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langchain/langchain/retrievers/azure_cognitive_search.py

99 lines
3.5 KiB
Python

"""Retriever wrapper for Azure Cognitive Search."""
from __future__ import annotations
import json
from typing import Dict, List, Optional
import aiohttp
import requests
from pydantic import BaseModel, Extra, root_validator
from langchain.schema import BaseRetriever, Document
from langchain.utils import get_from_dict_or_env
class AzureCognitiveSearchRetriever(BaseRetriever, BaseModel):
"""Wrapper around Azure Cognitive Search."""
service_name: str = ""
"""Name of Azure Cognitive Search service"""
index_name: str = ""
"""Name of Index inside Azure Cognitive Search service"""
api_key: str = ""
"""API Key. Both Admin and Query keys work, but for reading data it's
recommended to use a Query key."""
api_version: str = "2020-06-30"
"""API version"""
aiosession: Optional[aiohttp.ClientSession] = None
"""ClientSession, in case we want to reuse connection for better performance."""
content_key: str = "content"
"""Key in a retrieved result to set as the Document page_content."""
class Config:
extra = Extra.forbid
arbitrary_types_allowed = True
@root_validator(pre=True)
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that service name, index name and api key exists in environment."""
values["service_name"] = get_from_dict_or_env(
values, "service_name", "AZURE_COGNITIVE_SEARCH_SERVICE_NAME"
)
values["index_name"] = get_from_dict_or_env(
values, "index_name", "AZURE_COGNITIVE_SEARCH_INDEX_NAME"
)
values["api_key"] = get_from_dict_or_env(
values, "api_key", "AZURE_COGNITIVE_SEARCH_API_KEY"
)
return values
def _build_search_url(self, query: str) -> str:
base_url = f"https://{self.service_name}.search.windows.net/"
endpoint_path = f"indexes/{self.index_name}/docs?api-version={self.api_version}"
return base_url + endpoint_path + f"&search={query}"
@property
def _headers(self) -> Dict[str, str]:
return {
"Content-Type": "application/json",
"api-key": self.api_key,
}
def _search(self, query: str) -> List[dict]:
search_url = self._build_search_url(query)
response = requests.get(search_url, headers=self._headers)
if response.status_code != 200:
raise Exception(f"Error in search request: {response}")
return json.loads(response.text)["value"]
async def _asearch(self, query: str) -> List[dict]:
search_url = self._build_search_url(query)
if not self.aiosession:
async with aiohttp.ClientSession() as session:
async with session.get(search_url, headers=self._headers) as response:
response_json = await response.json()
else:
async with self.aiosession.get(
search_url, headers=self._headers
) as response:
response_json = await response.json()
return response_json["value"]
def get_relevant_documents(self, query: str) -> List[Document]:
search_results = self._search(query)
return [
Document(page_content=result.pop(self.content_key), metadata=result)
for result in search_results
]
async def aget_relevant_documents(self, query: str) -> List[Document]:
search_results = await self._asearch(query)
return [
Document(page_content=result.pop(self.content_key), metadata=result)
for result in search_results
]