1 files changed, 47 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..df820bc088
--- /dev/null
+++ b/activestorage/lib/active_storage/downloading.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require "tmpdir"
+require "active_support/core_ext/string/filters"
+
+module ActiveStorage
+  module Downloading
+    def self.included(klass)
+      ActiveSupport::Deprecation.warn <<~MESSAGE.squish, caller_locations(2)
+        ActiveStorage::Downloading is deprecated and will be removed in Active Storage 6.1.
+        Use ActiveStorage::Blob#open instead.
+      MESSAGE
+    end
+
+    private
+      # Opens a new tempfile in #tempdir and copies blob data into it. Yields the tempfile.
+      def download_blob_to_tempfile #:doc:
+        open_tempfile_for_blob do |file|
+          download_blob_to file
+          yield file
+        end
+      end
+
+      def open_tempfile_for_blob
+        tempfile = Tempfile.open([ "ActiveStorage", blob.filename.extension_with_delimiter ], tempdir)
+
+        begin
+          yield tempfile
+        ensure
+          tempfile.close!
+        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.flush
+        file.rewind
+      end
+
+      # Returns the directory in which tempfiles should be opened. Defaults to +Dir.tmpdir+.
+      def tempdir #:doc:
+        Dir.tmpdir
+      end
+  end
+end