search_api.module

<?php

/**
 * Default number of items indexed at each cron run for each enabled index.
 */
define('SEARCH_API_DEFAULT_CRON_LIMIT', 50);

/**
 * Implements hook_menu().
 */
function search_api_menu() {
  $pre = 'admin/config/search/search_api';
  $items[$pre] = array(
    'title' => 'Search API',
    'description' => 'Create and configure search engines.',
    'page callback' => 'search_api_admin_overview',
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
  );
  $items[$pre . '/overview'] = array(
    'title' => 'Overview',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items[$pre . '/add_server'] = array(
    'title' => 'Add server',
    'description' => 'Create a new search server.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_add_server'),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
    'weight' => -1,
    'type' => MENU_LOCAL_ACTION,
  );
  $items[$pre . '/add_index'] = array(
    'title' => 'Add index',
    'description' => 'Create a new search index.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_add_index'),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
    'type' => MENU_LOCAL_ACTION,
  );
  $items[$pre . '/server/%search_api_server'] = array(
    'title' => 'View server',
    'title callback' => 'search_api_admin_item_title',
    'title arguments' => array(5),
    'description' => 'View server details.',
    'page callback' => 'search_api_admin_server_view',
    'page arguments' => array(5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
  );
  $items[$pre . '/server/%search_api_server/view'] = array(
    'title' => 'View',
    'weight' => -10,
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );
  $items[$pre . '/server/%search_api_server/edit'] = array(
    'title' => 'Edit',
    'description' => 'Edit server details.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_server_edit', 5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
    'weight' => -1,
    'type' => MENU_LOCAL_TASK,
  );
  $items[$pre . '/server/%search_api_server/delete'] = array(
    'title' => 'Delete',
    'title callback' => 'search_api_title_delete_page',
    'title arguments' => array(5),
    'description' => 'Delete server.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_confirm', 'server', 'delete', 5),
    'access callback' => 'search_api_access_delete_page',
    'access arguments' => array(5),
    'file' => 'search_api.admin.inc',
    'type' => MENU_LOCAL_TASK,
  );
  $items[$pre . '/index/%search_api_index'] = array(
    'title' => 'View index',
    'title callback' => 'search_api_admin_item_title',
    'title arguments' => array(5),
    'description' => 'View index details.',
    'page callback' => 'search_api_admin_index_view',
    'page arguments' => array(5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
  );
  $items[$pre . '/index/%search_api_index/view'] = array(
    'title' => 'View',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items[$pre . '/index/%search_api_index/status'] = array(
    'title' => 'Status',
    'description' => 'Display and work on index status.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_index_status_form', 5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
    'weight' => -8,
    'type' => MENU_LOCAL_TASK,
    'context' => MENU_CONTEXT_INLINE | MENU_CONTEXT_PAGE,
  );
  $items[$pre . '/index/%search_api_index/edit'] = array(
    'title' => 'Settings',
    'description' => 'Edit index settings.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_index_edit', 5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
    'weight' => -6,
    'type' => MENU_LOCAL_TASK,
    'context' => MENU_CONTEXT_INLINE | MENU_CONTEXT_PAGE,
  );
  $items[$pre . '/index/%search_api_index/fields'] = array(
    'title' => 'Fields',
    'description' => 'Select indexed fields.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_index_fields', 5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
    'weight' => -4,
    'type' => MENU_LOCAL_TASK,
    'context' => MENU_CONTEXT_INLINE | MENU_CONTEXT_PAGE,
  );
  $items[$pre . '/index/%search_api_index/workflow'] = array(
    'title' => 'Workflow',
    'description' => 'Edit index workflow.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_index_workflow', 5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api.admin.inc',
    'weight' => -2,
    'type' => MENU_LOCAL_TASK,
    'context' => MENU_CONTEXT_INLINE | MENU_CONTEXT_PAGE,
  );
  $items[$pre . '/index/%search_api_index/delete'] = array(
    'title' => 'Delete',
    'title callback' => 'search_api_title_delete_page',
    'title arguments' => array(5),
    'description' => 'Delete index.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_admin_confirm', 'index', 'delete', 5),
    'access callback' => 'search_api_access_delete_page',
    'access arguments' => array(5),
    'file' => 'search_api.admin.inc',
    'type' => MENU_LOCAL_TASK,
  );

