Club Drupal

<?php

/**

 * @file

 * Contains the bulk export display plugin.

 *

 * This allows views to be rendered in parts by batch API.

 */

/**

 * The plugin that batches its rendering.

 *

 * We are based on a feed display for compatibility.

 *

 * @ingroup views_display_plugins

 */

class views_data_export_plugin_display_export extends views_plugin_display_feed {

  /**

   * The batched execution state of the view.

   */

  public $batched_execution_state;

  /**

   * The alias of the weight field in the index table.

   */

  var $weight_field_alias = '';

  /**

   * A map of the index column names to the expected views aliases.

   */

  var $field_aliases = array();

  /**

   * Private variable that stores the filename to save the results to.

   */

  var $_output_file = '';

  var $views_data_export_cached_view_loaded;

  var $errors = array();

  /**

   * Return the type of styles we require.

   */

  function get_style_type() { return 'data_export'; }

  /**

   * Return the sections that can be defaultable.

   */

  function defaultable_sections($section = NULL) {

    if (in_array($section, array('items_per_page', 'offset', 'use_pager', 'pager_element',))) {

      return FALSE;

    }

    return parent::defaultable_sections($section);

  }

  /**

   * Define the option for this view.

   */

  function option_definition() {

    $options = parent::option_definition();

    $options['use_batch'] = array('default' => 'no_batch');

    $options['items_per_page'] = array('default' => '0');

    $options['return_path'] = array('default' => '');

    $options['style_plugin']['default'] = 'views_data_export_csv';

    // This is the default size of a segment when doing a batched export.

    $options['segment_size']['default'] = 100;

    if (isset($options['defaults']['default']['items_per_page'])) {

      $options['defaults']['default']['items_per_page'] = FALSE;

    }

    return $options;

  }

  /**

   * Provide the summary for page options in the views UI.

   *

   * This output is returned as an array.

   */

  function options_summary(&$categories, &$options) {

    // It is very important to call the parent function here:

    parent::options_summary($categories, $options);

    $categories['page']['title'] = t('Data export settings');

    $options['use_batch'] = array(

      'category' => 'page',

      'title' => t('Batched export'),

      'value' => ($this->get_option('use_batch') == 'batch' ? t('Yes') : t('No')),

    );

    if (!$this->is_compatible() && $this->get_option('use_batch')) {

      $options['use_batch']['value'] .= ' <strong>' . t('(Warning: incompatible)') . '</strong>';

    }

  }

  /**

   * Provide the default form for setting options.

   */

  function options_form(&$form, &$form_state) {

    // It is very important to call the parent function here:

    parent::options_form($form, $form_state);

    switch ($form_state['section']) {

      case 'use_batch':

        $form['#title'] .= t('Batched export');

        $form['use_batch'] = array(

          '#type' => 'radios',

          '#description' => t(''),

          '#default_value' => $this->get_option('use_batch'),

          '#options' => array(

            'no_batch' => t('Export data all in one segment. Possible time and memory limit issues.'),

            'batch' => t('Export data in small segments to build a complete export. Recommended for large exports sets (1000+ rows)'),

          ),

        );

        // Allow the administrator to configure the number of items exported per batch.

        $form['segment_size'] = array(

          '#type' => 'select',

          '#title' => t('Segment size'),

          '#description' => t('If each row of your export consumes a lot of memory to render, then reduce this value. Higher values will generally mean that the export completes in less time but will have a higher peak memory usage.'),

          '#options' => drupal_map_assoc(range(1, 500)),

          '#default_value' => $this->get_option('segment_size'),

          '#process' => array('ctools_dependent_process'),

          '#dependency' => array(

            'radio:use_batch' => array('batch')

          ),

        );

        $form['return_path'] = array(

          '#title' => t('Return path'),

          '#type' => 'textfield',

          '#description' => t('Return path after the batched operation, leave empty for default. This path will only be used if the export URL is visited directly, and not by following a link when attached to another view display.'),

          '#default_value' => $this->get_option('return_path'),

          '#dependency' => array(

            'radio:use_batch' => array('batch')

          ),

        );

        if (!$this->is_compatible()) {

          $form['use_batch']['#disabled'] = TRUE;

          $form['use_batch']['#default_value'] = 'no_batch';

          $form['use_batch']['message'] = array (

            '#type' => 'markup',

            '#markup' => theme('views_data_export_message', array('message' => t('The underlying database (!db_driver) is incompatible with the batched export option and it has been disabled.', array('!db_driver' => $this->_get_database_driver())), 'type' => 'warning')),

            '#weight' => -10,

          );

        }

        break;

      case 'cache':

        // We're basically going to disable using cache plugins, by disabling

        // the UI.

        if (isset($form['cache']['type']['#options'])) {

          foreach ($form['cache']['type']['#options'] as $id => $v) {

            if ($id != 'none') {

              unset($form['cache']['type']['#options'][$id]);

            }

            $form['cache']['type']['#description'] = t("Views data export isn't currently compatible with caching plugins.");

          }

        }

        break;

    }

  }

  function get_option($option) {

    // Force people to never use caching with Views data export. Sorry folks,

    // but it causes too many issues for our workflow. If you really want to add

    // caching back, then you can subclass this display handler and override

    // this method to add it back.

    if ($option == 'cache') {

      return array('type' => 'none');

    }

    return parent::get_option($option);

  }

  /**

   * Save the options from the options form.

   */

  function options_submit(&$form, &$form_state) {

    // It is very important to call the parent function here:

    parent::options_submit($form, $form_state);

    switch ($form_state['section']) {

      case 'use_batch':

        $this->set_option('use_batch', $form_state['values']['use_batch']);

        $this->set_option('segment_size', $form_state['values']['segment_size']);

        $this->set_option('return_path', $form_state['values']['return_path']);

        break;

    }

  }

  /**

   * Determine if this view should run as a batch or not.

   */

  function is_batched() {

    // The source of this option may change in the future.

    return ($this->get_option('use_batch') == 'batch') && empty($this->view->live_preview);

  }

  /**

   * Add HTTP headers for the file export.

   */

  function add_http_headers() {

    // Ask the style plugin to add any HTTP headers if it wants.

    if (method_exists($this->view->style_plugin, 'add_http_headers')) {

      $this->view->style_plugin->add_http_headers();

    }

  }

  /**

   * Execute this display handler.

   *

   * This is the main entry point for this display. We do different things based

   * on the stage in the rendering process.

   *

   * If we are being called for the very first time, the user has usually just

   * followed a link to our view. For this phase we:

   * - Register a new batched export with our parent module.

   * - Build and execute the view, redirecting the output into a temporary table.

   * - Set up the batch.

   *

   * If we are being called during batch processing we:

   * - Set up our variables from the context into the display.

   * - Call the rendering layer.

   * - Return with the appropriate progress value for the batch.

   *

   * If we are being called after the batch has completed we:

   * - Remove the index table.

   * - Show the complete page with a download link.

   * - Transfer the file if the download link was clicked.

   */

  function execute() {

    if (!$this->is_batched()) {

      return parent::execute();

    }

    // Try and get a batch context if possible.

    if (!empty($_GET['eid']) && !empty($_GET['token']) && drupal_valid_token($_GET['token'], 'views_data_export/' . $_GET['eid'])) {

      $eid = $_GET['eid'];

    }

    elseif (!empty($this->batched_execution_state->eid)) {

      $eid = $this->batched_execution_state->eid;

    }

    else {

      $eid = FALSE;

    }

    if ($eid) {

      $this->batched_execution_state = views_data_export_get($eid);

    }

    // First time through

    if (empty($this->batched_execution_state)) {

      $output = $this->execute_initial();

    }

    // Call me on the cached version of this view please

    // This allows this view to be programatically executed with nothing

    // more than the eid in $_GET in order for it to execute the next chunk

    // TODO: What is going on here?

    /*

     Jamsilver tells me this might be useful one day.

    if (!$this->views_data_export_cached_view_loaded) {

      $view = views_data_export_view_retrieve($this->batched_execution_state->eid);

      $view->set_display($this->view->current_display);

      $view->display_handler->batched_execution_state->eid = $this->batched_execution_state->eid;

      $view->display_handler->views_data_export_cached_view_loaded = TRUE;

      $ret =  $view->execute_display($this->view->current_display);

      $this->batched_execution_state = &$view->display_handler->batched_execution_state;

      return $ret;

    }*/

    // Last time through

    if ($this->batched_execution_state->batch_state == VIEWS_DATA_EXPORT_FINISHED) {

      $output = $this->execute_final();

    }

    // In the middle of processing

    else {

      $output = $this->execute_normal();

    }

    //Ensure any changes we made to the database sandbox are saved

    views_data_export_update($this->batched_execution_state);

    return $output;

  }

  /**

   * Initializes the whole export process and starts off the batch process.

