def ref_doc_info(self) -> Dict[str, RefDocInfo]:
        """Retrieve a dict mapping of ingested documents and their nodes+metadata."""
        node_doc_ids_sets = list(self._index_struct.table.values())
        node_doc_ids = list(set().union(*node_doc_ids_sets))
        nodes = self.docstore.get_nodes(node_doc_ids)

        all_ref_doc_info = {}
        for node in nodes:
            ref_node = node.source_node
            if not ref_node:
                continue

            ref_doc_info = self.docstore.get_ref_doc_info(ref_node.node_id)
            if not ref_doc_info:
                continue

            all_ref_doc_info[ref_node.node_id] = ref_doc_info
        return all_ref_doc_info
Retrieve a dict mapping of ingested documents and their nodes+metadata.
llama-index-core/llama_index/core/indices/keyword_table/base.py