  return $items;
}

/**
 * Implements hook_theme().
 */
function search_api_theme() {
  $themes['search_api_server'] = array(
    'variables' => array(
      'id' => NULL,
      'name' => '',
      'machine_name' => '',
      'description' => NULL,
      'enabled' => NULL,
      'class_name' => NULL,
      'class_description' => NULL,
      'options' => array(),
      'status' => ENTITY_CUSTOM,
    ),
    'file' => 'search_api.admin.inc',
  );
  $themes['search_api_index'] = array(
    'variables' => array(
      'id' => NULL,
      'name' => '',
      'machine_name' => '',
      'description' => NULL,
      'entity_type' => NULL,
      'enabled' => NULL,
      'server' => NULL,
      'options' => array(),
      'indexed_items' => 0,
      'total_items' => 0,
      'status' => ENTITY_CUSTOM,
      'read_only' => 0,
    ),
    'file' => 'search_api.admin.inc',
  );
  $themes['search_api_admin_item_order'] = array(
    'render element' => 'element',
    'file' => 'search_api.admin.inc',
  );
  $themes['search_api_admin_fields_table'] = array(
    'render element' => 'element',
    'file' => 'search_api.admin.inc',
  );

  return $themes;
}

/**
 * Implements hook_permission().
 */
function search_api_permission() {
  return array(
    'administer search_api' => array(
      'title' => t('Administer Search API'),
      'description' => t('Create and configure Search API servers and indexes.'),
    ),
  );
}

/**
 * Implements hook_cron().
 *
 * Will index $options['cron-limit'] items for each enabled index.
 */
function search_api_cron() {
  foreach (search_api_index_load_multiple(FALSE, array('enabled' => TRUE, 'read_only' => 0)) as $index) {
    $limit = isset($index->options['cron_limit'])
        ? $index->options['cron_limit']
        : SEARCH_API_DEFAULT_CRON_LIMIT;
    if ($limit) {
      try {
        $num = search_api_index_items($index, $limit);
        if ($num) {
          watchdog('search_api', t('Indexed !num items for index !name', array('!num' => $num, '!name' => $index->name)), NULL, WATCHDOG_INFO);
        }
      }
      catch (SearchApiException $e) {
        watchdog('search_api', $e->getMessage(), NULL, WATCHDOG_WARNING);
      }
    }
  }
}

/**
 * Implements hook_entity_info().
 */
function search_api_entity_info() {
  $info['search_api_server'] = array(
    'label' => t('Search server'),
    'controller class' => 'EntityAPIControllerExportable',
    'metadata controller class' => FALSE,
    'entity class' => 'SearchApiServer',
    'base table' => 'search_api_server',
    'uri callback' => 'search_api_server_url',
    'module' => 'search_api',
    'exportable' => TRUE,
    'entity keys' => array(
      'id' => 'id',
      'label' => 'name',
      'name' => 'machine_name',
    ),
  );
  $info['search_api_index'] = array(
    'label' => t('Search index'),
    'controller class' => 'EntityAPIControllerExportable',
    'metadata controller class' => FALSE,
    'entity class' => 'SearchApiIndex',
    'base table' => 'search_api_index',
    'uri callback' => 'search_api_index_url',
    'module' => 'search_api',
    'exportable' => TRUE,
    'entity keys' => array(
      'id' => 'id',
      'label' => 'name',
      'name' => 'machine_name',
    ),
  );

