, return_val: RETURN_VAL_TYPE) -> None:
         """Update cache based on prompt and llm_string."""
-        for gen in return_val:
-            if not isinstance(gen, Generation):
-                raise ValueError(
-                    "RedisCache only supports caching of normal LLM generations, "
-                    f"got {type(gen)}"
-                )
-        # Write to a Redis HASH
+        self._ensure_generation_type(return_val)
         key = self._key(prompt, llm_string)
 
         with self.redis.pipeline() as pipe:
-            pipe.hset(
-                key,
-                mapping={
-                    str(idx): dumps(generation)
-                    for idx, generation in enumerate(return_val)
-                },
-            )
-            if self.ttl is not None:
-                pipe.expire(key, self.ttl)
-
+            self._configure_pipeline_for_update(key, pipe, return_val, self.ttl)
             pipe.execute()
 
     def clear(self, **kwargs: Any) -> None:
@@ -440,6 +459,89 @@ def clear(self, **kwargs: Any) -> None:
         self.redis.flushdb(asynchronous=asynchronous, **kwargs)
 
 
+class AsyncRedisCache(_RedisCacheBase):
+    """
+    Cache that uses Redis as a backend. Allows to use an
+    async `redis.asyncio.Redis` client.
+    """
+
+    def __init__(self, redis_: Any, *, ttl: Optional[int] = None):
+        """
+        Initialize an instance of AsyncRedisCache.
+
+        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.asyncio.Redis`), allowing the object
+        to interact with a Redis server for caching purposes.
+
+        Parameters:
+            redis_ (Any): An instance of a Redis client class
+                (`redis.asyncio.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.
+        """
+        try:
+            from redis.asyncio import Redis
+        except ImportError:
+            raise ValueError(
+                "Could not import `redis.asyncio` python package. "
+                "Please install it with `pip install redis`."
+            )
+        if not isinstance(redis_, Redis):
+            raise ValueError("Please pass a valid `redis.asyncio.Redis` client.")
+        self.redis = redis_
+        self.ttl = ttl
+
+    def lookup(self, prompt: str, llm_string: str) -> Optional[RETURN_VAL_TYPE]:
+        """Look up based on prompt and llm_string."""
+        raise NotImplementedError(
+            "This async Redis cache does not implement `lookup()` method. "
+            "Consider using the async `alookup()` version."
+        )
+
+    async def alookup(self, prompt: str, llm_string: str) -> Optional[RETURN_VAL_TYPE]:
+        """Look up based on prompt and llm_string. Async version."""
+        results = await self.redis.hgetall(self._key(prompt, llm_string))
+        return self._get_generations(results)  # type: ignore[arg-type]
+
+    def update(self, prompt: str, llm_string: str, return_val: RETURN_VAL_TYPE) -> None:
+        """Update cache based on prompt and llm_string."""
+        raise NotImplementedError(
+            "This async Redis cache does not implement `update()` method. "
+            "Consider using the async `aupdate()` version."
+        )
+
+    async def aupdate(
+        self, prompt: str, llm_string: str, return_val: RETURN_VAL_TYPE
+    ) -> None:
+        """Update cache based on prompt and llm_string. Async version."""
+        self._ensure_generation_type(return_val)
+        key = self._key(prompt, llm_string)
+
+        async with self.redis.pipeline() as pipe:
+            self._configure_pipeline_for_update(key, pipe, return_val, self.ttl)
+            await pipe.execute()  # type: ignore[attr-defined]
+
+    def clear(self, **kwargs: Any) -> None:
+        """Clear cache. If `asynchronous` is True, flush asynchronously."""
+        raise NotImplementedError(
+            "This async Redis cache does not implement `clear()` method. "
+            "Consider using the async `aclear()` version."
+        )
+
+    async def aclear(self, **kwargs: Any) -> None:
+        """
+        Clear cache. If `asynchronous` is True, flush asynchronously.
+        Async version.
+        """
+        asynchronous = kwargs.get("asynchronous", False)
+        await self.redis.flushdb(asynchronous=asynchronous, **kwargs)
+
+
 class RedisSemanticCache(BaseCache):
     """Cache that uses Redis as a vector-store backend."""
 

libs/core/langchain_core/caches.py

@@ -4,6 +4,7 @@
 from typing import Any, Optional, Sequence
 
 from langchain_core.outputs import Generation
+from langchain_core.runnables import run_in_executor
 
 RETURN_VAL_TYPE = Sequence[Generation]
 
@@ -22,3 +23,17 @@ def update(self, prompt: str, llm_string: str, return_val: RETURN_VAL_TYPE) -> N
     @abstractmethod
     def clear(self, **kwargs: Any) -> None:
         """Clear cache that can take additional keyword arguments."""
+
+    async def alookup(self, prompt: str, llm_string: str) -> Optional[RETURN_VAL_TYPE]:
+        """Look up based on prompt and llm_string."""
+        return await run_in_executor(None, self.lookup, prompt, llm_string)
+
+    async def aupdate(
+        self, prompt: str, llm_string: str, return_val: RETURN_VAL_TYPE
+    ) -> None:
+        """Update cache based on prompt and llm_string."""
+        return await run_in_executor(None, self.update, prompt, llm_string, return_val)
+
+    async def aclear(self, **kwargs: Any) -> None:
+        """Clear cache that can take additional keyword arguments."""
+        return await run_in_executor(None, self.clear, **kwargs)

libs/core/langchain_core/language_models/chat_models.py

@@ -622,7 +622,7 @@ async def _agenerate_with_cache(
         else:
             llm_string = self._get_llm_string(stop=stop, **kwargs)
             prompt = dumps(messages)
-            cache_val = llm_cache.lookup(prompt, llm_string)
+            cache_val = await llm_cache.alookup(prompt, llm_string)
             if isinstance(cache_val, list):
                 return ChatResult(generations=cache_val)
             else:
@@ -632,7 +632,7 @@ async def _agenerate_with_cache(
                     )
                 else:
                     result = await self._agenerate(messages, stop=stop, **kwargs)
-                llm_cache.update(prompt, llm_string, result.generations)
+                await llm_cache.aupdate(prompt, llm_string, result.generations)
                 return result
 
     @abstractmethod

libs/core/langchain_core/language_models/llms.py

@@ -139,6 +139,26 @@ def get_prompts(
     return existing_prompts, llm_string, missing_prompt_idxs, missing_prompts
 
 
+async def aget_prompts(
+    params: Dict[str, Any], prompts: List[str]
+) -> Tuple[Dict[int, List], str, List[int], List[str]]:
+    """Get prompts that are already cached. Async version."""
+    llm_string = str(sorted([(k, v) for k, v in params.items()]))
+    missing_prompts = []
+    missing_prompt_idxs = []
+    existing_prompts = {}
+    llm_cache = get_llm_cache()
+    for i, prompt in enumerate(prompts):
+        if llm_cache:
+            cache_val = await llm_cache.alookup(prompt, llm_string)
+            if isinstance(cache_val, list):
+                existing_prompts[i] = cache_val
+            else:
+                missing_prompts.append(prompt)
+                missing_prompt_idxs.append(i)
+    return existing_prompts, llm_string, missing_prompt_idxs, missing_prompts
+
+
 def update_cache(
     existing_prompts: Dict[int, List],
     llm_string: str,
@@ -157,6 +177,24 @@ def update_cache(
     return llm_output
 
 
+async def aupdate_cache(
+    existing_prompts: Dict[int, List],
+    llm_string: str,
+    missing_prompt_idxs: List[int],
+    new_results: LLMResult,
+    prompts: List[str],
+) -> Optional[dict]:
+    """Update the cache and get the LLM output. Async version"""
+    llm_cache = get_llm_cache()
+    for i, result in enumerate(new_results.generations):
+        existing_prompts[missing_prompt_idxs[i]] = result
+        prompt = prompts[missing_prompt_idxs[i]]
+        if llm_cache:
+            await llm_cache.aupdate(prompt, llm_string, result)
+    llm_output = new_results.llm_output
+    return llm_output
+
+
 class BaseLLM(BaseLanguageModel[str], ABC):
     """Base LLM abstract interface.
 
@@ -869,7 +907,7 @@ async def agenerate(
             llm_string,
             missing_prompt_idxs,
             missing_prompts,
-        ) = get_prompts(params, prompts)
+        ) = await aget_prompts(params, prompts)
         disregard_cache = self.cache is not None and not self.cache
         new_arg_supported = inspect.signature(self._agenerate).parameters.get(
             "run_manager"
@@ -917,7 +955,7 @@ async def agenerate(
             new_results = await self._agenerate_helper(
                 missing_prompts, stop, run_managers, bool(new_arg_supported), **kwargs
             )
-            llm_output = update_cache(
+            llm_output = await aupdate_cache(
                 existing_prompts, llm_string, missing_prompt_idxs, new_results, prompts
             )
             run_info = (

libs/langchain/langchain/cache.py

@@ -1,6 +1,7 @@
 from langchain_community.cache import (
     AstraDBCache,
     AstraDBSemanticCache,
+    AsyncRedisCache,
     CassandraCache,
     CassandraSemanticCache,
     FullLLMCache,
@@ -22,6 +23,7 @@
     "SQLAlchemyCache",
     "SQLiteCache",
     "UpstashRedisCache",
+    "AsyncRedisCache",
     "RedisCache",
     "RedisSemanticCache",
     "GPTCache",