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

   1 package com.google.appengine.api.datastore;
   2
   3 import com.google.apphosting.datastore.DatastoreV3Pb.Query;
   4 import com.google.apphosting.datastore.DatastoreV3Pb.Query.Filter;
   5 import com.google.apphosting.datastore.DatastoreV3Pb.Query.Filter.Operator;
   6 import com.google.apphosting.datastore.DatastoreV3Pb.Query.Order;
   7 import com.google.common.collect.Iterables;
   8 import com.google.storage.onestore.v3.OnestoreEntity.Property;
   9
  10 import java.util.Arrays;
  11 import java.util.Collections;
  12 import java.util.HashSet;
  13 import java.util.Iterator;
  14 import java.util.Set;
  15
  16 class NormalizedQuery {
  17   static final Set<Operator> INEQUALITY_OPERATORS = makeImmutableSet(
  18       Operator.GREATER_THAN,
  19       Operator.GREATER_THAN_OR_EQUAL,
  20       Operator.LESS_THAN,
  21       Operator.LESS_THAN_OR_EQUAL);
  22
  23   protected final Query query;
  24
  25   public NormalizedQuery(Query query) {
  26     this.query = query.clone();
  27     normalizeQuery();
  28   }
  29
  30   public Query getQuery() {
  31     return query;
  32   }
  33
  34   private void normalizeQuery() {
  35
  36     Set<Property> equalityFilterProperties = new HashSet<Property>();
  37     Set<String> equalityProperties = new HashSet<String>();
  38     Set<String> inequalityProperties = new HashSet<String>();
  39
  40     for (Iterator<Filter> itr = query.filterIterator(); itr.hasNext();) {
  41       Filter f = itr.next();
  42       if (f.propertySize() == 1 && f.getOpEnum() == Operator.IN) {
  43         f.setOp(Operator.EQUAL);
  44       }
  45       if (f.propertySize() >= 1) {
  46         String name = f.getProperty(0).getName();
  47         if (f.getOpEnum() == Operator.EQUAL) {
  48           if (!equalityFilterProperties.add(f.getProperty(0))) {
  49             itr.remove();
  50           } else {
  51             equalityProperties.add(name);
  52           }
  53         } else if (INEQUALITY_OPERATORS.contains(f.getOpEnum())) {
  54           inequalityProperties.add(name);
  55         }
  56       }
  57     }
  58
  59     equalityProperties.removeAll(inequalityProperties);
  60
  61     for (Iterator<Order> itr = query.orderIterator(); itr.hasNext();) {
  62       if (!equalityProperties.add(itr.next().getProperty())) {
  63         itr.remove();
  64       }
  65     }
  66
  67     Set<String> allProperties = equalityProperties;
  68     allProperties.addAll(inequalityProperties);
  69
  70     for (Iterator<Filter> itr = query.filterIterator(); itr.hasNext();) {
  71       Filter f = itr.next();
  72       if (f.getOpEnum() == Operator.EXISTS && f.propertySize() >= 1 &&
  73           !allProperties.add(f.getProperty(0).getName())) {
  74         itr.remove();
  75       }
  76     }
  77
  78     for (String propName : Iterables.concat(query.propertyNames(), query.groupByPropertyNames())) {
  79       if (allProperties.add(propName)) {
  80         query.addFilter().setOp(Operator.EXISTS).addProperty()
  81             .setName(propName).setMultiple(false).getMutableValue();
  82       }
  83     }
  84
  85     for (Filter f : query.filters()) {
  86       if (f.getOpEnum() == Operator.EQUAL && f.propertySize() >= 1 &&
  87           f.getProperty(0).getName().equals(Entity.KEY_RESERVED_PROPERTY)) {
  88         query.clearOrder();
  89         break;
  90       }
  91     }
  92
  93     boolean foundKeyOrder = false;
  94     for (Iterator<Order> i = query.orderIterator(); i.hasNext();) {
  95       String property = i.next().getProperty();
  96       if (foundKeyOrder) {
  97         i.remove();
  98       } else if (property.equals(Entity.KEY_RESERVED_PROPERTY)) {
  99         foundKeyOrder = true;
 100       }
 101     }
 102   }
 103
 104   static <T> Set<T> makeImmutableSet(T ...of) {
 105     return Collections.unmodifiableSet(new HashSet<T>(Arrays.asList(of)));
 106   }
 107 }