   *

   * Page execution will be ended at the end of this function.

   */

  function execute_initial() {

    // Register this export with our central table - get a unique eid

    // Also store our view in a cache to be retrieved with each batch call

    $this->batched_execution_state = views_data_export_new($this->view->name, $this->view->current_display, $this->outputfile_create());

    views_data_export_view_store($this->batched_execution_state->eid, $this->view);

    // Record a usage of our file, so we can identify our exports later.

    file_usage_add(file_load($this->batched_execution_state->fid), 'views_data_export', 'eid', $this->batched_execution_state->eid);

    // We need to build the index right now, before we lose $_GET etc.

    $this->initialize_index();

    //$this->batched_execution_state->fid = $this->outputfile_create();

    // Initialize the progress counter.

    if (db_table_exists($this->index_tablename())) {

      $this->batched_execution_state->sandbox['max'] = db_query('SELECT COUNT(*) FROM {' . $this->index_tablename() . '}')->fetchField();

    }

    // Record the time we started.

    list($usec, $sec) = explode(' ', microtime());

    $this->batched_execution_state->sandbox['started'] = (float) $usec + (float) $sec;

    // Pop something into the session to ensure it stays aorund.

    $_SESSION['views_data_export'][$this->batched_execution_state->eid] = TRUE;

    // Build up our querystring for the final page callback.

    $querystring = array(

      'eid' => $this->batched_execution_state->eid,

      'token' => drupal_get_token('views_data_export/' . $this->batched_execution_state->eid),

      'return-url' => NULL,

    );

    // If we have a configured return path, use that.

    if ($this->get_option('return_path')) {

      $querystring['return-url'] = $this->get_option('return_path');

    }

    // Else if we were attached to another view, grab that for the final URL.

    else if (!empty($_GET['attach']) && isset($this->view->display[$_GET['attach']])) {

      // Get the path of the attached display:

      $querystring['return-url'] = $this->view->get_url(NULL, $this->view->display[$_GET['attach']]->handler->get_path());

    }

    //Set the batch off

    $batch = array(

      'operations' => array (

        array('_views_data_export_batch_process', array($this->batched_execution_state->eid, $this->view->current_display,  $this->view->get_exposed_input())),

      ),

      'title' => t('Building export'),

      'init_message' => t('Export is starting up.'),

      'progress_message' => t('Exporting @percentage% complete,'),

      'error_message' => t('Export has encountered an error.'),

    );

    // We do not return, so update database sandbox now

    views_data_export_update($this->batched_execution_state);

    $final_destination = $this->view->get_url();

    // Provide a way in for others at this point

    // e.g. Drush to grab this batch and yet execute it in

    // it's own special way

    $batch['view_name'] = $this->view->name;

    $batch['exposed_filters'] = $this->view->get_exposed_input();

    $batch['display_id'] = $this->view->current_display;

    $batch['eid'] = $this->batched_execution_state->eid;

    $batch_redirect = array($final_destination, array('query' => $querystring));

    drupal_alter('views_data_export_batch', $batch, $batch_redirect);

    // Modules may have cleared out $batch, indicating that we shouldn't process further.

    if (!empty($batch)) {

      batch_set($batch);

      // batch_process exits

      batch_process($batch_redirect);

    }

  }

  /**

   * Compiles the next chunk of the output file

   */

  function execute_normal() {

    // Pass through to our render method,

    $output = $this->view->render();

    // Append what was rendered to the output file.

    $this->outputfile_write($output);

    // Store for convenience.

    $state = &$this->batched_execution_state;

    $sandbox = &$state->sandbox;

    // Update progress measurements & move our state forward

    switch ($state->batch_state) {

      case VIEWS_DATA_EXPORT_BODY:

        // Remove rendered results from our index

        if (count($this->view->result) && ($sandbox['weight_field_alias'])) {

          $last = end($this->view->result);

          db_delete($this->index_tablename())

            ->condition($sandbox['weight_field_alias'], $last->{$sandbox['weight_field_alias']}, '<=')

            ->execute();

          // Update progress.

          $progress = db_query('SELECT COUNT(*) FROM {' . $this->index_tablename() . '}')->fetchField();

          // TODO: These next few lines are messy, clean them up.

