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

   1 // Copyright 2009 Google Inc. All Rights Reserved.
   2 package com.google.appengine.api.datastore;
   3
   4 import com.google.apphosting.datastore.DatastoreV3Pb.Query.Filter;
   5 import com.google.apphosting.datastore.DatastoreV3Pb.Query.Order;
   6 import com.google.storage.onestore.v3.OnestoreEntity;
   7 import com.google.storage.onestore.v3.OnestoreEntity.EntityProto;
   8
   9 import java.util.ArrayList;
  10 import java.util.Collection;
  11 import java.util.Collections;
  12 import java.util.Comparator;
  13 import java.util.List;
  14
  15 /**
  16  * Utilities for comparing {@link EntityProto}.  This class is
  17  * only public because the dev appserver needs access to it.  It should not be
  18  * accessed by user code.
  19  *
  20  */
  21 public final class EntityProtoComparators {
  22
  23   public static final Comparator<Comparable<Object>> MULTI_TYPE_COMPARATOR =
  24       BaseEntityComparator.MULTI_TYPE_COMPARATOR;
  25
  26   /**
  27    * A comparator for {@link com.google.storage.onestore.v3.OnestoreEntity.EntityProto}
  28    * objects with the same ordering as {@link EntityComparator}.
  29    */
  30   public static final class EntityProtoComparator
  31       extends BaseEntityComparator<OnestoreEntity.EntityProto> {
  32
  33     public EntityProtoComparator(List<Order> orders) {
  34       super(orders, Collections.<Filter>emptyList());
  35     }
  36
  37     public EntityProtoComparator(List<Order> orders, List<Filter> filters) {
  38       super(orders, filters);
  39     }
  40
  41     public List<Order> getAdjustedOrders() {
  42       return Collections.unmodifiableList(orders);
  43     }
  44
  45     public boolean matches(OnestoreEntity.EntityProto proto) {
  46       for (String property : filters.keySet()) {
  47         List<Comparable<Object>> values = getComparablePropertyValues(proto, property);
  48         if (values == null || !filters.get(property).matches(values)) {
  49           return false;
  50         }
  51       }
  52       return true;
  53     }
  54
  55     public boolean matches(OnestoreEntity.Property prop) {
  56       FilterMatcher filter = filters.get(prop.getName());
  57       if (filter == null) {
  58         return true;
  59       }
  60       return filter.matches(Collections.singletonList(
  61           DataTypeTranslator.getComparablePropertyValue(prop)));
  62     }
  63
  64     @Override
  65     List<Comparable<Object>> getComparablePropertyValues(
  66         OnestoreEntity.EntityProto entityProto, String propertyName) {
  67       Collection<OnestoreEntity.Property> entityProperties =
  68           DataTypeTranslator.findIndexedPropertiesOnPb(entityProto, propertyName);
  69       if (entityProperties.isEmpty()) {
  70         return null;
  71       }
  72       if (propertyName.equals(Entity.KEY_RESERVED_PROPERTY) && !entityProto.hasKey()) {
  73         return null;
  74       }
  75       List<Comparable<Object>> values = new ArrayList<>(entityProperties.size());
  76       for (OnestoreEntity.Property prop : entityProperties) {
  77         values.add(DataTypeTranslator.getComparablePropertyValue(prop));
  78       }
  79       return values;
  80     }
  81   }
  82
  83   private EntityProtoComparators() {}
  84 }