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

   1 // Copyright 2013 Google Inc. All Rights Reserved.
   2 package com.google.appengine.api.datastore;
   3
   4 import com.google.apphosting.api.AppEngineInternal;
   5 import com.google.common.base.Function;
   6 import com.google.common.collect.ImmutableList;
   7 import com.google.common.collect.Iterables;
   8 import com.google.storage.onestore.v3.OnestoreEntity;
   9
  10 import java.util.List;
  11
  12 /**
  13  * Helper class to translate between {@link Index} to {@link
  14  * com.google.storage.onestore.v3.OnestoreEntity.Index}.
  15  *
  16  */
  17 @AppEngineInternal
  18 public class IndexTranslator {
  19
  20   public static OnestoreEntity.Index convertToPb(Index index) {
  21     OnestoreEntity.Index value = new OnestoreEntity.Index();
  22     value.setEntityType(index.getKind());
  23     value.setAncestor(index.isAncestor());
  24     for (Index.Property property : index.getProperties()) {
  25       value.mutablePropertys().add(convertToPb(property));
  26     }
  27     return value;
  28   }
  29
  30   public static OnestoreEntity.Index.Property convertToPb(Index.Property property) {
  31     OnestoreEntity.Index.Property value = new OnestoreEntity.Index.Property();
  32     value.setName(property.getName());
  33     Query.SortDirection dir = property.getDirection();
  34     if (dir != null) {
  35       value.setDirection(OnestoreEntity.Index.Property.Direction.valueOf(dir.name()));
  36     }
  37     return value;
  38   }
  39
  40   public static Index convertFromPb(OnestoreEntity.CompositeIndex ci) {
  41     OnestoreEntity.Index index = ci.getDefinition();
  42     List<Index.Property> properties = ImmutableList.copyOf(Iterables.transform(index.propertys(),
  43         new Function<OnestoreEntity.Index.Property, Index.Property>() {
  44           @Override public Index.Property apply(OnestoreEntity.Index.Property property) {
  45             return convertFromPb(property);
  46           }
  47         }));
  48     return new Index(ci.getId(), index.getEntityType(), index.isAncestor(), properties);
  49   }
  50
  51   public static Index.Property convertFromPb(OnestoreEntity.Index.Property property) {
  52     Query.SortDirection dir =
  53         property.hasDirection()
  54         ? Query.SortDirection.valueOf(property.getDirectionEnum().name())
  55         : null;
  56     return new Index.Property(property.getName(), dir);
  57   }
  58
  59   public static Index convertFromPb(OnestoreEntity.Index index) {
  60     return convertFromPb(new OnestoreEntity.CompositeIndex().setId(0).setDefinition(index));
  61   }
  62 }