a bit of debugging for media storage providers (#6757)

* a bit of debugging for media storage providers

* changelog

changelog.d/6757.misc

@@ -0,0 +1 @@
+Add some debugging for media storage providers.

synapse/rest/media/v1/media_storage.py

@@ -148,6 +148,7 @@ class MediaStorage(object):
         for provider in self.storage_providers:
             res = yield provider.fetch(path, file_info)
             if res:
+                logger.debug("Streaming %s from %s", path, provider)
                 return res
 
         return None

synapse/rest/media/v1/storage_provider.py

@@ -77,6 +77,9 @@ class StorageProviderWrapper(StorageProvider):
         self.store_synchronous = store_synchronous
         self.store_remote = store_remote
 
+    def __str__(self):
+        return "StorageProviderWrapper[%s]" % (self.backend,)
+
     def store_file(self, path, file_info):
         if not file_info.server_name and not self.store_local:
             return defer.succeed(None)
@@ -114,6 +117,9 @@ class FileStorageProviderBackend(StorageProvider):
         self.cache_directory = hs.config.media_store_path
         self.base_directory = config
 
+    def __str__(self):
+        return "FileStorageProviderBackend[%s]" % (self.base_directory,)
+
     def store_file(self, path, file_info):
         """See StorageProvider.store_file"""