function cache_set in File Cache 5.5

Store data in the persistent cache.

The persistent cache is split up into four database tables. Contributed modules can add additional tables.

'cache_page': This table stores generated pages for anonymous users. This is the only table affected by the page cache setting on the administrator panel.

'cache_menu': Stores the cachable part of the users' menus.

'cache_filter': Stores filtered pieces of content. This table is periodically cleared of stale entries by cron.

'cache': Generic cache storage table.

The reasons for having several tables are as follows:

• smaller tables allow for faster selects and inserts
• we try to put fast changing cache items and rather static ones into different tables. The effect is that only the fast changing tables will need a lot of writes to disk. The more static tables will also be better cachable with MySQL's query cache

Parameters

$cid: The cache ID of the data to store.

$table: The table $table to store the data in. Valid core values are 'cache_filter', 'cache_menu', 'cache_page', or 'cache'.

$data: The data to store in the cache. Complex data types must be serialized first.

$expire: One of the following values:

• CACHE_PERMANENT: Indicates that the item should never be removed unless explicitly told to using cache_clear_all() with a cache ID.
• CACHE_TEMPORARY: Indicates that the item should be removed at the next general cache wipe.
• A Unix timestamp: Indicates that the item should be kept at least until the given time, after which it behaves like CACHE_TEMPORARY.

$headers: A string containing HTTP header information for cached pages.

File

./filecache.inc, line 89

Code

function cache_set($cid, $table = 'cache', $data, $expire = CACHE_PERMANENT, $headers = NULL) {
  $cache = array(
    'data' => $data,
    'created' => time(),
    'expire' => $expire,
    'headers' => $headers,
  );
  $cache = serialize($cache);
  $path = variable_get('filecache_path', 'files/cache') . '/' . $table;
  if (!file_exists($path)) {
    mkdir($path, 0775, TRUE);
  }
  if (file_exists($path) && is_dir($path)) {
    $dest = $path . '/' . urlencode($cid);
    file_put_contents($dest, $cache);
  }
}