mv com/google/domain/registry google/registry

This change renames directories in preparation for the great package
rename. The repository is now in a broken state because the code
itself hasn't been updated. However this should ensure that git
correctly preserves history for each file.

java/google/registry/model/translators/CommitLogRevisionsTranslatorFactory.java

@@ -0,0 +1,77 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.domain.registry.model.translators;
+
+import static com.google.common.base.MoreObjects.firstNonNull;
+import static com.google.domain.registry.model.ofy.ObjectifyService.ofy;
+import static com.google.domain.registry.util.DateTimeUtils.START_OF_TIME;
+
+import com.google.common.collect.ImmutableSortedMap;
+import com.google.common.collect.Ordering;
+import com.google.domain.registry.config.RegistryEnvironment;
+import com.google.domain.registry.model.ofy.CommitLogManifest;
+
+import com.googlecode.objectify.Ref;
+
+import org.joda.time.DateTime;
+
+/**
+ * Objectify translator for {@code ImmutableSortedMap<DateTime, Ref<CommitLogManifest>>} fields.
+ *
+ * <p>This translator is responsible for doing three things:
+ * <ol>
+ * <li>Translating the data into two lists of {@code Date} and {@code Key} objects, in a manner
+ *   similar to {@code @Mapify}.
+ * <li>Inserting a reference to the transaction's {@link CommitLogManifest} on save.
+ * <li>Truncating the map to include only the last key per day for the last 30 days.
+ * </ol>
+ *
+ * <p>This allows you to have a field on your model object that tracks historical revisions of
+ * itself, which can be binary searched for point-in-time restoration.
+ *
+ * <p><b>Warning:</b> Fields of this type must not be {@code null}, or else new entries can't be
+ * inserted. You must take care to initialize the field to empty.
+ *
+ * @see com.google.domain.registry.model.EppResource
+ */
+public final class CommitLogRevisionsTranslatorFactory
+    extends ImmutableSortedMapTranslatorFactory<DateTime, Ref<CommitLogManifest>> {
+
+  private static final RegistryEnvironment ENVIRONMENT = RegistryEnvironment.get();
+
+  /**
+   * Add a reference to the current commit log to the resource's revisions map.
+   *
+   * <p>This method also prunes the revisions map. It guarantees to keep enough data so that floor
+   * will work going back N days. It does this by making sure one entry exists before that duration,
+   * and pruning everything after it. The size of the map is guaranteed to never exceed N+2.
+   *
+   * <p>We store a maximum of one entry per day. It will be the last transaction that happened on
+   * that day.
+   *
+   * @see com.google.domain.registry.config.RegistryConfig#getCommitLogDatastoreRetention()
+   */
+  @Override
+  ImmutableSortedMap<DateTime, Ref<CommitLogManifest>> transformBeforeSave(
+      ImmutableSortedMap<DateTime, Ref<CommitLogManifest>> revisions) {
+    DateTime now = ofy().getTransactionTime();
+    DateTime threshold = now.minus(ENVIRONMENT.config().getCommitLogDatastoreRetention());
+    DateTime preThresholdTime = firstNonNull(revisions.floorKey(threshold), START_OF_TIME);
+    return new ImmutableSortedMap.Builder<DateTime, Ref<CommitLogManifest>>(Ordering.natural())
+        .putAll(revisions.subMap(preThresholdTime, true, now.withTimeAtStartOfDay(), false))
+        .put(now, Ref.create(ofy().getCommitLogManifestKey()))
+        .build();
+  }
+}