  return $info;
}

/**
 * Implements hook_entity_property_info().
 */
function search_api_entity_property_info() {
  $info['search_api_server']['properties'] = array(
    'id' => array(
      'label' => t('ID'),
      'type' => 'integer',
      'description' => t('The primary identifier for a server.'),
    ),
    'name' => array(
      'label' => t('Name'),
      'type' => 'text',
      'description' => t('The displayed name for a server.'),
      'required' => TRUE,
    ),
    'machine_name' => array(
      'label' => t('Machine name'),
      'type' => 'token',
      'description' => t('The internally used machine name for a server.'),
      'required' => TRUE,
    ),
    'description' => array(
      'label' => t('Description'),
      'type' => 'text',
      'description' => t('The displayed description for a server.'),
      'sanitize' => 'filter_xss',
    ),
    'class' => array(
      'label' => t('Service class'),
      'type' => 'text',
      'description' => t('The ID of the service class to use for this server.'),
      'required' => TRUE,
    ),
    'enabled' => array(
      'label' => t('Enabled'),
      'type' => 'boolean',
      'description' => t('A flag indicating whether the server is enabled.'),
    ),
  );
  $info['search_api_index']['properties'] = array(
    'id' => array(
      'label' => t('ID'),
      'type' => 'integer',
      'description' => t('An integer identifying the index.'),
    ),
    'name' => array(
      'label' => t('Name'),
      'type' => 'text',
      'description' => t('A name to be displayed for the index.'),
      'required' => TRUE,
    ),
    'machine_name' => array(
      'label' => t('Machine name'),
      'type' => 'token',
      'description' => t('The internally used machine name for an index.'),
      'required' => TRUE,
    ),
    'description' => array(
      'label' => t('Description'),
      'type' => 'text',
      'description' => t("A string describing the index' use to users."),
      'sanitize' => 'filter_xss',
    ),
    'server' => array(
      'label' => t('Server ID'),
      'type' => 'token',
      'description' => t('The machine name of the search_api_server with which data should be indexed.'),
    ),
    'server_entity' => array(
      'label' => t('Server'),
      'type' => 'search_api_server',
      'description' => t('The search_api_server with which data should be indexed.'),
      'getter callback' => 'search_api_index_get_server',
    ),
    'entity_type' => array(
      'label' => t('Entity type'),
      'type' => 'text',
      'description' => t('The entity type of items stored in this index.'),
      'required' => TRUE,
    ),
    'enabled' => array(
      'label' => t('Enabled'),
      'type' => 'boolean',
      'description' => t('A flag indicating whether the index is enabled.'),
    ),
    'read_only' => array(
      'label' => t('Read only'),
      'type' => 'boolean',
      'description' => t('A flag indicating whether the index is read-only.'),
    ),
  );

  return $info;
}

/**
 * Implements hook_search_api_server_insert().
 *
 * Calls the postCreate() method for the server.
 */
function search_api_search_api_server_insert(SearchApiServer $server) {
  $server->postCreate();
}

/**
 * Implements hook_search_api_server_update().
 *
 * Calls the server's postUpdate() method and marks all of this server's indexes
 * for reindexing, if necessary.
 */
function search_api_search_api_server_update(SearchApiServer $server) {
  if ($server->postUpdate()) {
    foreach (search_api_index_load_multiple(FALSE, array('server' => $server->machine_name)) as $index) {
      $index->reindex();
    }
  }
  if ($server->enabled != $server->original->enabled) {
    if ($server->enabled) {
      // Were there any changes in the server's indexes while it was disabled?
      $tasks = variable_get('search_api_tasks', array());
      if (isset($tasks[$server->machine_name])) {
        foreach ($tasks[$server->machine_name] as $index_id => $index_tasks) {
          $index = search_api_index_load($index_id);
          foreach ($index_tasks as $task) {
            switch ($task) {
              case 'add':
                $server->addIndex($index);
                break;
              case 'clear':
                $server->deleteItems('all', $index);
                break;
              case 'clear all':
                // Would normally be used with a fake index ID of "", since it doesn't matter.
                $server->deleteItems('all');
                break;
              case 'fields':
                if ($server->fieldsUpdated($index)) {
                  _search_api_index_reindex($index->id);
                }
                break;
              case 'remove':
                $server->removeIndex($index ? $index : $index_id);
                break;
              default:
                if (substr($task, 0, 7) == 'delete-') {
                  $id = substr($task, 7);
                  $server->deleteItems(array($id), $index);
                }
                else {
                  watchdog('search_api', t('Unknown task "!task" for server "!name".', array('!task' => $task, '!name' => $server->machine_name)), NULL, 'warning');
                }
            }
          }
        }
        unset($tasks[$server->machine_name]);
        variable_set('search_api_tasks', $tasks);
      }
    }
    else {
      foreach (search_api_index_load_multiple(FALSE, array('server' => $server->machine_name, 'enabled' => 1)) as $index) {
        $index->update(array('enabled' => 0));
      }
    }
  }
}

/**
 * Implements hook_search_api_server_delete().
 *
 * Calls the preDelete() method for the server.
 */
function search_api_search_api_server_delete(SearchApiServer $server) {
  $server->preDelete();


