Introduced delete_knowledge_graph (#6605)

### What problem does this PR solve?

Introduced delete_knowledge_graph

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [ ] Documentation Update

api/apps/kb_app.py

@@ -322,4 +322,18 @@ def knowledge_graph(kb_id):
             node_id_set = { o["id"] for o in obj["graph"]["nodes"] }
             filtered_edges = [o for o in obj["graph"]["edges"] if o["source"] != o["target"] and o["source"] in node_id_set and o["target"] in node_id_set]
             obj["graph"]["edges"] = sorted(filtered_edges, key=lambda x: x.get("weight", 0), reverse=True)[:128]
-    return get_json_result(data=obj)
+    return get_json_result(data=obj)
+
+@manager.route('/<kb_id>/knowledge_graph', methods=['DELETE'])  # noqa: F821
+@login_required
+def delete_knowledge_graph(kb_id):
+    if not KnowledgebaseService.accessible(kb_id, current_user.id):
+        return get_json_result(
+            data=False,
+            message='No authorization.',
+            code=settings.RetCode.AUTHENTICATION_ERROR
+        )
+    _, kb = KnowledgebaseService.get_by_id(kb_id)
+    settings.docStoreConn.delete({"knowledge_graph_kwd": ["graph", "subgraph", "entity", "relation"]}, search.index_name(kb.tenant_id), kb_id)
+
+    return get_json_result(data=True)

graphrag/utils.py

@@ -466,8 +466,6 @@ async def set_graph(tenant_id: str, kb_id: str, embd_mdl, graph: nx.Graph, chang
         callback(msg=f"set_graph converted graph change to {len(chunks)} chunks in {now - start:.2f}s.")
     start = now
 
-    await trio.to_thread.run_sync(lambda: settings.docStoreConn.delete({"knowledge_graph_kwd": ["graph", "entity", "relation"]}, search.index_name(tenant_id), kb_id))
-
     es_bulk_size = 4
     for b in range(0, len(chunks), es_bulk_size):
         doc_store_result = await trio.to_thread.run_sync(lambda: settings.docStoreConn.insert(chunks[b:b + es_bulk_size], search.index_name(tenant_id), kb_id))