Refactor LevelDbFileBuilder to accept DS Entity (#599)

* Refactor LevelDbFileBuilder to accept DS Entity

Builder now can directly work with Datastore Entity objects.
No need to wrap data in ComparableEntity.

core/src/main/java/google/registry/tools/CompareDbBackups.java

@@ -39,16 +39,14 @@ class CompareDbBackups {
       return;
     }
 
-    ImmutableSet<ComparableEntity> entities1 =
-        RecordAccumulator.readDirectory(new File(args[0]), DATA_FILE_MATCHER)
-            .getComparableEntitySet();
-    ImmutableSet<ComparableEntity> entities2 =
-        RecordAccumulator.readDirectory(new File(args[1]), DATA_FILE_MATCHER)
-            .getComparableEntitySet();
+    ImmutableSet<EntityWrapper> entities1 =
+        RecordAccumulator.readDirectory(new File(args[0]), DATA_FILE_MATCHER).getEntityWrapperSet();
+    ImmutableSet<EntityWrapper> entities2 =
+        RecordAccumulator.readDirectory(new File(args[1]), DATA_FILE_MATCHER).getEntityWrapperSet();
 
     // Calculate the entities added and removed.
-    SetView<ComparableEntity> added = Sets.difference(entities2, entities1);
-    SetView<ComparableEntity> removed = Sets.difference(entities1, entities2);
+    SetView<EntityWrapper> added = Sets.difference(entities2, entities1);
+    SetView<EntityWrapper> removed = Sets.difference(entities1, entities2);
 
     printHeader(
         String.format("First backup: %d records", entities1.size()),
@@ -56,14 +54,14 @@ class CompareDbBackups {
 
     if (!removed.isEmpty()) {
       printHeader(removed.size() + " records were removed:");
-      for (ComparableEntity entity : removed) {
+      for (EntityWrapper entity : removed) {
         System.out.println(entity);
       }
     }
 
     if (!added.isEmpty()) {
       printHeader(added.size() + " records were added:");
-      for (ComparableEntity entity : added) {
+      for (EntityWrapper entity : added) {
         System.out.println(entity);
       }
     }

core/src/main/java/google/registry/tools/EntityWrapper.java

@@ -15,20 +15,32 @@
 package google.registry.tools;
 
 import com.google.appengine.api.datastore.Entity;
+import com.google.auto.value.AutoValue;
 import com.google.common.base.Objects;
 
-/** Wraps {@link Entity} to do hashCode/equals based on both the entity's key and its properties. */
-final class ComparableEntity {
+/**
+ * Wraps {@link Entity} for ease of processing in collections.
+ *
+ * <p>Note that the {@link #hashCode}/{@link #equals} methods are based on both the entity's key and
+ * its properties.
+ */
+final class EntityWrapper {
+  private static final String TEST_ENTITY_KIND = "TestEntity";
+
   private final Entity entity;
 
-  ComparableEntity(Entity entity) {
+  EntityWrapper(Entity entity) {
     this.entity = entity;
   }
 
+  public Entity getEntity() {
+    return entity;
+  }
+
   @Override
   public boolean equals(Object that) {
-    if (that instanceof ComparableEntity) {
-      ComparableEntity thatEntity = (ComparableEntity) that;
+    if (that instanceof EntityWrapper) {
+      EntityWrapper thatEntity = (EntityWrapper) that;
       return entity.equals(thatEntity.entity)
           && entity.getProperties().equals(thatEntity.entity.getProperties());
     }
@@ -43,6 +55,26 @@ final class ComparableEntity {
 
   @Override
   public String toString() {
-    return "ComparableEntity(" + entity + ")";
+    return "EntityWrapper(" + entity + ")";
+  }
+
+  public static EntityWrapper from(int id, Property... properties) {
+    Entity entity = new Entity(TEST_ENTITY_KIND, id);
+    for (Property prop : properties) {
+      entity.setProperty(prop.name(), prop.value());
+    }
+    return new EntityWrapper(entity);
+  }
+
+  @AutoValue
+  abstract static class Property {
+
+    static Property create(String name, Object value) {
+      return new AutoValue_EntityWrapper_Property(name, value);
+    }
+
+    abstract String name();
+
+    abstract Object value();
   }
 }

core/src/main/java/google/registry/tools/RecordAccumulator.java

@@ -48,14 +48,14 @@ class RecordAccumulator {
     return new RecordAccumulator(builder.build());
   }
 
-  /** Creates an entity set from the current set of raw records. */
-  ImmutableSet<ComparableEntity> getComparableEntitySet() {
-    ImmutableSet.Builder<ComparableEntity> builder = new ImmutableSet.Builder<>();
+  /** Creates an {@link EntityWrapper} set from the current set of raw records. */
+  ImmutableSet<EntityWrapper> getEntityWrapperSet() {
+    ImmutableSet.Builder<EntityWrapper> builder = new ImmutableSet.Builder<>();
     for (byte[] rawRecord : records) {
       // Parse the entity proto and create an Entity object from it.
       EntityProto proto = new EntityProto();
       proto.parseFrom(rawRecord);
-      ComparableEntity entity = new ComparableEntity(EntityTranslator.createFromPb(proto));
+      EntityWrapper entity = new EntityWrapper(EntityTranslator.createFromPb(proto));
 
       builder.add(entity);
     }