  // Only react on real delete, not revert.
  if ($server->status & ENTITY_IN_CODE == 0) {
    foreach (search_api_index_load_multiple(FALSE, array('server' => $server->machine_name)) as $index) {
      $index->update(array('server' => NULL, 'enabled' => FALSE));
    }
  }

  $tasks = variable_get('search_api_tasks', array());
  unset($tasks[$server->machine_name]);
  variable_set('search_api_tasks', $tasks);
}

/**
 * Implements hook_search_api_index_insert().
 *
 * Populates {search_api_item} for new indexes.
 */
function search_api_search_api_index_insert(SearchApiIndex $index) {
  $index->postCreate();
}

/**
 * Implements hook_search_api_index_update().
 */
function search_api_search_api_index_update(SearchApiIndex $index) {
  if ($index->server != $index->original->server) {
    // Server changed - inform old and new ones.
    if ($index->original->server) {
      $old_server = search_api_server_load($index->original->server);
      // The server might have changed because the old one was deleted:
      if ($old_server) {
        if ($old_server->enabled) {
          $old_server->removeIndex($index);
        }
        else {
          $tasks = variable_get('search_api_tasks', array());
          // When we add or remove an index, we can ignore all other tasks.
          $tasks[$old_server->machine_name][$index->machine_name] = array('remove');
          variable_set('search_api_tasks', $tasks);
        }
      }
    }

    if ($index->server) {
      $new_server = $index->server(TRUE);
      // If the server is enabled, we call addIndex(); otherwise, we save the task.
      if ($new_server->enabled) {
        $new_server->addIndex($index);
      }
      else {
        $tasks = variable_get('search_api_tasks', array());
        // When we add or remove an index, we can ignore all other tasks.
        $tasks[$new_server->machine_name][$index->machine_name] = array('add');
        variable_set('search_api_tasks', $tasks);
        unset($new_server);
      }
    }

    // We also have to re-index all content
    _search_api_index_reindex($index->id);
  }

  $old_fields = $index->original->options + array('fields' => array());
  $old_fields = $old_fields['fields'];
  $new_fields = $index->options + array('fields' => array());
  $new_fields = $new_fields['fields'];
  if ($old_fields != $new_fields) {
    if ($index->server && $index->server()->fieldsUpdated($index)) {
      _search_api_index_reindex($index->id);
    }
  }

  // If the index's enabled or read-only status is being changed, queue or
  // dequeue entities for indexing.
  if (!$index->read_only && $index->enabled != $index->original->enabled) {
    if ($index->enabled) {
      $index->queueItems();
    }
    else {
      $index->dequeueItems();
    }
  }
  elseif ($index->read_only != $index->original->read_only) {
    if ($index->read_only) {
      $index->dequeueItems();
    }
    else {
      $index->queueItems();
    }
  }
}

/**
 * Implements hook_search_api_index_delete().
 *
 * Removes all data for indexes not available any more.
 */
function search_api_search_api_index_delete(SearchApiIndex $index) {
  $index->postDelete();
}

/**
 * Implements hook_entity_insert().
 *
 * Marks the new item as to-index for all indexes on entities of the specified
 * type.
 *
 * @param $entity
 *   The new entity.
 * @param $type
 *   The entity's type.
 */
function search_api_entity_insert($entity, $type) {
  if ($type != 'search_api_index') {
    // When inserting a new search index, the new index was already inserted into search_api_item.
    // This would lead to a duplicate-key issue, if we would continue.
    $info = entity_get_info($type);
    $id = $info['entity keys']['id'];
    $id = $entity->$id;

    $query = db_select('search_api_index', 'i')
      ->condition('entity_type', $type)
      ->condition('enabled', 1)
      ->condition('read_only', 0);
    $query->addField('i', 'id', 'index_id');
    $query->addExpression(':item_id', 'item_id', array(':item_id' => $id));
    $query->addExpression(':changed', 'changed', array(':changed' => 1));

    db_insert('search_api_item')
      ->from($query)
      ->execute();
  }

  foreach (search_api_index_load_multiple(FALSE, array('enabled' => 1, 'entity_type' => $type, 'read_only' => 0)) as $index) {
    if (!empty($index->options['index_directly'])) {
      $item = clone $entity;
      search_api_index_specific_items($index, array($id => $item));
    }
  }
}

