<?php
// $Id$
/**
 * @file
 * APC instrumentation for Munin
 *
 * @author Frederic G. MARAND
 *
 * @copyright (c) 2011 Ouest Systèmes Informatiques
 *
 * Licensed under the General Public License version 2 or later.
 */

/**
 * Implements hook_munin_api_info().
 *
 * @return
 *   An array of Munin graph informations, index by graph name, each containing
 *   an array of field information.
 */
function munin_apc_munin_api_info() {
  $int = array(
    '#graph_printf' => '%d',
  );

  $ret = array(
    '#title'       => t('APC'),
    '#description' => t('Graphs about PHP APC'),

    'munin_apc' => array(
      '#title'     => t('APC Caching'),
      '#info'      => t('Collect cache information for the Alternative PHP Cache. This graph uses IEC binary sizes.'),
      '#graph_args'=> '--base 1024 --lower-limit 0',

      'total_size' => $int + array(
        '#label'     => t('Bytes allocated'),
        '#type'      => MUNIN_API_GAUGE,
        '#info'      => t('Number of bytes allocated to APC.')
      ),
      'used_size'  => $int + array(
        '#label'     => t('Bytes in use'),
        '#type'      => MUNIN_API_GAUGE,
        '#info'      => t('Number of bytes actually used by APC, either cached or deleted'),
      ),
      'num_hits'   => $int + array(
        '#label'     => t('Hits since last restart'),
        '#type'      => MUNIN_API_COUNTER,
      ),
      'num_misses' => $int + array(
        '#label'     => t('Misses since last restart'),
        '#type'      => MUNIN_API_COUNTER,
      ),
      'num_inserts' => $int + array(
        '#label'     => t('Insertions since last restart'),
        '#type'      => MUNIN_API_COUNTER,
      ),
//      'hit_rate'   => $int + array(
//        '#label'     => t('Hit/miss ratio since last restart'),
//        '#type'      => MUNIN_API_GAUGE,
//      ),
      'cache_entries' => $int + array(
        '#label'     => t('Number of cache entries'),
        '#type'      => MUNIN_API_GAUGE,
      ),
      'deleted_entries' => $int + array(
        '#label'     => t('Number of deleted entries'),
        '#type'      => MUNIN_API_GAUGE,
        '#info'      => t('Deleted entries lingering until the garbage collection TTL elapses'),
      ),
    ),

    'munin_apc_uptime' => array(
      '#title'     => t('APC Uptime'),
      '#info'      => t('Uptime information for the Alternative PHP Cache.'),
      '#graph_vlabel' => t('Uptime in days'),
      '#graph_scale'  => 'no',

      'uptime'     => $int + array(
        '#label'     => t('Up-time of APC instance'),
        '#type'      => MUNIN_API_GAUGE,
        '#info'      => t('Days since last APC restart.'),
        '#draw'      => MUNIN_API_DRAW_AREA,
      ),
    ),
  );

  return $ret;
}

/**
 * Implements hook_munin_api_fetch().
 *
 * The static cache is useless at this point, but will likely become useful
 * if module builds Munin multigraphs.
 */
function munin_apc_munin_api_fetch($graph_name) {

  static $cache = array();

  if (empty($cache)) {
    $info = apc_sma_info();
    $ret = array();

    // SMA Info
    $total = $info['num_seg'] * $info['seg_size'];
    $cache['munin_apc']['total_size'] = (int) $total;
    $cache['munin_apc']['used_size'] = (int) ($total - $info['avail_mem']);

    // Cache info
    $info = apc_cache_info();
    $cache['munin_apc_uptime']['uptime'] = (time() - $info['start_time']) / 86400;
    foreach (array('num_hits', 'num_misses', 'num_inserts') as $field) {
      $cache['munin_apc'][$field] = $info[$field];
    }

    $cache['munin_apc']['cache_entries']   = count($info['cache_list']);
    $cache['munin_apc']['deleted_entries'] = count($info['deleted_list']);
  }

  $ret = $cache[$graph_name];
  return $ret;
}