1 files changed, 30 insertions, 0 deletions
diff --git a/lib/gitlab/utils/gzip.rb b/lib/gitlab/utils/gzip.rb
new file mode 100644
index 00000000000..898be651554
--- /dev/null
+++ b/lib/gitlab/utils/gzip.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Utils
+    module Gzip
+      def gzip_compress(data)
+        # .compress returns ASCII-8BIT, so we need to force the encoding to
+        #   UTF-8 before caching it in redis, else we risk encoding mismatch
+        #   errors.
+        #
+        ActiveSupport::Gzip.compress(data).force_encoding("UTF-8")
+      rescue Zlib::GzipFile::Error
+        data
+      end
+
+      def gzip_decompress(data)
+        # Since we could be dealing with an already populated cache full of data
+        #   that isn't gzipped, we want to also check to see if the data is
+        #   gzipped before we attempt to .decompress it, thus we check the first
+        #   2 bytes for "\x1F\x8B" to confirm it is a gzipped string. While a
+        #   non-gzipped string will raise a Zlib::GzipFile::Error, which we're
+        #   rescuing, we don't want to count on rescue for control flow.
+        #
+        data[0..1] == "\x1F\x8B" ? ActiveSupport::Gzip.decompress(data) : data
+      rescue Zlib::GzipFile::Error
+        data
+      end
+    end
+  end
+end