          $progress = 0.99 - ($progress / $sandbox['max'] * 0.99);

          $progress = ((int)floor($progress * 100000));

          $progress = $progress / 100000;

          $sandbox['finished'] = $progress;

        }

        else {

          // No more results.

          $progress = 0.99;

          $state->batch_state = VIEWS_DATA_EXPORT_FOOTER;

        }

        break;

      case VIEWS_DATA_EXPORT_HEADER:

        $sandbox['finished'] = 0;

        $state->batch_state = VIEWS_DATA_EXPORT_BODY;

        break;

      case VIEWS_DATA_EXPORT_FOOTER:

        // Update the temporary file size, otherwise we would get a problematic

        // "Content-Length: 0" HTTP header, that may break the export download.

        $this->outputfile_update_size();

        $sandbox['finished'] = 1;

        $state->batch_state = VIEWS_DATA_EXPORT_FINISHED;

        break;

    }

    // Create a more helpful exporting message.

    $sandbox['message'] = $this->compute_time_remaining($sandbox['started'], $sandbox['finished']);

  }

  /**

   * Renders the final page

   *  We should be free of the batch at this point

   */

  function execute_final() {

    // Should we download the file.

    if (!empty($_GET['download'])) {

      // Clean up our session, if we need to.

      if (isset($_SESSION)) {

        unset($_SESSION['views_data_export'][$this->batched_execution_state->eid]);

        if (empty($_SESSION['views_data_export'])) {

          unset($_SESSION['views_data_export']);

        }

      }

      // This next method will exit.

      $this->transfer_file();

    }

    else {

      // Remove the index table.

      $this->remove_index();

      return $this->render_complete();

    }

  }

  /**

   * Render the display.

   *

   * We basically just work out if we should be rendering the header, body or

   * footer and call the appropriate functions on the style plugins.

   */

  function render() {

    if (!$this->is_batched()) {

      $result = parent::render();

      if (empty($this->view->live_preview)) {

        $this->add_http_headers();

      }

      return $result;

    }

    $this->view->build();

    switch ($this->batched_execution_state->batch_state) {

      case VIEWS_DATA_EXPORT_BODY:

        $output = $this->view->style_plugin->render_body();

        break;

      case VIEWS_DATA_EXPORT_HEADER:

        $output = $this->view->style_plugin->render_header();

        break;

      case VIEWS_DATA_EXPORT_FOOTER:

        $output = $this->view->style_plugin->render_footer();

        break;

    }

    return $output;

  }

  /**

   * Trick views into thinking that we have executed the query and got results.

   *

   * We are called in the build phase of the view, but short circuit straight to

   * getting the results and making the view think it has already executed the

   * query.

   */

  function query() {

    if (!$this->is_batched()) {

      return parent::query();

    }

    // Make the query distinct if the option was set.

    if ($this->get_option('distinct')) {

      $this->view->query->set_distinct();

    }

    if (!empty($this->batched_execution_state->batch_state) && !empty($this->batched_execution_state->sandbox['weight_field_alias'])) {

      switch ($this->batched_execution_state->batch_state) {

        case VIEWS_DATA_EXPORT_BODY:

        case VIEWS_DATA_EXPORT_HEADER:

        case VIEWS_DATA_EXPORT_FOOTER:

          // Tell views its been executed.

          $this->view->executed = TRUE;

          // Grab our results from the index, and push them into the view result.

          // TODO: Handle external databases.

          $result = db_query_range('SELECT * FROM {' . $this->index_tablename() . '} ORDER BY ' . $this->batched_execution_state->sandbox['weight_field_alias'] . ' ASC', 0, $this->get_option('segment_size'));

          $this->view->result = array();

          foreach ($result as $item_hashed) {

            $item = new stdClass();

            // We had to shorten some of the column names in the index, restore

            // those now.

            foreach ($item_hashed as $hash => $value) {

              if (isset($this->batched_execution_state->sandbox['field_aliases'][$hash])) {

                $item->{$this->batched_execution_state->sandbox['field_aliases'][$hash]} = $value;

              }

              else {

                $item->{$hash} = $value;

              }

            }

            // Push the restored $item in the views result array.

            $this->view->result[] = $item;

          }

          $this->view->_post_execute();

          break;

      }

    }

  }

  /**

   * Render the 'Export Finished' page with the link to the file on it.