/**
 * Implements hook_entity_update().
 *
 * Marks the item as changed for all indexes on entities of the specified type.
 *
 * @param $entity
 *   The updated entity.
 * @param $type
 *   The entity's type.
 */
function search_api_entity_update($entity, $type) {
  $info = entity_get_info($type);
  $id = $info['entity keys']['id'];
  $id = $entity->$id;

  search_api_mark_dirty($type, array($id));
}

/**
 * Implements hook_entity_delete().
 *
 * Removes the item from {search_api_item} and deletes it from all indexes.
 *
 * @param $entity
 *   The updated entity.
 * @param $type
 *   The entity's type.
 */
function search_api_entity_delete($entity, $type) {
  $info = entity_get_info($type);
  $id_field = $info['entity keys']['id'];
  $id = $entity->$id_field;
  foreach (search_api_index_load_multiple(FALSE, array('entity_type' => $type, 'read_only' => 0)) as $index) {
    db_delete('search_api_item')
      ->condition('item_id', $id)
      ->condition('index_id', $index->id)
      ->execute();
    if ($index->server) {
      $server = $index->server();
      if ($server->enabled) {
        $server->deleteItems(array($id), $index);
      }
      else {
        $tasks = variable_get('search_api_tasks', array());
        $tasks[$server->machine_name][$index->machine_name][] = 'delete-' . $id;
        variable_set('search_api_tasks', $tasks);
      }
    }
  }
}

/**
 * Implements hook_search_api_alter_callback_info().
 */
function search_api_search_api_alter_callback_info() {
  $callbacks['search_api_alter_add_url'] = array(
    'name' => t('URL field'),
    'description' => t("Adds the item's URL to the indexed data."),
    'class' => 'SearchApiAlterAddUrl',
  );
  $callbacks['search_api_alter_add_aggregation'] = array(
    'name' => t('Aggregated fields'),
    'description' => t('Gives you the ability to define additional fields, containing data from one or more other fields.'),
    'class' => 'SearchApiAlterAddAggregation',
  );
  $callbacks['search_api_alter_add_viewed_entity'] = array(
    'name' => t('Complete entity view'),
    'description' => t('Adds an additional field containing the whole HTML content of the entity when viewed.'),
    'class' => 'SearchApiAlterAddViewedEntity',
  );
  $callbacks['search_api_alter_bundle_filter'] = array(
    'name' => t('Bundle filter'),
    'description' => t('Exclude items from indexing based on their bundle (content type, vocabulary, …).'),
    'class' => 'SearchApiAlterBundleFilter',
  );

  return $callbacks;
}

/**
 * Implements hook_search_api_processor_info().
 */
function search_api_search_api_processor_info() {
  $processors['search_api_case_ignore'] = array(
    'name' => t('Ignore case'),
    'description' => t('This processor will make searches case-insensitive for all fulltext fields (and, optionally, also for filters on string fields).'),
    'class' => 'SearchApiIgnoreCase',
  );
  $processors['search_api_html_filter'] = array(
    'name' => t('HTML filter'),
    'description' => t('Strips HTML tags from fulltext fields and decodes HTML entities. ' .
        'Use this processor when indexing HTML data, e.g., node bodies for certain text formats.<br />' .
        'The processor also allows to boost (or ignore) the contents of specific elements.'),
    'class' => 'SearchApiHtmlFilter',
    'weight' => 10,
  );
  $processors['search_api_tokenizer'] = array(
    'name' => t('Tokenizer'),
    'description' => t('Tokenizes fulltext data by stripping whitespace. ' .
        'This processor allows you to specify which characters make up words and which characters should be ignored, using regular expression syntax. ' .
        'Otherwise it is up to the search server implementation to decide how to split indexed fulltext data.'),
    'class' => 'SearchApiTokenizer',
    'weight' => 20,
  );
  $processors['search_api_stopwords'] = array(
    'name' => t('Stopwords'),
    'description' => t('This processor prevents certain words from being indexed and removes them from search terms. ' .
        'For best results, it should only be executed after tokenizing.'),
    'class' => 'SearchApiStopWords',
    'weight' => 30,
  );

