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

181 lines
7.2 KiB
PHP

<?php
/**
* @file
* Provides support for field data purge after mass deletion.
*/
use Drupal\field\Entity\FieldStorageConfig;
use Drupal\field\FieldStorageConfigInterface;
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 performs the
* following operations:
* - Invoking the FieldItemListInterface 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.
* @param string $field_storage_uuid
* (optional) Limit the purge to a specific field storage.
*/
function field_purge_batch($batch_size, $field_storage_uuid = NULL) {
$properties = array(
'deleted' => TRUE,
'include_deleted' => TRUE,
);
if ($field_storage_uuid) {
$properties['field_storage_uuid'] = $field_storage_uuid;
}
$instances = entity_load_multiple_by_properties('field_instance_config', $properties);
$info = \Drupal::entityManager()->getDefinitions();
foreach ($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;
}
$count_purged = \Drupal::entityManager()->getStorage($entity_type)->purgeFieldData($instance, $batch_size);
if ($count_purged < $batch_size || $count_purged == 0) {
// No field data remains for the instance, so we can remove it.
field_purge_instance($instance);
}
$batch_size -= $count_purged;
// Only delete up to the maximum number of records.
if ($batch_size == 0) {
break;
}
}
// Retrieve all deleted field storages. Any that have no instances can be
// purged.
$deleted_storages = \Drupal::state()->get('field.storage.deleted') ?: array();
foreach ($deleted_storages as $field_storage) {
$field_storage = new FieldStorageConfig($field_storage);
if ($field_storage_uuid && $field_storage->uuid() != $field_storage_uuid) {
// If a specific UUID is provided, only purge the corresponding field.
continue;
}
// We cannot purge anything if the entity type is unknown (e.g. the
// providing module was uninstalled).
// @todo Revisit after https://drupal.org/node/2080823.
if (!isset($info[$field_storage->entity_type])) {
continue;
}
$instances = entity_load_multiple_by_properties('field_instance_config', array('field_storage_uuid' => $field_storage->uuid(), 'include_deleted' => TRUE));
if (empty($instances)) {
field_purge_field_storage($field_storage);
}
}
}
/**
* 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', $deleted_instances);
// Invoke external hooks after the cache is cleared for API consistency.
\Drupal::moduleHandler()->invokeAll('field_purge_instance', array($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 \Drupal\field\FieldStorageConfigInterface $field_storage
* The field storage to purge.
*/
function field_purge_field_storage(FieldStorageConfigInterface $field_storage) {
$instances = entity_load_multiple_by_properties('field_instance_config', array('field_storage_uuid' => $field_storage->uuid(), 'include_deleted' => TRUE));
if (count($instances) > 0) {
throw new FieldException(t('Attempt to purge a field storage @field_name that still has instances.', array('@field_name' => $field_storage->getName())));
}
$state = \Drupal::state();
$deleted_storages = $state->get('field.storage.deleted');
unset($deleted_storages[$field_storage->uuid()]);
$state->set('field.storage.deleted', $deleted_storages);
// Notify the storage layer.
\Drupal::entityManager()->getStorage($field_storage->entity_type)->finalizePurge($field_storage);
// Invoke external hooks after the cache is cleared for API consistency.
\Drupal::moduleHandler()->invokeAll('field_purge_field_storage', array($field_storage));
}
/**
* @} End of "defgroup field_purge".
*/