   */

  function render_complete() {

    $return_path = empty($_GET['return-url']) ? '' : $_GET['return-url'];

    $query = array(

      'download' => 1,

      'eid' => $this->batched_execution_state->eid,

      'token' => drupal_get_token('views_data_export/' . $this->batched_execution_state->eid),

    );

    return theme('views_data_export_complete_page', array(

      'file' => url($this->view->get_url(), array('query' => $query)),

      'errors' => $this->errors,

      'return_url' => $return_path));

  }

  /**

   * TBD - What does 'preview' mean for bulk exports?

   * According to doc:

   * "Fully render the display for the purposes of a live preview or

   * some other AJAXy reason. [views_plugin_display.inc:1877]"

   *

   * Not sure it makes sense for Bulk exports to be previewed in this manner?

   * We need the user's full attention to run the batch. Suggestions:

   * 1) Provide a link to execute the view?

   * 2) Provide a link to the last file we generated??

   * 3) Show a table of the first 20 results?

   */

  function preview() {

    if (!$this->is_batched()) {

      // Can replace with return parent::preview() when views 2.12 lands.

      if (!empty($this->view->live_preview)) {

        // Change the items per page.

        $this->view->set_items_per_page(20);

        // Force a pager to be used.

        $this->set_option('pager', array('type' => 'some', 'options' => array()));

        return '<p>' . t('A maximum of 20 items will be shown here, all results will be shown on export.') . '</p><pre>' . check_plain($this->view->render()) . '</pre>';

      }

      return $this->view->render();

    }

    return '';

  }

  /**

   * Transfer the output file to the client.

   */

  function transfer_file() {

    // Build the view so we can set the headers.

    $this->view->build();

    // Arguments can cause the style to not get built.

    if (!$this->view->init_style()) {

      $this->view->build_info['fail'] = TRUE;

    }

    // Set the headers.

    $this->add_http_headers();

    $headers = array(

      'Content-Length' => $this->outputfile_entity()->filesize,

    );

    file_transfer($this->outputfile_path(), $headers);

  }

  /**

   * Called on export initialization.

   *

   * Modifies the view query to insert the results into a table, which we call

   * the 'index', this means we essentially have a snapshot of the results,

   * which we can then take time over rendering.

   *

   * This method is essentially all the best bits of the view::execute() method.

   */

  protected function initialize_index() {

    $view = &$this->view;

    // Get views to build the query.

    $view->build();

    // Change the query object to use our custom one.

    switch ($this->_get_database_driver()) {

      case 'pgsql':

        $query_class = 'views_data_export_plugin_query_pgsql_batched';

        break;

      default:

        $query_class = 'views_data_export_plugin_query_default_batched';

        break;

    }

    $query = new $query_class();

    // Copy the query over:

    foreach ($view->query as $property => $value) {

      $query->$property = $value;

    }

    // Replace the query object.

    $view->query = $query;

    $view->execute();

  }

  /**

   * Given a view, construct an map of hashed aliases to aliases.

   *

   * The keys of the returned array will have a maximum length of 33 characters.

   */

  function field_aliases_create(&$view) {

    $all_aliases = array();

    foreach ($view->query->fields as $field) {

      if (strlen($field['alias']) > 32) {

        $all_aliases['a' . md5($field['alias'])] = $field['alias'];

      }

      else {

        $all_aliases[$field['alias']] = $field['alias'];

      }

    }

    return $all_aliases;

  }

  /**

   * Create an alias for the weight field in the index.

   *

   * This method ensures that it isn't the same as any other alias in the

   * supplied view's fields.

   */

  function _weight_alias_create(&$view) {

    $alias = 'vde_weight';

    $all_aliases = array();

    foreach ($view->query->fields as $field) {

      $all_aliases[] = $field['alias'];

    }

    // Keep appending '_' until we are unique.

    while (in_array($alias, $all_aliases)) {

      $alias .= '_';

    }

    return $alias;

  }

  /**

   * Remove the index.

   */

  function remove_index() {

    $ret = array();

    if (db_table_exists($this->index_tablename())) {

      db_drop_table($this->index_tablename());

    }

  }

  /**

   * Return the name of the unique table to store the index in.

   */

  function index_tablename() {

    return VIEWS_DATA_EXPORT_INDEX_TABLE_PREFIX . $this->batched_execution_state->eid;

  }

  /**

   * Get the output file entity.

   */

  public function outputfile_entity() {

    if (empty($this->_output_file)) {

      if (!empty($this->batched_execution_state->fid)) {

        // Return the filename associated with this file.

