1 files changed, 124 insertions, 0 deletions
diff --git a/app/services/packages/rubygems/process_gem_service.rb b/app/services/packages/rubygems/process_gem_service.rb
new file mode 100644
index 00000000000..59bf2a1ec28
--- /dev/null
+++ b/app/services/packages/rubygems/process_gem_service.rb
@@ -0,0 +1,124 @@
+# frozen_string_literal: true
+
+require 'rubygems/package'
+
+module Packages
+  module Rubygems
+    class ProcessGemService
+      include Gitlab::Utils::StrongMemoize
+      include ExclusiveLeaseGuard
+
+      ExtractionError = Class.new(StandardError)
+      DEFAULT_LEASE_TIMEOUT = 1.hour.to_i.freeze
+
+      def initialize(package_file)
+        @package_file = package_file
+      end
+
+      def execute
+        return success if process_gem
+
+        error('Gem was not processed')
+      end
+
+      private
+
+      attr_reader :package_file
+
+      def process_gem
+        return false unless package_file
+
+        try_obtain_lease do
+          package.transaction do
+            rename_package_and_set_version
+            rename_package_file
+            ::Packages::Rubygems::MetadataExtractionService.new(package, gemspec).execute
+            ::Packages::Rubygems::CreateGemspecService.new(package, gemspec).execute
+            ::Packages::Rubygems::CreateDependenciesService.new(package, gemspec).execute
+            cleanup_temp_package
+          end
+        end
+
+        true
+      end
+
+      def rename_package_and_set_version
+        package.update!(
+          name: gemspec.name,
+          version: gemspec.version,
+          status: :default
+        )
+      end
+
+      def rename_package_file
+        # Updating file_name updates the path where the file is stored.
+        # We must pass the file again so that CarrierWave can handle the update
+        package_file.update!(
+          file_name: "#{gemspec.name}-#{gemspec.version}.gem",
+          file: package_file.file,
+          package_id: package.id
+        )
+      end
+
+      def cleanup_temp_package
+        temp_package.destroy if package.id != temp_package.id
+      end
+
+      def gemspec
+        strong_memoize(:gemspec) do
+          gem.spec
+        end
+      end
+
+      def success
+        ServiceResponse.success(payload: { package: package })
+      end
+
+      def error(message)
+        ServiceResponse.error(message: message)
+      end
+
+      def temp_package
+        strong_memoize(:temp_package) do
+          package_file.package
+        end
+      end
+
+      def package
+        strong_memoize(:package) do
+          # if package with name/version already exists, use that package
+          package = temp_package.project
+                                .packages
+                                .rubygems
+                                .with_name(gemspec.name)
+                                .with_version(gemspec.version.to_s)
+                                .last
+          package || temp_package
+        end
+      end
+
+      def gem
+        # use_file will set an exclusive lease on the file for as long as
+        # the resulting gem object is being used. This means we are not
+        # able to rename the package_file while also using the gem object.
+        # We need to use a separate AR object to create the gem file to allow
+        # `package_file` to be free for update so we re-find the file here.
+        Packages::PackageFile.find(package_file.id).file.use_file do |file_path|
+          Gem::Package.new(File.open(file_path))
+        end
+      rescue
+        raise ExtractionError.new('Unable to read gem file')
+      end
+
+      # used by ExclusiveLeaseGuard
+      def lease_key
+        "packages:rubygems:process_gem_service:package:#{package.id}"
+      end
+
+      # used by ExclusiveLeaseGuard
+      def lease_timeout
+        DEFAULT_LEASE_TIMEOUT
+      end
+    end
+  end
+end