Issue #2545672 by mikeryan, benjy, phenaproxima: Handle various migration interruption scenarios

core/modules/migrate/src/Entity/Migration.php

@@ -458,6 +458,14 @@ class Migration extends ConfigEntityBase implements MigrationInterface, Requirem
     return \Drupal::keyValue('migrate_result')->get($this->id(), static::RESULT_INCOMPLETE);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function interruptMigration($result) {
+    $this->setStatus(MigrationInterface::STATUS_STOPPING);
+    $this->setMigrationResult($result);
+  }
+
   /**
    * {@inheritdoc}
    */

core/modules/migrate/src/Entity/MigrationInterface.php

@@ -206,6 +206,15 @@ interface MigrationInterface extends ConfigEntityInterface {
    */
   public function getMigrationResult();
 
+  /**
+   * Signal that the migration should be interrupted with the specified result
+   * code.
+   *
+   * @param int $result
+   *   One of the MigrationInterface::RESULT_* constants.
+   */
+  public function interruptMigration($result);
+
   /**
    * Get the normalized process pipeline configuration describing the process
    * plugins.

core/modules/migrate/src/MigrateExecutable.php

@@ -298,10 +298,17 @@ class MigrateExecutable implements MigrateExecutableInterface {
       unset($sourceValues, $destinationValues);
       $this->sourceRowStatus = MigrateIdMapInterface::STATUS_IMPORTED;
 
+      // Check for memory exhaustion.
       if (($return = $this->checkStatus()) != MigrationInterface::RESULT_COMPLETED) {
         break;
       }
 
+      // If anyone has requested we stop, return the requested result.
+      if ($this->migration->getStatus() == MigrationInterface::STATUS_STOPPING) {
+        $return = $this->migration->getMigrationResult();
+        break;
+      }
+
       try {
         $source->next();
       }

core/modules/migrate/src/Tests/MigrateEventsTest.php

@@ -95,8 +95,9 @@ class MigrateEventsTest extends KernelTestBase {
 
     $event = $this->state->get('migrate_events_test.map_save_event', []);
     $this->assertIdentical($event['event_name'], MigrateEvents::MAP_SAVE);
-    $this->assertIdentical($event['fields']['sourceid1'], 'dummy value');
-    $this->assertIdentical($event['fields']['destid1'], 'dummy value');
+    // Validating the last row processed.
+    $this->assertIdentical($event['fields']['sourceid1'], 'dummy value2');
+    $this->assertIdentical($event['fields']['destid1'], 'dummy value2');
     $this->assertIdentical($event['fields']['source_row_status'], 0);
 
     $event = $this->state->get('migrate_events_test.map_delete_event', []);
@@ -105,13 +106,15 @@ class MigrateEventsTest extends KernelTestBase {
     $event = $this->state->get('migrate_events_test.pre_row_save_event', []);
     $this->assertIdentical($event['event_name'], MigrateEvents::PRE_ROW_SAVE);
     $this->assertIdentical($event['migration']->id(), $migration->id());
-    $this->assertIdentical($event['row']->getSourceProperty('data'), 'dummy value');
+    // Validating the last row processed.
+    $this->assertIdentical($event['row']->getSourceProperty('data'), 'dummy value2');
 
     $event = $this->state->get('migrate_events_test.post_row_save_event', []);
     $this->assertIdentical($event['event_name'], MigrateEvents::POST_ROW_SAVE);
     $this->assertIdentical($event['migration']->id(), $migration->id());
-    $this->assertIdentical($event['row']->getSourceProperty('data'), 'dummy value');
-    $this->assertIdentical($event['destination_id_values']['value'], 'dummy value');
+    // Validating the last row processed.
+    $this->assertIdentical($event['row']->getSourceProperty('data'), 'dummy value2');
+    $this->assertIdentical($event['destination_id_values']['value'], 'dummy value2');
 
     // Generate a map delete event.
     $migration->getIdMap()->delete(['data' => 'dummy value']);

core/modules/migrate/src/Tests/MigrateInterruptionTest.php

@@ -0,0 +1,81 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\migrate\Tests\MigrateInterruptionTest.
+ */
+
+namespace Drupal\migrate\Tests;
+
+use Drupal\migrate\Entity\Migration;
+use Drupal\migrate\Event\MigratePostRowSaveEvent;
+use Drupal\migrate\MigrateMessage;
+use Drupal\migrate\Entity\MigrationInterface;
+use Drupal\migrate\Event\MigrateEvents;
+use Drupal\migrate\MigrateExecutable;
+use Drupal\simpletest\KernelTestBase;
+
+/**
+ * Tests interruptions triggered during migrations.
+ *
+ * @group migrate
+ */
+class MigrateInterruptionTest extends KernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['migrate', 'migrate_events_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+    \Drupal::service('event_dispatcher')->addListener(MigrateEvents::POST_ROW_SAVE,
+      array($this, 'postRowSaveEventRecorder'));
+  }
+
+  /**
+   * Tests migration interruptions.
+   */
+  public function testMigrateEvents() {
+    // Run a simple little migration, which should trigger one of each event
+    // other than map_delete.
+    $config = [
+      'id' => 'sample_data',
+      'migration_tags' => ['Event test'],
+      'source' => ['plugin' => 'data'],
+      'process' => ['value' => 'data'],
+      'destination' => ['plugin' => 'dummy'],
+      'load' => ['plugin' => 'null'],
+    ];
+
+    $migration = Migration::create($config);
+
+    /** @var MigrationInterface $migration */
+    $executable = new MigrateExecutable($migration, new MigrateMessage);
+    // When the import runs, the first row imported will trigger an interruption.
+    $result = $executable->import();
+
+    $this->assertEqual($result, MigrationInterface::RESULT_INCOMPLETE);
+
+    // The status should have been reset to IDLE.
+    $this->assertEqual($migration->getStatus(), MigrationInterface::STATUS_IDLE);
+  }
+
+  /**
+   * Reacts to post-row-save event.
+   *
+   * @param \Drupal\Migrate\Event\MigratePostRowSaveEvent $event
+   *   The migration event.
+   * @param string $name
+   *   The event name.
+   */
+  public function postRowSaveEventRecorder(MigratePostRowSaveEvent $event, $name) {
+    $event->getMigration()->interruptMigration(MigrationInterface::RESULT_INCOMPLETE);
+  }
+
+}

core/modules/migrate/tests/modules/migrate_events_test/src/Plugin/migrate/source/DataSource.php

@@ -31,11 +31,15 @@ class DataSource extends SourcePluginBase {
    * {@inheritdoc}
    */
   public function initializeIterator() {
-    return new \ArrayIterator(array(array('data' => 'dummy value')));
+    return new \ArrayIterator([
+      ['data' => 'dummy value'],
+      ['data' => 'dummy value2'],
+    ]);
+
   }
 
   public function __toString() {
-    return '';
+    return 'Sample data for testing';
   }
 
   /**
@@ -50,7 +54,7 @@ class DataSource extends SourcePluginBase {
    * {@inheritdoc}
    */
   public function count() {
-    return 1;
+    return 2;
   }
 
 }