        $this->_output_file = $this->file_load($this->batched_execution_state->fid);

      }

      else {

        return NULL;

      }

    }

    return $this->_output_file;

  }

  /**

   * Get the output file path.

   */

  public function outputfile_path() {

    if ($file = $this->outputfile_entity()) {

      return $file->uri;

    }

  }

  /**

   * Called on export initialization

   * Creates the output file, registers it as a temporary file with Drupal

   * and returns the fid

   */

  protected function outputfile_create() {

    $dir = variable_get('views_data_export_directory', 'temporary://views_plugin_display');

    // Make sure the directory exists first.

    if (!file_prepare_directory($dir, FILE_CREATE_DIRECTORY | FILE_MODIFY_PERMISSIONS)) {

      $this->abort_export(t('Could not create temporary directory for result export (@dir). Check permissions.', array ('@dir' => $dir)));

    }

    $path = drupal_tempnam($dir, 'views_data_export');

    // Save the file into the DB.

    $file = $this->file_save_file($path);

    // Make sure the file is marked as temporary.

    // There is no FILE_STATUS_TEMPORARY constant.

    $file->status = 0;

    file_save($file);

    return $file->fid;

  }

  /**

   * Write to the output file.

   */

  protected function outputfile_write($string) {

    $output_file = $this->outputfile_path();

    if (file_put_contents($output_file, $string, FILE_APPEND) === FALSE) {

      $this->abort_export(t('Could not write to temporary output file for result export (@file). Check permissions.', array ('@file' => $output_file)));

    }

  }

  /**

   * Updates the file size in the file entity.

   */

  protected function outputfile_update_size() {

    if ($file = $this->outputfile_entity()) {

      $file->filesize = filesize($file->uri);

      file_save($file);

    }

  }

  function abort_export($errors) {

    // Just cause the next batch to do the clean-up

    if (!is_array($errors)) {

      $errors = array($errors);

    }

    foreach ($errors as $error) {

      drupal_set_message($error . ' ['. t('Export Aborted') . ']', 'error');

    }

    $this->batched_execution_state->batch_state = VIEWS_DATA_EXPORT_FINISHED;

  }

  /**

    * Load a file from the database.

    *

    * @param $fid

    *   A numeric file id or string containing the file path.

    * @return

    *   A file object.

    */

  function file_load($fid) {

    return file_load($fid);

  }

  /**

  * Save a file into a file node after running all the associated validators.

  *

  * This function is usually used to move a file from the temporary file

  * directory to a permanent location. It may be used by import scripts or other

  * modules that want to save an existing file into the database.

  *

  * @param $filepath

  *   The local file path of the file to be saved.

  * @return

  *   An array containing the file information, or 0 in the event of an error.

  */

  function file_save_file($filepath) {

    return file_save_data('', $filepath, FILE_EXISTS_REPLACE);

  }

  /**

   * Helper function that computes the time remaining

   */

  function compute_time_remaining($started, $finished) {

    list($usec, $sec) = explode(' ', microtime());

    $now = (float) $usec + (float) $sec;

    $diff = round(($now - $started), 0);

    // So we've taken $diff seconds to get this far.

    if ($finished > 0) {

      $estimate_total = $diff / $finished;

      $stamp = max(1, $estimate_total - $diff);

      // Round up to nearest 30 seconds.

      $stamp = ceil($stamp / 30) * 30;

      // Set the message in the batch context.

      return t('Time remaining: about @interval.', array('@interval' => format_interval($stamp)));

    }

  }

  /**

   * Checks the driver of the database underlying

   * this query and returns FALSE if it is imcompatible

   * with the approach taken in this display.

   * Basically mysql & mysqli will be fine, pg will not

   */

  function is_compatible() {

    $incompatible_drivers = array (

      //'pgsql',

    );

    $db_driver = $this->_get_database_driver();

    return !in_array($db_driver, $incompatible_drivers);

  }

  function  _get_database_driver() {

    $name = !empty($this->view->base_database) ? $this->view->base_database : 'default';

    $conn_info = Database::getConnectionInfo($name);

    return $conn_info['default']['driver'];

  }

}

class views_data_export_plugin_query_default_batched extends views_plugin_query_default {

  /**

   * Executes the query and fills the associated view object with according

   * values.

   *

   * Values to set: $view->result, $view->total_rows, $view->execute_time,

   * $view->current_page.

