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Documentation for QueryRetriever Class

Overview

The QueryRetriever class is designed to facilitate the processing and retrieval of query items within a system. It encompasses multiple methods, each handling a specific aspect of query management including determining model classes, converting queries, extracting identifiers, obtaining storage metadata, and retrieving payload information.

Method Summaries

1. get_model_class

  • Functionality: Returns the model class for queries. Concrete classes should implement this method to return the actual class that implements the query model logic.
  • Parameters: None.
  • Usage: This method is used during the parsing of query dictionaries to determine the concrete model class for queries.

Example: 

def get_model_class(self) -> Type[CustomQueryItem]:
    return CustomQueryItem

2. _convert_query

  • Functionality: Converts a query object into an appropriate format for retrieval. It receives a query model instance (extending QueryItemType) and returns a representation suitable for search or storage backends.
  • Parameters:
  • query: An instance of QueryItemType containing the query details, typically a Pydantic model with search parameters.
  • Usage: This method translates the query model into a format compatible with the underlying retrieval system.

Example: 

def _convert_query(self, query: CustomQueryItem) -> str:
    return query.search_text

3. _get_id

  • Functionality: Extracts a unique identifier from the query object. This method is key for converting a query into a string that uniquely identifies it.
  • Parameters:
  • query: A query object (e.g., CustomQueryItem) from which the unique identifier is derived.
  • Usage: This method generates a unique string identifier for a query instance.

Example: 

def _get_id(self, query: CustomQueryItem) -> str:
    return f"query_{query.search_text[:20]}"

4. _get_storage_metadata

  • Functionality: Extracts metadata from the query for storage purposes. This method returns a dictionary with metadata required for storage, obtained by processing the query object.
  • Parameters:
  • query: The query object or dictionary from which metadata is extracted.
  • Usage: It is used to extract storage-specific metadata from a given query.

Example: 

def _get_storage_metadata(self, query: CustomQueryItem) -> Dict[str, Any]:
    return query.model_dump()

5. _get_payload

  • Functionality: Extracts optional payload information from a query object, returning a dict of payload info if available or None.
  • Parameters:
  • query: A query object from which to extract payload info.
  • Usage: This method retrieves extra data from a query.

Example: 

payload = retriever.get_payload(query)
if payload:
    print(payload)