The default value of the $format parameter of the APCIterator constructur is
APC_ITER_ALL which instructs the iterator to provide all available information
on cache values being iterated over. Only the key value is necessary for
matching and deletion via apc_delete(), though.
This prevents a "Format values FILENAME, DEVICE, INODE, MD5, NUM_HITS, MTIME,
CTIME, DTIME, ATIME, REFCOUNT not supported yet." notice on HHVM.
Sometimes it's not possible to disable APC entirely and some of
apc_functions are disabled. Only thing which is possible is
to disable apc.enable option.
Andreas Fischer
icewind1991
Otto Sabart
Robin Appelman
Thomas Müller