Adds a new setting to avoid checking if a thumbnail already exists be…

…fore overwrite - #96 #351

docs/reference/settings.rst

@@ -364,3 +364,12 @@ that regex replaces references to images with thumbnails.
 
 This value sets the timeout value in seconds when retrieving a source image from a URL. 
 If no timeout value is specified, it will wait indefinitely for a response.
+
+``THUMBNAIL_FORCE_OVERWRITE``
+=========================
+
+- Default: ``False``
+
+Whenever we will check an existing thumbnail exists and avoid to overwrite or not.
+Set this to true if you have an slow .exists() implementation on your storage backend of choice,
+this will create the thumbnail without checking if it already exists.

sorl/thumbnail/base.py

@@ -98,7 +98,8 @@ def get_thumbnail(self, file_, geometry_string, **options):
 
         # We have to check exists() because the Storage backend does not
         # overwrite in some implementations.
-        if not thumbnail.exists():
+
+        if not (settings.THUMBNAIL_FORCE_OVERWRITE and thumbnail.exists()):
             try:
                 source_image = default.engine.get_image(source)
             except IOError:

sorl/thumbnail/conf/defaults.py

@@ -113,3 +113,7 @@
 # Should we flatten images by default (fixes a lot of transparency issues with
 # imagemagick)
 THUMBNAIL_FLATTEN = False
+
+# Whenever we will check an existing thumbnail exists and avoid to overwrite or not.
+# Set this to true if you have an slow .exists() implementation on your storage backend of choice.
+THUMBNAIL_FORCE_OVERWRITE = False