Formerly part of the FlightPath class, this function will read in or reload the course inventory into a file, which then goes into the SESSION to make it faster to access.

File

modules/system/system.module, line 3615

Code

function system_reload_and_cache_course_inventory() {

  // Load from file.  If not there, or if we cannot unserialize, then we will rebuild cache and save new file.
  if (file_exists(fp_get_files_path() . "/cache_data/courses_serialized.info")) {
    if ($_SESSION ["fp_cache_course_inventory"] = file_get_contents(fp_get_files_path() . "/cache_data/courses_serialized.info")) 
     {
      if ($GLOBALS ["fp_course_inventory"] = unserialize($_SESSION ["fp_cache_course_inventory"])) {
        $last_generated = intval(variable_get('cache_course_inventory_last_generated', 0));
        $_SESSION ['fp_cache_course_inventory_last_generated'] = $last_generated;
        //fpm('reloading from file');
        return;
      }
    }
  }

  $array_valid_names_by_course = array();

  //fpm('rebuilding course cache');

  //fpm("LIMIT $limit_start, $limit_size");

  // To save memory, we're only going to keep a certain number of catalog years in the cache, and even then, only up to a max number of rows. 

  $start_year = intval(date('Y', strtotime('NOW + 1 YEAR'))); // start with one year into the future.
  $end_year = intval(date('Y', strtotime('NOW - 10 YEARS'))); // end with 10 years into the past

  $in_years = "";
  for ($t = $end_year; $t <= $start_year; $t++) {
    $in_years .= $t . ",";
  }
  $in_years .= "1900"; // add in the 1900 year as well.

  $result = db_query("SELECT * FROM courses
                      WHERE delete_flag = 0
                      AND catalog_year IN ($in_years)
                      ORDER BY catalog_year DESC
                      LIMIT 50000");

  while ($cur = db_fetch_array($result)) 
   {
    $course_id = $cur ["course_id"];

    //$this->db->load_course_descriptive_data(null, $course_id);

    $title = $cur ["title"];
    $description = trim($cur ["description"]);
    $subject_id = trim(strtoupper($cur ["subject_id"]));
    $course_num = trim(strtoupper($cur ["course_num"]));
    $cache_catalog_year = $cur ['catalog_year'];

    $min_hours = $cur ["min_hours"];
    $max_hours = $cur ["max_hours"];
    $repeat_hours = $cur ["repeat_hours"];
    if ($repeat_hours * 1 == 0) 
     {
      $repeat_hours = $max_hours;
    }


    $db_exclude = $cur ["exclude"];
    $db_school_id = $cur ['school_id'];
    $data_entry_comment = $cur ["data_entry_comment"];

    // Now, lets get a list of all the valid names for this course.
    // In other words, all the non-excluded names.  For most
    // courses, this will just be one name.  But for cross-listed
    // courses, this will be 2 or more (probably just 2 though).
    // Example: MATH 373 and CSCI 373 are both valid names for that course.

    if (!isset($array_valid_names_by_course [$course_id])) {

      $array_valid_names = array();
      $res2 = db_query("SELECT * FROM courses
                      WHERE course_id = ?                        
                      AND delete_flag = 0 ", $course_id);
      while ($cur2 = db_fetch_array($res2)) 
       {
        $si = $cur2 ["subject_id"];
        $cn = $cur2 ["course_num"];
        if (in_array("$si~$cn", $array_valid_names)) 
         {
          continue;
        }
        $array_valid_names [] = "$si~$cn";
      }
      $array_valid_names_by_course [$course_id] = $array_valid_names;
    }

    $array_valid_names = $array_valid_names_by_course [$course_id];

    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["subject_id"] = $subject_id;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["course_num"] = $course_num;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["title"] = $title;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["description"] = $description;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["min_hours"] = $min_hours;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["max_hours"] = $max_hours;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["repeat_hours"] = $repeat_hours;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["db_exclude"] = $db_exclude;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["school_id"] = $db_school_id;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["array_valid_names"] = $array_valid_names;

    $cache_catalog_year = 0;

    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["subject_id"] = $subject_id;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["course_num"] = $course_num;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["title"] = $title;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["description"] = $description;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["min_hours"] = $min_hours;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["max_hours"] = $max_hours;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["repeat_hours"] = $repeat_hours;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["db_exclude"] = $db_exclude;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["school_id"] = $db_school_id;
    $GLOBALS ["fp_course_inventory"][$course_id][$cache_catalog_year]["array_valid_names"] = $array_valid_names;

    $GLOBALS ["cache_course_inventory"] = TRUE;
  } // while cur

  // Should we re-cache the course inventory?  If there have been any changes
  // to it, then we will see that in a GLOBALS variable...
  if ($GLOBALS ["cache_course_inventory"] == true) 
   {
    $_SESSION ["fp_cache_course_inventory"] = serialize($GLOBALS ["fp_course_inventory"]);
  }

  // Save to file.
  if (!is_dir(fp_get_files_path() . "/cache_data")) {
    $x = mkdir(fp_get_files_path() . "/cache_data");
    if (!$x) {
      fpm("Cannot create cache_data directory under custom/files.  Permission error?");
      watchdog("system", "Cannot create cache_data directory under custom/files.  Permission error?", array(), WATCHDOG_ERROR);
    }
  }

  // It is named .info because in our htaccess, it already says that file extension cannot be downloaded.
  $x = file_put_contents(fp_get_files_path() . "/cache_data/courses_serialized.info", $_SESSION ["fp_cache_course_inventory"]);
  if ($x === FALSE) {
    fpm("Cannot create cache_data/courses_serialized.info under custom/files.  Permission error?");
    watchdog("system", "Cannot create cache_data/courses_serialized.info under custom/files.  Permission error?", array(), WATCHDOG_ERROR);
  }

  // Also put in when we LAST performed this operation in a variable for reading later on.
  $last_generated = time();
  $_SESSION ['fp_cache_course_inventory_last_generated'] = $last_generated;
  variable_set('cache_course_inventory_last_generated', $last_generated);


}