java/src/main/com/google/appengine/api/datastore/DatastoreCallbacks.java

   1 // Copyright 2011 Google Inc. All Rights Reserved.
   2 package com.google.appengine.api.datastore;
   3
   4 /**
   5  * Internal interface describing the callback operations we support.
   6  *
   7  */
   8 interface DatastoreCallbacks {
   9
  10   /**
  11    * Runs all PrePut callbacks for the given context.
  12    *
  13    * @param context The callback context
  14    */
  15   void executePrePutCallbacks(PutContext context);
  16
  17   /**
  18    * Runs all PostPut callbacks for the given context.
  19    *
  20    * @param context The callback context
  21    */
  22   void executePostPutCallbacks(PutContext context);
  23
  24   /**
  25    * Runs all PreDelete callbacks for the given context.
  26    *
  27    * @param context The callback context
  28    */
  29   void executePreDeleteCallbacks(DeleteContext context);
  30
  31   /**
  32    * Runs all PostDelete callbacks for the given context.
  33    *
  34    * @param context The callback context
  35    */
  36   void executePostDeleteCallbacks(DeleteContext context);
  37
  38   /**
  39    * Runs all PreGet callbacks for the given context.
  40    *
  41    * @param context The callback context
  42    */
  43   void executePreGetCallbacks(PreGetContext context);
  44
  45   /**
  46    * Runs all PostLoad callbacks for the given context.
  47    *
  48    * @param context The callback context
  49    */
  50   void executePostLoadCallbacks(PostLoadContext context);
  51
  52   /**
  53    * Runs all PreQuery callbacks for the given context.
  54    *
  55    * @param context The callback context
  56    */
  57   void executePreQueryCallbacks(PreQueryContext context);
  58
  59   /**
  60    * Class that provides a no-op implementation of the {@code DatastoreCallbacks} interface.
  61    */
  62   static class NoOpDatastoreCallbacks implements DatastoreCallbacks {
  63     static final DatastoreCallbacks INSTANCE = new NoOpDatastoreCallbacks();
  64
  65     @Override
  66     public void executePrePutCallbacks(PutContext context) { }
  67
  68     @Override
  69     public void executePostPutCallbacks(PutContext context) { }
  70
  71     @Override
  72     public void executePreDeleteCallbacks(DeleteContext context) { }
  73
  74     @Override
  75     public void executePostDeleteCallbacks(DeleteContext context) { }
  76
  77     @Override
  78     public void executePreGetCallbacks(PreGetContext context) { }
  79
  80     @Override
  81     public void executePostLoadCallbacks(PostLoadContext context) { }
  82
  83     @Override
  84     public void executePreQueryCallbacks(PreQueryContext context) { }
  85   }
  86 }