feat: add GraphRAG framework and integrate TuGraph (#1506)

Co-authored-by: KingSkyLi <15566300566@163.com>
Co-authored-by: aries_ckt <916701291@qq.com>
Co-authored-by: Fangyin Cheng <staneyffer@gmail.com>

dbgpt/storage/knowledge_graph/open_spg.py

@@ -0,0 +1,49 @@
+"""OpenSPG class."""
+import logging
+from typing import List, Optional
+
+from dbgpt._private.pydantic import ConfigDict
+from dbgpt.core import Chunk
+from dbgpt.storage.graph_store.graph import Graph, MemoryGraph
+from dbgpt.storage.knowledge_graph.base import KnowledgeGraphBase, KnowledgeGraphConfig
+from dbgpt.storage.vector_store.filters import MetadataFilters
+
+logger = logging.getLogger(__name__)
+
+
+class OpenSPGConfig(KnowledgeGraphConfig):
+    """OpenSPG config."""
+
+    model_config = ConfigDict(arbitrary_types_allowed=True)
+
+
+class OpenSPG(KnowledgeGraphBase):
+    """OpenSPG class."""
+
+    # todo: add OpenSPG implementation
+
+    def __init__(self, config: OpenSPGConfig):
+        """Initialize the OpenSPG with config details."""
+        pass
+
+    def load_document(self, chunks: List[Chunk]) -> List[str]:
+        """Load document."""
+        return []
+
+    def similar_search_with_scores(
+        self,
+        text,
+        topk,
+        score_threshold: float,
+        filters: Optional[MetadataFilters] = None,
+    ) -> List[Chunk]:
+        """Similar with scores."""
+        return []
+
+    def query_graph(self, limit: Optional[int] = None) -> Graph:
+        """Query graph."""
+        return MemoryGraph()
+
+    def delete_vector_name(self, index_name: str):
+        """Delete vector name."""
+        pass