CacheCollector::updateCache

protected CacheCollector::updateCache($lock = TRUE)

protected function updateCache($lock = TRUE) {
  $data = array();
  foreach ($this->keysToPersist as $offset => $persist) {
    if ($persist) {
      $data[$offset] = $this->storage[$offset];
    }
  }
  if (empty($data) && empty($this->keysToRemove)) {
    return;
  }

  // Lock cache writes to help avoid stampedes.
  $cid = $this->getCid();
  $lock_name = $this->normalizeLockName($cid . ':' . __CLASS__);
  if (!$lock || $this->lock->acquire($lock_name)) {
    // Set and delete operations invalidate the cache item. Try to also load
    // an eventually invalidated cache entry, only update an invalidated cache
    // entry if the creation date did not change as this could result in an
    // inconsistent cache.
    if ($cache = $this->cache->get($cid, $this->cacheInvalidated)) {
      if ($this->cacheInvalidated && $cache->created != $this->cacheCreated) {
        // We have invalidated the cache in this request and got a different
        // cache entry. Do not attempt to overwrite data that might have been
        // changed in a different request. We'll let the cache rebuild in
        // later requests.
        $this->cache->delete($cid);
        $this->lock->release($lock_name);
        return;
      }
      $data = array_merge($cache->data, $data);
    }
    // Remove keys marked for deletion.
    foreach ($this->keysToRemove as $delete_key) {
      unset($data[$delete_key]);
    }
    $this->cache->set($cid, $data, Cache::PERMANENT, $this->tags);
    if ($lock) {
      $this->lock->release($lock_name);
    }
  }

  $this->keysToPersist = array();
  $this->keysToRemove = array();
}