// Copyright 2007 Google Inc. All rights reserved.
package com.google.appengine.api.datastore;
import com.google.common.collect.Maps;
import com.google.storage.onestore.v3.OnestoreEntity.EntityProto;
import com.google.storage.onestore.v3.OnestoreEntity.Path;
import com.google.storage.onestore.v3.OnestoreEntity.Reference;
import java.util.Collection;
import java.util.Map;
/**
* {@code EntityTranslator} contains the logic to translate an {@code
* Entity} into the protocol buffers that are used to pass it to the
* implementation of the API.
*
*/
public class EntityTranslator {
public static Entity createFromPb(EntityProto proto, Collection<Projection> projections) {
Key key = KeyTranslator.createFromPb(proto.getKey());
Entity entity = new Entity(key);
Map<String, Object> values = Maps.newHashMap();
DataTypeTranslator.extractPropertiesFromPb(proto, values);
for (Projection projection : projections) {
entity.setProperty(projection.getName(), projection.getValue(values));
}
return entity;
}
public static Entity createFromPb(EntityProto proto) {
Key key = KeyTranslator.createFromPb(proto.getKey());
Entity entity = new Entity(key);
DataTypeTranslator.extractPropertiesFromPb(proto, entity.getPropertyMap());
return entity;
}
public static Entity createFromPbBytes(byte[] pbBytes) {
EntityProto proto = new EntityProto();
proto.mergeFrom(pbBytes);
return createFromPb(proto);
}
public static EntityProto convertToPb(Entity entity) {
Reference reference = KeyTranslator.convertToPb(entity.getKey());
EntityProto proto = new EntityProto();
proto.setKey(reference);
Path entityGroup = proto.getMutableEntityGroup();
Key key = entity.getKey();
if (key.isComplete()) {
entityGroup.addElement(reference.getPath().elements().get(0));
}
DataTypeTranslator.addPropertiesToPb(entity.getPropertyMap(), proto);
return proto;
}
private EntityTranslator() {
}
}