   */

  function execute(&$view) {

    $display_handler = &$view->display_handler;

    $external = FALSE; // Whether this query will run against an external database.

    $query = $view->build_info['query'];

    $count_query = $view->build_info['count_query'];

    $query->addMetaData('view', $view);

    $count_query->addMetaData('view', $view);

    if (empty($this->options['disable_sql_rewrite'])) {

      $base_table_data = views_fetch_data($this->base_table);

      if (isset($base_table_data['table']['base']['access query tag'])) {

        $access_tag = $base_table_data['table']['base']['access query tag'];

        $query->addTag($access_tag);

        $count_query->addTag($access_tag);

      }

    }

    $items = array();

    if ($query) {

      $additional_arguments = module_invoke_all('views_query_substitutions', $view);

      // Count queries must be run through the preExecute() method.

      // If not, then hook_query_node_access_alter() may munge the count by

      // adding a distinct against an empty query string

      // (e.g. COUNT DISTINCT(1) ...) and no pager will return.

      // See pager.inc > PagerDefault::execute()

      // http://api.drupal.org/api/drupal/includes--pager.inc/function/PagerDefault::execute/7

      // See http://drupal.org/node/1046170.

      $count_query->preExecute();

      // Build the count query.

      $count_query = $count_query->countQuery();

      // Add additional arguments as a fake condition.

      // XXX: this doesn't work... because PDO mandates that all bound arguments

      // are used on the query. TODO: Find a better way to do this.

      if (!empty($additional_arguments)) {

        // $query->where('1 = 1', $additional_arguments);

        // $count_query->where('1 = 1', $additional_arguments);

      }

      $start = microtime(TRUE);

      if ($this->pager->use_count_query() || !empty($view->get_total_rows)) {

        $this->pager->execute_count_query($count_query);

      }

      // Let the pager modify the query to add limits.

      $this->pager->pre_execute($query);

      if (!empty($this->limit) || !empty($this->offset)) {

        // We can't have an offset without a limit, so provide a very large limit instead.

        $limit  = intval(!empty($this->limit) ? $this->limit : 999999);

        $offset = intval(!empty($this->offset) ? $this->offset : 0);

        $query->range($offset, $limit);

      }

      try {

        // The $query is final and ready to go, we are going to redirect it to

        // become an insert into our table, sneaky!

        // Our query will look like:

        // CREATE TABLE {idx} SELECT @row := @row + 1 AS weight_alias, cl.* FROM

        // (-query-) AS cl, (SELECT @row := 0) AS r

        // We do some magic to get the row count.

        $display_handler->batched_execution_state->sandbox['weight_field_alias'] = $display_handler->_weight_alias_create($view);

        $display_handler->batched_execution_state->sandbox['field_aliases'] = $display_handler->field_aliases_create($view);

        $select_aliases = array();

        foreach ($display_handler->batched_execution_state->sandbox['field_aliases'] as $hash => $alias) {

          $select_aliases[] = "cl.$alias AS $hash";

        }

        // TODO: this could probably be replaced with a query extender and new query type.

        $query->preExecute();

        $args = $query->getArguments();

        $insert_query = 'CREATE TABLE {' . $display_handler->index_tablename() . '} SELECT @row := @row + 1 AS ' . $display_handler->batched_execution_state->sandbox['weight_field_alias'] . ', ' . implode(', ', $select_aliases) . ' FROM (' . (string)$query . ') AS cl, (SELECT @row := 0) AS r';

        db_query($insert_query, $args);

        $view->result = array();

        $this->pager->post_execute($view->result);

        if ($this->pager->use_pager()) {

          $view->total_rows = $this->pager->get_total_items();

        }

        // Now create an index for the weight field, otherwise the queries on the

        // index will take a long time to execute.

        db_add_unique_key($display_handler->index_tablename(), $display_handler->batched_execution_state->sandbox['weight_field_alias'], array($display_handler->batched_execution_state->sandbox['weight_field_alias']));

      }

      catch (Exception $e) {

        $view->result = array();

        debug('Exception: ' . $e->getMessage());

      }

    }

    $view->execute_time = microtime(TRUE) - $start;

  }

}

class views_data_export_plugin_query_pgsql_batched extends views_data_export_plugin_query_default_batched {

  /**

   * Executes the query and fills the associated view object with according

   * values.

