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

   1 // Copyright 2009 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.api.datastore;
   4
   5 import com.google.appengine.api.datastore.Query.FilterPredicate;
   6 import com.google.appengine.api.datastore.Query.SortDirection;
   7 import com.google.appengine.api.datastore.Query.SortPredicate;
   8
   9 import java.util.ArrayList;
  10 import java.util.Arrays;
  11 import java.util.List;
  12
  13 /**
  14  * A class that holds information about a given query component that will later
  15  * be converted into a {@link MultiQueryComponent}.
  16  *
  17  */
  18 class QuerySplitComponent implements Comparable<QuerySplitComponent> {
  19   public enum Order {SEQUENTIAL, ARBITRARY}
  20
  21   private final Order order;
  22   private final String propertyName;
  23   private final int sortIndex;
  24   private final SortDirection direction;
  25   private final List<List<FilterPredicate>> filters =
  26       new ArrayList<List<FilterPredicate>>();
  27
  28   /**
  29    * Constructs a new component and uses {@code sorts} to determine how this
  30    * property should be handled in {@link QuerySplitHelper}
  31    *
  32    * @param propertyName the name of the property to which this component
  33    * applies
  34    * @param sorts the sort values from the original query
  35    */
  36   public QuerySplitComponent(String propertyName, List<SortPredicate> sorts) {
  37     this.propertyName = propertyName;
  38     for (int i = 0; i < sorts.size(); ++i) {
  39       if (sorts.get(i).getPropertyName().equals(propertyName)) {
  40         this.order = Order.SEQUENTIAL;
  41         this.sortIndex = i;
  42         this.direction = sorts.get(i).getDirection();
  43         return;
  44       }
  45     }
  46     this.order = Order.ARBITRARY;
  47     this.sortIndex = -1;
  48     this.direction = null;
  49   }
  50
  51   /**
  52    * Adds a set of filters that are then applied to {@link Query}s generated
  53    * by {@link MultiQueryBuilder} (in order if order = {@link
  54    * Order#SEQUENTIAL}).
  55    */
  56   public void addFilters(FilterPredicate... filters) {
  57     this.filters.add(Arrays.asList(filters));
  58   }
  59
  60   public List<List<FilterPredicate>> getFilters() {
  61     return filters;
  62   }
  63
  64   public Order getOrder() {
  65     return order;
  66   }
  67
  68   public int getSortIndex() {
  69     return sortIndex;
  70   }
  71
  72   public SortDirection getDirection() {
  73     return direction;
  74   }
  75
  76   @Override
  77   public int compareTo(QuerySplitComponent o) {
  78     if (!order.equals(o.order)) {
  79       return order.compareTo(o.order);
  80     } else {
  81       return sortIndex - o.sortIndex;
  82     }
  83   }
  84
  85   @Override
  86   public int hashCode() {
  87     return Arrays.hashCode(new Object[] {direction, filters, order, propertyName, sortIndex});
  88   }
  89
  90   @Override
  91   public boolean equals(Object obj) {
  92     if (this == obj) {
  93       return true;
  94     } else if (!(obj instanceof QuerySplitComponent)) {
  95       return false;
  96     }
  97
  98     QuerySplitComponent other = (QuerySplitComponent) obj;
  99
 100     return (direction == other.direction)
 101             || ((direction != null) && (direction.equals(other.direction)))
 102         && (filters == other.filters) || ((filters != null) && (filters.equals(other.filters)))
 103         && (order == other.order) || ((order != null) && (order.equals(other.order)))
 104         && (propertyName == other.propertyName)
 105             || ((propertyName != null) && (propertyName.equals(other.propertyName)))
 106         && (sortIndex == other.sortIndex);
 107   }
 108
 109   @Override
 110   public String toString() {
 111     String result = "QuerySplitComponent [filters=" + filters;
 112     if (direction != null) {
 113       result += ", direction=" + direction + ", " + "sortIndex=" + sortIndex;
 114     }
 115     return result + "]";
 116   }
 117 }