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/graph_store/base.py

@@ -0,0 +1,68 @@
+"""Graph store base class."""
+import logging
+from abc import ABC, abstractmethod
+from typing import List, Optional, Tuple
+
+from dbgpt._private.pydantic import BaseModel, ConfigDict, Field
+from dbgpt.core import Embeddings
+from dbgpt.storage.graph_store.graph import Direction, Graph
+
+logger = logging.getLogger(__name__)
+
+
+class GraphStoreConfig(BaseModel):
+    """Graph store config."""
+
+    model_config = ConfigDict(arbitrary_types_allowed=True, extra="allow")
+
+    name: str = Field(
+        default="dbgpt_collection",
+        description="The name of graph store, inherit from index store.",
+    )
+    embedding_fn: Optional[Embeddings] = Field(
+        default=None,
+        description="The embedding function of graph store, optional.",
+    )
+
+
+class GraphStoreBase(ABC):
+    """Graph store base class."""
+
+    @abstractmethod
+    def insert_triplet(self, sub: str, rel: str, obj: str):
+        """Add triplet."""
+
+    @abstractmethod
+    def get_triplets(self, sub: str) -> List[Tuple[str, str]]:
+        """Get triplets."""
+
+    @abstractmethod
+    def delete_triplet(self, sub: str, rel: str, obj: str):
+        """Delete triplet."""
+
+    @abstractmethod
+    def drop(self):
+        """Drop graph."""
+
+    @abstractmethod
+    def get_schema(self, refresh: bool = False) -> str:
+        """Get schema."""
+
+    @abstractmethod
+    def get_full_graph(self, limit: Optional[int] = None) -> Graph:
+        """Get full graph."""
+
+    @abstractmethod
+    def explore(
+        self,
+        subs: List[str],
+        direct: Direction = Direction.BOTH,
+        depth: Optional[int] = None,
+        fan: Optional[int] = None,
+        limit: Optional[int] = None,
+    ) -> Graph:
+        """Explore on graph."""
+
+    @abstractmethod
+    def query(self, query: str, **args) -> Graph:
+        """Execute a query."""