Added panels plugin.

  return $plugins;

}

/**

 * Implementation of hook_ctools_plugin_directory().

 */

function cache_graceful_ctools_plugin_directory($module, $plugin) {

  // Safety: go away if CTools is not at an appropriate version.

  if (!module_invoke('ctools', 'api_version', '1.7.2')) {

    return;

  }

  // We don't support the 'ctools' 'cache' plugin and pretending to causes

  // errors when they're in use.

  if ($module == 'ctools' && $plugin == 'cache') {

    return;

    // if we did we'd make a plugin/ctools_cache or something.

  }

  if ($module == 'page_manager' || $module == 'panels' || $module == 'ctools') {

    return 'plugins/' . $plugin;

  }

}

function cache_graceful_options($callback = NULL, $options = NULL) {

  static $callback_options = array();

  if (isset($options)) {

    return $result;

  }

  elseif ($options['wait_for_cache']) {

    $cache = NULL;

    // watchdog('cache_graceful', 'Could not obtain lock, waiting for cache', array(), WATCHDOG_DEBUG);

    // Could not get lock, but we should wait for the cache to be updated.

    $timeout = microtime(TRUE) + $options['wait_for_cache'];

  );

}

/**

 * Render display or pane in background process.

 *

 * @param object $renderer

 * @param object $pane

 *

 * @return

 */

function _cache_graceful_panels_recache($renderer, $pane = NULL) {

  if ($pane) {

    ctools_include('content');

    $content = ctools_content_render($pane->type, $pane->subtype, $pane->configuration, array(), $renderer->display->args, $renderer->display->context);

    if ($content) {

      foreach (module_implements('panels_pane_content_alter') as $module) {

        $function = $module . '_panels_pane_content_alter';

        $function($content, $pane, $renderer->display->args, $renderer->display->context, $renderer, $renderer->display);

      }

    }

  }

  else {

    $content = $renderer->render_layout();

  }

  $cache = new panels_cache_object();

  $cache->set_content($content);

  panels_set_cached_content($cache, $renderer->display, $renderer->display->args, $renderer->display->context, $pane);

  $result = new stdClass();

  $result->data = $cache;

  return $result;

}

<?php

/**

 * @file

 * Provides a simple time-based caching option for panel panes.

 */

// Plugin definition

$plugin = array(

  'title' => t("Graceful cache"),

  'description' => t('Graceul caching is a two factor time-based cache (hard expire and soft expire).'),

  'cache get' => 'cache_graceful_panels_cache_get_cache',

  'cache set' => 'cache_graceful_panels_cache_set_cache',

  'cache clear' => 'cache_graceful_panels_cache_clear_cache',

  'settings form' => 'cache_graceful_panels_cache_settings_form',

  'settings form submit' => 'cache_graceful_panels_cache_settings_form_submit',

  'defaults' => array(

    'lifetime' => 60,

    'prefetch' => 30,

    'granularity' => 'none',

  ),

);

/**

 * Get cached content.

 */

function cache_graceful_panels_cache_get_cache($conf, $display, $args, $contexts, $pane = NULL) {

  $cid = cache_graceful_panels_cache_get_id($conf, $display, $args, $contexts, $pane);

  $cache = cache_graceful(

             $cid,

             array('_cache_graceful_panels_recache', $display->renderer_handler, $pane), 

             'cache',

             $conf['lifetime'], $conf['prefetch'],

             array('ensure_result' => TRUE)

           );

  return $cache ? $cache->data : FALSE;

}

/**

 * Set cached content.

 */

function cache_graceful_panels_cache_set_cache($conf, $content, $display, $args, $contexts, $pane = NULL) {

}

/**

 * Clear cached content.

 *

 * Cache clears are always for an entire display, regardless of arguments.

 */

function cache_graceful_panels_cache_clear_cache($display) {

  $cid = 'cache_graceful_panels_cache';

  // This is used in case this is an in-code display, which means did will be something like 'new-1'.

  if (isset($display->owner) && isset($display->owner->id)) {

    $cid .= ':' . $display->owner->id;

  }

  $cid .= ':' . $display->did;

  cache_clear_all($cid, 'cache', TRUE);

}

/**

 * Figure out an id for our cache based upon input and settings.

 */

function cache_graceful_panels_cache_get_id($conf, $display, $args, $contexts, $pane) {

  $id = 'cache_graceful_panels_cache';

  // If the panel is stored in the database it'll have a numeric did value.

  if (is_numeric($display->did)) {

    $id .= ':' . $display->did;

  }

  // Exported panels won't have a numeric did but may have a usable cache_key.

  elseif (!empty($display->cache_key)) {

    $id .= ':' . str_replace('panel_context:', '', $display->cache_key);

  }

  // Alternatively use the css_id.

  elseif (!empty($display->css_id)) {

    $id .= ':' . $display->css_id;

  }

  // Failover to just appending the did, which may be the completely unusable

  // string 'new'.

  else {

    $id .= ':' . $display->did;

  }

  if ($pane) {

    $id .= ':' . $pane->pid;

  }

  if (user_access('view pane admin links')) {

    $id .= ':admin';

  }

  switch ($conf['granularity']) {

    case 'args':

      foreach ($args as $arg) {

        $id .= ':' . $arg;

      }

      break;

    case 'context':

      if (!is_array($contexts)) {

        $contexts = array($contexts);

      }

      foreach ($contexts as $context) {

        if (isset($context->argument)) {

          $id .= ':' . $context->argument;

        }

      }

  }

  if (module_exists('locale')) {

    global $language;

    $id .= ':' . $language->language;

  }

  if(!empty($pane->configuration['use_pager']) && !empty($_GET['page'])) {

    $id .= ':p' . check_plain($_GET['page']);

  }

  return $id;

}

function cache_graceful_panels_cache_settings_form($conf, $display, $pid) {

  $options = drupal_map_assoc(array(15, 30, 60, 120, 180, 240, 300, 600, 900, 1200, 1800, 3600, 7200, 14400, 28800, 43200, 86400, 172800, 259200, 345600, 604800), 'format_interval');

  $form['lifetime'] = array(

    '#title' => t('Lifetime'),

    '#type' => 'select',

    '#options' => $options,

    '#default_value' => $conf['lifetime'],

  );

  $form['prefetch'] = array(

    '#title' => t('Prefetch'),

    '#type' => 'select',

    '#options' => $options,

    '#default_value' => $conf['prefetch'],

  );

  $form['granularity'] = array(

    '#title' => t('Granularity'),

    '#type' => 'select',

    '#options' => array(

      'args' => t('Arguments'),

      'context' => t('Context'),

      'none' => t('None'),

    ),

    '#description' => t('If "arguments" are selected, this content will be cached per individual argument to the entire display; if "contexts" are selected, this content will be cached per unique context in the pane or display; if "neither" there will be only one cache for this pane.'),

    '#default_value' => $conf['granularity'],

  );

  return $form;

}