[Enhance] Add conf_path in PetrelBackend (open-mmlab#2459)

* feat: add conf_path in PetrelBackend

* fix: add conf_path in MockPetrelClient

* fix: adjust parameters order

mmcv/fileio/file_client.py

@@ -97,6 +97,8 @@ class PetrelBackend(BaseStorageBackend):
             ``filepath`` will be replaced by ``dst``. Default: None.
         enable_mc (bool, optional): Whether to enable memcached support.
             Default: True.
+        conf_path (str, optional): Config path of Petrel client. Default: None.
+            `New in version 1.7.1`.
 
     Examples:
         >>> filepath1 = 's3://path/of/file'
@@ -108,14 +110,15 @@ class PetrelBackend(BaseStorageBackend):
 
     def __init__(self,
                  path_mapping: Optional[dict] = None,
-                 enable_mc: bool = True):
+                 enable_mc: bool = True,
+                 conf_path: str = None):
         try:
             from petrel_client import client
         except ImportError:
             raise ImportError('Please install petrel_client to enable '
                               'PetrelBackend.')
 
-        self._client = client.Client(enable_mc=enable_mc)
+        self._client = client.Client(conf_path=conf_path, enable_mc=enable_mc)
         assert isinstance(path_mapping, dict) or path_mapping is None
         self.path_mapping = path_mapping
 

tests/test_fileclient.py

@@ -78,9 +78,13 @@ def Get(self, filepath):
 
 class MockPetrelClient:
 
-    def __init__(self, enable_mc=True, enable_multi_cluster=False):
+    def __init__(self,
+                 enable_mc=True,
+                 enable_multi_cluster=False,
+                 conf_path=None):
         self.enable_mc = enable_mc
         self.enable_multi_cluster = enable_multi_cluster
+        self.conf_path = conf_path
 
     def Get(self, filepath):
         with open(filepath, 'rb') as f: