private-gpt/private_gpt/components/vector_store/retriever.py
Saurab-Shrestha9639*969**9858//852 fbd298212f Hybrid search
2024-05-29 14:20:11 +05:45

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1.6 KiB
Python

# import QueryBundle
from llama_index.core import QueryBundle
# import NodeWithScore
from llama_index.core.schema import NodeWithScore
# Retrievers
from llama_index.core.retrievers import (
BaseRetriever,
VectorIndexRetriever,
KeywordTableSimpleRetriever,
)
from typing import List
class CustomRetriever(BaseRetriever):
"""Custom retriever that performs both semantic search and hybrid search."""
def __init__(
self,
vector_retriever: VectorIndexRetriever,
keyword_retriever: KeywordTableSimpleRetriever,
mode: str = "AND",
) -> None:
"""Init params."""
self._vector_retriever = vector_retriever
self._keyword_retriever = keyword_retriever
if mode not in ("AND", "OR"):
raise ValueError("Invalid mode.")
self._mode = mode
super().__init__()
def _retrieve(self, query_bundle: QueryBundle) -> List[NodeWithScore]:
"""Retrieve nodes given query."""
vector_nodes = self._vector_retriever.retrieve(query_bundle)
keyword_nodes = self._keyword_retriever.retrieve(query_bundle)
vector_ids = {n.node.node_id for n in vector_nodes}
keyword_ids = {n.node.node_id for n in keyword_nodes}
combined_dict = {n.node.node_id: n for n in vector_nodes}
combined_dict.update({n.node.node_id: n for n in keyword_nodes})
if self._mode == "AND":
retrieve_ids = vector_ids.intersection(keyword_ids)
else:
retrieve_ids = vector_ids.union(keyword_ids)
retrieve_nodes = [combined_dict[rid] for rid in retrieve_ids]
return retrieve_nodes