Performance: Do not store attribute in TIFF new API

sigal/__init__.py

@@ -34,7 +34,7 @@
 from .gallery import Gallery
 from .log import init_logging
 from .settings import read_settings
-from .utils import copy
+from .utils import copy, monkey_patch_pil_tiff_imagefiledirectory_v1
 
 try:
     __version__ = get_distribution(__name__).version
@@ -139,6 +139,8 @@ def build(source, destination, debug, verbose, force, config, theme, title,
                      "directory.")
         sys.exit(1)
 
+    monkey_patch_pil_tiff_imagefiledirectory_v1()
+
     if title:
         settings['title'] = title
 

sigal/utils.py

@@ -135,3 +135,27 @@ def __get__(self, obj, cls):
             return self
         value = obj.__dict__[self.func.__name__] = self.func(obj)
         return value
+
+
+def monkey_patch_pil_tiff_imagefiledirectory_v1():
+    '''
+    Check that **only** legacy api is used
+    '''
+    from PIL.TiffImagePlugin import ImageFileDirectory_v1
+
+    def __setitem__(self, tag, value):
+        self._setitem(tag, value, True)
+
+    def __getitem__(self, tag):
+        if tag not in self._tags_v1:  # unpack on the fly
+            data = self._tagdata[tag]
+            typ = self.tagtype[tag]
+            size, handler = self._load_dispatch[typ]
+            self._setitem(tag, handler(self, data, True), True)
+        val = self._tags_v1[tag]
+        if not isinstance(val, (tuple, bytes)):
+            val = val,
+        return val
+
+    ImageFileDirectory_v1.__setitem__ = __setitem__
+    ImageFileDirectory_v1.__getitem__ = __getitem__