   *

   * Values to set: $view->result, $view->total_rows, $view->execute_time,

   * $view->current_page.

   */

  function execute(&$view) {

    $display_handler = &$view->display_handler;

    $external = FALSE; // Whether this query will run against an external database.

    $query = $view->build_info['query'];

    $count_query = $view->build_info['count_query'];

    $query->addMetaData('view', $view);

    $count_query->addMetaData('view', $view);

    if (empty($this->options['disable_sql_rewrite'])) {

      $base_table_data = views_fetch_data($this->base_table);

      if (isset($base_table_data['table']['base']['access query tag'])) {

        $access_tag = $base_table_data['table']['base']['access query tag'];

        $query->addTag($access_tag);

        $count_query->addTag($access_tag);

      }

    }

    $items = array();

    if ($query) {

      $additional_arguments = module_invoke_all('views_query_substitutions', $view);

      // Count queries must be run through the preExecute() method.

      // If not, then hook_query_node_access_alter() may munge the count by

      // adding a distinct against an empty query string

      // (e.g. COUNT DISTINCT(1) ...) and no pager will return.

      // See pager.inc > PagerDefault::execute()

      // http://api.drupal.org/api/drupal/includes--pager.inc/function/PagerDefault::execute/7

      // See http://drupal.org/node/1046170.

      $count_query->preExecute();

      // Build the count query.

      $count_query = $count_query->countQuery();

      // Add additional arguments as a fake condition.

      // XXX: this doesn't work... because PDO mandates that all bound arguments

      // are used on the query. TODO: Find a better way to do this.

      if (!empty($additional_arguments)) {

        // $query->where('1 = 1', $additional_arguments);

        // $count_query->where('1 = 1', $additional_arguments);

      }

      $start = microtime(TRUE);

      if ($this->pager->use_count_query() || !empty($view->get_total_rows)) {

        $this->pager->execute_count_query($count_query);

      }

      // Let the pager modify the query to add limits.

      $this->pager->pre_execute($query);

      if (!empty($this->limit) || !empty($this->offset)) {

        // We can't have an offset without a limit, so provide a very large limit instead.

        $limit  = intval(!empty($this->limit) ? $this->limit : 999999);

        $offset = intval(!empty($this->offset) ? $this->offset : 0);

        $query->range($offset, $limit);

      }

      try {

        // The $query is final and ready to go, we are going to redirect it to

        // become an insert into our table, sneaky!

        // Our query will look like:

        // CREATE TABLE {idx} SELECT @row := @row + 1 AS weight_alias, cl.* FROM

        // (-query-) AS cl, (SELECT @row := 0) AS r

        // We do some magic to get the row count.

        $display_handler->batched_execution_state->sandbox['weight_field_alias'] = $display_handler->_weight_alias_create($view);

        $display_handler->batched_execution_state->sandbox['field_aliases'] = $display_handler->field_aliases_create($view);

        $select_aliases = array();

        foreach ($display_handler->batched_execution_state->sandbox['field_aliases'] as $hash => $alias) {

          $select_aliases[] = "cl.$alias AS $hash";

        }

        // TODO: this could probably be replaced with a query extender and new query type.

        $query->preExecute();

        $args = $query->getArguments();

        // Create temporary sequence

        $seq_name = $display_handler->index_tablename() . '_seq';

        db_query('CREATE TEMP sequence ' . $seq_name);

        // Query uses sequence to create row number

        $insert_query = 'CREATE TABLE {' . $display_handler->index_tablename() . "} AS SELECT nextval('". $seq_name . "') AS " . $display_handler->batched_execution_state->sandbox['weight_field_alias'] . ', ' . implode(', ', $select_aliases) . ' FROM (' . (string)$query . ') AS cl';

        db_query($insert_query, $args);

        $view->result = array();

        $this->pager->post_execute($view->result);

        if ($this->pager->use_pager()) {

          $view->total_rows = $this->pager->get_total_items();

        }

        // Now create an index for the weight field, otherwise the queries on the

        // index will take a long time to execute.

        db_add_unique_key($display_handler->index_tablename(), $display_handler->batched_execution_state->sandbox['weight_field_alias'], array($display_handler->batched_execution_state->sandbox['weight_field_alias']));

      }

      catch (Exception $e) {

        $view->result = array();

        debug('Exception: ' . $e->getMessage());

      }

    }

    $view->execute_time = microtime(TRUE) - $start;

  }

}