Line data    Source code

       1             : // Copyright (C) 2018 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.server;
      16             : 
      17             : import com.google.inject.Module;
      18             : import java.util.List;
      19             : import java.util.Map;
      20             : import java.util.stream.Collectors;
      21             : 
      22             : public class ModuleOverloader {
      23             :   public static List<Module> override(List<Module> modules, List<Module> overrideCandidates) {
      24         138 :     if (overrideCandidates == null || overrideCandidates.isEmpty()) {
      25          15 :       return modules;
      26             :     }
      27             : 
      28             :     // group candidates by annotation existence
      29         138 :     Map<Boolean, List<Module>> grouped =
      30         138 :         overrideCandidates.stream()
      31         138 :             .collect(
      32         138 :                 Collectors.groupingBy(m -> m.getClass().getAnnotation(ModuleImpl.class) != null));
      33             : 
      34             :     // add all non annotated libs to modules list
      35         138 :     List<Module> libs = grouped.get(Boolean.FALSE);
      36         138 :     if (libs != null) {
      37         138 :       modules.addAll(libs);
      38             :     }
      39             : 
      40         138 :     List<Module> overrides = grouped.get(Boolean.TRUE);
      41         138 :     if (overrides == null) {
      42         137 :       return modules;
      43             :     }
      44             : 
      45             :     // swap module implementations with the matching alternative ones provided in lib
      46           2 :     return modules.stream()
      47           2 :         .map(
      48             :             m -> {
      49           2 :               ModuleImpl a = m.getClass().getAnnotation(ModuleImpl.class);
      50           2 :               if (a == null) {
      51           2 :                 return m;
      52             :               }
      53           2 :               return overrides.stream()
      54           2 :                   .filter(
      55             :                       o ->
      56           2 :                           o.getClass()
      57           2 :                               .getAnnotation(ModuleImpl.class)
      58           2 :                               .name()
      59           2 :                               .equalsIgnoreCase(a.name()))
      60           2 :                   .findFirst()
      61           2 :                   .orElse(m);
      62             :             })
      63           2 :         .collect(Collectors.toList());
      64             :   }
      65             : 
      66             :   private ModuleOverloader() {}
      67             : }