constants/base.py

@@ -107,6 +107,5 @@ ABUSE_TYPE = Choices(
 THUMBNAIL_SIZE_L = (1920, 1080)
 THUMBNAIL_SIZE_S = (640, 360)
 THUMBNAIL_SIZES = [THUMBNAIL_SIZE_L, THUMBNAIL_SIZE_S]
-THUMBNAIL_META = {'l': THUMBNAIL_SIZE_L, 's': THUMBNAIL_SIZE_S}
 THUMBNAIL_FORMAT = 'PNG'
 THUMBNAIL_QUALITY = 83

files/admin.py

@@ -19,6 +19,12 @@ def scan_selected_files(self, request, queryset):
         files.signals.schedule_scan(instance)
 
 
+def schedule_thumbnails(self, request, queryset):
+    """Schedule thumbnails generationg for selected files."""
+    for instance in queryset.filter(type__in=(File.TYPES.IMAGE, File.TYPES.VIDEO)):
+        files.tasks.make_thumbnails(file_id=instance.pk)
+
+
 def make_thumbnails(self, request, queryset):
     """Make thumbnails for selected files."""
     for instance in queryset.filter(type__in=(File.TYPES.IMAGE, File.TYPES.VIDEO)):
@@ -60,9 +66,8 @@ class FileAdmin(admin.ModelAdmin):
             raise
 
     def get_form(self, request, obj=None, **kwargs):
-        # Only override if the obj exisits
+        """Override metadata help text for depending on type."""
-        if obj:
+        if obj and (obj.is_image or obj.is_video):
-            if obj.is_image or obj.is_video:
             help_text = 'Additional information about the file, e.g. existing thumbnails.'
             kwargs.update({'help_texts': {'metadata': help_text}})
         return super().get_form(request, obj, **kwargs)
@@ -141,7 +146,7 @@ class FileAdmin(admin.ModelAdmin):
     )
 
     inlines = [FileValidationInlineAdmin]
-    actions = [scan_selected_files, make_thumbnails]
+    actions = [scan_selected_files, schedule_thumbnails, make_thumbnails]
 
     def is_ok(self, obj):
         return obj.validation.is_ok if hasattr(obj, 'validation') else None

files/signals.py

@@ -39,7 +39,7 @@ def _scan_new_file(
 def schedule_thumbnails(file: files.models.File) -> None:
     """Schedule thumbnail generation for a given file."""
     args = {'pk': file.pk, 'type': file.get_type_display()}
-    logger.info('Scheduling thumbnail generation for file pk=%s type=%s', args)
+    logger.info('Scheduling thumbnail generation for file pk=%(pk)s type=%(type)s', args)
     verbose_name = f'make thumbnails for "{file.source.name}"'
     files.tasks.make_thumbnails(file_id=file.pk, creator=file, verbose_name=verbose_name)
 

files/tasks.py

@@ -5,7 +5,7 @@ from background_task import background
 from background_task.tasks import TaskSchedule
 from django.conf import settings
 
-from constants.base import THUMBNAIL_FORMAT, THUMBNAIL_SIZE_L, THUMBNAIL_QUALITY, THUMBNAIL_META
+from constants.base import THUMBNAIL_SIZE_L
 import files.models
 import files.utils
 
@@ -43,33 +43,22 @@ def make_thumbnails(file_id: int) -> None:
 
     source_path = os.path.join(settings.MEDIA_ROOT, file.source.path)
     thumbnail_field = file.thumbnail
-    thumbnails_paths = file.thumbnails
-    thumbnail_default_path = thumbnails_paths[THUMBNAIL_SIZE_L]
 
-    # For a video, source of the thumbnail is some frame fetched with ffpeg
     if file.is_video:
-        output_path = os.path.join(settings.MEDIA_ROOT, thumbnail_default_path)
+        # For a video, source of the thumbnail is some frame fetched with ffpeg
+        output_path = os.path.join(settings.MEDIA_ROOT, thumbnail_field.upload_to(file, 'x.png'))
         files.utils.extract_frame(source_path, output_path)
         source_path = output_path
 
-    files.utils.make_thumbnails(
+    thumbnails = files.utils.make_thumbnails(source_path, file.hash)
-        source_path,
+    thumbnail_default_path = next(_['path'] for _ in thumbnails if _['size'] == THUMBNAIL_SIZE_L)
-        thumbnails_paths,
-        output_format=THUMBNAIL_FORMAT,
-        quality=THUMBNAIL_QUALITY,
-        optimize=True,
-        progressive=True,
-    )
 
     update_fields = set()
     if thumbnail_default_path != thumbnail_field.name:
         thumbnail_field.name = thumbnail_default_path
         update_fields.add('thumbnail')
-    thumbnail_metadata = {
+    if file.metadata.get('thumbnails') != thumbnails:
-        key: {'size': size, 'path': thumbnails_paths[size]} for key, size in THUMBNAIL_META.items()
+        file.metadata.update({'thumbnails': thumbnails})
-    }
-    if file.metadata.get('thumbnails') != thumbnail_metadata:
-        file.metadata.update({'thumbnails': thumbnail_metadata})
         update_fields.add('metadata')
     if update_fields:
         file.save(update_fields=update_fields)

files/templates/files/admin/thumbnails.html

@@ -1,5 +1,5 @@
 <div class="file-thumbnails">
-{% for key, thumb in file.metadata.thumbnails.items %}
+{% for thumb in file.metadata.thumbnails %}
   <div class="file-thumbnail">
     <span class="file-thumbnail-size">{{ thumb.size.0 }}x{{ thumb.size.1 }}px</span>
     <img height="{% widthratio thumb.size.1 10 1 %}" src="{{ MEDIA_URL }}{{ thumb.path }}" title={{ thumb.path }}>

