(PECL apc >= 3.1.1)
The APCIterator class makes it easier to iterate over large APC caches. This is helpful as it allows iterating over large caches in steps, while grabbing a defined number of entries per lock instance, so it frees the cache locks for other activities rather than hold up the entire cache to grab 100 (the default) entries. Also, using regular expression matching is more efficient as it's been moved to the C level.
$cache
[, mixed $search
= null
[, int $format
[, int $chunk_size
= 100
[, int $list
]]]] )