fix: #478 make s3 upload confirmation resilient

Author: vastsa

core/storage.py

@@ -536,18 +536,31 @@ async def file_exists(self, save_path: str) -> bool:
         :param save_path: 文件路径
         :return: 文件是否存在
         """
-        async with self.session.client(
-            "s3",
-            endpoint_url=self.endpoint_url,
-            aws_session_token=self.aws_session_token,
-            region_name=self.region_name,
-            config=Config(signature_version=self.signature_version),
-        ) as s3:
+        async with self._client() as s3:
+            last_error = None
+            for attempt in range(3):
+                try:
+                    await s3.head_object(Bucket=self.bucket_name, Key=save_path)
+                    return True
+                except Exception as e:
+                    last_error = e
+                    if attempt < 2:
+                        await asyncio.sleep(0.2 * (attempt + 1))
+
             try:
-                await s3.head_object(Bucket=self.bucket_name, Key=save_path)
-                return True
-            except Exception:
-                return False
+                result = await s3.list_objects_v2(
+                    Bucket=self.bucket_name,
+                    Prefix=save_path,
+                    MaxKeys=1,
+                )
+                for item in result.get("Contents", []):
+                    if item.get("Key") == save_path:
+                        return True
+            except Exception as e:
+                last_error = e
+
+            logger.warning(f"S3文件确认失败 key={save_path}: {last_error}")
+            return False
 
 
 class OneDriveFileStorage(FileStorageInterface):

tests/test_issue_478_s3_file_exists.py

@@ -0,0 +1,46 @@
+import asyncio
+import unittest
+
+from core.storage import S3FileStorage
+
+
+class FakeS3Client:
+    def __init__(self, list_response):
+        self.list_response = list_response
+        self.head_calls = 0
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, exc_type, exc, traceback):
+        return False
+
+    async def head_object(self, **kwargs):
+        self.head_calls += 1
+        raise RuntimeError("head not supported")
+
+    async def list_objects_v2(self, **kwargs):
+        return self.list_response
+
+
+class S3FileExistsTests(unittest.TestCase):
+    def test_file_exists_falls_back_to_list_objects(self):
+        client = FakeS3Client({"Contents": [{"Key": "share/data/file.txt"}]})
+        storage = S3FileStorage.__new__(S3FileStorage)
+        storage.bucket_name = "bucket"
+        storage._client = lambda: client
+
+        exists = asyncio.run(storage.file_exists("share/data/file.txt"))
+
+        self.assertTrue(exists)
+        self.assertEqual(client.head_calls, 3)
+
+    def test_file_exists_returns_false_when_missing(self):
+        client = FakeS3Client({"Contents": [{"Key": "share/data/other.txt"}]})
+        storage = S3FileStorage.__new__(S3FileStorage)
+        storage.bucket_name = "bucket"
+        storage._client = lambda: client
+
+        exists = asyncio.run(storage.file_exists("share/data/file.txt"))
+
+        self.assertFalse(exists)