  return $processors;
}

/**
 * Mark the entities with the specified IDs as "dirty", i.e., as needing to be reindexed.
 *
 * For indexes for which items should be indexed immediately, the items are
 * indexed directly, instead.
 *
 * @param $entity_type
 *   The type of entity, e.g., 'node'.
 * @param array $ids
 *   The entity IDs of the entities to be marked dirty.
 */
function search_api_mark_dirty($entity_type, array $ids) {
  $index_ids = array();
  foreach (search_api_index_load_multiple(FALSE, array('enabled' => 1, 'entity_type' => $entity_type, 'read_only' => 0)) as $index) {
    if (empty($index->options['index_directly'])) {
      $index_ids[] = $index->id;
    }
    else {
      // For indexes with the index_directly set, index the items right away.
      $items = entity_load($entity_type, $ids, array(), TRUE);
      $indexed = search_api_index_specific_items($index, $items);
      if (count($indexed) < count($ids)) {
        // If indexing failed for some items, mark those as dirty.
        $diff = array_diff($ids, $indexed);
        db_update('search_api_item')
          ->fields(array(
            'changed' => REQUEST_TIME,
          ))
          ->condition('item_id', $ids, 'IN')
          ->condition('index_id', $index->id)
          ->condition('changed', 0)
          ->execute();
      }
    }
  }
  if ($index_ids) {
    db_update('search_api_item')
      ->fields(array(
        'changed' => REQUEST_TIME,
      ))
      ->condition('item_id', $ids, 'IN')
      ->condition('index_id', $index_ids, 'IN')
      ->condition('changed', 0)
      ->execute();
  }
}

/**
 * Indexes items for the specified index. Only items marked as changed are
 * indexed, in their order of change (if known).
 *
 * @param SearchApiIndex $index
 *   The index on which items should be indexed.
 * @param $limit
 *   The number of items which should be indexed at most. -1 means no limit.
 *
 * @throws SearchApiException
 *   If the index' entity type is unknown or another error occurs during
 *   indexing.
 *
 * @return
 *   Number of successfully indexed items.
 */
function search_api_index_items(SearchApiIndex $index, $limit = -1) {
  // Safety check if entity type is known (prevent failing of whole cron run/page request)
  if (!entity_get_info($index->entity_type)) {
    throw new SearchApiException(t("Couldn't index values for '!name' index (unknown entity type '!type')", array('!name' => $index->name, '!type' => $index->entity_type)));
  }

  // Don't try to index read-only indexes.
  if ($index->read_only) {
    return 0;
  }

  $items = search_api_get_items_to_index($index, $limit);
  if (!$items) {
    return 0;
  }

  return count(search_api_index_specific_items($index, $items));
}

/**
 * Indexes the given items on the specified index.
 *
 * Items which were successfully indexed are marked as such afterwards.
 *
 * @param SearchApiIndex $index
 *   The index on which items should be indexed.
 * @param array $items
 *   The items which should be indexed. Have to be entities of the appropriate
 *   type.
 *
 * @throws SearchApiException
 *   If the index' entity type is unknown or another error occurs during
 *   indexing.
 *
 * @return
 *   The IDs of all successfully indexed items.
 */
function search_api_index_specific_items(SearchApiIndex $index, array $items) {
  $indexed = $index->index($items);
  if (!empty($indexed)) {
    search_api_set_items_indexed($index, $indexed);
  }
  return $indexed;
}

/**
 * Returns a list of at most $limit items that need to be indexed for the
 * specified index.
 *
 * @param SearchApiIndex $index
 *   The index for which items should be retrieved.
 * @param $limit
 *   The maximum number of items to retrieve. -1 means no limit.
 *
 * @return array
 *   An array of items (entities) that need to be indexed.
 */
function search_api_get_items_to_index(SearchApiIndex $index, $limit = -1) {
  if ($limit == 0) {
    return array();
  }
  $select = db_select('search_api_item', 'i');
  $select->addField('i', 'item_id');
  $select->condition('index_id', $index->id);
  $select->condition('changed', 0, '<>');
  $select->orderBy('changed', 'ASC');
  if ($limit > 0) {
    $select->range(0, $limit);
  }

  $ids = $select->execute()->fetchCol();
  return entity_load($index->entity_type, $ids, array(), TRUE);
}

/**
 * Marks the items as successfully indexed for the specified index.
 *
 * @param SearchApiIndex $index
 *   The index on which items were indexed.
 * @param array $ids
 *   The ids of the indexed items.
 *
 * @return
 *   The number of index entries changed.
 */
function search_api_set_items_indexed(SearchApiIndex $index, array $ids) {
  return db_update('search_api_item')
    ->fields(array(
      'changed' => 0,
    ))
    ->condition('index_id', $index->id)
    ->condition('item_id', $ids, 'IN')
    ->execute();
}

