1 files changed, 31 insertions, 0 deletions
diff --git a/lib/gitlab/github_import/page_counter.rb b/lib/gitlab/github_import/page_counter.rb
new file mode 100644
index 00000000000..c3db2d0b469
--- /dev/null
+++ b/lib/gitlab/github_import/page_counter.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module GithubImport
+    # PageCounter can be used to keep track of the last imported page of a
+    # collection, allowing workers to resume where they left off in the event of
+    # an error.
+    class PageCounter
+      attr_reader :cache_key
+
+      # The base cache key to use for storing the last page number.
+      CACHE_KEY = 'github-importer/page-counter/%{project}/%{collection}'.freeze
+
+      def initialize(project, collection)
+        @cache_key = CACHE_KEY % { project: project.id, collection: collection }
+      end
+
+      # Sets the page number to the given value.
+      #
+      # Returns true if the page number was overwritten, false otherwise.
+      def set(page)
+        Caching.write_if_greater(cache_key, page)
+      end
+
+      # Returns the current value from the cache.
+      def current
+        Caching.read_integer(cache_key) || 1
+      end
+    end
+  end
+end