Limit width of uploaded images to 3840 pixels

Author: jrief

finder/admin/inode.py

@@ -188,7 +188,7 @@ def get_favorite_folders(self, request, current_folder):
         return folders
 
     def changelist_view(self, request, extra_context=None):
-        # always redirect the list view to the detail view of either the last used, or the root folder
+        # always redirect the list view to the detail view of either the latest used, or the root folder
         fallback_folder = self.get_fallback_folder(request)
         return HttpResponseRedirect(reverse(
             'admin:finder_inodemodel_change',
@@ -228,8 +228,10 @@ def get_editor_settings(self, request, inode):
         return settings
 
     def get_folderitem_settings(self, request, inode):
+        """
+        Hook to return the context for the folder item.
+        """
         raise NotImplementedError()
-        return {}
 
     def get_menu_extension_settings(self, request):
         """

finder/contrib/image/pil/models.py

@@ -13,6 +13,7 @@ class PILImageModel(ImageFileModel):
     """
     accept_mime_types = ['image/jpeg', 'image/webp', 'image/png', 'image/gif']
     exif_values = set(ExifTags.Base.__members__.values())  # TODO: some EXIF values can be removed
+    MAX_STORED_IMAGE_WIDTH = 3840
 
     class Meta:
         app_label = 'finder'
@@ -23,6 +24,15 @@ class Meta:
     def save(self, **kwargs):
         try:
             image = Image.open(default_storage.open(self.file_path))
+            image = self.orientate_top(image)
+            if self.MAX_STORED_IMAGE_WIDTH and image.width > self.MAX_STORED_IMAGE_WIDTH:
+                # limit the width of the stored image to prevent excessive disk usage
+                height = round(self.MAX_STORED_IMAGE_WIDTH * image.height / image.width)
+                image = image.resize((self.MAX_STORED_IMAGE_WIDTH, height))
+                image.save(default_storage.open(self.file_path, 'wb'), image.format)
+                # recompute the file size and SHA1 hash
+                self.file_size = default_storage.size(self.file_path)
+                self.sha1 = self.digest_sha1()
             self.width = image.width
             self.height = image.height
         except Exception:
@@ -75,7 +85,9 @@ def orientate_top(self, image):
     def crop(self, thumbnail_path, width, height):
         aspect_ratio = width / height
         image = Image.open(default_storage.open(self.file_path))
-        image = self.orientate_top(image)
+        assert width <= image.width and height <= image.height, \
+            "The requested thumbnail size ({width}x{height}) is larger than the original image " \
+            "({0}x{1})".format(*image.size, width=width, height=height)
         orig_aspect_ratio = image.width / image.height
         crop_x, crop_y, crop_size, gravity = (
             self.meta_data.get('crop_x'),
@@ -137,7 +149,6 @@ def crop(self, thumbnail_path, width, height):
             crop_y = max(crop_y - max(min(crop_height - crop_size, crop_height), 0), 0)
         else:  # centered crop
             crop_y = max(crop_y - (crop_height - crop_size) / 2, 0)
-        crop_size = crop_resize
 
         min_x = crop_x
         if min_x + crop_width > image.width:

finder/models/file.py

@@ -242,6 +242,16 @@ def receive_file(self, uploaded_file):
         self.sha1 = sha1.hexdigest()
         self._for_write = True
 
+    def digest_sha1(self):
+        """
+        Generate the SHA1 hash for the file.
+        """
+        sha1 = hashlib.sha1()
+        with self.open('rb') as readhandle:
+            for chunk in readhandle.chunks():
+                sha1.update(chunk)
+        return sha1.hexdigest()
+
     def copy_to(self, folder, **kwargs):
         """
         Copy the file to a destination folder and returns it.