files/utils.py

@@ -17,7 +17,7 @@ from lxml import etree
 import clamd
 import magic
 
-from constants.base import THUMBNAIL_FORMAT, THUMBNAIL_SIZES
+from constants.base import THUMBNAIL_FORMAT, THUMBNAIL_SIZES, THUMBNAIL_QUALITY
 
 logger = logging.getLogger(__name__)
 MODULE_DIR = Path(__file__).resolve().parent
@@ -195,7 +195,7 @@ def delete_file_in_storage(file_name: str) -> None:
 def delete_thumbnails(file_metadata: dict) -> None:
     """Read thumbnail paths from given metadata and delete them from storage."""
     thumbnails = file_metadata.get('thumbnails', {})
-    for _, thumb in thumbnails.items:
+    for _, thumb in thumbnails.items():
         path = thumb.get('path', '')
         if not path:
             continue
@@ -208,47 +208,6 @@ def get_base_path(file_path: str) -> str:
     return base_path
 
 
-def _resize(image: Image, size: tuple, output, output_format: str = 'PNG', **output_params):
-    """Resize a models.ImageField to a given size and write it into output file."""
-    source_image = image.convert('RGBA' if output_format == 'PNG' else 'RGB')
-    source_image.thumbnail(size, Image.LANCZOS)
-    source_image.save(output, output_format, **output_params)
-
-
-def make_thumbnails(image_field, output_paths: dict, output_format: str = 'PNG', **output_params):
-    """Generate thumbnail files for given models.ImageField and list of dimensions.
-
-    Currently only intended to be used manually from shell, e.g.:
-
-        from files.models import File
-        import files.utils
-        files_wo_thumbs = File.objects.filter(type__in=(File.TYPES.IMAGE, File.TYPES.VIDEO))
-        for b in badges:
-            # TODO: thumbnail should be set to THUMBNAIL_SIZE_L of the source for IMAGE
-            base_path = files.utils.get_base_path(b.thumbnail.path)
-            files.utils.make_thumbnails(b.thumbnail, base_path, THUMBNAIL_SIZES)
-
-    """
-    thumbnail_ext = output_format.lower()
-    if thumbnail_ext == 'jpeg':
-        thumbnail_ext = 'jpg'
-    thumbnails = {}
-    for (w, h), output_path in output_paths.items():
-        # output_path = f'{base_path}_{w}x{h}.{thumbnail_ext}'
-        with tempfile.TemporaryFile() as f:
-            size = (w, h)
-            logger.info('Resizing %s to %s (%s)', image_field, size, output_format)
-            image = Image.open(image_field)
-            _resize(image, size, f, output_format=output_format, **output_params)
-            logger.info('Saving a new thumbnail to %s', output_path)
-            if default_storage.exists(output_path):
-                logger.warning('%s exists, overwriting', output_path)
-                default_storage.delete(output_path)
-            default_storage.save(output_path, f)
-            thumbnails[size] = output_path
-    return thumbnails
-
-
 def get_thumbnail_upload_to(file_hash: str):
     prefix = 'thumbnails/'
     _hash = file_hash.split(':')[-1]
@@ -257,11 +216,47 @@ def get_thumbnail_upload_to(file_hash: str):
     return path
 
 
-def get_thumbnails_paths(file_hash: str) -> dict:
+def _resize(image: Image, size: tuple, output, output_format: str = 'PNG', **output_params):
-    """Return a dictionary of paths, derived from hash and predefined thumbnails dimensions."""
+    """Resize a models.ImageField to a given size and write it into output file."""
+    source_image = image.convert('RGBA' if output_format == 'PNG' else 'RGB')
+    source_image.thumbnail(size, Image.LANCZOS)
+    source_image.save(output, output_format, **output_params)
+
+
+def make_thumbnails(file_path: str, file_hash: str, output_format: str = THUMBNAIL_FORMAT) -> list:
+    """Generate thumbnail files for given file and a predefined list of dimensions.
+
+    Resulting thumbnail paths a derived from the given file hash and thumbnail sizes.
+    Return a list of sizes and output paths of generated thumbnail images.
+    """
+    thumbnail_ext = output_format.lower()
+    if thumbnail_ext == 'jpeg':
+        thumbnail_ext = 'jpg'
     base_path = get_base_path(get_thumbnail_upload_to(file_hash))
-    extension = f'.{THUMBNAIL_FORMAT.lower()}'
+    thumbnails = []
-    return {size: f'{base_path}_{size[0]}x{size[1]}{extension}' for size in THUMBNAIL_SIZES}
+    for w, h in THUMBNAIL_SIZES:
+        output_path = f'{base_path}_{w}x{h}.{thumbnail_ext}'
+        size = (w, h)
+        with tempfile.TemporaryFile() as f:
+            logger.info('Resizing %s to %s (%s)', file_path, size, output_format)
+            image = Image.open(file_path)
+            _resize(
+                image,
+                size,
+                f,
+                output_format=THUMBNAIL_FORMAT,
+                quality=THUMBNAIL_QUALITY,
+                optimize=True,
+                progressive=True,
+            )
+            logger.info('Saving a new thumbnail to %s', output_path)
+            # Overwrite files instead of allowing storage generate a deduplicating suffix
+            if default_storage.exists(output_path):
+                logger.warning('%s exists, overwriting', output_path)
+                default_storage.delete(output_path)
+            default_storage.save(output_path, f)
+            thumbnails.append({'size': size, 'path': output_path})
+    return thumbnails
 
 
 def extract_frame(source_path: str, output_path: str):