* Each cache must be registered so that it can be cleaned regularly.
* When the cache is unregistered, it is flushed completely.
*
- * Entries have a ref count and a 'hashed' flag which counts the existance
+ * Entries have a ref count and a 'hashed' flag which counts the existence
* in the hash table.
* We only expire entries when refcount is zero.
- * Existance in the cache is counted the refcount.
+ * Existence in the cache is counted the refcount.
*/
/* Every cache item has a common header that is used