Merge pull request #730: cap Zep edge pagination safely

Add a bounded edge paginator while preserving the existing positional retry API.

backend/app/utils/zep_paging.py

@@ -19,6 +19,7 @@ logger = get_logger('mirofish.zep_paging')
 
 _DEFAULT_PAGE_SIZE = 100
 _MAX_NODES = 2000
+_MAX_EDGES = 5000
 _DEFAULT_MAX_RETRIES = 3
 _DEFAULT_RETRY_DELAY = 2.0  # seconds, doubles each retry
 
@@ -108,8 +109,9 @@ def fetch_all_edges(
     page_size: int = _DEFAULT_PAGE_SIZE,
     max_retries: int = _DEFAULT_MAX_RETRIES,
     retry_delay: float = _DEFAULT_RETRY_DELAY,
+    max_items: int = _MAX_EDGES,
 ) -> list[Any]:
-    """分页获取图谱所有边，返回完整列表。每页请求自带重试。"""
+    """分页获取图谱所有边，最多返回 max_items 条（默认 5000）。每页请求自带重试。"""
     all_edges: list[Any] = []
     cursor: str | None = None
     page_num = 0
@@ -132,6 +134,10 @@ def fetch_all_edges(
             break
 
         all_edges.extend(batch)
+        if len(all_edges) >= max_items:
+            all_edges = all_edges[:max_items]
+            logger.warning(f"Edge count reached limit ({max_items}), stopping pagination for graph {graph_id}")
+            break
         if len(batch) < page_size:
             break
 

backend/tests/test_zep_edge_paging.py

@@ -0,0 +1,44 @@
+from types import SimpleNamespace
+
+from app.utils import zep_paging
+
+
+def _client():
+    edge_api = SimpleNamespace(get_by_graph_id=lambda *args, **kwargs: [])
+    return SimpleNamespace(graph=SimpleNamespace(edge=edge_api))
+
+
+def test_edge_cap_stops_pagination_at_requested_limit(monkeypatch):
+    pages = [
+        [SimpleNamespace(uuid_="e1"), SimpleNamespace(uuid_="e2")],
+        [SimpleNamespace(uuid_="e3"), SimpleNamespace(uuid_="e4")],
+    ]
+    calls = []
+
+    def fake_fetch(*args, **kwargs):
+        calls.append(kwargs)
+        return pages[len(calls) - 1]
+
+    monkeypatch.setattr(zep_paging, "_fetch_page_with_retry", fake_fetch)
+
+    result = zep_paging.fetch_all_edges(_client(), "graph", page_size=2, max_items=3)
+
+    assert [edge.uuid_ for edge in result] == ["e1", "e2", "e3"]
+    assert len(calls) == 2
+    assert calls[1]["uuid_cursor"] == "e2"
+
+
+def test_existing_positional_retry_arguments_keep_their_meaning(monkeypatch):
+    observed = {}
+
+    def fake_fetch(*args, **kwargs):
+        observed.update(kwargs)
+        return []
+
+    monkeypatch.setattr(zep_paging, "_fetch_page_with_retry", fake_fetch)
+
+    zep_paging.fetch_all_edges(_client(), "graph", 25, 7, 0.25)
+
+    assert observed["limit"] == 25
+    assert observed["max_retries"] == 7
+    assert observed["retry_delay"] == 0.25