/**
 * Creates a search query on a specified search index.
 *
 * @param $id
 *   The ID or machine name of the index to execute the search on.
 * @param $options
 *   An associative array of options. The following are recognized:
 *   - filters: Either a SearchApiQueryFilterInterface object or an array of
 *     filters used to filter the search.
 *   - sort: An array of sort directives of the form $field => $order, where
 *     $order is either 'ASC' or 'DESC'.
 *   - offset: The position of the first returned search results relative to the
 *     whole result in the index.
 *   - limit: The maximum number of search results to return. -1 means no limit.
 *   - 'query class': The query class to use. Must be a subtype of
 *     SearchApiQueryInterface.
 *   - conjunction: The type of conjunction to use for this query - either
 *     'AND' or 'OR'. 'AND' by default.
 *   - 'parse mode': The mode with which to parse the $keys variable, if it
 *     is set and not already an array. See SearchApiQuery::parseModes() for
 *     parse modes recognized by the SearchApiQuery class.
 *     Subclasses might define additional modes.
 *
 * @return SearchApiQueryInterface
 *   An object for searching on the specified index.
 */
function search_api_query($id, array $options = array()) {
  $index = search_api_index_load($id);
  if (!$index) {
    throw new SearchApiException(t('Unknown index with ID !id.', array('!id' => $id)));
  }
  return $index->query($options);
}

/**
 * Static store for the searches executed on the current page. Can either be
 * used to store an executed search, or to retrieve a previously stored
 * search.
 *
 * @param $search_id
 *   For pages displaying multiple searches, an optional ID identifying the
 *   search in questions. When storing a search, this is filled automatically,
 *   unless it is manually set.
 * @param SearchApiQuery $query
 *   When storing an executed search, the query that was executed. NULL
 *   otherwise.
 * @param array $results
 *   When storing an executed search, the returned results as specified by
 *   SearchApiQueryInterface::execute(). An empty array, otherwise.
 *
 * @return array
 *   If a search with the specified ID was executed, an array containing
 *   ($query, $results) as used in this function's parameters. If $search_id is
 *   NULL, an array of all executed searches will be returned, keyed by ID.
 */
function search_api_current_search($search_id = NULL, SearchApiQuery $query = NULL, array $results = array()) {
  $searches = &drupal_static(__FUNCTION__, array());

  if (isset($query)) {
    if (!isset($search_id)) {
      $search_id = $query->getOption('search id');
    }
    $base = $search_id;
    $i = 0;
    while (isset($searches[$search_id])) {
      $search_id = $base . '-' . ++$i;
    }
    $searches[$search_id] = array($query, $results);
  }

  if (isset($search_id)) {
    return isset($searches[$search_id]) ? $searches[$search_id] : NULL;
  }
  return $searches;
}

/**
 * Returns all field types recognized by the Search API framework.
 *
 * @return array
 *   An associative array with all recognized types as keys, mapped to their
 *   translated display names.
 */
function search_api_field_types() {
  return array(
    'text' => t('Fulltext'),
    'string' => t('String'),
    'integer' => t('Integer'),
    'decimal' => t('Decimal'),
    'date' => t('Date'),
    'duration' => t('Duration'),
    'boolean' => t('Boolean'),
    'uri' => t('URI'),
  );
}

/**
 * Returns either a list of all available service infos, or a specific one.
 *
 * @see hook_search_api_service_info()
 *
 * @param $id
 *   The ID of the service info to retrieve.
 *
 * @return array
 *   If $id was not specified, an array of all available service classes.
 *   Otherwise, either the service info with the specified id (if it exists),
 *   or NULL.
 */
function search_api_get_service_info($id = NULL) {
  $services = &drupal_static(__FUNCTION__);

  if (!isset($services)) {
    $services = module_invoke_all('search_api_service_info');

    // Allow other modules to alter definitions
    drupal_alter('search_api_service_info', $services);
  }

  if (isset($id)) {
    return isset($services[$id]) ? $services[$id] : NULL;
  }
  return $services;
}

/**
 * Returns a list of all available data alter callbacks.
 *
 * @see hook_search_api_alter_callback_info()
 *
 * @return array
 *   An array of all available data alter callbacks, keyed by function name.
 */
function search_api_get_alter_callbacks() {