Move into nested docroot

web/core/modules/file/src/FileUsage/DatabaseFileUsageBackend.php

@@ -0,0 +1,111 @@
+<?php
+
+namespace Drupal\file\FileUsage;
+
+use Drupal\Core\Database\Connection;
+use Drupal\file\FileInterface;
+
+/**
+ * Defines the database file usage backend. This is the default Drupal backend.
+ */
+class DatabaseFileUsageBackend extends FileUsageBase {
+
+  /**
+   * The database connection used to store file usage information.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $connection;
+
+  /**
+   * The name of the SQL table used to store file usage information.
+   *
+   * @var string
+   */
+  protected $tableName;
+
+  /**
+   * Construct the DatabaseFileUsageBackend.
+   *
+   * @param \Drupal\Core\Database\Connection $connection
+   *   The database connection which will be used to store the file usage
+   *   information.
+   * @param string $table
+   *   (optional) The table to store file usage info. Defaults to 'file_usage'.
+   */
+  public function __construct(Connection $connection, $table = 'file_usage') {
+    $this->connection = $connection;
+
+    $this->tableName = $table;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function add(FileInterface $file, $module, $type, $id, $count = 1) {
+    $this->connection->merge($this->tableName)
+      ->keys(array(
+        'fid' => $file->id(),
+        'module' => $module,
+        'type' => $type,
+        'id' => $id,
+      ))
+      ->fields(array('count' => $count))
+      ->expression('count', 'count + :count', array(':count' => $count))
+      ->execute();
+
+    parent::add($file, $module, $type, $id, $count);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function delete(FileInterface $file, $module, $type = NULL, $id = NULL, $count = 1) {
+    // Delete rows that have a exact or less value to prevent empty rows.
+    $query = $this->connection->delete($this->tableName)
+      ->condition('module', $module)
+      ->condition('fid', $file->id());
+    if ($type && $id) {
+      $query
+        ->condition('type', $type)
+        ->condition('id', $id);
+    }
+    if ($count) {
+      $query->condition('count', $count, '<=');
+    }
+    $result = $query->execute();
+
+    // If the row has more than the specified count decrement it by that number.
+    if (!$result && $count > 0) {
+      $query = $this->connection->update($this->tableName)
+        ->condition('module', $module)
+        ->condition('fid', $file->id());
+      if ($type && $id) {
+        $query
+          ->condition('type', $type)
+          ->condition('id', $id);
+      }
+      $query->expression('count', 'count - :count', array(':count' => $count));
+      $query->execute();
+    }
+
+    parent::delete($file, $module, $type, $id, $count);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function listUsage(FileInterface $file) {
+    $result = $this->connection->select($this->tableName, 'f')
+      ->fields('f', array('module', 'type', 'id', 'count'))
+      ->condition('fid', $file->id())
+      ->condition('count', 0, '>')
+      ->execute();
+    $references = array();
+    foreach ($result as $usage) {
+      $references[$usage->module][$usage->type][$usage->id] = $usage->count;
+    }
+    return $references;
+  }
+
+}

web/core/modules/file/src/FileUsage/FileUsageBase.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Drupal\file\FileUsage;
+
+use Drupal\file\FileInterface;
+
+/**
+ * Defines the base class for database file usage backend.
+ */
+abstract class FileUsageBase implements FileUsageInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function add(FileInterface $file, $module, $type, $id, $count = 1) {
+    // Make sure that a used file is permanent.
+    if (!$file->isPermanent()) {
+      $file->setPermanent();
+      $file->save();
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function delete(FileInterface $file, $module, $type = NULL, $id = NULL, $count = 1) {
+    // If there are no more remaining usages of this file, mark it as temporary,
+    // which result in a delete through system_cron().
+    $usage = \Drupal::service('file.usage')->listUsage($file);
+    if (empty($usage)) {
+      $file->setTemporary();
+      $file->save();
+    }
+  }
+
+}

web/core/modules/file/src/FileUsage/FileUsageInterface.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace Drupal\file\FileUsage;
+
+use Drupal\file\FileInterface;
+
+/**
+ * File usage backend interface.
+ */
+interface FileUsageInterface {
+
+  /**
+   * Records that a module is using a file.
+   *
+   * Examples:
+   * - A module that associates files with nodes, so $type would be
+   *   'node' and $id would be the node's nid. Files for all revisions are
+   *   stored within a single nid.
+   * - The User module associates an image with a user, so $type would be 'user'
+   *   and the $id would be the user's uid.
+   *
+   * @param \Drupal\file\FileInterface $file
+   *   A file entity.
+   * @param string $module
+   *   The name of the module using the file.
+   * @param string $type
+   *   The type of the object that contains the referenced file.
+   * @param int $id
+   *   The unique, numeric ID of the object containing the referenced file.
+   * @param int $count
+   *   (optional) The number of references to add to the object. Defaults to 1.
+   */
+  public function add(FileInterface $file, $module, $type, $id, $count = 1);
+
+  /**
+   * Removes a record to indicate that a module is no longer using a file.
+   *
+   * @param \Drupal\file\FileInterface $file
+   *   A file entity.
+   * @param string $module
+   *   The name of the module using the file.
+   * @param string $type
+   *   (optional) The type of the object that contains the referenced file. May
+   *   be omitted if all module references to a file are being deleted. Defaults
+   *   to NULL.
+   * @param int $id
+   *   (optional) The unique, numeric ID of the object containing the referenced
+   *   file. May be omitted if all module references to a file are being
+   *   deleted. Defaults to NULL.
+   * @param int $count
+   *   (optional) The number of references to delete from the object. Defaults
+   *   to 1. Zero may be specified to delete all references to the file within a
+   *   specific object.
+   */
+  public function delete(FileInterface $file, $module, $type = NULL, $id = NULL, $count = 1);
+
+  /**
+   * Determines where a file is used.
+   *
+   * @param \Drupal\file\FileInterface $file
+   *   A file entity.
+   *
+   * @return array
+   *   A nested array with usage data. The first level is keyed by module name,
+   *   the second by object type and the third by the object id. The value of
+   *   the third level contains the usage count.
+   */
+  public function listUsage(FileInterface $file);
+
+}