Batch NORDN pull queue task deletions

They were failing because the maximum App Engine task batch size is 1,000, and
we currently have more than 4,000 tasks in the pull queue. We keep re-uploading
those to NORDN because we're unable to delete the tasks after successful upload,
so the leases expire and they get processed again.

Also renames TaskEnqueuer to TaskQueueUtils to reflect its newly expanded role.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=197060903

javatests/google/registry/util/TaskQueueUtilsTest.java

@@ -1,4 +1,4 @@
-// Copyright 2017 The Nomulus Authors. All Rights Reserved.
+// Copyright 2018 The Nomulus 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.
@@ -17,12 +17,14 @@ package google.registry.util;
 import static com.google.appengine.api.taskqueue.TaskOptions.Builder.withUrl;
 import static com.google.common.truth.Truth.assertThat;
 import static google.registry.testing.JUnitBackports.assertThrows;
+import static google.registry.testing.TaskQueueHelper.getQueueInfo;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.google.appengine.api.taskqueue.Queue;
+import com.google.appengine.api.taskqueue.QueueFactory;
 import com.google.appengine.api.taskqueue.TaskHandle;
 import com.google.appengine.api.taskqueue.TaskOptions;
 import com.google.appengine.api.taskqueue.TransientFailureException;
@@ -31,33 +33,39 @@ import google.registry.testing.AppEngineRule;
 import google.registry.testing.FakeClock;
 import google.registry.testing.FakeSleeper;
 import org.joda.time.DateTime;
+import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
-/** Unit tests for {@link TaskEnqueuer}. */
+/** Unit tests for {@link TaskQueueUtils}. */
 @RunWith(JUnit4.class)
-public final class TaskEnqueuerTest {
+public final class TaskQueueUtilsTest {
 
   private static final int MAX_RETRIES = 3;
+
   @Rule
-  public final AppEngineRule appEngine = AppEngineRule.builder()
-      .withDatastore()
-      .build();
+  public final AppEngineRule appEngine =
+      AppEngineRule.builder().withDatastore().withTaskQueue().build();
 
   private final FakeClock clock = new FakeClock(DateTime.parse("2000-01-01TZ"));
   private final FakeSleeper sleeper = new FakeSleeper(clock);
-  private final TaskEnqueuer taskEnqueuer =
-      new TaskEnqueuer(new Retrier(sleeper, MAX_RETRIES));
+  private final TaskQueueUtils taskQueueUtils =
+      new TaskQueueUtils(new Retrier(sleeper, MAX_RETRIES));
   private final Queue queue = mock(Queue.class);
   private final TaskOptions task = withUrl("url").taskName("name");
   private final TaskHandle handle = new TaskHandle(task, "handle");
 
+  @Before
+  public void before() {
+    TaskQueueUtils.BATCH_SIZE = 2;
+  }
+
   @Test
   public void testEnqueue_worksOnFirstTry_doesntSleep() throws Exception {
     when(queue.add(ImmutableList.of(task))).thenReturn(ImmutableList.of(handle));
-    assertThat(taskEnqueuer.enqueue(queue, task)).isSameAs(handle);
+    assertThat(taskQueueUtils.enqueue(queue, task)).isSameAs(handle);
     verify(queue).add(ImmutableList.of(task));
     assertThat(clock.nowUtc()).isEqualTo(DateTime.parse("2000-01-01TZ"));
   }
@@ -68,7 +76,7 @@ public final class TaskEnqueuerTest {
         .thenThrow(new TransientFailureException(""))
         .thenThrow(new TransientFailureException(""))
         .thenReturn(ImmutableList.of(handle));
-    assertThat(taskEnqueuer.enqueue(queue, task)).isSameAs(handle);
+    assertThat(taskQueueUtils.enqueue(queue, task)).isSameAs(handle);
     verify(queue, times(3)).add(ImmutableList.of(task));
     assertThat(clock.nowUtc()).isEqualTo(DateTime.parse("2000-01-01T00:00:00.6Z"));  // 200 + 400ms
   }
@@ -80,7 +88,7 @@ public final class TaskEnqueuerTest {
     ImmutableList<TaskHandle> handles =
         ImmutableList.of(new TaskHandle(taskA, "a"), new TaskHandle(taskB, "b"));
     when(queue.add(ImmutableList.of(taskA, taskB))).thenReturn(handles);
-    assertThat(taskEnqueuer.enqueue(queue, ImmutableList.of(taskA, taskB))).isSameAs(handles);
+    assertThat(taskQueueUtils.enqueue(queue, ImmutableList.of(taskA, taskB))).isSameAs(handles);
     assertThat(clock.nowUtc()).isEqualTo(DateTime.parse("2000-01-01TZ"));
   }
 
@@ -92,7 +100,7 @@ public final class TaskEnqueuerTest {
         .thenThrow(new TransientFailureException("three"))
         .thenThrow(new TransientFailureException("four"));
     TransientFailureException thrown =
-        assertThrows(TransientFailureException.class, () -> taskEnqueuer.enqueue(queue, task));
+        assertThrows(TransientFailureException.class, () -> taskQueueUtils.enqueue(queue, task));
     assertThat(thrown).hasMessageThat().contains("three");
   }
 
@@ -101,9 +109,27 @@ public final class TaskEnqueuerTest {
     when(queue.add(ImmutableList.of(task))).thenThrow(new TransientFailureException(""));
     try {
       Thread.currentThread().interrupt();
-      assertThrows(TransientFailureException.class, () -> taskEnqueuer.enqueue(queue, task));
+      assertThrows(TransientFailureException.class, () -> taskQueueUtils.enqueue(queue, task));
     } finally {
       Thread.interrupted();  // Clear interrupt state so it doesn't pwn other tests.
     }
   }
+
+  @Test
+  public void testDeleteTasks_usesMultipleBatches() {
+    Queue defaultQ = QueueFactory.getQueue("default");
+    TaskOptions taskOptA = withUrl("/a").taskName("a");
+    TaskOptions taskOptB = withUrl("/b").taskName("b");
+    TaskOptions taskOptC = withUrl("/c").taskName("c");
+    taskQueueUtils.enqueue(defaultQ, ImmutableList.of(taskOptA, taskOptB, taskOptC));
+    assertThat(getQueueInfo("default").getTaskInfo()).hasSize(3);
+
+    taskQueueUtils.deleteTasks(
+        defaultQ,
+        ImmutableList.of(
+            new TaskHandle(taskOptA, "default"),
+            new TaskHandle(taskOptB, "default"),
+            new TaskHandle(taskOptC, "default")));
+    assertThat(getQueueInfo("default").getTaskInfo()).hasSize(0);
+  }
 }