--- /dev/null
+<?php
+
+namespace Drupal\layout_builder;
+
+use Drupal\Core\Database\Connection;
+use Drupal\Core\Entity\EntityInterface;
+
+/**
+ * Service class to track inline block usage.
+ *
+ * @internal
+ */
+class InlineBlockUsage {
+
+ /**
+ * The database connection.
+ *
+ * @var \Drupal\Core\Database\Connection
+ */
+ protected $database;
+
+ /**
+ * Creates an InlineBlockUsage object.
+ *
+ * @param \Drupal\Core\Database\Connection $database
+ * The database connection.
+ */
+ public function __construct(Connection $database) {
+ $this->database = $database;
+ }
+
+ /**
+ * Adds a usage record.
+ *
+ * @param int $block_content_id
+ * The block content id.
+ * @param \Drupal\Core\Entity\EntityInterface $entity
+ * The layout entity.
+ */
+ public function addUsage($block_content_id, EntityInterface $entity) {
+ $this->database->merge('inline_block_usage')
+ ->keys([
+ 'block_content_id' => $block_content_id,
+ 'layout_entity_id' => $entity->id(),
+ 'layout_entity_type' => $entity->getEntityTypeId(),
+ ])->execute();
+ }
+
+ /**
+ * Gets unused inline block IDs.
+ *
+ * @param int $limit
+ * The maximum number of block content entity IDs to return.
+ *
+ * @return int[]
+ * The entity IDs.
+ */
+ public function getUnused($limit = 100) {
+ $query = $this->database->select('inline_block_usage', 't');
+ $query->fields('t', ['block_content_id']);
+ $query->isNull('layout_entity_id');
+ $query->isNull('layout_entity_type');
+ return $query->range(0, $limit)->execute()->fetchCol();
+ }
+
+ /**
+ * Remove usage record by layout entity.
+ *
+ * @param \Drupal\Core\Entity\EntityInterface $entity
+ * The layout entity.
+ */
+ public function removeByLayoutEntity(EntityInterface $entity) {
+ $query = $this->database->update('inline_block_usage')
+ ->fields([
+ 'layout_entity_type' => NULL,
+ 'layout_entity_id' => NULL,
+ ]);
+ $query->condition('layout_entity_type', $entity->getEntityTypeId());
+ $query->condition('layout_entity_id', $entity->id());
+ $query->execute();
+ }
+
+ /**
+ * Delete the inline blocks' the usage records.
+ *
+ * @param int[] $block_content_ids
+ * The block content entity IDs.
+ */
+ public function deleteUsage(array $block_content_ids) {
+ if (!empty($block_content_ids)) {
+ $query = $this->database->delete('inline_block_usage')->condition('block_content_id', $block_content_ids, 'IN');
+ $query->execute();
+ }
+ }
+
+ /**
+ * Gets usage record for inline block by ID.
+ *
+ * @param int $block_content_id
+ * The block content entity ID.
+ *
+ * @return object
+ * The usage record with properties layout_entity_id and layout_entity_type.
+ */
+ public function getUsage($block_content_id) {
+ $query = $this->database->select('inline_block_usage');
+ $query->condition('block_content_id', $block_content_id);
+ $query->fields('inline_block_usage', ['layout_entity_id', 'layout_entity_type']);
+ $query->range(0, 1);
+ return $query->execute()->fetchObject();
+ }
+
+}