Initial commit to support staging file background image generation and caching.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/sources/settings.py

@@ -1,5 +1,8 @@
 from __future__ import unicode_literals
 
+import os
+
+from django.conf import settings
 from django.utils.translation import ugettext_lazy as _
 
 from smart_settings import Namespace
@@ -7,9 +10,31 @@ from smart_settings import Namespace
 namespace = Namespace(name='sources', label=_('Sources'))
 
 setting_scanimage_path = namespace.add_setting(
-    global_name='SOURCE_SCANIMAGE_PATH', default='/usr/bin/scanimage',
+    global_name='SOURCES_SCANIMAGE_PATH', default='/usr/bin/scanimage',
     help_text=_(
         'File path to the scanimage program used to control image scanners.'
     ),
     is_path=True
 )
+setting_staging_file_image_cache_storage = namespace.add_setting(
+    global_name='SOURCES_STAGING_FILE_CACHE_STORAGE_BACKEND',
+    default='django.core.files.storage.FileSystemStorage', help_text=_(
+        'Path to the Storage subclass to use when storing the cached '
+        'staging_file image files.'
+    ), quoted=True
+)
+setting_staging_file_image_cache_storage_arguments = namespace.add_setting(
+    global_name='SOURCES_STAGING_FILE_CACHE_STORAGE_BACKEND_ARGUMENTS',
+    default='{{location: {}}}'.format(
+        os.path.join(settings.MEDIA_ROOT, 'staging_file_cache')
+    ), help_text=_(
+        'Arguments to pass to the SOURCES_STAGING_FILE_CACHE_STORAGE_BACKEND.'
+    ), quoted=True,
+)
+settings_staging_file_image_cache_time = namespace.add_setting(
+    global_name='SOURCES_STAGING_FILE_IMAGE_CACHE_TIME', default='31556926',
+    help_text=_(
+        'Time in seconds that the browser should cache the supplied staging '
+        'file images. The default of 31559626 seconds corresponde to 1 year.'
+    )
+)