Line data    Source code

       1             : // Copyright (C) 2017 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.update;
      16             : 
      17             : /**
      18             :  * Interface for {@link BatchUpdate} operations that touch a change.
      19             :  *
      20             :  * <p>Each operation has {@link #updateChange(ChangeContext)} called once the change is read in a
      21             :  * transaction. Ops are associated with updates via {@link
      22             :  * BatchUpdate#addOp(com.google.gerrit.entities.Change.Id, BatchUpdateOp)}.
      23             :  *
      24             :  * <p>Usually, a single {@code BatchUpdateOp} instance is only associated with a single change, i.e.
      25             :  * {@code addOp} is only called once with that instance. Additionally, each method in {@code
      26             :  * BatchUpdateOp} is called at most once per {@link BatchUpdate} execution.
      27             :  *
      28             :  * <p>Taken together, these two properties mean an instance may communicate between phases by
      29             :  * storing data in private fields, and a single instance must not be reused.
      30             :  */
      31             : public interface BatchUpdateOp extends RepoOnlyOp {
      32             :   /**
      33             :    * Override this method to modify a change.
      34             :    *
      35             :    * @param ctx context
      36             :    * @return whether anything was changed that might require a write to the metadata storage.
      37             :    */
      38             :   default boolean updateChange(ChangeContext ctx) throws Exception {
      39          30 :     return false;
      40             :   }
      41             : }