Import code from internal repository to git

java/com/google/domain/registry/model/ofy/TimestampInversionException.java

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+// Copyright 2016 Google Inc. 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.ofy;
+
+import static java.util.Arrays.asList;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Predicate;
+import com.google.common.collect.FluentIterable;
+import com.google.domain.registry.model.BackupGroupRoot;
+
+import com.googlecode.objectify.Key;
+import com.googlecode.objectify.Objectify;
+
+import org.joda.time.DateTime;
+
+import java.util.Map;
+
+/**
+ * Exception when trying to write to the datastore with a timestamp that is inconsistent with
+ * a partial ordering on transactions that touch the same entities.
+ */
+class TimestampInversionException extends RuntimeException {
+
+  static String getFileAndLine(StackTraceElement callsite) {
+    return callsite.getFileName() + ":" + callsite.getLineNumber();
+  }
+
+  TimestampInversionException(
+      DateTime transactionTime, Map<Key<BackupGroupRoot>, DateTime> problematicRoots) {
+    this(transactionTime, "entities rooted under:\n" + problematicRoots);
+  }
+
+  TimestampInversionException(DateTime transactionTime, DateTime updateTimestamp) {
+    this(transactionTime, String.format("update timestamp (%s)", updateTimestamp));
+  }
+
+  private TimestampInversionException(DateTime transactionTime, String problem) {
+    super(Joiner.on('\n').join(
+        String.format(
+            "Timestamp inversion between transaction time (%s) and %s",
+            transactionTime,
+            problem),
+        getFileAndLine(FluentIterable.from(asList(new Exception().getStackTrace()))
+          .firstMatch(new Predicate<StackTraceElement>() {
+            @Override
+            public boolean apply(StackTraceElement element) {
+              return !element.getClassName().startsWith(Objectify.class.getPackage().getName())
+                  && !element.getClassName().startsWith(Ofy.class.getName());
+            }}).get())));
+  }
+}