#434

backend/app/services/counts_export_jobs.rb

@@ -184,7 +184,29 @@ class CountsExportJobs
         write(state)
       end
       state.slice('status', 'phase', 'processed', 'total', 'format', 'token', 'error',
-          'updated_at', 'heartbeat_at')
+          'updated_at', 'heartbeat_at', 'download_attempt', 'download_status')
+    end
+  end
+
+  def self.download_attempt(token, owner, file_token: nil, attempt: nil, status: nil)
+    id = authorised_id(token, owner)
+    return unless id
+
+    synchronise do
+      state = read(id)
+      return unless (state && state['owner'] == owner && state['status'] == 'ready' &&
+          state['expires_at'] > Time.current.to_f && HistoryAccess.authorised_artifact?(state))
+      if attempt
+        return unless state['download_attempt'] == attempt && state['token'] == file_token
+        return unless state['download_status'] == 'pending'
+
+        state['download_status'] = status if status
+      else
+        state['download_attempt'] = SecureRandom.hex(24)
+        state['download_status'] = 'pending'
+      end
+      write(state)
+      state.slice('download_attempt', 'download_status', 'token')
     end
   end