make possible to set compressor class from settings (or command line …

…argument)

docs/django.rst

@@ -389,6 +389,13 @@ arguments upper-cased with a 'WHITENOISE\_' prefix.
     just skip over them.
 
 
+.. attribute:: WHITENOISE_COMPRESSOR_CLASS
+
+    :default: ``'whitenoise.compress.Compressor'``
+
+    String with custom Compressor class dotted path.
+
+
 .. attribute:: WHITENOISE_ADD_HEADERS_FUNCTION
 
     :default: ``None``

src/whitenoise/compress.py

@@ -6,6 +6,10 @@
 import re
 from io import BytesIO
 
+from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
+from django.utils.module_loading import import_string
+
 try:
     import brotli
 
@@ -134,6 +138,20 @@ def write_data(self, path, data, suffix, stat_result):
         return filename
 
 
+def get_compressor_class():
+    try:
+        compressor_class = import_string(
+            getattr(
+                settings,
+                "WHITENOISE_COMPRESSOR_CLASS",
+                "whitenoise.compress.Compressor",
+            ),
+        )
+    except ImproperlyConfigured:
+        compressor_class = Compressor
+    return compressor_class
+
+
 def main(argv=None):
     parser = argparse.ArgumentParser(
         description="Search for all files inside <root> *not* matching "
@@ -150,26 +168,34 @@ def main(argv=None):
         action="store_false",
         dest="use_gzip",
     )
+    parser.add_argument(
+        "--compressor-class",
+        nargs="*",
+        help="Path to compressor class",
+        dest="compressor_class",
+        default="whitenoise.compress.Compressor",
+    )
     parser.add_argument(
         "--no-brotli",
         help="Don't produce brotli '.br' files",
         action="store_false",
         dest="use_brotli",
     )
     parser.add_argument("root", help="Path root from which to search for files")
-    default_exclude = ", ".join(Compressor.SKIP_COMPRESS_EXTENSIONS)
+    compressor_class = import_string(parser.parse_args(argv).compressor_class)
+    default_exclude = ", ".join(compressor_class.SKIP_COMPRESS_EXTENSIONS)
     parser.add_argument(
         "extensions",
         nargs="*",
         help=(
             "File extensions to exclude from compression "
             + f"(default: {default_exclude})"
         ),
-        default=Compressor.SKIP_COMPRESS_EXTENSIONS,
+        default=compressor_class.SKIP_COMPRESS_EXTENSIONS,
     )
     args = parser.parse_args(argv)
 
-    compressor = Compressor(
+    compressor = compressor_class(
         extensions=args.extensions,
         use_gzip=args.use_gzip,
         use_brotli=args.use_brotli,

src/whitenoise/storage.py

@@ -13,7 +13,7 @@
 from django.contrib.staticfiles.storage import ManifestStaticFilesStorage
 from django.contrib.staticfiles.storage import StaticFilesStorage
 
-from whitenoise.compress import Compressor
+from .compress import get_compressor_class, Compressor
 
 _PostProcessT = Iterator[Union[Tuple[str, str, bool], Tuple[str, None, RuntimeError]]]
 
@@ -41,7 +41,7 @@ def post_process(
                     yield path, compressed_name, True
 
     def create_compressor(self, **kwargs: Any) -> Compressor:
-        return Compressor(**kwargs)
+        return get_compressor_class()(**kwargs)
 
 
 class MissingFileError(ValueError):
@@ -126,7 +126,7 @@ def delete_files(self, files_to_delete):
                     raise
 
     def create_compressor(self, **kwargs):
-        return Compressor(**kwargs)
+        return get_compressor_class()(**kwargs)
 
     def compress_files(self, names):
         extensions = getattr(settings, "WHITENOISE_SKIP_COMPRESS_EXTENSIONS", None)