1 files changed, 77 insertions, 0 deletions
diff --git a/lib/gitlab/ci/pipeline/seed/build/cache.rb b/lib/gitlab/ci/pipeline/seed/build/cache.rb
new file mode 100644
index 00000000000..7671035b896
--- /dev/null
+++ b/lib/gitlab/ci/pipeline/seed/build/cache.rb
@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Ci
+    module Pipeline
+      module Seed
+        class Build
+          class Cache
+            def initialize(pipeline, cache)
+              @pipeline = pipeline
+              local_cache = cache.to_h.deep_dup
+              @key = local_cache.delete(:key)
+              @paths = local_cache.delete(:paths)
+              @policy = local_cache.delete(:policy)
+              @untracked = local_cache.delete(:untracked)
+
+              raise ArgumentError, "unknown cache keys: #{local_cache.keys}" if local_cache.any?
+            end
+
+            def build_attributes
+              {
+                options: {
+                  cache: {
+                    key: key_string,
+                    paths: @paths,
+                    policy: @policy,
+                    untracked: @untracked
+                  }.compact.presence
+                }.compact
+              }
+            end
+
+            private
+
+            def key_string
+              key_from_string || key_from_files
+            end
+
+            def key_from_string
+              @key.to_s if @key.is_a?(String) || @key.is_a?(Symbol)
+            end
+
+            def key_from_files
+              return unless @key.is_a?(Hash)
+
+              [@key[:prefix], files_digest].select(&:present?).join('-')
+            end
+
+            def files_digest
+              hash_of_the_latest_changes || 'default'
+            end
+
+            def hash_of_the_latest_changes
+              return unless Feature.enabled?(:ci_file_based_cache, @pipeline.project, default_enabled: true)
+
+              ids = files.map { |path| last_commit_id_for_path(path) }
+              ids = ids.compact.sort.uniq
+
+              Digest::SHA1.hexdigest(ids.join('-')) if ids.any?
+            end
+
+            def files
+              @key[:files]
+                .to_a
+                .select(&:present?)
+                .uniq
+            end
+
+            def last_commit_id_for_path(path)
+              @pipeline.project.repository.last_commit_id_for_path(@pipeline.sha, path)
+            end
+          end
+        end
+      end
+    end
+  end
+end