Added setting to skip archive generation if archive file is already present

sigal/gallery.py

@@ -482,6 +482,10 @@ class Album(UnicodeMixin):
 
         if zip_gallery and len(self) > 0:
             archive_path = join(self.dst_path, zip_gallery)
+            if self.settings.get('zip_skip_if_exists', False) and isfile(archive_path):
+                self.logger.debug("Archive %s already created, passing", archive_path)
+                return zip_gallery
+
             archive = zipfile.ZipFile(archive_path, 'w', allowZip64=True)
             attr = ('src_path' if self.settings['zip_media_format'] == 'orig'
                     else 'dst_path')

sigal/templates/sigal.conf.py

@@ -187,6 +187,7 @@ ignore_files = []
 # contain all resized or original files (depending on `zip_media_format`).
 # zip_gallery = False   # False or 'archive.zip'
 # zip_media_format = 'resized'  # 'resized' or 'orig'
+# zip_skip_if_exists = false # Skip archive generation if archive is already present. Warning: new photos in an album won't be added to archive
 
 # Specify a different locale. If set to '', the default locale is used.
 # locale = ''