[gcloud] fix saving content as gzipped

storages/backends/gcloud.py

@@ -1,3 +1,5 @@
+import gzip
+import io
 import mimetypes
 import warnings
 from datetime import timedelta
@@ -11,11 +13,9 @@
 
 from storages.base import BaseStorage
 from storages.compress import CompressedFileMixin
-from storages.compress import CompressStorageMixin
 from storages.utils import check_location
 from storages.utils import clean_name
 from storages.utils import get_available_overwrite_name
-from storages.utils import is_seekable
 from storages.utils import safe_join
 from storages.utils import setting
 from storages.utils import to_bytes
@@ -102,7 +102,7 @@ def close(self):
 
 
 @deconstructible
-class GoogleCloudStorage(CompressStorageMixin, BaseStorage):
+class GoogleCloudStorage(BaseStorage):
     def __init__(self, **settings):
         super().__init__(**settings)
 
@@ -174,6 +174,13 @@ def _open(self, name, mode='rb'):
             raise FileNotFoundError('File does not exist: %s' % name)
         return file_object
 
+    def _compress_content(self, content):
+        zbuf = io.BytesIO()
+        with gzip.GzipFile(mode='wb', fileobj=zbuf, mtime=0.0) as zfile:
+            zfile.write(to_bytes(content.read()))
+        zbuf.seek(0)
+        return zbuf
+
     def _save(self, name, content):
         cleaned_name = clean_name(name)
         name = self._normalize_name(cleaned_name)
@@ -195,10 +202,9 @@ def _save(self, name, content):
         for prop, val in blob_params.items():
             setattr(file_object.blob, prop, val)
 
-        rewind = is_seekable(content)
         file_object.blob.upload_from_file(
             content,
-            rewind=rewind,
+            rewind=True,
             retry=DEFAULT_RETRY,
             size=getattr(content, 'size', None),
             **upload_params
@@ -300,9 +306,9 @@ def get_created_time(self, name):
 
     def url(self, name, parameters=None):
         """
-        Return public url or a signed url for the Blob.
-        This DOES NOT check for existance of Blob - that makes codes too slow
-        for many use cases.
+        Return public URL or a signed URL for the Blob.
+
+        The existnce of blobs are not verified for public URLs, it makes the code too slow.
         """
         name = self._normalize_name(clean_name(name))
         blob = self.bucket.blob(name)