Add local_files_only parameter to pretrained items (#2930)

* Add disable_outgoing to pretrained items

Setting disable_outgoing=True disables outgonig traffic:
- etags are not looked up
- models are not downloaded

* parameter name change

* Remove forgotten print

src/transformers/configuration_utils.py

@@ -198,6 +198,7 @@ class PretrainedConfig(object):
         force_download = kwargs.pop("force_download", False)
         resume_download = kwargs.pop("resume_download", False)
         proxies = kwargs.pop("proxies", None)
+        local_files_only = kwargs.pop("local_files_only", False)
 
         if pretrained_config_archive_map is None:
             pretrained_config_archive_map = cls.pretrained_config_archive_map
@@ -219,6 +220,7 @@ class PretrainedConfig(object):
                 force_download=force_download,
                 proxies=proxies,
                 resume_download=resume_download,
+                local_files_only=local_files_only,
             )
             # Load config dict
             if resolved_config_file is None:

src/transformers/file_utils.py

@@ -214,6 +214,7 @@ def cached_path(
     user_agent=None,
     extract_compressed_file=False,
     force_extract=False,
+    local_files_only=False,
 ) -> Optional[str]:
     """
     Given something that might be a URL (or might be a local path),
@@ -250,6 +251,7 @@ def cached_path(
             proxies=proxies,
             resume_download=resume_download,
             user_agent=user_agent,
+            local_files_only=local_files_only,
         )
     elif os.path.exists(url_or_filename):
         # File, and it exists.
@@ -378,7 +380,14 @@ def http_get(url, temp_file, proxies=None, resume_size=0, user_agent=None):
 
 
 def get_from_cache(
-    url, cache_dir=None, force_download=False, proxies=None, etag_timeout=10, resume_download=False, user_agent=None
+    url,
+    cache_dir=None,
+    force_download=False,
+    proxies=None,
+    etag_timeout=10,
+    resume_download=False,
+    user_agent=None,
+    local_files_only=False,
 ) -> Optional[str]:
     """
     Given a URL, look for the corresponding file in the local cache.
@@ -395,18 +404,19 @@ def get_from_cache(
 
     os.makedirs(cache_dir, exist_ok=True)
 
+    etag = None
+    if not local_files_only:
         # Get eTag to add to filename, if it exists.
         if url.startswith("s3://"):
             etag = s3_etag(url, proxies=proxies)
         else:
             try:
                 response = requests.head(url, allow_redirects=True, proxies=proxies, timeout=etag_timeout)
-            if response.status_code != 200:
-                etag = None
-            else:
+                if response.status_code == 200:
                     etag = response.headers.get("ETag")
             except (EnvironmentError, requests.exceptions.Timeout):
-            etag = None
+                # etag is already None
+                pass
 
     filename = url_to_filename(url, etag)
 
@@ -427,6 +437,15 @@ def get_from_cache(
             if len(matching_files) > 0:
                 return os.path.join(cache_dir, matching_files[-1])
             else:
+                # If files cannot be found and local_files_only=True,
+                # the models might've been found if local_files_only=False
+                # Notify the user about that
+                if local_files_only:
+                    raise ValueError(
+                        "Cannot find the requested files in the cached path and outgoing traffic has been"
+                        " disabled. To enable model look-ups and downloads online, set 'local_files_only'"
+                        " to False."
+                    )
                 return None
 
     # From now on, etag is not None.

src/transformers/modeling_utils.py

@@ -376,6 +376,7 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin):
         resume_download = kwargs.pop("resume_download", False)
         proxies = kwargs.pop("proxies", None)
         output_loading_info = kwargs.pop("output_loading_info", False)
+        local_files_only = kwargs.pop("local_files_only", False)
 
         # Load config if we don't provide a configuration
         if not isinstance(config, PretrainedConfig):
@@ -388,6 +389,7 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin):
                 force_download=force_download,
                 resume_download=resume_download,
                 proxies=proxies,
+                local_files_only=local_files_only,
                 **kwargs,
             )
         else:
@@ -435,6 +437,7 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin):
                     force_download=force_download,
                     proxies=proxies,
                     resume_download=resume_download,
+                    local_files_only=local_files_only,
                 )
             except EnvironmentError:
                 if pretrained_model_name_or_path in cls.pretrained_model_archive_map:

src/transformers/tokenization_utils.py

@@ -395,6 +395,7 @@ class PreTrainedTokenizer(object):
         force_download = kwargs.pop("force_download", False)
         resume_download = kwargs.pop("resume_download", False)
         proxies = kwargs.pop("proxies", None)
+        local_files_only = kwargs.pop("local_files_only", False)
 
         s3_models = list(cls.max_model_input_sizes.keys())
         vocab_files = {}
@@ -462,6 +463,7 @@ class PreTrainedTokenizer(object):
                         force_download=force_download,
                         proxies=proxies,
                         resume_download=resume_download,
+                        local_files_only=local_files_only,
                     )
         except EnvironmentError:
             if pretrained_model_name_or_path in s3_models: