Source code for

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

from langchain_core.documents import Document
from langchain_core.stores import BaseStore

[docs]class MongoDBStore(BaseStore[str, Document]): """BaseStore implementation using MongoDB as the underlying store. Examples: Create a MongoDBStore instance and perform operations on it: .. code-block:: python # Instantiate the MongoDBStore with a MongoDB connection from import MongoDBStore mongo_conn_str = "mongodb://localhost:27017/" mongodb_store = MongoDBStore(mongo_conn_str, db_name="test-db", collection_name="test-collection") # Set values for keys doc1 = Document(...) doc2 = Document(...) mongodb_store.mset([("key1", doc1), ("key2", doc2)]) # Get values for keys values = mongodb_store.mget(["key1", "key2"]) # [doc1, doc2] # Iterate over keys for key in mongodb_store.yield_keys(): print(key) # Delete keys mongodb_store.mdelete(["key1", "key2"]) """
[docs] def __init__( self, connection_string: str, db_name: str, collection_name: str, *, client_kwargs: Optional[dict] = None, ) -> None: """Initialize the MongoDBStore with a MongoDB connection string. Args: connection_string (str): MongoDB connection string db_name (str): name to use collection_name (str): collection name to use client_kwargs (dict): Keyword arguments to pass to the Mongo client """ try: from pymongo import MongoClient except ImportError as e: raise ImportError( "The MongoDBStore requires the pymongo library to be " "installed. " "pip install pymongo" ) from e if not connection_string: raise ValueError("connection_string must be provided.") if not db_name: raise ValueError("db_name must be provided.") if not collection_name: raise ValueError("collection_name must be provided.") self.client = MongoClient(connection_string, **(client_kwargs or {})) self.collection = self.client[db_name][collection_name]
[docs] def mget(self, keys: Sequence[str]) -> List[Optional[Document]]: """Get the list of documents associated with the given keys. Args: keys (list[str]): A list of keys representing Document IDs.. Returns: list[Document]: A list of Documents corresponding to the provided keys, where each Document is either retrieved successfully or represented as None if not found. """ result = self.collection.find({"_id": {"$in": keys}}) result_dict = {doc["_id"]: Document(**doc["value"]) for doc in result} return [result_dict.get(key) for key in keys]
[docs] def mset(self, key_value_pairs: Sequence[Tuple[str, Document]]) -> None: """Set the given key-value pairs. Args: key_value_pairs (list[tuple[str, Document]]): A list of id-document pairs. Returns: None """ from pymongo import UpdateOne updates = [{"_id": k, "value": v.__dict__} for k, v in key_value_pairs] self.collection.bulk_write( [UpdateOne({"_id": u["_id"]}, {"$set": u}, upsert=True) for u in updates] )
[docs] def mdelete(self, keys: Sequence[str]) -> None: """Delete the given ids. Args: keys (list[str]): A list of keys representing Document IDs.. """ self.collection.delete_many({"_id": {"$in": keys}})
[docs] def yield_keys(self, prefix: Optional[str] = None) -> Iterator[str]: """Yield keys in the store. Args: prefix (str): prefix of keys to retrieve. """ if prefix is None: for doc in self.collection.find(projection=["_id"]): yield doc["_id"] else: for doc in self.collection.find( {"_id": {"$regex": f"^{prefix}"}}, projection=["_id"] ): yield doc["_id"]