Stores data in the private update status cache table.
$cid: The cache ID to save the data with.
$data: The data to store.
$expire: One of the following values:
function _update_cache_set($cid, $data, $expire) {
$fields = array(
'created' => REQUEST_TIME,
'expire' => $expire,
);
if (!is_string($data)) {
$fields['data'] = serialize($data);
$fields['serialized'] = 1;
}
else {
$fields['data'] = $data;
$fields['serialized'] = 0;
}
db_merge('cache_update')
->key(array(
'cid' => $cid,
))
->fields($fields)
->execute();
}