drupal/core/modules/field/field.purge.inc

197 lines
7.4 KiB
PHP

<?php
/**
* @file
* Provides support for field data purge after mass deletion.
*/
use Drupal\field\Entity\Field;
use Drupal\field\FieldException;
/**
* @defgroup field_purge Field API bulk data deletion
* @{
* Cleans up after Field API bulk deletion operations.
*
* Field API provides functions for deleting data attached to individual
* entities as well as deleting entire fields or field instances in a single
* operation.
*
* When a single entity is deleted, the Entity storage controller performs the
* following operations:
* - Invoking the FieldInterface delete() method for each field on the
* entity. A file field type might use this method to delete uploaded files
* from the filesystem.
* - Removing the data from storage.
* - Invoking the global hook_entity_delete() for all modules that implement it.
* Each hook implementation receives the entity being deleted and can operate
* on whichever subset of the entity's bundle's fields it chooses to.
*
* Similar operations are performed on deletion of a single entity revision.
*
* When a field, bundle, or field instance is deleted, it is not practical to
* perform those operations immediately on every affected entity in a single
* page request; there could be thousands or millions of them. Instead, the
* appropriate field data items, instances, and/or fields are marked as deleted
* so that subsequent load or query operations will not return them. Later, a
* separate process cleans up, or "purges", the marked-as-deleted data by going
* through the three-step process described above and, finally, removing deleted
* field and instance records.
*
* Purging field data is made somewhat tricky by the fact that, while
* $entity->delete() has a complete entity to pass to the various deletion
* steps, the Field API purge process only has the field data it has previously
* stored. It cannot reconstruct complete original entities to pass to the
* deletion operations. It is even possible that the original entity to which
* some Field API data was attached has been itself deleted before the field
* purge operation takes place.
*
* Field API resolves this problem by using stub entities during purge
* operations, containing only the information from the original entity that
* Field API knows about: entity type, ID, revision ID, and bundle. It also
* contains the field data for whichever field instance is currently being
* purged.
*
* See @link field Field API @endlink for information about the other parts of
* the Field API.
*/
/**
* Purges a batch of deleted Field API data, instances, or fields.
*
* This function will purge deleted field data in batches. The batch size
* is defined as an argument to the function, and once each batch is finished,
* it continues with the next batch until all have completed. If a deleted field
* instance with no remaining data records is found, the instance itself will
* be purged. If a deleted field with no remaining field instances is found, the
* field itself will be purged.
*
* @param $batch_size
* The maximum number of field data records to purge before returning.
*/
function field_purge_batch($batch_size) {
// Retrieve all deleted field instances. We cannot use field_info_instances()
// because that function does not return deleted instances.
$instances = field_read_instances(array('deleted' => TRUE), array('include_deleted' => TRUE));
$factory = Drupal::service('entity.query');
$info = entity_get_info();
foreach ($instances as $instance) {
$entity_type = $instance['entity_type'];
// We cannot purge anything if the entity type is unknown (e.g. the
// providing module was uninstalled).
// @todo Revisit after https://drupal.org/node/2080823.
if (!isset($info[$entity_type])) {
continue;
}
// EntityFieldQuery currently fails on conditions on comment bundle.
// Remove when http://drupal.org/node/731724 is fixed.
if ($entity_type == 'comment') {
continue;
}
$ids = (object) array(
'entity_type' => $entity_type,
'bundle' => $instance['bundle'],
);
// field_purge_data() will need the field array.
$field = $instance->getField();
// Retrieve some entities.
$query = $factory->get($entity_type)
->condition('id:' . $field['uuid'] . '.deleted', 1)
->range(0, $batch_size);
// If there's no bundle key, all results will have the same bundle.
if (!empty($info[$entity_type]['entity_keys']['bundle'])) {
$query->condition($info[$entity_type]['entity_keys']['bundle'], $ids->bundle);
}
$results = $query->execute();
if ($results) {
foreach ($results as $revision_id => $entity_id) {
$ids->revision_id = $revision_id;
$ids->entity_id = $entity_id;
$entity = _field_create_entity_from_ids($ids);
Drupal::entityManager()->getStorageController($entity_type)->onFieldItemsPurge($entity, $instance);
}
}
else {
// No field data remains for the instance, so we can remove it.
field_purge_instance($instance);
}
}
// Retrieve all deleted fields. Any that have no instances can be purged.
$deleted_fields = Drupal::state()->get('field.field.deleted') ?: array();
foreach ($deleted_fields as $field) {
$field = new Field($field);
// We cannot purge anything if the entity type is unknown (e.g. the
// providing module was uninstalled).
// @todo Revisit after https://drupal.org/node/2080823.
if (!isset($info[$field->entity_type])) {
continue;
}
$instances = field_read_instances(array('field_id' => $field['uuid']), array('include_deleted' => 1));
if (empty($instances)) {
field_purge_field($field);
}
}
}
/**
* Purges a field instance record from the database.
*
* This function assumes all data for the instance has already been purged and
* should only be called by field_purge_batch().
*
* @param $instance
* The instance record to purge.
*/
function field_purge_instance($instance) {
$state = Drupal::state();
$deleted_instances = $state->get('field.instance.deleted');
unset($deleted_instances[$instance['uuid']]);
$state->set('field.instance.deleted', $deleted_instances);
// Clear the cache.
field_info_cache_clear();
// Invoke external hooks after the cache is cleared for API consistency.
Drupal::moduleHandler()->invokeAll('field_purge_instance', array($instance));
}
/**
* Purges a field record from the database.
*
* This function assumes all instances for the field has already been purged,
* and should only be called by field_purge_batch().
*
* @param $field
* The field record to purge.
*/
function field_purge_field($field) {
$instances = field_read_instances(array('field_id' => $field['uuid']), array('include_deleted' => 1));
if (count($instances) > 0) {
throw new FieldException(t('Attempt to purge a field @field_name that still has instances.', array('@field_name' => $field['field_name'])));
}
$state = Drupal::state();
$deleted_fields = $state->get('field.field.deleted');
unset($deleted_fields[$field['uuid']]);
$state->set('field.field.deleted', $deleted_fields);
// Notify the storage layer.
Drupal::entityManager()->getStorageController($field->entity_type)->onFieldPurge($field);
// Clear the cache.
field_info_cache_clear();
// Invoke external hooks after the cache is cleared for API consistency.
Drupal::moduleHandler()->invokeAll('field_purge_field', array($field));
}
/**
* @} End of "defgroup field_purge".
*/