1 files changed, 26 insertions, 0 deletions
diff --git a/activestorage/lib/active_storage/downloading.rb b/activestorage/lib/active_storage/downloading.rb
new file mode 100644
index 0000000000..3dac6b116a
--- /dev/null
+++ b/activestorage/lib/active_storage/downloading.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module ActiveStorage
+  module Downloading
+    private
+      # Opens a new tempfile in #tempdir and copies blob data into it. Yields the tempfile.
+      def download_blob_to_tempfile # :doc:
+        Tempfile.open("ActiveStorage", tempdir) do |file|
+          download_blob_to file
+          yield file
+        end
+      end
+
+      # Efficiently downloads blob data into the given file.
+      def download_blob_to(file) # :doc:
+        file.binmode
+        blob.download { |chunk| file.write(chunk) }
+        file.rewind
+      end
+
+      # Returns the directory in which tempfiles should be opened. Defaults to +Dir.tmpdir+.
+      def tempdir # :doc:
+        Dir.tmpdir
+      end
+  end
+end